fix fpga_comress sending no-error messages to stderr (#430)

[proxmark3-svn] / common / lfdemod.c

diff --git a/common/lfdemod.c b/common/lfdemod.c
index 406b0445f462ec1b823607614a999ea2d6b746a2..f470371a3b399e6292f799eea6e3f90ac628d179 100644 (file)
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -5,16 +5,47 @@
 // at your option, any later version. See the LICENSE.txt file for the text of
 // the license.
 //-----------------------------------------------------------------------------
 // at your option, any later version. See the LICENSE.txt file for the text of
 // the license.
 //-----------------------------------------------------------------------------

-// Low frequency demod/decode commands
+// Low frequency demod/decode commands   - by marshmellow, holiman, iceman and
+//                                         many others who came before
+//
+// NOTES: 
+// LF Demod functions are placed here to allow the flexability to use client or
+// device side. Most BUT NOT ALL of these functions are currenlty safe for 
+// device side use currently. (DetectST for example...)
+//
+// There are likely many improvements to the code that could be made, please
+// make suggestions...
+//
+// we tried to include author comments so any questions could be directed to 
+// the source.
+//
+// There are 4 main sections of code below:
+// Utilities Section: 
+//    for general utilities used by multiple other functions
+// Clock / Bitrate Detection Section:
+//    for clock detection functions for each modulation
+// Modulation Demods &/or Decoding Section:
+//    for main general modulation demodulating and encoding decoding code.
+// Tag format detection section:
+//    for detection of specific tag formats within demodulated data
+//
+// marshmellow

 //-----------------------------------------------------------------------------
 
 //-----------------------------------------------------------------------------
 

-#include <stdlib.h>
+#include <string.h>  // for memset, memcmp and size_t

 #include "lfdemod.h"
 #include "lfdemod.h"

-#include <string.h>
+#include <stdint.h>  // for uint_32+
+#include <stdbool.h> // for bool
+#include "parity.h"  // for parity test
+
+//**********************************************************************************************
+//---------------------------------Utilities Section--------------------------------------------
+//**********************************************************************************************
+#define LOWEST_DEFAULT_CLOCK 32
+#define FSK_PSK_THRESHOLD   123

 
 //to allow debug print calls when used not on device
 void dummy(char *fmt, ...){}
 
 //to allow debug print calls when used not on device
 void dummy(char *fmt, ...){}

-

 #ifndef ON_DEVICE
 #include "ui.h"
 #include "cmdparser.h"
 #ifndef ON_DEVICE
 #include "ui.h"
 #include "cmdparser.h"


@@ -25,21 +56,18 @@ void dummy(char *fmt, ...){}
 #define prnt dummy
 #endif
 
 #define prnt dummy
 #endif
 

-uint8_t justNoise(uint8_t *BitStream, size_t size)
-{
-       static const uint8_t THRESHOLD = 123;
+uint8_t justNoise(uint8_t *BitStream, size_t size) {

        //test samples are not just noise
        uint8_t justNoise1 = 1;
        for(size_t idx=0; idx < size && justNoise1 ;idx++){
        //test samples are not just noise
        uint8_t justNoise1 = 1;
        for(size_t idx=0; idx < size && justNoise1 ;idx++){

-               justNoise1 = BitStream[idx] < THRESHOLD;
+               justNoise1 = BitStream[idx] < FSK_PSK_THRESHOLD;

        }
        return justNoise1;
 }
 
 //by marshmellow
 //get high and low values of a wave with passed in fuzz factor. also return noise test = 1 for passed or 0 for only noise
        }
        return justNoise1;
 }
 
 //by marshmellow
 //get high and low values of a wave with passed in fuzz factor. also return noise test = 1 for passed or 0 for only noise

-int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi, uint8_t fuzzLo)
-{
+int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi, uint8_t fuzzLo) {

        *high=0;
        *low=255;
        // get high and low thresholds 
        *high=0;
        *low=255;
        // get high and low thresholds 


@@ -47,7 +75,7 @@ int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi
                if (BitStream[i] > *high) *high = BitStream[i];
                if (BitStream[i] < *low) *low = BitStream[i];
        }
                if (BitStream[i] > *high) *high = BitStream[i];
                if (BitStream[i] < *low) *low = BitStream[i];
        }

-       if (*high < 123) return -1; // just noise
+       if (*high < FSK_PSK_THRESHOLD) return -1; // just noise

        *high = ((*high-128)*fuzzHi + 12800)/100;
        *low = ((*low-128)*fuzzLo + 12800)/100;
        return 1;
        *high = ((*high-128)*fuzzHi + 12800)/100;
        *low = ((*low-128)*fuzzLo + 12800)/100;
        return 1;


@@ -56,42 +84,35 @@ int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi
 // by marshmellow
 // pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType
 // returns 1 if passed
 // by marshmellow
 // pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType
 // returns 1 if passed

-uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType)
-{
-       uint8_t ans = 0;
-       for (uint8_t i = 0; i < bitLen; i++){
-               ans ^= ((bits >> i) & 1);
-       }
-       if (g_debugMode) prnt("DEBUG: ans: %d, ptype: %d, bits: %08X",ans,pType,bits);
-       return (ans == pType);
+bool parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType) {
+       return oddparity32(bits) ^ pType;

 }
 
 // by marshmellow
 }
 
 // by marshmellow

-// takes a array of binary values, start position, length of bits per parity (includes parity bit),
-//   Parity Type (1 for odd; 0 for even; 2 for Always 1's; 3 for Always 0's), and binary Length (length to run) 
-size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen)
-{
+// takes a array of binary values, start position, length of bits per parity (includes parity bit - MAX 32),
+//   Parity Type (1 for odd; 0 for even; 2 for Always 1's; 3 for Always 0's), and binary Length (length to run)
+size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen) {

        uint32_t parityWd = 0;
        uint32_t parityWd = 0;

-       size_t j = 0, bitCnt = 0;
+       size_t bitCnt = 0;

        for (int word = 0; word < (bLen); word+=pLen) {
                for (int bit=0; bit < pLen; bit++) {
        for (int word = 0; word < (bLen); word+=pLen) {
                for (int bit=0; bit < pLen; bit++) {

+                       if (word+bit >= bLen) break;

                        parityWd = (parityWd << 1) | BitStream[startIdx+word+bit];
                        parityWd = (parityWd << 1) | BitStream[startIdx+word+bit];

-                       BitStream[j++] = (BitStream[startIdx+word+bit]);
+                       BitStream[bitCnt++] = (BitStream[startIdx+word+bit]);

                }
                }

-               if (word+pLen >= bLen) break;
+               if (word+pLen > bLen) break;

 
 

-               j--; // overwrite parity with next data
+               bitCnt--; // overwrite parity with next data

                // if parity fails then return 0
                switch (pType) {
                // if parity fails then return 0
                switch (pType) {

-                       case 3: if (BitStream[j]==1) {return 0;} break; //should be 0 spacer bit
-                       case 2: if (BitStream[j]==0) {return 0;} break; //should be 1 spacer bit
+                       case 3: if (BitStream[bitCnt]==1) {return 0;} break; //should be 0 spacer bit
+                       case 2: if (BitStream[bitCnt]==0) {return 0;} break; //should be 1 spacer bit

                        default: if (parityTest(parityWd, pLen, pType) == 0) {return 0;} break; //test parity
                }
                        default: if (parityTest(parityWd, pLen, pType) == 0) {return 0;} break; //test parity
                }

-               bitCnt+=(pLen-1);

                parityWd = 0;
        }
        // if we got here then all the parities passed
                parityWd = 0;
        }
        // if we got here then all the parities passed

-       //return ID start index and size
+       //return size

        return bitCnt;
 }
 
        return bitCnt;
 }
 


@@ -99,8 +120,7 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p
 // takes a array of binary values, length of bits per parity (includes parity bit),
 //   Parity Type (1 for odd; 0 for even; 2 Always 1's; 3 Always 0's), and binary Length (length to run)
 //   Make sure *dest is long enough to store original sourceLen + #_of_parities_to_be_added
 // takes a array of binary values, length of bits per parity (includes parity bit),
 //   Parity Type (1 for odd; 0 for even; 2 Always 1's; 3 Always 0's), and binary Length (length to run)
 //   Make sure *dest is long enough to store original sourceLen + #_of_parities_to_be_added

-size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t pLen, uint8_t pType)
-{
+size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t pLen, uint8_t pType) {

        uint32_t parityWd = 0;
        size_t j = 0, bitCnt = 0;
        for (int word = 0; word < sourceLen; word+=pLen-1) {
        uint32_t parityWd = 0;
        size_t j = 0, bitCnt = 0;
        for (int word = 0; word < sourceLen; word+=pLen-1) {


@@ -124,8 +144,7 @@ size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t p
        return bitCnt;
 }
 
        return bitCnt;
 }
 

-uint32_t bytebits_to_byte(uint8_t *src, size_t numbits)
-{
+uint32_t bytebits_to_byte(uint8_t *src, size_t numbits) {

        uint32_t num = 0;
        for(int i = 0 ; i < numbits ; i++)
        {
        uint32_t num = 0;
        for(int i = 0 ; i < numbits ; i++)
        {


@@ -136,8 +155,7 @@ uint32_t bytebits_to_byte(uint8_t *src, size_t numbits)
 }
 
 //least significant bit first
 }
 
 //least significant bit first

-uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits)
-{
+uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits) {

        uint32_t num = 0;
        for(int i = 0 ; i < numbits ; i++)
        {
        uint32_t num = 0;
        for(int i = 0 ; i < numbits ; i++)
        {


@@ -146,60 +164,49 @@ uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits)
        return num;
 }
 
        return num;
 }
 

-//by marshmellow
-//search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length
-uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx)
-{
+// search for given preamble in given BitStream and return success=1 or fail=0 and startIndex (where it was found) and length if not fineone 
+// fineone does not look for a repeating preamble for em4x05/4x69 sends preamble once, so look for it once in the first pLen bits
+bool preambleSearchEx(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx, bool findone) {

        // Sanity check.  If preamble length is bigger than bitstream length.
        // Sanity check.  If preamble length is bigger than bitstream length.

-       if ( *size <= pLen ) return 0;
+       if ( *size <= pLen ) return false;

 
 

-       uint8_t foundCnt=0;
-       for (int idx=0; idx < *size - pLen; idx++){
-               if (memcmp(BitStream+idx, preamble, pLen) == 0){
+       uint8_t foundCnt = 0;
+       for (size_t idx = 0; idx < *size - pLen; idx++) {
+               if (memcmp(BitStream+idx, preamble, pLen) == 0) {

                        //first index found
                        foundCnt++;
                        //first index found
                        foundCnt++;

-                       if (foundCnt == 1){
+                       if (foundCnt == 1) {
+                               if (g_debugMode) prnt("DEBUG: preamble found at %u", idx);

                                *startIdx = idx;
                                *startIdx = idx;

-                       }
-                       if (foundCnt == 2){
+                               if (findone) return true;
+                       } else if (foundCnt == 2) {

                                *size = idx - *startIdx;
                                *size = idx - *startIdx;

-                               return 1;
+                               return true;

                        }
                }
        }
                        }
                }
        }

-       return 0;
+       return false;

 }
 
 }
 

-// search for given preamble in given BitStream and return success=1 or fail=0 and startIndex (where it was found)
-// does not look for a repeating preamble
-// em4x05/4x69 only sends preamble once, so look for it once in the first pLen bits
-// leave it generic so it could be reused later...
-bool onePreambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t size, size_t *startIdx) {
-       // Sanity check.  If preamble length is bigger than bitstream length.
-       if ( size <= pLen ) return false;
-       for (size_t idx = 0; idx < size - pLen; idx++) {
-               if (memcmp(BitStream+idx, preamble, pLen) == 0) {
-                       if (g_debugMode) prnt("DEBUG: preamble found at %u", idx);
-                       *startIdx = idx;
-                       return true;
-               }
-       }
-       return false;
+//by marshmellow
+//search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length
+uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx) {
+       return (preambleSearchEx(BitStream, preamble, pLen, size, startIdx, false)) ? 1 : 0;

 }
 
 // find start of modulating data (for fsk and psk) in case of beginning noise or slow chip startup.
 }
 
 // find start of modulating data (for fsk and psk) in case of beginning noise or slow chip startup.

-size_t findModStart(uint8_t dest[], size_t size, uint8_t threshold_value, uint8_t expWaveSize) {
+size_t findModStart(uint8_t dest[], size_t size, uint8_t expWaveSize) {

        size_t i = 0;
        size_t waveSizeCnt = 0;
        uint8_t thresholdCnt = 0;
        size_t i = 0;
        size_t waveSizeCnt = 0;
        uint8_t thresholdCnt = 0;

-       bool isAboveThreshold = dest[i++] >= threshold_value;
+       bool isAboveThreshold = dest[i++] >= FSK_PSK_THRESHOLD;

        for (; i < size-20; i++ ) {
        for (; i < size-20; i++ ) {

-               if(dest[i] < threshold_value && isAboveThreshold) {
+               if(dest[i] < FSK_PSK_THRESHOLD && isAboveThreshold) {

                        thresholdCnt++;
                        if (thresholdCnt > 2 && waveSizeCnt < expWaveSize+1) break;                     
                        isAboveThreshold = false;
                        waveSizeCnt = 0;
                        thresholdCnt++;
                        if (thresholdCnt > 2 && waveSizeCnt < expWaveSize+1) break;                     
                        isAboveThreshold = false;
                        waveSizeCnt = 0;

-               } else if (dest[i] >= threshold_value && !isAboveThreshold) {
+               } else if (dest[i] >= FSK_PSK_THRESHOLD && !isAboveThreshold) {

                        thresholdCnt++;
                        if (thresholdCnt > 2 && waveSizeCnt < expWaveSize+1) break;                     
                        isAboveThreshold = true;
                        thresholdCnt++;
                        if (thresholdCnt > 2 && waveSizeCnt < expWaveSize+1) break;                     
                        isAboveThreshold = true;


@@ -213,221 +220,104 @@ size_t findModStart(uint8_t dest[], size_t size, uint8_t threshold_value, uint8_
        return i;
 }
 
        return i;
 }
 

-//by marshmellow
-//takes 1s and 0s and searches for EM410x format - output EM ID
-uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo)
-{
-       //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
-       //  otherwise could be a void with no arguments
-       //set defaults
-       uint32_t i = 0;
-       if (BitStream[1]>1) return 0;  //allow only 1s and 0s
+int getClosestClock(int testclk) {
+       uint8_t fndClk[] = {8,16,32,40,50,64,128};
+
+       for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++)
+               if (testclk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && testclk <= fndClk[clkCnt]+1)
+                       return fndClk[clkCnt];

 
 

-       // 111111111 bit pattern represent start of frame
-       //  include 0 in front to help get start pos
-       uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1};
-       uint32_t idx = 0;
-       uint32_t parityBits = 0;
-       uint8_t errChk = 0;
-       uint8_t FmtLen = 10;
-       *startIdx = 0;
-       errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx);
-       if (errChk == 0 || *size < 64) return 0;
-       if (*size > 64) FmtLen = 22;
-       *startIdx += 1; //get rid of 0 from preamble
-       idx = *startIdx + 9;
-       for (i=0; i<FmtLen; i++){ //loop through 10 or 22 sets of 5 bits (50-10p = 40 bits or 88 bits)
-               parityBits = bytebits_to_byte(BitStream+(i*5)+idx,5);
-               //check even parity - quit if failed
-               if (parityTest(parityBits, 5, 0) == 0) return 0;
-               //set uint64 with ID from BitStream
-               for (uint8_t ii=0; ii<4; ii++){
-                       *hi = (*hi << 1) | (*lo >> 63);
-                       *lo = (*lo << 1) | (BitStream[(i*5)+ii+idx]);
-               }
-       }
-       if (errChk != 0) return 1;
-       //skip last 5 bit parity test for simplicity.
-       // *size = 64 | 128;

        return 0;
 }
 
        return 0;
 }
 

-//by marshmellow
-//demodulates strong heavily clipped samples
-int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low)
-{
-       size_t bitCnt=0, smplCnt=0, errCnt=0;
-       uint8_t waveHigh = 0;
-       for (size_t i=0; i < *size; i++){
-               if (BinStream[i] >= high && waveHigh){
-                       smplCnt++;
-               } else if (BinStream[i] <= low && !waveHigh){
-                       smplCnt++;
-               } else { //transition
-                       if ((BinStream[i] >= high && !waveHigh) || (BinStream[i] <= low && waveHigh)){
-                               if (smplCnt > clk-(clk/4)-1) { //full clock
-                                       if (smplCnt > clk + (clk/4)+1) { //too many samples
-                                               errCnt++;
-                                               if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
-                                               BinStream[bitCnt++]=7;
-                                       } else if (waveHigh) {
-                                               BinStream[bitCnt++] = invert;
-                                               BinStream[bitCnt++] = invert;
-                                       } else if (!waveHigh) {
-                                               BinStream[bitCnt++] = invert ^ 1;
-                                               BinStream[bitCnt++] = invert ^ 1;
-                                       }
-                                       waveHigh ^= 1;  
-                                       smplCnt = 0;
-                               } else if (smplCnt > (clk/2) - (clk/4)-1) {
-                                       if (waveHigh) {
-                                               BinStream[bitCnt++] = invert;
-                                       } else if (!waveHigh) {
-                                               BinStream[bitCnt++] = invert ^ 1;
-                                       }
-                                       waveHigh ^= 1;  
-                                       smplCnt = 0;
-                               } else if (!bitCnt) {
-                                       //first bit
-                                       waveHigh = (BinStream[i] >= high);
-                                       smplCnt = 1;
-                               } else {
-                                       smplCnt++;
-                                       //transition bit oops
-                               }
-                       } else { //haven't hit new high or new low yet
-                               smplCnt++;
-                       }
-               }
-       }
-       *size = bitCnt;
-       return errCnt;
+void getNextLow(uint8_t samples[], size_t size, int low, size_t *i) {
+       while ((samples[*i] > low) && (*i < size))
+               *i+=1;

 }
 
 }
 

-//by marshmellow
-void askAmp(uint8_t *BitStream, size_t size)
-{
-       uint8_t Last = 128;
-       for(size_t i = 1; i<size; i++){
-               if (BitStream[i]-BitStream[i-1]>=30) //large jump up
-                       Last = 255;
-               else if(BitStream[i-1]-BitStream[i]>=20) //large jump down
-                       Last = 0;
+void getNextHigh(uint8_t samples[], size_t size, int high, size_t *i) {
+       while ((samples[*i] < high) && (*i < size))
+               *i+=1;
+}

 
 

-               BitStream[i-1] = Last;
+// load wave counters
+bool loadWaveCounters(uint8_t samples[], size_t size, int lowToLowWaveLen[], int highToLowWaveLen[], int *waveCnt, int *skip, int *minClk, int *high, int *low) {
+       size_t i=0, firstLow, firstHigh;
+       size_t testsize = (size < 512) ? size : 512;
+
+       if ( getHiLo(samples, testsize, high, low, 80, 80) == -1 ) {
+               if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting");
+               return false; //just noise

        }
        }

-       return;
-}
- 
-//by marshmellow
-//attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester
-int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType)
-{
-       if (*size==0) return -1;
-       int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default
-       if (*clk==0 || start < 0) return -3;
-       if (*invert != 1) *invert = 0;
-       if (amp==1) askAmp(BinStream, *size);
-       if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d, amp %d", *clk, start, amp);

 
 

-       uint8_t initLoopMax = 255;
-       if (initLoopMax > *size) initLoopMax = *size;
-       // Detect high and lows
-       //25% clip in case highs and lows aren't clipped [marshmellow]
-       int high, low;
-       if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1) 
-               return -2; //just noise
+       // get to first full low to prime loop and skip incomplete first pulse
+       getNextHigh(samples, size, *high, &i);
+       getNextLow(samples, size, *low, &i);
+       *skip = i;

 
 

-       size_t errCnt = 0;
-       // if clean clipped waves detected run alternate demod
-       if (DetectCleanAskWave(BinStream, *size, high, low)) {
-               if (g_debugMode==2) prnt("DEBUG ASK: Clean Wave Detected - using clean wave demod");
-               errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
-               if (askType) //askman
-                       return manrawdecode(BinStream, size, 0);        
-               else //askraw
-                       return errCnt;
+       // populate tmpbuff buffer with pulse lengths
+       while (i < size) {
+               // measure from low to low
+               firstLow = i;
+               //find first high point for this wave
+               getNextHigh(samples, size, *high, &i);
+               firstHigh = i;
+
+               getNextLow(samples, size, *low, &i);
+
+               if (*waveCnt >= (size/LOWEST_DEFAULT_CLOCK))
+                       break;
+
+               highToLowWaveLen[*waveCnt] = i - firstHigh; //first high to first low
+               lowToLowWaveLen[*waveCnt] = i - firstLow;
+               *waveCnt += 1;
+               if (i-firstLow < *minClk && i < size) {
+                       *minClk = i - firstLow;
+               }

        }
        }

-       if (g_debugMode==2) prnt("DEBUG ASK: Weak Wave Detected - using weak wave demod");
+       return true;
+}

 
 

-       int lastBit;              //set first clock check - can go negative
-       size_t i, bitnum = 0;     //output counter
-       uint8_t midBit = 0;
-       uint8_t tol = 0;  //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave
-       if (*clk <= 32) tol = 1;  //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely
-       size_t MaxBits = 3072;    //max bits to collect
-       lastBit = start - *clk;
+size_t pskFindFirstPhaseShift(uint8_t samples[], size_t size, uint8_t *curPhase, size_t waveStart, uint16_t fc, uint16_t *fullWaveLen) {
+       uint16_t loopCnt = (size+3 < 4096) ? size : 4096;  //don't need to loop through entire array...

 
 

-       for (i = start; i < *size; ++i) {
-               if (i-lastBit >= *clk-tol){
-                       if (BinStream[i] >= high) {
-                               BinStream[bitnum++] = *invert;
-                       } else if (BinStream[i] <= low) {
-                               BinStream[bitnum++] = *invert ^ 1;
-                       } else if (i-lastBit >= *clk+tol) {
-                               if (bitnum > 0) {
-                                       if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
-                                       BinStream[bitnum++]=7;
-                                       errCnt++;                                               
-                               } 
-                       } else { //in tolerance - looking for peak
-                               continue;
-                       }
-                       midBit = 0;
-                       lastBit += *clk;
-               } else if (i-lastBit >= (*clk/2-tol) && !midBit && !askType){
-                       if (BinStream[i] >= high) {
-                               BinStream[bitnum++] = *invert;
-                       } else if (BinStream[i] <= low) {
-                               BinStream[bitnum++] = *invert ^ 1;
-                       } else if (i-lastBit >= *clk/2+tol) {
-                               BinStream[bitnum] = BinStream[bitnum-1];
-                               bitnum++;
-                       } else { //in tolerance - looking for peak
-                               continue;
+       uint16_t avgWaveVal=0, lastAvgWaveVal=0;
+       size_t i = waveStart, waveEnd, waveLenCnt, firstFullWave;
+       for (; i<loopCnt; i++) {
+               // find peak // was "samples[i] + fc" but why?  must have been used to weed out some wave error... removed..
+               if (samples[i] < samples[i+1] && samples[i+1] >= samples[i+2]){
+                       waveEnd = i+1;
+                       if (g_debugMode == 2) prnt("DEBUG PSK: waveEnd: %u, waveStart: %u", waveEnd, waveStart);
+                       waveLenCnt = waveEnd-waveStart;
+                       if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+8)){ //not first peak and is a large wave but not out of whack
+                               lastAvgWaveVal = avgWaveVal/(waveLenCnt);
+                               firstFullWave = waveStart;
+                               *fullWaveLen = waveLenCnt;
+                               //if average wave value is > graph 0 then it is an up wave or a 1 (could cause inverting)
+                               if (lastAvgWaveVal > FSK_PSK_THRESHOLD) *curPhase ^= 1;
+                               return firstFullWave;

                        }
                        }

-                       midBit = 1;
+                       waveStart = i+1;
+                       avgWaveVal = 0;

                }
                }

-               if (bitnum >= MaxBits) break;
+               avgWaveVal += samples[i+2];

        }
        }

-       *size = bitnum;
-       return errCnt;
+       return 0;

 }
 
 //by marshmellow
 }
 
 //by marshmellow

-//take 10 and 01 and manchester decode
-//run through 2 times and take least errCnt
-int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert)
-{
-       uint16_t bitnum=0, MaxBits = 512, errCnt = 0;
-       size_t i, ii;
-       uint16_t bestErr = 1000, bestRun = 0;
-       if (*size < 16) return -1;
-       //find correct start position [alignment]
-       for (ii=0;ii<2;++ii){
-               for (i=ii; i<*size-3; i+=2)
-                       if (BitStream[i]==BitStream[i+1])
-                               errCnt++;
+//amplify based on ask edge detection  -  not accurate enough to use all the time
+void askAmp(uint8_t *BitStream, size_t size) {
+       uint8_t Last = 128;
+       for(size_t i = 1; i<size; i++){
+               if (BitStream[i]-BitStream[i-1]>=30) //large jump up
+                       Last = 255;
+               else if(BitStream[i-1]-BitStream[i]>=20) //large jump down
+                       Last = 0;

 
 

-               if (bestErr>errCnt){
-                       bestErr=errCnt;
-                       bestRun=ii;
-               }
-               errCnt=0;
-       }
-       //decode
-       for (i=bestRun; i < *size-3; i+=2){
-               if(BitStream[i] == 1 && (BitStream[i+1] == 0)){
-                       BitStream[bitnum++]=invert;
-               } else if((BitStream[i] == 0) && BitStream[i+1] == 1){
-                       BitStream[bitnum++]=invert^1;
-               } else {
-                       BitStream[bitnum++]=7;
-               }
-               if(bitnum>MaxBits) break;
+               BitStream[i-1] = Last;

        }
        }

-       *size=bitnum;
-       return bestErr;
+       return;

 }
 
 uint32_t manchesterEncode2Bytes(uint16_t datain) {
 }
 
 uint32_t manchesterEncode2Bytes(uint16_t datain) {


@@ -442,789 +332,1185 @@ uint32_t manchesterEncode2Bytes(uint16_t datain) {
 
 //by marshmellow
 //encode binary data into binary manchester 
 
 //by marshmellow
 //encode binary data into binary manchester 

-int ManchesterEncode(uint8_t *BitStream, size_t size)
-{
-       size_t modIdx=20000, i=0;
-       if (size>modIdx) return -1;
+//NOTE: BitStream must have triple the size of "size" available in memory to do the swap
+int ManchesterEncode(uint8_t *BitStream, size_t size) {
+       //allow up to 4K out (means BitStream must be at least 2048+4096 to handle the swap)
+       size = (size>2048) ? 2048 : size;
+       size_t modIdx = size;
+       size_t i;

        for (size_t idx=0; idx < size; idx++){
                BitStream[idx+modIdx++] = BitStream[idx];
                BitStream[idx+modIdx++] = BitStream[idx]^1;
        }
        for (size_t idx=0; idx < size; idx++){
                BitStream[idx+modIdx++] = BitStream[idx];
                BitStream[idx+modIdx++] = BitStream[idx]^1;
        }

-       for (; i<(size*2); i++){
-               BitStream[i] = BitStream[i+20000];
+       for (i=0; i<(size*2); i++){
+               BitStream[i] = BitStream[i+size];

        }
        return i;
 }
 
        }
        return i;
 }
 

-//by marshmellow
-//take 01 or 10 = 1 and 11 or 00 = 0
-//check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010
-//decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding
-int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert)
-{
-       uint16_t bitnum = 0;
-       uint16_t errCnt = 0;
-       size_t i = offset;
-       uint16_t MaxBits=512;
-       //if not enough samples - error
-       if (*size < 51) return -1;
-       //check for phase change faults - skip one sample if faulty
-       uint8_t offsetA = 1, offsetB = 1;
-       for (; i<48; i+=2){
-               if (BitStream[i+1]==BitStream[i+2]) offsetA=0; 
-               if (BitStream[i+2]==BitStream[i+3]) offsetB=0;                                  
-       }
-       if (!offsetA && offsetB) offset++;
-       for (i=offset; i<*size-3; i+=2){
-               //check for phase error
-               if (BitStream[i+1]==BitStream[i+2]) {
-                       BitStream[bitnum++]=7;
-                       errCnt++;
-               }
-               if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){
-                       BitStream[bitnum++]=1^invert;
-               } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){
-                       BitStream[bitnum++]=invert;
-               } else {
-                       BitStream[bitnum++]=7;
-                       errCnt++;
-               }
-               if(bitnum>MaxBits) break;
-       }
-       *size=bitnum;
-       return errCnt;
-}
-

 // by marshmellow
 // by marshmellow

-// demod gProxIIDemod 
-// error returns as -x 
-// success returns start position in BitStream
-// BitStream must contain previously askrawdemod and biphasedemoded data
-int gProxII_Demod(uint8_t BitStream[], size_t *size)
-{
-       size_t startIdx=0;
-       uint8_t preamble[] = {1,1,1,1,1,0};
-
-       uint8_t errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, &startIdx);
-       if (errChk == 0) return -3; //preamble not found
-       if (*size != 96) return -2; //should have found 96 bits
-       //check first 6 spacer bits to verify format
-       if (!BitStream[startIdx+5] && !BitStream[startIdx+10] && !BitStream[startIdx+15] && !BitStream[startIdx+20] && !BitStream[startIdx+25] && !BitStream[startIdx+30]){
-               //confirmed proper separator bits found
-               //return start position
-               return (int) startIdx;
+// to detect a wave that has heavily clipped (clean) samples
+uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low) {
+       bool allArePeaks = true;
+       uint16_t cntPeaks=0;
+       size_t loopEnd = 512+160;
+       if (loopEnd > size) loopEnd = size;
+       for (size_t i=160; i<loopEnd; i++){
+               if (dest[i]>low && dest[i]<high) 
+                       allArePeaks = false;
+               else
+                       cntPeaks++;

        }
        }

-       return -5; //spacer bits not found - not a valid gproxII
+       if (!allArePeaks){
+               if (cntPeaks > 300) return true;
+       }
+       return allArePeaks;

 }
 
 }
 

-//translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq])
-size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow)
-{
-       size_t last_transition = 0;
-       size_t idx = 1;
-       if (fchigh==0) fchigh=10;
-       if (fclow==0) fclow=8;
-       //set the threshold close to 0 (graph) or 128 std to avoid static
-       uint8_t threshold_value = 123; 
-       size_t preLastSample = 0;
-       size_t LastSample = 0;
-       size_t currSample = 0;
-       if ( size < 1024 ) return 0; // not enough samples
+//**********************************************************************************************
+//-------------------Clock / Bitrate Detection Section------------------------------------------
+//**********************************************************************************************

 
 

-       //find start of modulating data in trace 
-       idx = findModStart(dest, size, threshold_value, fchigh);
+// by marshmellow
+// to help detect clocks on heavily clipped samples
+// based on count of low to low
+int DetectStrongAskClock(uint8_t dest[], size_t size, int high, int low, int *clock) {
+       size_t startwave;
+       size_t i = 100;
+       size_t minClk = 255;
+       int shortestWaveIdx = 0;
+               // get to first full low to prime loop and skip incomplete first pulse
+       getNextHigh(dest, size, high, &i);
+       getNextLow(dest, size, low, &i);

 
 

-       // Need to threshold first sample
-       if(dest[idx] < threshold_value) dest[0] = 0;
-       else dest[0] = 1;
-       idx++;
-       
-       size_t numBits = 0;
-       // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
-       // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere
-       // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
-       //  (could also be fc/5 && fc/7 for fsk1 = 4-9)
-       for(; idx < size-20; idx++) {
-               // threshold current value
+       // loop through all samples
+       while (i < size) {
+               // measure from low to low
+               startwave = i;

 
 

-               if (dest[idx] < threshold_value) dest[idx] = 0;
-               else dest[idx] = 1;
+               getNextHigh(dest, size, high, &i);
+               getNextLow(dest, size, low, &i);
+               //get minimum measured distance
+               if (i-startwave < minClk && i < size) {
+                       minClk = i - startwave;
+                       shortestWaveIdx = startwave;
+               }
+       }
+       // set clock
+       if (g_debugMode==2) prnt("DEBUG ASK: DetectStrongAskClock smallest wave: %d",minClk);
+       *clock = getClosestClock(minClk);
+       if (*clock == 0) 
+               return 0;
+       
+       return shortestWaveIdx;
+}

 
 

-               // Check for 0->1 transition
-               if (dest[idx-1] < dest[idx]) {
-                       preLastSample = LastSample;
-                       LastSample = currSample;
-                       currSample = idx-last_transition;
-                       if (currSample < (fclow-2)) {                   //0-5 = garbage noise (or 0-3)
-                               //do nothing with extra garbage
-                       } else if (currSample < (fchigh-1)) {           //6-8 = 8 sample waves  (or 3-6 = 5)
-                               //correct previous 9 wave surrounded by 8 waves (or 6 surrounded by 5)
-                               if (LastSample > (fchigh-2) && (preLastSample < (fchigh-1))){
-                                       dest[numBits-1]=1;
-                               }
-                               dest[numBits++]=1;
+// by marshmellow
+// not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)
+// maybe somehow adjust peak trimming value based on samples to fix?
+// return start index of best starting position for that clock and return clock (by reference)
+int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr) {
+       size_t i=1;
+       uint8_t clk[] = {255,8,16,32,40,50,64,100,128,255};
+       uint8_t clkEnd = 9;
+       uint8_t loopCnt = 255;  //don't need to loop through entire array...
+       if (size <= loopCnt+60) return -1; //not enough samples
+       size -= 60; //sometimes there is a strange end wave - filter out this....
+       //if we already have a valid clock
+       uint8_t clockFnd=0;
+       for (;i<clkEnd;++i)
+               if (clk[i] == *clock) clockFnd = i;
+               //clock found but continue to find best startpos

 
 

-                       } else if (currSample > (fchigh+1) && numBits < 3) { //12 + and first two bit = unusable garbage
-                               //do nothing with beginning garbage and reset..  should be rare..
-                               numBits = 0; 
-                       } else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's (or 4 then a 6 should be two 5's)
-                               dest[numBits++]=1;
-                       } else {                                        //9+ = 10 sample waves (or 6+ = 7)
-                               dest[numBits++]=0;
+       //get high and low peak
+       int peak, low;
+       if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return -1;
+       
+       //test for large clean peaks
+       if (!clockFnd){
+               if (DetectCleanAskWave(dest, size, peak, low)==1){
+                       int ans = DetectStrongAskClock(dest, size, peak, low, clock);
+                       if (g_debugMode==2) prnt("DEBUG ASK: detectaskclk Clean Ask Wave Detected: clk %i, ShortestWave: %i",clock, ans);
+                       if (ans > 0) {
+                               return ans; //return shortest wave start position

                        }
                        }

-                       last_transition = idx;

                }
        }
                }
        }

-       return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
-}
+       uint8_t ii;
+       uint8_t clkCnt, tol = 0;
+       uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
+       uint8_t bestStart[]={0,0,0,0,0,0,0,0,0};
+       size_t errCnt = 0;
+       size_t arrLoc, loopEnd;

 
 

-//translate 11111100000 to 10
-//rfLen = clock, fchigh = larger field clock, fclow = smaller field clock
-size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen,
-               uint8_t invert, uint8_t fchigh, uint8_t fclow)
-{
-       uint8_t lastval=dest[0];
-       size_t idx=0;
-       size_t numBits=0;
-       uint32_t n=1;
-       for( idx=1; idx < size; idx++) {
-               n++;
-               if (dest[idx]==lastval) continue; //skip until we hit a transition
-               
-               //find out how many bits (n) we collected
-               //if lastval was 1, we have a 1->0 crossing
-               if (dest[idx-1]==1) {
-                       n = (n * fclow + rfLen/2) / rfLen;
-               } else {// 0->1 crossing 
-                       n = (n * fchigh + rfLen/2) / rfLen; 
+       if (clockFnd>0) {
+               clkCnt = clockFnd;
+               clkEnd = clockFnd+1;
+       }
+       else clkCnt=1;
+
+       //test each valid clock from smallest to greatest to see which lines up
+       for(; clkCnt < clkEnd; clkCnt++){
+               if (clk[clkCnt] <= 32){
+                       tol=1;
+               }else{
+                       tol=0;

                }
                }

-               if (n == 0) n = 1;
+               //if no errors allowed - keep start within the first clock
+               if (!maxErr && size > clk[clkCnt]*2 + tol && clk[clkCnt]<128) loopCnt=clk[clkCnt]*2;
+               bestErr[clkCnt]=1000;
+               //try lining up the peaks by moving starting point (try first few clocks)
+               for (ii=0; ii < loopCnt; ii++){
+                       if (dest[ii] < peak && dest[ii] > low) continue;

 
 

-               //add to our destination the bits we collected          
-               memset(dest+numBits, dest[idx-1]^invert , n);
-               numBits += n;
-               n=0;
-               lastval=dest[idx];
-       }//end for
-       // if valid extra bits at the end were all the same frequency - add them in
-       if (n > rfLen/fchigh) {
-               if (dest[idx-2]==1) {
-                       n = (n * fclow + rfLen/2) / rfLen;
-               } else {
-                       n = (n * fchigh + rfLen/2) / rfLen;
+                       errCnt=0;
+                       // now that we have the first one lined up test rest of wave array
+                       loopEnd = ((size-ii-tol) / clk[clkCnt]) - 1;
+                       for (i=0; i < loopEnd; ++i){
+                               arrLoc = ii + (i * clk[clkCnt]);
+                               if (dest[arrLoc] >= peak || dest[arrLoc] <= low){
+                               }else if (dest[arrLoc-tol] >= peak || dest[arrLoc-tol] <= low){
+                               }else if (dest[arrLoc+tol] >= peak || dest[arrLoc+tol] <= low){
+                               }else{  //error no peak detected
+                                       errCnt++;
+                               }
+                       }
+                       //if we found no errors then we can stop here and a low clock (common clocks)
+                       //  this is correct one - return this clock
+                       if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, err %d, startpos %d, endpos %d",clk[clkCnt],errCnt,ii,i);
+                       if(errCnt==0 && clkCnt<7) { 
+                               if (!clockFnd) *clock = clk[clkCnt];
+                               return ii;
+                       }
+                       //if we found errors see if it is lowest so far and save it as best run
+                       if(errCnt<bestErr[clkCnt]){
+                               bestErr[clkCnt]=errCnt;
+                               bestStart[clkCnt]=ii;
+                       }

                }
                }

-               memset(dest+numBits, dest[idx-1]^invert , n);
-               numBits += n;

        }
        }

-       return numBits;
-}
-
-//by marshmellow  (from holiman's base)
-// full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod)
-int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow)
-{
-       // FSK demodulator
-       size = fsk_wave_demod(dest, size, fchigh, fclow);
-       size = aggregate_bits(dest, size, rfLen, invert, fchigh, fclow);
-       return size;
+       uint8_t iii;
+       uint8_t best=0;
+       for (iii=1; iii<clkEnd; ++iii){
+               if (bestErr[iii] < bestErr[best]){
+                       if (bestErr[iii] == 0) bestErr[iii]=1;
+                       // current best bit to error ratio     vs  new bit to error ratio
+                       if ( (size/clk[best])/bestErr[best] < (size/clk[iii])/bestErr[iii] ){
+                               best = iii;
+                       }
+               }
+               if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, # Errors %d, Current Best Clk %d, bestStart %d",clk[iii],bestErr[iii],clk[best],bestStart[best]);
+       }
+       if (!clockFnd) *clock = clk[best];
+       return bestStart[best];

 }
 
 }
 

-// loop to get raw HID waveform then FSK demodulate the TAG ID from it
-int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo)
-{
-       if (justNoise(dest, *size)) return -1;
+int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low, bool *strong) {
+       //find shortest transition from high to low
+       *strong = false;
+       size_t i = 0;
+       size_t transition1 = 0;
+       int lowestTransition = 255;
+       bool lastWasHigh = false;
+       size_t transitionSampleCount = 0;
+       //find first valid beginning of a high or low wave
+       while ((dest[i] >= peak || dest[i] <= low) && (i < size))
+               ++i;
+       while ((dest[i] < peak && dest[i] > low) && (i < size))
+               ++i;
+       lastWasHigh = (dest[i] >= peak);

 
 

-       size_t numStart=0, size2=*size, startIdx=0; 
-       // FSK demodulator
-       *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
-       if (*size < 96*2) return -2;
-       // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
-       uint8_t preamble[] = {0,0,0,1,1,1,0,1};
-       // find bitstring in array  
-       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
-       if (errChk == 0) return -3; //preamble not found
+       if (i==size) return 0;
+       transition1 = i;

 
 

-       numStart = startIdx + sizeof(preamble);
-       // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
-       for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
-               if (dest[idx] == dest[idx+1]){
-                       return -4; //not manchester data
+       for (;i < size; i++) {
+               if ((dest[i] >= peak && !lastWasHigh) || (dest[i] <= low && lastWasHigh)) {
+                       lastWasHigh = (dest[i] >= peak);
+                       if (i-transition1 < lowestTransition) lowestTransition = i-transition1;
+                       transition1 = i;
+               } else if (dest[i] < peak && dest[i] > low) {
+                       transitionSampleCount++;

                }
                }

-               *hi2 = (*hi2<<1)|(*hi>>31);
-               *hi = (*hi<<1)|(*lo>>31);
-               //Then, shift in a 0 or one into low
-               if (dest[idx] && !dest[idx+1])  // 1 0
-                       *lo=(*lo<<1)|1;
-               else // 0 1
-                       *lo=(*lo<<1)|0;

        }
        }

-       return (int)startIdx;
+       if (lowestTransition == 255) lowestTransition = 0;
+       if (g_debugMode==2) prnt("DEBUG NRZ: detectstrongNRZclk smallest wave: %d",lowestTransition);
+       // if less than 10% of the samples were not peaks (or 90% were peaks) then we have a strong wave
+       if (transitionSampleCount / size < 10) {
+               *strong = true;
+               lowestTransition = getClosestClock(lowestTransition);
+       }
+       return lowestTransition;

 }
 
 }
 

-// loop to get raw paradox waveform then FSK demodulate the TAG ID from it
-int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo)
-{
-       if (justNoise(dest, *size)) return -1;
-       
-       size_t numStart=0, size2=*size, startIdx=0;
-       // FSK demodulator
-       *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
-       if (*size < 96) return -2;
-
-       // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
-       uint8_t preamble[] = {0,0,0,0,1,1,1,1};
+//by marshmellow
+//detect nrz clock by reading #peaks vs no peaks(or errors)
+int DetectNRZClock(uint8_t dest[], size_t size, int clock, size_t *clockStartIdx) {
+       size_t i=0;
+       uint8_t clk[]={8,16,32,40,50,64,100,128,255};
+       size_t loopCnt = 4096;  //don't need to loop through entire array...
+       if (size == 0) return 0;
+       if (size<loopCnt) loopCnt = size-20;
+       //if we already have a valid clock quit
+       for (; i < 8; ++i)
+               if (clk[i] == clock) return clock;

 
 

-       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
-       if (errChk == 0) return -3; //preamble not found
+       //get high and low peak
+       int peak, low;
+       if (getHiLo(dest, loopCnt, &peak, &low, 90, 90) < 1) return 0;

 
 

-       numStart = startIdx + sizeof(preamble);
-       // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
-       for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
-               if (dest[idx] == dest[idx+1]) 
-                       return -4; //not manchester data
-               *hi2 = (*hi2<<1)|(*hi>>31);
-               *hi = (*hi<<1)|(*lo>>31);
-               //Then, shift in a 0 or one into low
-               if (dest[idx] && !dest[idx+1])  // 1 0
-                       *lo=(*lo<<1)|1;
-               else // 0 1
-                       *lo=(*lo<<1)|0;
+       bool strong = false;
+       int lowestTransition = DetectStrongNRZClk(dest, size-20, peak, low, &strong);
+       if (strong) return lowestTransition;
+       size_t ii;
+       uint8_t clkCnt;
+       uint8_t tol = 0;
+       uint16_t smplCnt = 0;
+       int16_t peakcnt = 0;
+       int16_t peaksdet[] = {0,0,0,0,0,0,0,0};
+       uint16_t minPeak = 255;
+       bool firstpeak = true;
+       //test for large clipped waves - ignore first peak
+       for (i=0; i<loopCnt; i++) {
+               if (dest[i] >= peak || dest[i] <= low) {
+                       if (firstpeak) continue;
+                       smplCnt++;
+               } else {
+                       firstpeak = false;
+                       if (smplCnt > 0) {
+                               if (minPeak > smplCnt && smplCnt > 7) minPeak = smplCnt;
+                               peakcnt++;
+                               if (g_debugMode == 2) prnt("DEBUG NRZ: minPeak: %d, smplCnt: %d, peakcnt: %d",minPeak,smplCnt,peakcnt);
+                               smplCnt = 0;                            
+                       }
+               }

        }
        }

-       return (int)startIdx;
+       if (minPeak < 8) return 0;
+       bool errBitHigh = 0;
+       bool bitHigh = 0;
+       uint8_t ignoreCnt = 0;
+       uint8_t ignoreWindow = 4;
+       bool lastPeakHigh = 0;
+       int lastBit = 0; 
+       size_t bestStart[]={0,0,0,0,0,0,0,0,0};
+       peakcnt=0;
+       //test each valid clock from smallest to greatest to see which lines up
+       for(clkCnt=0; clkCnt < 8; ++clkCnt) {
+               //ignore clocks smaller than smallest peak
+               if (clk[clkCnt] < minPeak - (clk[clkCnt]/4)) continue;
+               //try lining up the peaks by moving starting point (try first 256)
+               for (ii=20; ii < loopCnt; ++ii) {
+                       if ((dest[ii] >= peak) || (dest[ii] <= low)) {
+                               peakcnt = 0;
+                               bitHigh = false;
+                               ignoreCnt = 0;
+                               lastBit = ii-clk[clkCnt]; 
+                               //loop through to see if this start location works
+                               for (i = ii; i < size-20; ++i) {
+                                       //if we are at a clock bit
+                                       if ((i >= lastBit + clk[clkCnt] - tol) && (i <= lastBit + clk[clkCnt] + tol)) {
+                                               //test high/low
+                                               if (dest[i] >= peak || dest[i] <= low) {
+                                                       //if same peak don't count it
+                                                       if ((dest[i] >= peak && !lastPeakHigh) || (dest[i] <= low && lastPeakHigh)) {
+                                                               peakcnt++;
+                                                       }
+                                                       lastPeakHigh = (dest[i] >= peak);
+                                                       bitHigh = true;
+                                                       errBitHigh = false;
+                                                       ignoreCnt = ignoreWindow;
+                                                       lastBit += clk[clkCnt];
+                                               } else if (i == lastBit + clk[clkCnt] + tol) {
+                                                       lastBit += clk[clkCnt];
+                                               }
+                                       //else if not a clock bit and no peaks
+                                       } else if (dest[i] < peak && dest[i] > low) {
+                                               if (ignoreCnt==0) {
+                                                       bitHigh=false;
+                                                       if (errBitHigh==true) peakcnt--;
+                                                       errBitHigh=false;
+                                               } else {
+                                                       ignoreCnt--;
+                                               }
+                                               // else if not a clock bit but we have a peak
+                                       } else if ((dest[i]>=peak || dest[i]<=low) && (!bitHigh)) {
+                                               //error bar found no clock...
+                                               errBitHigh=true;
+                                       }
+                               }
+                               if(peakcnt>peaksdet[clkCnt]) {
+                                       bestStart[clkCnt]=ii;
+                                       peaksdet[clkCnt]=peakcnt;
+                               }
+                       }
+               }
+       }
+       int iii=7;
+       uint8_t best=0;
+       for (iii=7; iii > 0; iii--) {
+               if ((peaksdet[iii] >= (peaksdet[best]-1)) && (peaksdet[iii] <= peaksdet[best]+1) && lowestTransition) {
+                       if (clk[iii] > (lowestTransition - (clk[iii]/8)) && clk[iii] < (lowestTransition + (clk[iii]/8))) {
+                               best = iii;
+                       }
+               } else if (peaksdet[iii] > peaksdet[best]) {
+                       best = iii;
+               }
+               if (g_debugMode==2) prnt("DEBUG NRZ: Clk: %d, peaks: %d, minPeak: %d, bestClk: %d, lowestTrs: %d",clk[iii],peaksdet[iii],minPeak, clk[best], lowestTransition);
+       }
+       *clockStartIdx  = bestStart[best];
+       return clk[best];

 }
 
 }
 

-int IOdemodFSK(uint8_t *dest, size_t size)
-{
-       if (justNoise(dest, size)) return -1;
-       //make sure buffer has data
-       if (size < 66*64) return -2;
-       // FSK demodulator
-       size = fskdemod(dest, size, 64, 1, 10, 8);  // FSK2a RF/64 
-       if (size < 65) return -3;  //did we get a good demod?
-       //Index map
-       //0           10          20          30          40          50          60
-       //|           |           |           |           |           |           |
-       //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
-       //-----------------------------------------------------------------------------
-       //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
-       //
-       //XSF(version)facility:codeone+codetwo
-       //Handle the data
-       size_t startIdx = 0;
-       uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,1};
-       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), &size, &startIdx);
-       if (errChk == 0) return -4; //preamble not found
+//by marshmellow
+//countFC is to detect the field clock lengths.
+//counts and returns the 2 most common wave lengths
+//mainly used for FSK field clock detection
+uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj) {
+       uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+       uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+       uint8_t fcLensFnd = 0;
+       uint8_t lastFCcnt = 0;
+       uint8_t fcCounter = 0;
+       size_t i;
+       if (size < 180) return 0;

 
 

-       if (!dest[startIdx+8] && dest[startIdx+17]==1 && dest[startIdx+26]==1 && dest[startIdx+35]==1 && dest[startIdx+44]==1 && dest[startIdx+53]==1){
-               //confirmed proper separator bits found
-               //return start position
-               return (int) startIdx;
-       }
-       return -5;
-} 
+       // prime i to first up transition
+       for (i = 160; i < size-20; i++)
+               if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1])
+                       break;

 
 

-// by marshmellow
-// find viking preamble 0xF200 in already demoded data
-int VikingDemod_AM(uint8_t *dest, size_t *size) {
-       //make sure buffer has data
-       if (*size < 64*2) return -2;
+       for (; i < size-20; i++){
+               if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){
+                       // new up transition
+                       fcCounter++;
+                       if (fskAdj){
+                               //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8)
+                               if (lastFCcnt==5 && fcCounter==9) fcCounter--;
+                               //if fc=9 or 4 add one (for when we get a fc 9 instead of 10 or a 4 instead of a 5)
+                               if ((fcCounter==9) || fcCounter==4) fcCounter++;
+                       // save last field clock count  (fc/xx)
+                       lastFCcnt = fcCounter;
+                       }
+                       // find which fcLens to save it to:
+                       for (int ii=0; ii<15; ii++){
+                               if (fcLens[ii]==fcCounter){
+                                       fcCnts[ii]++;
+                                       fcCounter=0;
+                                       break;
+                               }
+                       }
+                       if (fcCounter>0 && fcLensFnd<15){
+                               //add new fc length 
+                               fcCnts[fcLensFnd]++;
+                               fcLens[fcLensFnd++]=fcCounter;
+                       }
+                       fcCounter=0;
+               } else {
+                       // count sample
+                       fcCounter++;
+               }
+       }
+       
+       uint8_t best1=14, best2=14, best3=14;
+       uint16_t maxCnt1=0;
+       // go through fclens and find which ones are bigest 2  
+       for (i=0; i<15; i++){
+               // get the 3 best FC values
+               if (fcCnts[i]>maxCnt1) {
+                       best3=best2;
+                       best2=best1;
+                       maxCnt1=fcCnts[i];
+                       best1=i;
+               } else if(fcCnts[i]>fcCnts[best2]){
+                       best3=best2;
+                       best2=i;
+               } else if(fcCnts[i]>fcCnts[best3]){
+                       best3=i;
+               }
+               if (g_debugMode==2) prnt("DEBUG countfc: FC %u, Cnt %u, best fc: %u, best2 fc: %u",fcLens[i],fcCnts[i],fcLens[best1],fcLens[best2]);
+               if (fcLens[i]==0) break;
+       }
+       if (fcLens[best1]==0) return 0;
+       uint8_t fcH=0, fcL=0;
+       if (fcLens[best1]>fcLens[best2]){
+               fcH=fcLens[best1];
+               fcL=fcLens[best2];
+       } else{
+               fcH=fcLens[best2];
+               fcL=fcLens[best1];
+       }
+       if ((size-180)/fcH/3 > fcCnts[best1]+fcCnts[best2]) {
+               if (g_debugMode==2) prnt("DEBUG countfc: fc is too large: %u > %u. Not psk or fsk",(size-180)/fcH/3,fcCnts[best1]+fcCnts[best2]);
+               return 0; //lots of waves not psk or fsk
+       }
+       // TODO: take top 3 answers and compare to known Field clocks to get top 2

 
 

-       size_t startIdx = 0;
-       uint8_t preamble[] = {1,1,1,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
-       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
-       if (errChk == 0) return -4; //preamble not found
-       uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^ bytebits_to_byte(dest+startIdx+8,8) ^ bytebits_to_byte(dest+startIdx+16,8)
-           ^ bytebits_to_byte(dest+startIdx+24,8) ^ bytebits_to_byte(dest+startIdx+32,8) ^ bytebits_to_byte(dest+startIdx+40,8) 
-           ^ bytebits_to_byte(dest+startIdx+48,8) ^ bytebits_to_byte(dest+startIdx+56,8);
-       if ( checkCalc != 0xA8 ) return -5;
-       if (*size != 64) return -6;
-       //return start position
-       return (int) startIdx;
+       uint16_t fcs = (((uint16_t)fcH)<<8) | fcL;
+       if (fskAdj) return fcs;
+       return (uint16_t)fcLens[best2] << 8 | fcLens[best1];

 }
 
 }
 

-// find presco preamble 0x10D in already demoded data
-int PrescoDemod(uint8_t *dest, size_t *size) {
-       //make sure buffer has data
-       if (*size < 64*2) return -2;
+//by marshmellow
+//detect psk clock by reading each phase shift
+// a phase shift is determined by measuring the sample length of each wave
+int DetectPSKClock(uint8_t dest[], size_t size, int clock, size_t *firstPhaseShift, uint8_t *curPhase, uint8_t *fc) {
+       uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock
+       uint16_t loopCnt = 4096;  //don't need to loop through entire array...
+       if (size == 0) return 0;
+       if (size+3<loopCnt) loopCnt = size-20;

 
 

-       size_t startIdx = 0;
-       uint8_t preamble[] = {1,0,0,0,0,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0};
-       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
-       if (errChk == 0) return -4; //preamble not found
-       //return start position
-       return (int) startIdx;
-}
+       uint16_t fcs = countFC(dest, size, 0);
+       *fc = fcs & 0xFF;
+       if (g_debugMode==2) prnt("DEBUG PSK: FC: %d, FC2: %d",*fc, fcs>>8);
+       if ((fcs>>8) == 10 && *fc == 8) return 0;
+       if (*fc!=2 && *fc!=4 && *fc!=8) return 0;

 
 

-// Ask/Biphase Demod then try to locate an ISO 11784/85 ID
-// BitStream must contain previously askrawdemod and biphasedemoded data
-int FDXBdemodBI(uint8_t *dest, size_t *size)
-{
-       //make sure buffer has enough data
-       if (*size < 128) return -1;
+       //if we already have a valid clock quit
+       size_t i=1;
+       for (; i < 8; ++i)
+               if (clk[i] == clock) return clock;

 
 

-       size_t startIdx = 0;
-       uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,1};
+       size_t waveStart=0, waveEnd=0, firstFullWave=0, lastClkBit=0;

 
 

-       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
-       if (errChk == 0) return -2; //preamble not found
-       return (int)startIdx;
-}
+       uint8_t clkCnt, tol=1;
+       uint16_t peakcnt=0, errCnt=0, waveLenCnt=0, fullWaveLen=0;
+       uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
+       uint16_t peaksdet[]={0,0,0,0,0,0,0,0,0};

 
 

-// by marshmellow
-// FSK Demod then try to locate an AWID ID
-int AWIDdemodFSK(uint8_t *dest, size_t *size)
-{
-       //make sure buffer has enough data
-       if (*size < 96*50) return -1;
+       //find start of modulating data in trace 
+       i = findModStart(dest, size, *fc);

 
 

-       if (justNoise(dest, *size)) return -2;
+       firstFullWave = pskFindFirstPhaseShift(dest, size, curPhase, i, *fc, &fullWaveLen);
+       if (firstFullWave == 0) {
+               // no phase shift detected - could be all 1's or 0's - doesn't matter where we start
+               // so skip a little to ensure we are past any Start Signal
+               firstFullWave = 160;
+               fullWaveLen = 0;
+       }

 
 

-       // FSK demodulator
-       *size = fskdemod(dest, *size, 50, 1, 10, 8);  // fsk2a RF/50 
-       if (*size < 96) return -3;  //did we get a good demod?
+       *firstPhaseShift = firstFullWave;
+       if (g_debugMode ==2) prnt("DEBUG PSK: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);
+       //test each valid clock from greatest to smallest to see which lines up
+       for(clkCnt=7; clkCnt >= 1 ; clkCnt--) {
+               tol = *fc/2;
+               lastClkBit = firstFullWave; //set end of wave as clock align
+               waveStart = 0;
+               errCnt=0;
+               peakcnt=0;
+               if (g_debugMode == 2) prnt("DEBUG PSK: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit);

 
 

-       uint8_t preamble[] = {0,0,0,0,0,0,0,1};
-       size_t startIdx = 0;
-       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
-       if (errChk == 0) return -4; //preamble not found
-       if (*size != 96) return -5;
-       return (int)startIdx;
+               for (i = firstFullWave+fullWaveLen-1; i < loopCnt-2; i++){
+                       //top edge of wave = start of new wave 
+                       if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
+                               if (waveStart == 0) {
+                                       waveStart = i+1;
+                                       waveLenCnt=0;
+                               } else { //waveEnd
+                                       waveEnd = i+1;
+                                       waveLenCnt = waveEnd-waveStart;
+                                       if (waveLenCnt > *fc){ 
+                                               //if this wave is a phase shift
+                                               if (g_debugMode == 2) prnt("DEBUG PSK: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+clk[clkCnt]-tol,i+1,*fc);
+                                               if (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit
+                                                       peakcnt++;
+                                                       lastClkBit+=clk[clkCnt];
+                                               } else if (i<lastClkBit+8){
+                                                       //noise after a phase shift - ignore
+                                               } else { //phase shift before supposed to based on clock
+                                                       errCnt++;
+                                               }
+                                       } else if (i+1 > lastClkBit + clk[clkCnt] + tol + *fc){
+                                               lastClkBit+=clk[clkCnt]; //no phase shift but clock bit
+                                       }
+                                       waveStart=i+1;
+                               }
+                       }
+               }
+               if (errCnt == 0){
+                       return clk[clkCnt];
+               }
+               if (errCnt <= bestErr[clkCnt]) bestErr[clkCnt]=errCnt;
+               if (peakcnt > peaksdet[clkCnt]) peaksdet[clkCnt]=peakcnt;
+       } 
+       //all tested with errors 
+       //return the highest clk with the most peaks found
+       uint8_t best=7;
+       for (i=7; i>=1; i--){
+               if (peaksdet[i] > peaksdet[best]) {
+                       best = i;
+               }
+               if (g_debugMode == 2) prnt("DEBUG PSK: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[i],peaksdet[i],bestErr[i],clk[best]);
+       }
+       return clk[best];

 }
 
 }
 

-// by marshmellow
-// FSK Demod then try to locate a Farpointe Data (pyramid) ID
-int PyramiddemodFSK(uint8_t *dest, size_t *size)
-{
-       //make sure buffer has data
-       if (*size < 128*50) return -5;
+//by marshmellow
+//detects the bit clock for FSK given the high and low Field Clocks
+uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow, int *firstClockEdge) {
+       uint8_t clk[] = {8,16,32,40,50,64,100,128,0};
+       uint16_t rfLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+       uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+       uint8_t rfLensFnd = 0;
+       uint8_t lastFCcnt = 0;
+       uint16_t fcCounter = 0;
+       uint16_t rfCounter = 0;
+       uint8_t firstBitFnd = 0;
+       size_t i;
+       if (size == 0) return 0;

 
 

-       //test samples are not just noise
-       if (justNoise(dest, *size)) return -1;
+       uint8_t fcTol = ((fcHigh*100 - fcLow*100)/2 + 50)/100; //(uint8_t)(0.5+(float)(fcHigh-fcLow)/2);
+       rfLensFnd=0;
+       fcCounter=0;
+       rfCounter=0;
+       firstBitFnd=0;
+       //PrintAndLog("DEBUG: fcTol: %d",fcTol);
+       // prime i to first peak / up transition
+       for (i = 160; i < size-20; i++)
+               if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1])
+                       break;
+
+       for (; i < size-20; i++){
+               fcCounter++;
+               rfCounter++;
+
+               if (BitStream[i] <= BitStream[i-1] || BitStream[i] < BitStream[i+1]) 
+                       continue;               
+               // else new peak 
+               // if we got less than the small fc + tolerance then set it to the small fc
+               // if it is inbetween set it to the last counter
+               if (fcCounter < fcHigh && fcCounter > fcLow)
+                       fcCounter = lastFCcnt;
+               else if (fcCounter < fcLow+fcTol) 
+                       fcCounter = fcLow;
+               else //set it to the large fc
+                       fcCounter = fcHigh;
+
+               //look for bit clock  (rf/xx)
+               if ((fcCounter < lastFCcnt || fcCounter > lastFCcnt)){
+                       //not the same size as the last wave - start of new bit sequence
+                       if (firstBitFnd > 1){ //skip first wave change - probably not a complete bit
+                               for (int ii=0; ii<15; ii++){
+                                       if (rfLens[ii] >= (rfCounter-4) && rfLens[ii] <= (rfCounter+4)){
+                                               rfCnts[ii]++;
+                                               rfCounter = 0;
+                                               break;
+                                       }
+                               }
+                               if (rfCounter > 0 && rfLensFnd < 15){
+                                       //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
+                                       rfCnts[rfLensFnd]++;
+                                       rfLens[rfLensFnd++] = rfCounter;
+                               }
+                       } else {
+                               *firstClockEdge = i;
+                               firstBitFnd++;
+                       }
+                       rfCounter=0;
+                       lastFCcnt=fcCounter;
+               }
+               fcCounter=0;
+       }
+       uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15;
+
+       for (i=0; i<15; i++){
+               //get highest 2 RF values  (might need to get more values to compare or compare all?)
+               if (rfCnts[i]>rfCnts[rfHighest]){
+                       rfHighest3=rfHighest2;
+                       rfHighest2=rfHighest;
+                       rfHighest=i;
+               } else if(rfCnts[i]>rfCnts[rfHighest2]){
+                       rfHighest3=rfHighest2;
+                       rfHighest2=i;
+               } else if(rfCnts[i]>rfCnts[rfHighest3]){
+                       rfHighest3=i;
+               }
+               if (g_debugMode==2) prnt("DEBUG FSK: RF %d, cnts %d",rfLens[i], rfCnts[i]);
+       }  
+       // set allowed clock remainder tolerance to be 1 large field clock length+1 
+       //   we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off  
+       uint8_t tol1 = fcHigh+1; 
+       
+       if (g_debugMode==2) prnt("DEBUG FSK: most counted rf values: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]);
+
+       // loop to find the highest clock that has a remainder less than the tolerance
+       //   compare samples counted divided by
+       // test 128 down to 32 (shouldn't be possible to have fc/10 & fc/8 and rf/16 or less)
+       int ii=7;
+       for (; ii>=2; ii--){
+               if (rfLens[rfHighest] % clk[ii] < tol1 || rfLens[rfHighest] % clk[ii] > clk[ii]-tol1){
+                       if (rfLens[rfHighest2] % clk[ii] < tol1 || rfLens[rfHighest2] % clk[ii] > clk[ii]-tol1){
+                               if (rfLens[rfHighest3] % clk[ii] < tol1 || rfLens[rfHighest3] % clk[ii] > clk[ii]-tol1){
+                                       if (g_debugMode==2) prnt("DEBUG FSK: clk %d divides into the 3 most rf values within tolerance",clk[ii]);
+                                       break;
+                               }
+                       }
+               }
+       }

 
 

-       // FSK demodulator
-       *size = fskdemod(dest, *size, 50, 1, 10, 8);  // fsk2a RF/50 
-       if (*size < 128) return -2;  //did we get a good demod?
+       if (ii<2) return 0; // oops we went too far

 
 

-       uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
-       size_t startIdx = 0;
-       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
-       if (errChk == 0) return -4; //preamble not found
-       if (*size != 128) return -3;
-       return (int)startIdx;
+       return clk[ii];

 }
 
 }
 

-// by marshmellow
-// to detect a wave that has heavily clipped (clean) samples
-uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low)
-{
-       bool allArePeaks = true;
-       uint16_t cntPeaks=0;
-       size_t loopEnd = 512+160;
-       if (loopEnd > size) loopEnd = size;
-       for (size_t i=160; i<loopEnd; i++){
-               if (dest[i]>low && dest[i]<high) 
-                       allArePeaks = false;
-               else
-                       cntPeaks++;
-       }
-       if (!allArePeaks){
-               if (cntPeaks > 300) return true;
+//**********************************************************************************************
+//--------------------Modulation Demods &/or Decoding Section-----------------------------------
+//**********************************************************************************************
+
+// look for Sequence Terminator - should be pulses of clk*(1 or 2), clk*2, clk*(1.5 or 2), by idx we mean graph position index...
+bool findST(int *stStopLoc, int *stStartIdx, int lowToLowWaveLen[], int highToLowWaveLen[], int clk, int tol, int buffSize, size_t *i) {
+       if (buffSize < *i+4) return false;
+
+       for (; *i < buffSize - 4; *i+=1) {
+               *stStartIdx += lowToLowWaveLen[*i]; //caution part of this wave may be data and part may be ST....  to be accounted for in main function for now...
+               if (lowToLowWaveLen[*i] >= clk*1-tol && lowToLowWaveLen[*i] <= (clk*2)+tol && highToLowWaveLen[*i] < clk+tol) {           //1 to 2 clocks depending on 2 bits prior
+                       if (lowToLowWaveLen[*i+1] >= clk*2-tol && lowToLowWaveLen[*i+1] <= clk*2+tol && highToLowWaveLen[*i+1] > clk*3/2-tol) {       //2 clocks and wave size is 1 1/2
+                               if (lowToLowWaveLen[*i+2] >= (clk*3)/2-tol && lowToLowWaveLen[*i+2] <= clk*2+tol && highToLowWaveLen[*i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave
+                                       if (lowToLowWaveLen[*i+3] >= clk*1-tol && lowToLowWaveLen[*i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit
+                                               *stStopLoc = *i + 3;
+                                               return true;
+                                       }
+                               }
+                       }
+               }

        }
        }

-       return allArePeaks;
+       return false;

 }
 }

-// by marshmellow
-// to help detect clocks on heavily clipped samples
-// based on count of low to low
-int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low)
-{
-       uint8_t fndClk[] = {8,16,32,40,50,64,128};
-       size_t startwave;
-       size_t i = 100;
-       size_t minClk = 255;
-               // get to first full low to prime loop and skip incomplete first pulse
-       while ((dest[i] < high) && (i < size))
-               ++i;
-       while ((dest[i] > low) && (i < size))
-               ++i;
+//by marshmellow
+//attempt to identify a Sequence Terminator in ASK modulated raw wave
+bool DetectST(uint8_t buffer[], size_t *size, int *foundclock, size_t *ststart, size_t *stend) {
+       size_t bufsize = *size;
+       //need to loop through all samples and identify our clock, look for the ST pattern
+       int clk = 0; 
+       int tol = 0;
+       int j=0, high, low, skip=0, start=0, end=0, minClk=255;
+       size_t i = 0;
+       //probably should malloc... || test if memory is available ... handle device side? memory danger!!! [marshmellow]
+       int tmpbuff[bufsize / LOWEST_DEFAULT_CLOCK]; // low to low wave count //guess rf/32 clock, if click is smaller we will only have room for a fraction of the samples captured
+       int waveLen[bufsize / LOWEST_DEFAULT_CLOCK]; // high to low wave count //if clock is larger then we waste memory in array size that is not needed...
+       //size_t testsize = (bufsize < 512) ? bufsize : 512;
+       int phaseoff = 0;
+       high = low = 128;
+       memset(tmpbuff, 0, sizeof(tmpbuff));
+       memset(waveLen, 0, sizeof(waveLen));

 
 

-       // loop through all samples
-       while (i < size) {
-               // measure from low to low
-               while ((dest[i] > low) && (i < size))
-                       ++i;
-               startwave= i;
-               while ((dest[i] < high) && (i < size))
-                       ++i;
-               while ((dest[i] > low) && (i < size))
-                       ++i;
-               //get minimum measured distance
-               if (i-startwave < minClk && i < size)
-                       minClk = i - startwave;
-       }
-       // set clock
-       if (g_debugMode==2) prnt("DEBUG ASK: detectstrongASKclk smallest wave: %d",minClk);
-       for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
-               if (minClk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1)
-                       return fndClk[clkCnt];
+       if (!loadWaveCounters(buffer, bufsize, tmpbuff, waveLen, &j, &skip, &minClk, &high, &low)) return false;
+       // set clock  - might be able to get this externally and remove this work...
+       clk = getClosestClock(minClk);
+       // clock not found - ERROR
+       if (clk == 0) {
+               if (g_debugMode==2) prnt("DEBUG STT: clock not found - quitting");
+               return false;

        }
        }

-       return 0;
-}
-
-// by marshmellow
-// not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)
-// maybe somehow adjust peak trimming value based on samples to fix?
-// return start index of best starting position for that clock and return clock (by reference)
-int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
-{
-       size_t i=1;
-       uint8_t clk[] = {255,8,16,32,40,50,64,100,128,255};
-       uint8_t clkEnd = 9;
-       uint8_t loopCnt = 255;  //don't need to loop through entire array...
-       if (size <= loopCnt+60) return -1; //not enough samples
-       size -= 60; //sometimes there is a strange end wave - filter out this....
-       //if we already have a valid clock
-       uint8_t clockFnd=0;
-       for (;i<clkEnd;++i)
-               if (clk[i] == *clock) clockFnd = i;
-               //clock found but continue to find best startpos
+       *foundclock = clk;

 
 

-       //get high and low peak
-       int peak, low;
-       if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return -1;
+       tol = clk/8;
+       if (!findST(&start, &skip, tmpbuff, waveLen, clk, tol, j, &i)) {
+               // first ST not found - ERROR
+               if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting");
+               return false;
+       } else {
+               if (g_debugMode==2) prnt("DEBUG STT: first STT found at wave: %i, skip: %i, j=%i", start, skip, j);
+       }
+       if (waveLen[i+2] > clk*1+tol)
+               phaseoff = 0;
+       else
+               phaseoff = clk/2;

        
        

-       //test for large clean peaks
-       if (!clockFnd){
-               if (DetectCleanAskWave(dest, size, peak, low)==1){
-                       int ans = DetectStrongAskClock(dest, size, peak, low);
-                       if (g_debugMode==2) prnt("DEBUG ASK: detectaskclk Clean Ask Wave Detected: clk %d",ans);
-                       for (i=clkEnd-1; i>0; i--){
-                               if (clk[i] == ans) {
-                                       *clock = ans;
-                                       //clockFnd = i;
-                                       return 0;  // for strong waves i don't use the 'best start position' yet...
-                                       //break; //clock found but continue to find best startpos [not yet]
-                               }
+       // skip over the remainder of ST
+       skip += clk*7/2; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point
+
+       // now do it again to find the end
+       int dummy1 = 0;
+       end = skip;
+       i+=3;
+       if (!findST(&dummy1, &end, tmpbuff, waveLen, clk, tol, j, &i)) {
+               //didn't find second ST - ERROR
+               if (g_debugMode==2) prnt("DEBUG STT: second STT not found - quitting");
+               return false;
+       }
+       end -= phaseoff;
+       if (g_debugMode==2) prnt("DEBUG STT: start of data: %d end of data: %d, datalen: %d, clk: %d, bits: %d, phaseoff: %d", skip, end, end-skip, clk, (end-skip)/clk, phaseoff);
+       //now begin to trim out ST so we can use normal demod cmds
+       start = skip;
+       size_t datalen = end - start;
+       // check validity of datalen (should be even clock increments)  - use a tolerance of up to 1/8th a clock
+       if ( clk - (datalen % clk) <= clk/8) {
+               // padd the amount off - could be problematic...  but shouldn't happen often
+               datalen += clk - (datalen % clk);
+       } else if ( (datalen % clk) <= clk/8 ) {
+               // padd the amount off - could be problematic...  but shouldn't happen often
+               datalen -= datalen % clk;
+       } else {
+               if (g_debugMode==2) prnt("DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting", datalen, clk, datalen % clk);
+               return false;
+       }
+       // if datalen is less than one t55xx block - ERROR
+       if (datalen/clk < 8*4) {
+               if (g_debugMode==2) prnt("DEBUG STT: datalen is less than 1 full t55xx block - quitting");              
+               return false;
+       }
+       size_t dataloc = start;
+       if (buffer[dataloc-(clk*4)-(clk/4)] <= low && buffer[dataloc] <= low && buffer[dataloc-(clk*4)] >= high) {
+               //we have low drift (and a low just before the ST and a low just after the ST) - compensate by backing up the start 
+               for ( i=0; i <= (clk/4); ++i ) {
+                       if ( buffer[dataloc - (clk*4) - i] <= low ) {
+                               dataloc -= i;
+                               break;

                        }
                }
        }
                        }
                }
        }

-       uint8_t ii;
-       uint8_t clkCnt, tol = 0;
-       uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
-       uint8_t bestStart[]={0,0,0,0,0,0,0,0,0};
-       size_t errCnt = 0;
-       size_t arrLoc, loopEnd;
+       
+       size_t newloc = 0;
+       i=0;
+       if (g_debugMode==2) prnt("DEBUG STT: Starting STT trim - start: %d, datalen: %d ",dataloc, datalen);            
+       bool firstrun = true;
+       // warning - overwriting buffer given with raw wave data with ST removed...
+       while ( dataloc < bufsize-(clk/2) ) {
+               //compensate for long high at end of ST not being high due to signal loss... (and we cut out the start of wave high part)
+               if (buffer[dataloc]<high && buffer[dataloc]>low && buffer[dataloc+clk/4]<high && buffer[dataloc+clk/4]>low) {
+                       for(i=0; i < clk/2-tol; ++i) {
+                               buffer[dataloc+i] = high+5;
+                       }
+               } //test for small spike outlier (high between two lows) in the case of very strong waves
+               if (buffer[dataloc] > low && buffer[dataloc+clk/4] <= low) {
+                       for(i=0; i < clk/4; ++i) {
+                               buffer[dataloc+i] = buffer[dataloc+clk/4];
+                       }
+               }
+               if (firstrun) {
+                       *stend = dataloc;
+                       *ststart = dataloc-(clk*4);
+                       firstrun=false;
+               }
+               for (i=0; i<datalen; ++i) {
+                       if (i+newloc < bufsize) {
+                               if (i+newloc < dataloc)
+                                       buffer[i+newloc] = buffer[dataloc];

 
 

-       if (clockFnd>0) {
-               clkCnt = clockFnd;
-               clkEnd = clockFnd+1;
+                               dataloc++;
+                       }
+               }
+               newloc += i;
+               //skip next ST  -  we just assume it will be there from now on...
+               if (g_debugMode==2) prnt("DEBUG STT: skipping STT at %d to %d", dataloc, dataloc+(clk*4));
+               dataloc += clk*4;

        }
        }

-       else clkCnt=1;
+       *size = newloc;
+       return true;
+}

 
 

-       //test each valid clock from smallest to greatest to see which lines up
-       for(; clkCnt < clkEnd; clkCnt++){
-               if (clk[clkCnt] <= 32){
-                       tol=1;
-               }else{
-                       tol=0;
+//by marshmellow
+//take 11 10 01 11 00 and make 01100 ... miller decoding 
+//check for phase errors - should never have half a 1 or 0 by itself and should never exceed 1111 or 0000 in a row
+//decodes miller encoded binary
+//NOTE  askrawdemod will NOT demod miller encoded ask unless the clock is manually set to 1/2 what it is detected as!
+int millerRawDecode(uint8_t *BitStream, size_t *size, int invert) {
+       if (*size < 16) return -1;
+       uint16_t MaxBits = 512, errCnt = 0;
+       size_t i, bitCnt=0;
+       uint8_t alignCnt = 0, curBit = BitStream[0], alignedIdx = 0;
+       uint8_t halfClkErr = 0;
+       //find alignment, needs 4 1s or 0s to properly align
+       for (i=1; i < *size-1; i++) {
+               alignCnt = (BitStream[i] == curBit) ? alignCnt+1 : 0;
+               curBit = BitStream[i];
+               if (alignCnt == 4) break;
+       }
+       // for now error if alignment not found.  later add option to run it with multiple offsets...
+       if (alignCnt != 4) {
+               if (g_debugMode) prnt("ERROR MillerDecode: alignment not found so either your bitstream is not miller or your data does not have a 101 in it");
+               return -1;
+       }
+       alignedIdx = (i-1) % 2;
+       for (i=alignedIdx; i < *size-3; i+=2) {
+               halfClkErr = (uint8_t)((halfClkErr << 1 | BitStream[i]) & 0xFF);
+               if ( (halfClkErr & 0x7) == 5 || (halfClkErr & 0x7) == 2 || (i > 2 && (halfClkErr & 0x7) == 0) || (halfClkErr & 0x1F) == 0x1F) {
+                       errCnt++;
+                       BitStream[bitCnt++] = 7;
+                       continue;

                }
                }

-               //if no errors allowed - keep start within the first clock
-               if (!maxErr && size > clk[clkCnt]*2 + tol && clk[clkCnt]<128) loopCnt=clk[clkCnt]*2;
-               bestErr[clkCnt]=1000;
-               //try lining up the peaks by moving starting point (try first few clocks)
-               for (ii=0; ii < loopCnt; ii++){
-                       if (dest[ii] < peak && dest[ii] > low) continue;
+               BitStream[bitCnt++] = BitStream[i] ^ BitStream[i+1] ^ invert;

 
 

-                       errCnt=0;
-                       // now that we have the first one lined up test rest of wave array
-                       loopEnd = ((size-ii-tol) / clk[clkCnt]) - 1;
-                       for (i=0; i < loopEnd; ++i){
-                               arrLoc = ii + (i * clk[clkCnt]);
-                               if (dest[arrLoc] >= peak || dest[arrLoc] <= low){
-                               }else if (dest[arrLoc-tol] >= peak || dest[arrLoc-tol] <= low){
-                               }else if (dest[arrLoc+tol] >= peak || dest[arrLoc+tol] <= low){
-                               }else{  //error no peak detected
-                                       errCnt++;
-                               }
-                       }
-                       //if we found no errors then we can stop here and a low clock (common clocks)
-                       //  this is correct one - return this clock
-                       if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, err %d, startpos %d, endpos %d",clk[clkCnt],errCnt,ii,i);
-                       if(errCnt==0 && clkCnt<7) { 
-                               if (!clockFnd) *clock = clk[clkCnt];
-                               return ii;
-                       }
-                       //if we found errors see if it is lowest so far and save it as best run
-                       if(errCnt<bestErr[clkCnt]){
-                               bestErr[clkCnt]=errCnt;
-                               bestStart[clkCnt]=ii;
-                       }
+               if (bitCnt > MaxBits) break;
+       }
+       *size = bitCnt;
+       return errCnt;
+}
+
+//by marshmellow
+//take 01 or 10 = 1 and 11 or 00 = 0
+//check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010
+//decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding
+int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int *offset, int invert) {
+       uint16_t bitnum = 0;
+       uint16_t errCnt = 0;
+       size_t i = *offset;
+       uint16_t MaxBits=512;
+       //if not enough samples - error
+       if (*size < 51) return -1;
+       //check for phase change faults - skip one sample if faulty
+       uint8_t offsetA = 1, offsetB = 1;
+       for (; i<48; i+=2){
+               if (BitStream[i+1]==BitStream[i+2]) offsetA=0; 
+               if (BitStream[i+2]==BitStream[i+3]) offsetB=0;                                  
+       }
+       if (!offsetA && offsetB) *offset+=1;
+       for (i=*offset; i<*size-3; i+=2){
+               //check for phase error
+               if (BitStream[i+1]==BitStream[i+2]) {
+                       BitStream[bitnum++]=7;
+                       errCnt++;
+               }
+               if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){
+                       BitStream[bitnum++]=1^invert;
+               } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){
+                       BitStream[bitnum++]=invert;
+               } else {
+                       BitStream[bitnum++]=7;
+                       errCnt++;
+               }
+               if(bitnum>MaxBits) break;
+       }
+       *size=bitnum;
+       return errCnt;
+}
+
+//by marshmellow
+//take 10 and 01 and manchester decode
+//run through 2 times and take least errCnt
+int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert, uint8_t *alignPos) {
+       uint16_t bitnum=0, MaxBits = 512, errCnt = 0;
+       size_t i, ii;
+       uint16_t bestErr = 1000, bestRun = 0;
+       if (*size < 16) return -1;
+       //find correct start position [alignment]
+       for (ii=0;ii<2;++ii){
+               for (i=ii; i<*size-3; i+=2)
+                       if (BitStream[i]==BitStream[i+1])
+                               errCnt++;
+
+               if (bestErr>errCnt){
+                       bestErr=errCnt;
+                       bestRun=ii;

                }
                }

+               errCnt=0;

        }
        }

-       uint8_t iii;
-       uint8_t best=0;
-       for (iii=1; iii<clkEnd; ++iii){
-               if (bestErr[iii] < bestErr[best]){
-                       if (bestErr[iii] == 0) bestErr[iii]=1;
-                       // current best bit to error ratio     vs  new bit to error ratio
-                       if ( (size/clk[best])/bestErr[best] < (size/clk[iii])/bestErr[iii] ){
-                               best = iii;
-                       }
+       *alignPos=bestRun;
+       //decode
+       for (i=bestRun; i < *size-3; i+=2){
+               if(BitStream[i] == 1 && (BitStream[i+1] == 0)){
+                       BitStream[bitnum++]=invert;
+               } else if((BitStream[i] == 0) && BitStream[i+1] == 1){
+                       BitStream[bitnum++]=invert^1;
+               } else {
+                       BitStream[bitnum++]=7;

                }
                }

-               if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, # Errors %d, Current Best Clk %d, bestStart %d",clk[iii],bestErr[iii],clk[best],bestStart[best]);
+               if(bitnum>MaxBits) break;

        }
        }

-       if (!clockFnd) *clock = clk[best];
-       return bestStart[best];
+       *size=bitnum;
+       return bestErr;

 }
 
 //by marshmellow
 }
 
 //by marshmellow

-//detect psk clock by reading each phase shift
-// a phase shift is determined by measuring the sample length of each wave
-int DetectPSKClock(uint8_t dest[], size_t size, int clock)
+//demodulates strong heavily clipped samples
+int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low, int *startIdx)

 {
 {

-       uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock
-       uint16_t loopCnt = 4096;  //don't need to loop through entire array...
-       if (size == 0) return 0;
-       if (size<loopCnt) loopCnt = size-20;
+       *startIdx=0;
+       size_t bitCnt=0, smplCnt=1, errCnt=0;
+       bool waveHigh = (BinStream[0] >= high);
+       for (size_t i=1; i < *size; i++){
+               if (BinStream[i] >= high && waveHigh){
+                       smplCnt++;
+               } else if (BinStream[i] <= low && !waveHigh){
+                       smplCnt++;
+               } else { //transition
+                       if ((BinStream[i] >= high && !waveHigh) || (BinStream[i] <= low && waveHigh)){
+                               if (smplCnt > clk-(clk/4)-1) { //full clock
+                                       if (smplCnt > clk + (clk/4)+1) { //too many samples
+                                               errCnt++;
+                                               if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
+                                               BinStream[bitCnt++] = 7;
+                                       } else if (waveHigh) {
+                                               BinStream[bitCnt++] = invert;
+                                               BinStream[bitCnt++] = invert;
+                                       } else if (!waveHigh) {
+                                               BinStream[bitCnt++] = invert ^ 1;
+                                               BinStream[bitCnt++] = invert ^ 1;
+                                       }
+                                       if (*startIdx==0) *startIdx = i-clk;
+                                       waveHigh = !waveHigh;  
+                                       smplCnt = 0;
+                               } else if (smplCnt > (clk/2) - (clk/4)-1) { //half clock
+                                       if (waveHigh) {
+                                               BinStream[bitCnt++] = invert;
+                                       } else if (!waveHigh) {
+                                               BinStream[bitCnt++] = invert ^ 1;
+                                       }
+                                       if (*startIdx==0) *startIdx = i-(clk/2);
+                                       waveHigh = !waveHigh;  
+                                       smplCnt = 0;
+                               } else {
+                                       smplCnt++;
+                                       //transition bit oops
+                               }
+                       } else { //haven't hit new high or new low yet
+                               smplCnt++;
+                       }
+               }
+       }
+       *size = bitCnt;
+       return errCnt;
+}

 
 

-       //if we already have a valid clock quit
-       size_t i=1;
-       for (; i < 8; ++i)
-               if (clk[i] == clock) return clock;
+//by marshmellow
+//attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester
+int askdemod_ext(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType, int *startIdx) {
+       if (*size==0) return -1;
+       int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default
+       if (*clk==0 || start < 0) return -3;
+       if (*invert != 1) *invert = 0;
+       if (amp==1) askAmp(BinStream, *size);
+       if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d, amp %d", *clk, start, amp);

 
 

-       size_t waveStart=0, waveEnd=0, firstFullWave=0, lastClkBit=0;
-       uint8_t clkCnt, fc=0, fullWaveLen=0, tol=1;
-       uint16_t peakcnt=0, errCnt=0, waveLenCnt=0;
-       uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
-       uint16_t peaksdet[]={0,0,0,0,0,0,0,0,0};
-       fc = countFC(dest, size, 0);
-       if (fc!=2 && fc!=4 && fc!=8) return -1;
-       if (g_debugMode==2) prnt("DEBUG PSK: FC: %d",fc);
+       //start pos from detect ask clock is 1/2 clock offset
+       // NOTE: can be negative (demod assumes rest of wave was there)
+       *startIdx = start - (*clk/2); 
+       uint8_t initLoopMax = 255;
+       if (initLoopMax > *size) initLoopMax = *size;
+       // Detect high and lows
+       //25% clip in case highs and lows aren't clipped [marshmellow]
+       int high, low;
+       if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1) 
+               return -2; //just noise

 
 

-       //find first full wave
-       for (i=160; i<loopCnt; i++){
-               if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
-                       if (waveStart == 0) {
-                               waveStart = i+1;
-                               //prnt("DEBUG: waveStart: %d",waveStart);
-                       } else {
-                               waveEnd = i+1;
-                               //prnt("DEBUG: waveEnd: %d",waveEnd);
-                               waveLenCnt = waveEnd-waveStart;
-                               if (waveLenCnt > fc){
-                                       firstFullWave = waveStart;
-                                       fullWaveLen=waveLenCnt;
-                                       break;
-                               } 
-                               waveStart=0;
-                       }
+       size_t errCnt = 0;
+       // if clean clipped waves detected run alternate demod
+       if (DetectCleanAskWave(BinStream, *size, high, low)) {
+               if (g_debugMode==2) prnt("DEBUG ASK: Clean Wave Detected - using clean wave demod");
+               errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low, startIdx);
+               if (askType) { //askman
+                       uint8_t alignPos = 0;
+                       errCnt = manrawdecode(BinStream, size, 0, &alignPos);
+                       *startIdx += *clk/2 * alignPos;
+                       if (g_debugMode) prnt("DEBUG ASK CLEAN: startIdx %i, alignPos %u", *startIdx, alignPos);
+                       return errCnt;
+               } else { //askraw
+                       return errCnt;

                }
        }
                }
        }

-       if (g_debugMode ==2) prnt("DEBUG PSK: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);
-       
-       //test each valid clock from greatest to smallest to see which lines up
-       for(clkCnt=7; clkCnt >= 1 ; clkCnt--){
-               lastClkBit = firstFullWave; //set end of wave as clock align
-               waveStart = 0;
-               errCnt=0;
-               peakcnt=0;
-               if (g_debugMode == 2) prnt("DEBUG PSK: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit);
+       if (g_debugMode) prnt("DEBUG ASK WEAK: startIdx %i", *startIdx);
+       if (g_debugMode==2) prnt("DEBUG ASK: Weak Wave Detected - using weak wave demod");

 
 

-               for (i = firstFullWave+fullWaveLen-1; i < loopCnt-2; i++){
-                       //top edge of wave = start of new wave 
-                       if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
-                               if (waveStart == 0) {
-                                       waveStart = i+1;
-                                       waveLenCnt=0;
-                               } else { //waveEnd
-                                       waveEnd = i+1;
-                                       waveLenCnt = waveEnd-waveStart;
-                                       if (waveLenCnt > fc){ 
-                                               //if this wave is a phase shift
-                                               if (g_debugMode == 2) prnt("DEBUG PSK: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+clk[clkCnt]-tol,i+1,fc);
-                                               if (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit
-                                                       peakcnt++;
-                                                       lastClkBit+=clk[clkCnt];
-                                               } else if (i<lastClkBit+8){
-                                                       //noise after a phase shift - ignore
-                                               } else { //phase shift before supposed to based on clock
-                                                       errCnt++;
-                                               }
-                                       } else if (i+1 > lastClkBit + clk[clkCnt] + tol + fc){
-                                               lastClkBit+=clk[clkCnt]; //no phase shift but clock bit
-                                       }
-                                       waveStart=i+1;
-                               }
+       int lastBit;              //set first clock check - can go negative
+       size_t i, bitnum = 0;     //output counter
+       uint8_t midBit = 0;
+       uint8_t tol = 0;          //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave
+       if (*clk <= 32) tol = 1;  //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely
+       size_t MaxBits = 3072;    //max bits to collect
+       lastBit = start - *clk;
+
+       for (i = start; i < *size; ++i) {
+               if (i-lastBit >= *clk-tol){
+                       if (BinStream[i] >= high) {
+                               BinStream[bitnum++] = *invert;
+                       } else if (BinStream[i] <= low) {
+                               BinStream[bitnum++] = *invert ^ 1;
+                       } else if (i-lastBit >= *clk+tol) {
+                               if (bitnum > 0) {
+                                       if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
+                                       BinStream[bitnum++]=7;
+                                       errCnt++;                                               
+                               } 
+                       } else { //in tolerance - looking for peak
+                               continue;

                        }
                        }

+                       midBit = 0;
+                       lastBit += *clk;
+               } else if (i-lastBit >= (*clk/2-tol) && !midBit && !askType){
+                       if (BinStream[i] >= high) {
+                               BinStream[bitnum++] = *invert;
+                       } else if (BinStream[i] <= low) {
+                               BinStream[bitnum++] = *invert ^ 1;
+                       } else if (i-lastBit >= *clk/2+tol) {
+                               BinStream[bitnum] = BinStream[bitnum-1];
+                               bitnum++;
+                       } else { //in tolerance - looking for peak
+                               continue;
+                       }
+                       midBit = 1;

                }
                }

-               if (errCnt == 0){
-                       return clk[clkCnt];
-               }
-               if (errCnt <= bestErr[clkCnt]) bestErr[clkCnt]=errCnt;
-               if (peakcnt > peaksdet[clkCnt]) peaksdet[clkCnt]=peakcnt;
-       } 
-       //all tested with errors 
-       //return the highest clk with the most peaks found
-       uint8_t best=7;
-       for (i=7; i>=1; i--){
-               if (peaksdet[i] > peaksdet[best]) {
-                       best = i;
-               }
-               if (g_debugMode == 2) prnt("DEBUG PSK: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[i],peaksdet[i],bestErr[i],clk[best]);
+               if (bitnum >= MaxBits) break;

        }
        }

-       return clk[best];
+       *size = bitnum;
+       return errCnt;

 }
 
 }
 

-int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low){
-       //find shortest transition from high to low
-       size_t i = 0;
-       size_t transition1 = 0;
-       int lowestTransition = 255;
-       bool lastWasHigh = false;
-
-       //find first valid beginning of a high or low wave
-       while ((dest[i] >= peak || dest[i] <= low) && (i < size))
-               ++i;
-       while ((dest[i] < peak && dest[i] > low) && (i < size))
-               ++i;
-       lastWasHigh = (dest[i] >= peak);
-
-       if (i==size) return 0;
-       transition1 = i;
+int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType) {
+       int start = 0;
+       return askdemod_ext(BinStream, size, clk, invert, maxErr, amp, askType, &start);
+}

 
 

-       for (;i < size; i++) {
-               if ((dest[i] >= peak && !lastWasHigh) || (dest[i] <= low && lastWasHigh)) {
-                       lastWasHigh = (dest[i] >= peak);
-                       if (i-transition1 < lowestTransition) lowestTransition = i-transition1;
-                       transition1 = i;
+// by marshmellow - demodulate NRZ wave - requires a read with strong signal
+// peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
+int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert, int *startIdx) {
+       if (justNoise(dest, *size)) return -1;
+       size_t clkStartIdx = 0;
+       *clk = DetectNRZClock(dest, *size, *clk, &clkStartIdx);
+       if (*clk==0) return -2;
+       size_t i, gLen = 4096;
+       if (gLen>*size) gLen = *size-20;
+       int high, low;
+       if (getHiLo(dest, gLen, &high, &low, 75, 75) < 1) return -3; //25% fuzz on high 25% fuzz on low
+       
+       uint8_t bit=0;
+       //convert wave samples to 1's and 0's
+       for(i=20; i < *size-20; i++){
+               if (dest[i] >= high) bit = 1;
+               if (dest[i] <= low)  bit = 0;
+               dest[i] = bit;
+       }
+       //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit) 
+       size_t lastBit = 0;
+       size_t numBits = 0;
+       for(i=21; i < *size-20; i++) {
+               //if transition detected or large number of same bits - store the passed bits
+               if (dest[i] != dest[i-1] || (i-lastBit) == (10 * *clk)) {
+                       memset(dest+numBits, dest[i-1] ^ *invert, (i - lastBit + (*clk/4)) / *clk);
+                       numBits += (i - lastBit + (*clk/4)) / *clk;
+                       if (lastBit == 0) {
+                               *startIdx = i - (numBits * *clk);
+                               if (g_debugMode==2) prnt("DEBUG NRZ: startIdx %i", *startIdx);
+                       }
+                       lastBit = i-1;

                }
        }
                }
        }

-       if (lowestTransition == 255) lowestTransition = 0;
-       if (g_debugMode==2) prnt("DEBUG NRZ: detectstrongNRZclk smallest wave: %d",lowestTransition);
-       return lowestTransition;
+       *size = numBits;
+       return 0;

 }
 
 }
 

-//by marshmellow
-//detect nrz clock by reading #peaks vs no peaks(or errors)
-int DetectNRZClock(uint8_t dest[], size_t size, int clock)
-{
-       size_t i=0;
-       uint8_t clk[]={8,16,32,40,50,64,100,128,255};
-       size_t loopCnt = 4096;  //don't need to loop through entire array...
-       if (size == 0) return 0;
-       if (size<loopCnt) loopCnt = size-20;
-       //if we already have a valid clock quit
-       for (; i < 8; ++i)
-               if (clk[i] == clock) return clock;
+//translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq])
+size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow, int *startIdx) {
+       size_t last_transition = 0;
+       size_t idx = 1;
+       if (fchigh==0) fchigh=10;
+       if (fclow==0) fclow=8;
+       //set the threshold close to 0 (graph) or 128 std to avoid static
+       size_t preLastSample = 0;
+       size_t LastSample = 0;
+       size_t currSample = 0;
+       if ( size < 1024 ) return 0; // not enough samples

 
 

-       //get high and low peak
-       int peak, low;
-       if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return 0;
+       //find start of modulating data in trace 
+       idx = findModStart(dest, size, fchigh);
+       // Need to threshold first sample
+       if(dest[idx] < FSK_PSK_THRESHOLD) dest[0] = 0;
+       else dest[0] = 1;
+       
+       last_transition = idx;
+       idx++;
+       size_t numBits = 0;
+       // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
+       // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere
+       // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
+       //  (could also be fc/5 && fc/7 for fsk1 = 4-9)
+       for(; idx < size; idx++) {
+               // threshold current value
+               if (dest[idx] < FSK_PSK_THRESHOLD) dest[idx] = 0;
+               else dest[idx] = 1;

 
 

-       int lowestTransition = DetectStrongNRZClk(dest, size-20, peak, low);
-       size_t ii;
-       uint8_t clkCnt;
-       uint8_t tol = 0;
-       uint16_t smplCnt = 0;
-       int16_t peakcnt = 0;
-       int16_t peaksdet[] = {0,0,0,0,0,0,0,0};
-       uint16_t maxPeak = 255;
-       bool firstpeak = false;
-       //test for large clipped waves
-       for (i=0; i<loopCnt; i++){
-               if (dest[i] >= peak || dest[i] <= low){
-                       if (!firstpeak) continue;
-                       smplCnt++;
-               } else {
-                       firstpeak=true;
-                       if (smplCnt > 6 ){
-                               if (maxPeak > smplCnt){
-                                       maxPeak = smplCnt;
-                                       //prnt("maxPk: %d",maxPeak);
+               // Check for 0->1 transition
+               if (dest[idx-1] < dest[idx]) {
+                       preLastSample = LastSample;
+                       LastSample = currSample;
+                       currSample = idx-last_transition;
+                       if (currSample < (fclow-2)) {                   //0-5 = garbage noise (or 0-3)
+                               //do nothing with extra garbage
+                       } else if (currSample < (fchigh-1)) {           //6-8 = 8 sample waves  (or 3-6 = 5)
+                               //correct previous 9 wave surrounded by 8 waves (or 6 surrounded by 5)
+                               if (numBits > 1 && LastSample > (fchigh-2) && (preLastSample < (fchigh-1))){
+                                       dest[numBits-1]=1;

                                }
                                }

-                               peakcnt++;
-                               //prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt);
-                               smplCnt=0;
+                               dest[numBits++]=1;
+                       if (numBits > 0 && *startIdx==0) *startIdx = idx - fclow;
+                       } else if (currSample > (fchigh+1) && numBits < 3) { //12 + and first two bit = unusable garbage
+                               //do nothing with beginning garbage and reset..  should be rare..
+                               numBits = 0; 
+                       } else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's (or 4 then a 6 should be two 5's)
+                               dest[numBits++]=1;
+                       if (numBits > 0 && *startIdx==0) *startIdx = idx - fclow;
+                       } else {                                        //9+ = 10 sample waves (or 6+ = 7)
+                               dest[numBits++]=0;
+                       if (numBits > 0 && *startIdx==0) *startIdx = idx - fchigh;

                        }
                        }

+                       last_transition = idx;

                }
        }
                }
        }

-       bool errBitHigh = 0;
-       bool bitHigh = 0;
-       uint8_t ignoreCnt = 0;
-       uint8_t ignoreWindow = 4;
-       bool lastPeakHigh = 0;
-       int lastBit = 0; 
-       peakcnt=0;
-       //test each valid clock from smallest to greatest to see which lines up
-       for(clkCnt=0; clkCnt < 8; ++clkCnt){
-               //ignore clocks smaller than smallest peak
-               if (clk[clkCnt] < maxPeak - (clk[clkCnt]/4)) continue;
-               //try lining up the peaks by moving starting point (try first 256)
-               for (ii=20; ii < loopCnt; ++ii){
-                       if ((dest[ii] >= peak) || (dest[ii] <= low)){
-                               peakcnt = 0;
-                               bitHigh = false;
-                               ignoreCnt = 0;
-                               lastBit = ii-clk[clkCnt]; 
-                               //loop through to see if this start location works
-                               for (i = ii; i < size-20; ++i) {
-                                       //if we are at a clock bit
-                                       if ((i >= lastBit + clk[clkCnt] - tol) && (i <= lastBit + clk[clkCnt] + tol)) {
-                                               //test high/low
-                                               if (dest[i] >= peak || dest[i] <= low) {
-                                                       //if same peak don't count it
-                                                       if ((dest[i] >= peak && !lastPeakHigh) || (dest[i] <= low && lastPeakHigh)) {
-                                                               peakcnt++;
-                                                       }
-                                                       lastPeakHigh = (dest[i] >= peak);
-                                                       bitHigh = true;
-                                                       errBitHigh = false;
-                                                       ignoreCnt = ignoreWindow;
-                                                       lastBit += clk[clkCnt];
-                                               } else if (i == lastBit + clk[clkCnt] + tol) {
-                                                       lastBit += clk[clkCnt];
-                                               }
-                                       //else if not a clock bit and no peaks
-                                       } else if (dest[i] < peak && dest[i] > low){
-                                               if (ignoreCnt==0){
-                                                       bitHigh=false;
-                                                       if (errBitHigh==true) peakcnt--;
-                                                       errBitHigh=false;
-                                               } else {
-                                                       ignoreCnt--;
-                                               }
-                                               // else if not a clock bit but we have a peak
-                                       } else if ((dest[i]>=peak || dest[i]<=low) && (!bitHigh)) {
-                                               //error bar found no clock...
-                                               errBitHigh=true;
-                                       }
-                               }
-                               if(peakcnt>peaksdet[clkCnt]) {
-                                       peaksdet[clkCnt]=peakcnt;
-                               }
-                       }
+       return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
+}
+
+//translate 11111100000 to 10
+//rfLen = clock, fchigh = larger field clock, fclow = smaller field clock
+size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow, int *startIdx) {
+       uint8_t lastval=dest[0];
+       size_t idx=0;
+       size_t numBits=0;
+       uint32_t n=1;
+       for( idx=1; idx < size; idx++) {
+               n++;
+               if (dest[idx]==lastval) continue; //skip until we hit a transition
+               
+               //find out how many bits (n) we collected (use 1/2 clk tolerance)
+               //if lastval was 1, we have a 1->0 crossing
+               if (dest[idx-1]==1) {
+                       n = (n * fclow + rfLen/2) / rfLen;
+               } else {// 0->1 crossing 
+                       n = (n * fchigh + rfLen/2) / rfLen; 

                }
                }

-       }
-       int iii=7;
-       uint8_t best=0;
-       for (iii=7; iii > 0; iii--){
-               if ((peaksdet[iii] >= (peaksdet[best]-1)) && (peaksdet[iii] <= peaksdet[best]+1) && lowestTransition) {
-                       if (clk[iii] > (lowestTransition - (clk[iii]/8)) && clk[iii] < (lowestTransition + (clk[iii]/8))) {
-                               best = iii;
+               if (n == 0) n = 1;
+               
+               //first transition - save startidx
+               if (numBits == 0) {
+                       if (lastval == 1) {  //high to low
+                               *startIdx += (fclow * idx) - (n*rfLen);
+                               if (g_debugMode==2) prnt("DEBUG FSK: startIdx %i, fclow*idx %i, n*rflen %u", *startIdx, fclow*(idx), n*rfLen);
+                       } else {
+                               *startIdx += (fchigh * idx) - (n*rfLen);
+                               if (g_debugMode==2) prnt("DEBUG FSK: startIdx %i, fchigh*idx %i, n*rflen %u", *startIdx, fchigh*(idx), n*rfLen);

                        }
                        }

-               } else if (peaksdet[iii] > peaksdet[best]){
-                       best = iii;

                }
                }

-               if (g_debugMode==2) prnt("DEBUG NRZ: Clk: %d, peaks: %d, maxPeak: %d, bestClk: %d, lowestTrs: %d",clk[iii],peaksdet[iii],maxPeak, clk[best], lowestTransition);
+
+               //add to our destination the bits we collected          
+               memset(dest+numBits, dest[idx-1]^invert , n);
+               numBits += n;
+               n=0;
+               lastval=dest[idx];
+       }//end for
+       // if valid extra bits at the end were all the same frequency - add them in
+       if (n > rfLen/fchigh) {
+               if (dest[idx-2]==1) {
+                       n = (n * fclow + rfLen/2) / rfLen;
+               } else {
+                       n = (n * fchigh + rfLen/2) / rfLen;
+               }
+               memset(dest+numBits, dest[idx-1]^invert , n);
+               numBits += n;

        }
        }

+       return numBits;
+}

 
 

-       return clk[best];
+//by marshmellow  (from holiman's base)
+// full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod)
+int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow, int *startIdx) {
+       if (justNoise(dest, size)) return 0;
+       // FSK demodulator
+       size = fsk_wave_demod(dest, size, fchigh, fclow, startIdx);
+       size = aggregate_bits(dest, size, rfLen, invert, fchigh, fclow, startIdx);
+       return size;

 }
 
 // by marshmellow
 // convert psk1 demod to psk2 demod
 // only transition waves are 1s
 }
 
 // by marshmellow
 // convert psk1 demod to psk2 demod
 // only transition waves are 1s

-void psk1TOpsk2(uint8_t *BitStream, size_t size)
-{
+void psk1TOpsk2(uint8_t *BitStream, size_t size) {

        size_t i=1;
        uint8_t lastBit=BitStream[0];
        for (; i<size; i++){
        size_t i=1;
        uint8_t lastBit=BitStream[0];
        for (; i<size; i++){


@@ -1243,8 +1529,7 @@ void psk1TOpsk2(uint8_t *BitStream, size_t size)
 // by marshmellow
 // convert psk2 demod to psk1 demod
 // from only transition waves are 1s to phase shifts change bit
 // by marshmellow
 // convert psk2 demod to psk1 demod
 // from only transition waves are 1s to phase shifts change bit

-void psk2TOpsk1(uint8_t *BitStream, size_t size)
-{
+void psk2TOpsk1(uint8_t *BitStream, size_t size) {

        uint8_t phase=0;
        for (size_t i=0; i<size; i++){
                if (BitStream[i]==1){
        uint8_t phase=0;
        for (size_t i=0; i<size; i++){
                if (BitStream[i]==1){


@@ -1255,537 +1540,381 @@ void psk2TOpsk1(uint8_t *BitStream, size_t size)
        return;
 }
 
        return;
 }
 

-// redesigned by marshmellow adjusted from existing decode functions
-// indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
-int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert)
-{
-       //26 bit 40134 format  (don't know other formats)
-       uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
-       uint8_t preamble_i[] = {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0};
-       size_t startidx = 0; 
-       if (!preambleSearch(bitStream, preamble, sizeof(preamble), size, &startidx)){
-               // if didn't find preamble try again inverting
-               if (!preambleSearch(bitStream, preamble_i, sizeof(preamble_i), size, &startidx)) return -1;
-               *invert ^= 1;
-       } 
-       if (*size != 64 && *size != 224) return -2;
-       if (*invert==1)
-               for (size_t i = startidx; i < *size; i++)
-                       bitStream[i] ^= 1;
-
-       return (int) startidx;
-}
+//by marshmellow - demodulate PSK1 wave 
+//uses wave lengths (# Samples) 
+int pskRawDemod_ext(uint8_t dest[], size_t *size, int *clock, int *invert, int *startIdx) {
+       if (*size < 170) return -1;

 
 

-// by marshmellow - demodulate NRZ wave - requires a read with strong signal
-// peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
-int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert){
-       if (justNoise(dest, *size)) return -1;
-       *clk = DetectNRZClock(dest, *size, *clk);
-       if (*clk==0) return -2;
-       size_t i, gLen = 4096;
-       if (gLen>*size) gLen = *size-20;
-       int high, low;
-       if (getHiLo(dest, gLen, &high, &low, 75, 75) < 1) return -3; //25% fuzz on high 25% fuzz on low
+       uint8_t curPhase = *invert;
+       uint8_t fc=0;
+       size_t i=0, numBits=0, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0;
+       uint16_t fullWaveLen=0, waveLenCnt=0, avgWaveVal;
+       uint16_t errCnt=0, errCnt2=0;

        
        

-       uint8_t bit=0;
-       //convert wave samples to 1's and 0's
-       for(i=20; i < *size-20; i++){
-               if (dest[i] >= high) bit = 1;
-               if (dest[i] <= low)  bit = 0;
-               dest[i] = bit;
-       }
-       //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit) 
-       size_t lastBit = 0;
-       size_t numBits = 0;
-       for(i=21; i < *size-20; i++) {
-               //if transition detected or large number of same bits - store the passed bits
-               if (dest[i] != dest[i-1] || (i-lastBit) == (10 * *clk)) {
-                       memset(dest+numBits, dest[i-1] ^ *invert, (i - lastBit + (*clk/4)) / *clk);
-                       numBits += (i - lastBit + (*clk/4)) / *clk;
-                       lastBit = i-1;
+       *clock = DetectPSKClock(dest, *size, *clock, &firstFullWave, &curPhase, &fc);
+       if (*clock <= 0) return -1;
+       //if clock detect found firstfullwave...
+       uint16_t tol = fc/2;
+       if (firstFullWave == 0) {
+               //find start of modulating data in trace 
+               i = findModStart(dest, *size, fc);
+               //find first phase shift
+               firstFullWave = pskFindFirstPhaseShift(dest, *size, &curPhase, i, fc, &fullWaveLen);
+               if (firstFullWave == 0) {
+                       // no phase shift detected - could be all 1's or 0's - doesn't matter where we start
+                       // so skip a little to ensure we are past any Start Signal
+                       firstFullWave = 160;
+                       memset(dest, curPhase, firstFullWave / *clock);
+               } else {
+                       memset(dest, curPhase^1, firstFullWave / *clock);

                }
                }

+       } else {
+               memset(dest, curPhase^1, firstFullWave / *clock);

        }
        }

-       *size = numBits;
-       return 0;
-}
-
-//by marshmellow
-//detects the bit clock for FSK given the high and low Field Clocks
-uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow)
-{
-       uint8_t clk[] = {8,16,32,40,50,64,100,128,0};
-       uint16_t rfLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
-       uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
-       uint8_t rfLensFnd = 0;
-       uint8_t lastFCcnt = 0;
-       uint16_t fcCounter = 0;
-       uint16_t rfCounter = 0;
-       uint8_t firstBitFnd = 0;
-       size_t i;
-       if (size == 0) return 0;
-
-       uint8_t fcTol = ((fcHigh*100 - fcLow*100)/2 + 50)/100; //(uint8_t)(0.5+(float)(fcHigh-fcLow)/2);
-       rfLensFnd=0;
-       fcCounter=0;
-       rfCounter=0;
-       firstBitFnd=0;
-       //PrintAndLog("DEBUG: fcTol: %d",fcTol);
-       // prime i to first peak / up transition
-       for (i = 160; i < size-20; i++)
-               if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1])
-                       break;
-
-       for (; i < size-20; i++){
-               fcCounter++;
-               rfCounter++;
-
-               if (BitStream[i] <= BitStream[i-1] || BitStream[i] < BitStream[i+1]) 
-                       continue;               
-               // else new peak 
-               // if we got less than the small fc + tolerance then set it to the small fc
-               if (fcCounter < fcLow+fcTol) 
-                       fcCounter = fcLow;
-               else //set it to the large fc
-                       fcCounter = fcHigh;
-
-               //look for bit clock  (rf/xx)
-               if ((fcCounter < lastFCcnt || fcCounter > lastFCcnt)){
-                       //not the same size as the last wave - start of new bit sequence
-                       if (firstBitFnd > 1){ //skip first wave change - probably not a complete bit
-                               for (int ii=0; ii<15; ii++){
-                                       if (rfLens[ii] >= (rfCounter-4) && rfLens[ii] <= (rfCounter+4)){
-                                               rfCnts[ii]++;
-                                               rfCounter = 0;
-                                               break;
+       //advance bits
+       numBits += (firstFullWave / *clock);
+       *startIdx = firstFullWave - (*clock * numBits)+2;
+       //set start of wave as clock align
+       lastClkBit = firstFullWave;
+       if (g_debugMode==2) prnt("DEBUG PSK: firstFullWave: %u, waveLen: %u, startIdx %i",firstFullWave,fullWaveLen, *startIdx);
+       if (g_debugMode==2) prnt("DEBUG PSK: clk: %d, lastClkBit: %u, fc: %u", *clock, lastClkBit,(unsigned int) fc);
+       waveStart = 0;
+       dest[numBits++] = curPhase; //set first read bit
+       for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++) {
+               //top edge of wave = start of new wave 
+               if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]) {
+                       if (waveStart == 0) {
+                               waveStart = i+1;
+                               waveLenCnt = 0;
+                               avgWaveVal = dest[i+1];
+                       } else { //waveEnd
+                               waveEnd = i+1;
+                               waveLenCnt = waveEnd-waveStart;
+                               if (waveLenCnt > fc) {
+                                       //this wave is a phase shift
+                                       //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc);
+                                       if (i+1 >= lastClkBit + *clock - tol) { //should be a clock bit
+                                               curPhase ^= 1;
+                                               dest[numBits++] = curPhase;
+                                               lastClkBit += *clock;
+                                       } else if (i < lastClkBit+10+fc) {
+                                               //noise after a phase shift - ignore
+                                       } else { //phase shift before supposed to based on clock
+                                               errCnt++;
+                                               dest[numBits++] = 7;

                                        }
                                        }

+                               } else if (i+1 > lastClkBit + *clock + tol + fc) {
+                                       lastClkBit += *clock; //no phase shift but clock bit
+                                       dest[numBits++] = curPhase;
+                               } else if (waveLenCnt < fc - 1) { //wave is smaller than field clock (shouldn't happen often)
+                                       errCnt2++;
+                                       if(errCnt2 > 101) return errCnt2;
+                                       avgWaveVal += dest[i+1];
+                                       continue;

                                }
                                }

-                               if (rfCounter > 0 && rfLensFnd < 15){
-                                       //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
-                                       rfCnts[rfLensFnd]++;
-                                       rfLens[rfLensFnd++] = rfCounter;
-                               }
-                       } else {
-                               firstBitFnd++;
+                               avgWaveVal = 0;
+                               waveStart = i+1;

                        }
                        }

-                       rfCounter=0;
-                       lastFCcnt=fcCounter;

                }
                }

-               fcCounter=0;
+               avgWaveVal += dest[i+1];

        }
        }

-       uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15;
+       *size = numBits;
+       return errCnt;
+}

 
 

-       for (i=0; i<15; i++){
-               //get highest 2 RF values  (might need to get more values to compare or compare all?)
-               if (rfCnts[i]>rfCnts[rfHighest]){
-                       rfHighest3=rfHighest2;
-                       rfHighest2=rfHighest;
-                       rfHighest=i;
-               } else if(rfCnts[i]>rfCnts[rfHighest2]){
-                       rfHighest3=rfHighest2;
-                       rfHighest2=i;
-               } else if(rfCnts[i]>rfCnts[rfHighest3]){
-                       rfHighest3=i;
-               }
-               if (g_debugMode==2) prnt("DEBUG FSK: RF %d, cnts %d",rfLens[i], rfCnts[i]);
-       }  
-       // set allowed clock remainder tolerance to be 1 large field clock length+1 
-       //   we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off  
-       uint8_t tol1 = fcHigh+1; 
-       
-       if (g_debugMode==2) prnt("DEBUG FSK: most counted rf values: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]);
+int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) {
+       int startIdx = 0;
+       return pskRawDemod_ext(dest, size, clock, invert, &startIdx);
+}

 
 

-       // loop to find the highest clock that has a remainder less than the tolerance
-       //   compare samples counted divided by
-       // test 128 down to 32 (shouldn't be possible to have fc/10 & fc/8 and rf/16 or less)
-       int ii=7;
-       for (; ii>=2; ii--){
-               if (rfLens[rfHighest] % clk[ii] < tol1 || rfLens[rfHighest] % clk[ii] > clk[ii]-tol1){
-                       if (rfLens[rfHighest2] % clk[ii] < tol1 || rfLens[rfHighest2] % clk[ii] > clk[ii]-tol1){
-                               if (rfLens[rfHighest3] % clk[ii] < tol1 || rfLens[rfHighest3] % clk[ii] > clk[ii]-tol1){
-                                       if (g_debugMode==2) prnt("DEBUG FSK: clk %d divides into the 3 most rf values within tolerance",clk[ii]);
-                                       break;
-                               }
-                       }
-               }
-       }
+//**********************************************************************************************
+//-----------------Tag format detection section-------------------------------------------------
+//**********************************************************************************************
+
+// by marshmellow
+// FSK Demod then try to locate an AWID ID
+int AWIDdemodFSK(uint8_t *dest, size_t *size, int *waveStartIdx) {
+       //make sure buffer has enough data
+       if (*size < 96*50) return -1;

 
 

-       if (ii<0) return 0; // oops we went too far
+       // FSK demodulator
+       *size = fskdemod(dest, *size, 50, 1, 10, 8, waveStartIdx);  // fsk2a RF/50 
+       if (*size < 96) return -3;  //did we get a good demod?

 
 

-       return clk[ii];
+       uint8_t preamble[] = {0,0,0,0,0,0,0,1};
+       size_t startIdx = 0;
+       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+       if (errChk == 0) return -4; //preamble not found
+       if (*size != 96) return -5;
+       return (int)startIdx;

 }
 
 //by marshmellow
 }
 
 //by marshmellow

-//countFC is to detect the field clock lengths.
-//counts and returns the 2 most common wave lengths
-//mainly used for FSK field clock detection
-uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj)
+//takes 1s and 0s and searches for EM410x format - output EM ID
+uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo)

 {
 {

-       uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
-       uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
-       uint8_t fcLensFnd = 0;
-       uint8_t lastFCcnt = 0;
-       uint8_t fcCounter = 0;
-       size_t i;
-       if (size < 180) return 0;
+       //sanity checks
+       if (*size < 64) return 0;
+       if (BitStream[1]>1) return 0;  //allow only 1s and 0s

 
 

-       // prime i to first up transition
-       for (i = 160; i < size-20; i++)
-               if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1])
-                       break;
+       // 111111111 bit pattern represent start of frame
+       //  include 0 in front to help get start pos
+       uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1};
+       uint8_t errChk = 0;
+       uint8_t FmtLen = 10; // sets of 4 bits = end data 
+       *startIdx = 0;
+       errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx);
+       if ( errChk == 0 || (*size != 64 && *size != 128) ) return 0;
+       if (*size == 128) FmtLen = 22; // 22 sets of 4 bits
+
+       //skip last 4bit parity row for simplicity
+       *size = removeParity(BitStream, *startIdx + sizeof(preamble), 5, 0, FmtLen * 5);
+       if (*size == 40) { // std em410x format
+               *hi = 0;
+               *lo = ((uint64_t)(bytebits_to_byte(BitStream, 8)) << 32) | (bytebits_to_byte(BitStream + 8, 32));
+       } else if (*size == 88) { // long em format
+               *hi = (bytebits_to_byte(BitStream, 24)); 
+               *lo = ((uint64_t)(bytebits_to_byte(BitStream + 24, 32)) << 32) | (bytebits_to_byte(BitStream + 24 + 32, 32));
+       } else {
+               if (g_debugMode) prnt("Error removing parity: %u", *size);
+               return 0;
+       }
+       return 1;
+}

 
 

-       for (; i < size-20; i++){
-               if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){
-                       // new up transition
-                       fcCounter++;
-                       if (fskAdj){
-                               //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8)
-                               if (lastFCcnt==5 && fcCounter==9) fcCounter--;
-                               //if fc=9 or 4 add one (for when we get a fc 9 instead of 10 or a 4 instead of a 5)
-                               if ((fcCounter==9) || fcCounter==4) fcCounter++;
-                       // save last field clock count  (fc/xx)
-                       lastFCcnt = fcCounter;
-                       }
-                       // find which fcLens to save it to:
-                       for (int ii=0; ii<15; ii++){
-                               if (fcLens[ii]==fcCounter){
-                                       fcCnts[ii]++;
-                                       fcCounter=0;
-                                       break;
-                               }
-                       }
-                       if (fcCounter>0 && fcLensFnd<15){
-                               //add new fc length 
-                               fcCnts[fcLensFnd]++;
-                               fcLens[fcLensFnd++]=fcCounter;
-                       }
-                       fcCounter=0;
-               } else {
-                       // count sample
-                       fcCounter++;
-               }
+// Ask/Biphase Demod then try to locate an ISO 11784/85 ID
+// BitStream must contain previously askrawdemod and biphasedemoded data
+int FDXBdemodBI(uint8_t *dest, size_t *size) {
+       //make sure buffer has enough data
+       if (*size < 128) return -1;
+
+       size_t startIdx = 0;
+       uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,1};
+
+       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+       if (errChk == 0) return -2; //preamble not found
+       if (*size != 128) return -3; //wrong size for fdxb
+       //return start position
+       return (int)startIdx;
+}
+
+// by marshmellow
+// demod gProxIIDemod 
+// error returns as -x 
+// success returns start position in BitStream
+// BitStream must contain previously askrawdemod and biphasedemoded data
+int gProxII_Demod(uint8_t BitStream[], size_t *size) {
+       size_t startIdx=0;
+       uint8_t preamble[] = {1,1,1,1,1,0};
+
+       uint8_t errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, &startIdx);
+       if (errChk == 0) return -3; //preamble not found
+       if (*size != 96) return -2; //should have found 96 bits
+       //check first 6 spacer bits to verify format
+       if (!BitStream[startIdx+5] && !BitStream[startIdx+10] && !BitStream[startIdx+15] && !BitStream[startIdx+20] && !BitStream[startIdx+25] && !BitStream[startIdx+30]){
+               //confirmed proper separator bits found
+               //return start position
+               return (int) startIdx;

        }
        }

-       
-       uint8_t best1=14, best2=14, best3=14;
-       uint16_t maxCnt1=0;
-       // go through fclens and find which ones are bigest 2  
-       for (i=0; i<15; i++){
-               // get the 3 best FC values
-               if (fcCnts[i]>maxCnt1) {
-                       best3=best2;
-                       best2=best1;
-                       maxCnt1=fcCnts[i];
-                       best1=i;
-               } else if(fcCnts[i]>fcCnts[best2]){
-                       best3=best2;
-                       best2=i;
-               } else if(fcCnts[i]>fcCnts[best3]){
-                       best3=i;
+       return -5; //spacer bits not found - not a valid gproxII
+}
+
+// loop to get raw HID waveform then FSK demodulate the TAG ID from it
+int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo, int *waveStartIdx) {
+       size_t numStart=0, size2=*size, startIdx=0; 
+       // FSK demodulator  fsk2a so invert and fc/10/8
+       *size = fskdemod(dest, size2, 50, 1, 10, 8, waveStartIdx);
+       if (*size < 96*2) return -2;
+       // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
+       uint8_t preamble[] = {0,0,0,1,1,1,0,1};
+       // find bitstring in array  
+       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+       if (errChk == 0) return -3; //preamble not found
+
+       numStart = startIdx + sizeof(preamble);
+       // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
+       for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
+               if (dest[idx] == dest[idx+1]){
+                       return -4; //not manchester data

                }
                }

-               if (g_debugMode==2) prnt("DEBUG countfc: FC %u, Cnt %u, best fc: %u, best2 fc: %u",fcLens[i],fcCnts[i],fcLens[best1],fcLens[best2]);
+               *hi2 = (*hi2<<1)|(*hi>>31);
+               *hi = (*hi<<1)|(*lo>>31);
+               //Then, shift in a 0 or one into low
+               if (dest[idx] && !dest[idx+1])  // 1 0
+                       *lo=(*lo<<1)|1;
+               else // 0 1
+                       *lo=(*lo<<1)|0;

        }
        }

-       if (fcLens[best1]==0) return 0;
-       uint8_t fcH=0, fcL=0;
-       if (fcLens[best1]>fcLens[best2]){
-               fcH=fcLens[best1];
-               fcL=fcLens[best2];
-       } else{
-               fcH=fcLens[best2];
-               fcL=fcLens[best1];
+       return (int)startIdx;
+}
+
+int IOdemodFSK(uint8_t *dest, size_t size, int *waveStartIdx) {
+       //make sure buffer has data
+       if (size < 66*64) return -2;
+       // FSK demodulator  RF/64, fsk2a so invert, and fc/10/8
+       size = fskdemod(dest, size, 64, 1, 10, 8, waveStartIdx); 
+       if (size < 65) return -3;  //did we get a good demod?
+       //Index map
+       //0           10          20          30          40          50          60
+       //|           |           |           |           |           |           |
+       //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
+       //-----------------------------------------------------------------------------
+       //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
+       //
+       //XSF(version)facility:codeone+codetwo
+       //Handle the data
+       size_t startIdx = 0;
+       uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,1};
+       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), &size, &startIdx);
+       if (errChk == 0) return -4; //preamble not found
+
+       if (!dest[startIdx+8] && dest[startIdx+17]==1 && dest[startIdx+26]==1 && dest[startIdx+35]==1 && dest[startIdx+44]==1 && dest[startIdx+53]==1){
+               //confirmed proper separator bits found
+               //return start position
+               return (int) startIdx;
+       }
+       return -5;
+} 
+
+// redesigned by marshmellow adjusted from existing decode functions
+// indala id decoding
+int indala64decode(uint8_t *bitStream, size_t *size, uint8_t *invert) {
+       //standard 64 bit indala formats including 26 bit 40134 format
+       uint8_t preamble64[] = {1,0,1,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 1};
+       uint8_t preamble64_i[] = {0,1,0,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 0};
+       size_t startidx = 0;
+       size_t found_size = *size;
+       bool found = preambleSearch(bitStream, preamble64, sizeof(preamble64), &found_size, &startidx);
+       if (!found) {
+               found = preambleSearch(bitStream, preamble64_i, sizeof(preamble64_i), &found_size, &startidx);
+               if (!found) return -1;
+               *invert ^= 1;

        }
        }

-       if ((size-180)/fcH/3 > fcCnts[best1]+fcCnts[best2]) {
-               if (g_debugMode==2) prnt("DEBUG countfc: fc is too large: %u > %u. Not psk or fsk",(size-180)/fcH/3,fcCnts[best1]+fcCnts[best2]);
-               return 0; //lots of waves not psk or fsk
+       if (found_size != 64) return -2;
+       if (*invert==1)
+               for (size_t i = startidx; i < found_size + startidx; i++) 
+                       bitStream[i] ^= 1;
+
+       // note: don't change *size until we are sure we got it... 
+       *size = found_size;
+       return (int) startidx;
+}
+
+int indala224decode(uint8_t *bitStream, size_t *size, uint8_t *invert) {
+       //large 224 bit indala formats (different preamble too...)
+       uint8_t preamble224[] = {1,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,1};
+       uint8_t preamble224_i[] = {0,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,0};
+       size_t startidx = 0;
+       size_t found_size = *size;
+       bool found = preambleSearch(bitStream, preamble224, sizeof(preamble224), &found_size, &startidx);
+       if (!found) {
+               found = preambleSearch(bitStream, preamble224_i, sizeof(preamble224_i), &found_size, &startidx);
+               if (!found) return -1;
+               *invert ^= 1;

        }
        }

-       // TODO: take top 3 answers and compare to known Field clocks to get top 2
+       if (found_size != 224) return -2;
+       if (*invert==1 && startidx > 0)
+               for (size_t i = startidx-1; i < found_size + startidx + 2; i++) 
+                       bitStream[i] ^= 1;

 
 

-       uint16_t fcs = (((uint16_t)fcH)<<8) | fcL;
-       if (fskAdj) return fcs; 
-       return fcLens[best1];
+       // 224 formats are typically PSK2 (afaik 2017 Marshmellow)
+       // note loses 1 bit at beginning of transformation...
+       // don't need to verify array is big enough as to get here there has to be a full preamble after all of our data
+       psk1TOpsk2(bitStream + (startidx-1), found_size+2);
+       startidx++;
+
+       *size = found_size;
+       return (int) startidx;

 }
 
 }
 

-//by marshmellow - demodulate PSK1 wave 
-//uses wave lengths (# Samples) 
-int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
-{
-       if (size == 0) return -1;
-       uint16_t loopCnt = 4096;  //don't need to loop through entire array...
-       if (*size<loopCnt) loopCnt = *size;
+// loop to get raw paradox waveform then FSK demodulate the TAG ID from it
+int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo, int *waveStartIdx) {
+       size_t numStart=0, size2=*size, startIdx=0;
+       // FSK demodulator
+       *size = fskdemod(dest, size2,50,1,10,8,waveStartIdx); //fsk2a
+       if (*size < 96) return -2;

 
 

-       size_t numBits=0;
-       uint8_t curPhase = *invert;
-       size_t i=0, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0;
-       uint16_t fc=0, fullWaveLen=0, tol=1;
-       uint16_t errCnt=0, waveLenCnt=0, errCnt2=0;
-       fc = countFC(dest, *size, 1);
-       uint8_t fc2 = fc >> 8;
-       if (fc2 == 10) return -1; //fsk found - quit
-       fc = fc & 0xFF;
-       if (fc!=2 && fc!=4 && fc!=8) return -1;
-       //PrintAndLog("DEBUG: FC: %d",fc);
-       *clock = DetectPSKClock(dest, *size, *clock);
-       if (*clock == 0) return -1;
+       // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
+       uint8_t preamble[] = {0,0,0,0,1,1,1,1};

 
 

-       //find start of modulating data in trace 
-       uint8_t threshold_value = 123; //-5
-       i = findModStart(dest, *size, threshold_value, fc);
+       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+       if (errChk == 0) return -3; //preamble not found

 
 

-       //find first phase shift
-       int avgWaveVal=0, lastAvgWaveVal=0;
-       waveStart = i;
-       for (; i<loopCnt; i++) {
-               // find peak 
-               if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
-                       waveEnd = i+1;
-                       if (g_debugMode == 2) prnt("DEBUG PSK: waveEnd: %u, waveStart: %u",waveEnd, waveStart);
-                       waveLenCnt = waveEnd-waveStart;
-                       if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+3)){ //not first peak and is a large wave but not out of whack
-                               lastAvgWaveVal = avgWaveVal/(waveLenCnt);
-                               firstFullWave = waveStart;
-                               fullWaveLen=waveLenCnt;
-                               //if average wave value is > graph 0 then it is an up wave or a 1 (could cause inverting)
-                               if (lastAvgWaveVal > threshold_value) curPhase ^= 1;
-                               break;
-                       } 
-                       waveStart = i+1;
-                       avgWaveVal = 0;
-               }
-               avgWaveVal += dest[i+2];
-       }
-       if (firstFullWave == 0) {
-               // no phase shift detected - could be all 1's or 0's - doesn't matter where we start
-               // so skip a little to ensure we are past any Start Signal
-               firstFullWave = 160;
-               memset(dest, curPhase, firstFullWave / *clock);
-       } else {
-               memset(dest, curPhase^1, firstFullWave / *clock);
-       }
-       //advance bits
-       numBits += (firstFullWave / *clock);
-       //set start of wave as clock align
-       lastClkBit = firstFullWave;
-       if (g_debugMode==2) prnt("DEBUG PSK: firstFullWave: %u, waveLen: %u",firstFullWave,fullWaveLen);  
-       if (g_debugMode==2) prnt("DEBUG PSK: clk: %d, lastClkBit: %u, fc: %u", *clock, lastClkBit,(unsigned int) fc);
-       waveStart = 0;
-       dest[numBits++] = curPhase; //set first read bit
-       for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){
-               //top edge of wave = start of new wave 
-               if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
-                       if (waveStart == 0) {
-                               waveStart = i+1;
-                               waveLenCnt = 0;
-                               avgWaveVal = dest[i+1];
-                       } else { //waveEnd
-                               waveEnd = i+1;
-                               waveLenCnt = waveEnd-waveStart;
-                               lastAvgWaveVal = avgWaveVal/waveLenCnt;
-                               if (waveLenCnt > fc){  
-                                       //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);
-                                       //this wave is a phase shift
-                                       //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc);
-                                       if (i+1 >= lastClkBit + *clock - tol){ //should be a clock bit
-                                               curPhase ^= 1;
-                                               dest[numBits++] = curPhase;
-                                               lastClkBit += *clock;
-                                       } else if (i < lastClkBit+10+fc){
-                                               //noise after a phase shift - ignore
-                                       } else { //phase shift before supposed to based on clock
-                                               errCnt++;
-                                               dest[numBits++] = 7;
-                                       }
-                               } else if (i+1 > lastClkBit + *clock + tol + fc){
-                                       lastClkBit += *clock; //no phase shift but clock bit
-                                       dest[numBits++] = curPhase;
-                               } else if (waveLenCnt < fc - 1) { //wave is smaller than field clock (shouldn't happen often)
-                                       errCnt2++;
-                                       if(errCnt2 > 101) return errCnt2;
-                               }
-                               avgWaveVal = 0;
-                               waveStart = i+1;
-                       }
-               }
-               avgWaveVal += dest[i+1];
+       numStart = startIdx + sizeof(preamble);
+       // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
+       for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
+               if (dest[idx] == dest[idx+1]) 
+                       return -4; //not manchester data
+               *hi2 = (*hi2<<1)|(*hi>>31);
+               *hi = (*hi<<1)|(*lo>>31);
+               //Then, shift in a 0 or one into low
+               if (dest[idx] && !dest[idx+1])  // 1 0
+                       *lo=(*lo<<1)|1;
+               else // 0 1
+                       *lo=(*lo<<1)|0;

        }
        }

-       *size = numBits;
-       return errCnt;
+       return (int)startIdx;

 }
 
 }
 

-//by marshmellow
-//attempt to identify a Sequence Terminator in ASK modulated raw wave
-bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
-       size_t bufsize = *size;
-       //need to loop through all samples and identify our clock, look for the ST pattern
-       uint8_t fndClk[] = {8,16,32,40,50,64,128};
-       int clk = 0; 
-       int tol = 0;
-       int i, j, skip, start, end, low, high, minClk, waveStart;
-       bool complete = false;
-       int tmpbuff[bufsize / 32]; //guess rf/32 clock, if click is smaller we will only have room for a fraction of the samples captured
-       int waveLen[bufsize / 32]; //  if clock is larger then we waste memory in array size that is not needed...
-       size_t testsize = (bufsize < 512) ? bufsize : 512;
-       int phaseoff = 0;
-       high = low = 128;
-       memset(tmpbuff, 0, sizeof(tmpbuff));
+// find presco preamble 0x10D in already demoded data
+int PrescoDemod(uint8_t *dest, size_t *size) {
+       //make sure buffer has data
+       if (*size < 64*2) return -2;

 
 

-       if ( getHiLo(buffer, testsize, &high, &low, 80, 80) == -1 ) {
-               if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting");
-               return false; //just noise
-       }
-       i = 0;
-       j = 0;
-       minClk = 255;
-       // get to first full low to prime loop and skip incomplete first pulse
-       while ((buffer[i] < high) && (i < bufsize))
-               ++i;
-       while ((buffer[i] > low) && (i < bufsize))
-               ++i;
-       skip = i;
+       size_t startIdx = 0;
+       uint8_t preamble[] = {1,0,0,0,0,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0};
+       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+       if (errChk == 0) return -4; //preamble not found
+       //return start position
+       return (int) startIdx;
+}

 
 

-       // populate tmpbuff buffer with pulse lengths
-       while (i < bufsize) {
-               // measure from low to low
-               while ((buffer[i] > low) && (i < bufsize))
-                       ++i;
-               start= i;
-               while ((buffer[i] < high) && (i < bufsize))
-                       ++i;
-               //first high point for this wave
-               waveStart = i;
-               while ((buffer[i] > low) && (i < bufsize))
-                       ++i;
-               if (j >= (bufsize/32)) {
-                       break;
-               }
-               waveLen[j] = i - waveStart; //first high to first low
-               tmpbuff[j++] = i - start;
-               if (i-start < minClk && i < bufsize) {
-                       minClk = i - start;
-               }
-       }
-       // set clock  - might be able to get this externally and remove this work...
-       if (!clk) {
-               for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
-                       tol = fndClk[clkCnt]/8;
-                       if (minClk >= fndClk[clkCnt]-tol && minClk <= fndClk[clkCnt]+1) { 
-                               clk=fndClk[clkCnt];
-                               break;
-                       }
-               }
-               // clock not found - ERROR
-               if (!clk) {
-                       if (g_debugMode==2) prnt("DEBUG STT: clock not found - quitting");
-                       return false;
-               }
-       } else tol = clk/8;
+// by marshmellow
+// FSK Demod then try to locate a Farpointe Data (pyramid) ID
+int PyramiddemodFSK(uint8_t *dest, size_t *size, int *waveStartIdx) {
+       //make sure buffer has data
+       if (*size < 128*50) return -5;

 
 

-       *foundclock = clk;
+       // FSK demodulator
+       *size = fskdemod(dest, *size, 50, 1, 10, 8, waveStartIdx);  // fsk2a RF/50 
+       if (*size < 128) return -2;  //did we get a good demod?

 
 

-       // look for Sequence Terminator - should be pulses of clk*(1 or 1.5), clk*2, clk*(1.5 or 2)
-       start = -1;
-       for (i = 0; i < j - 4; ++i) {
-               skip += tmpbuff[i];
-               if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol && waveLen[i] < clk+tol) {           //1 to 2 clocks depending on 2 bits prior
-                       if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) {       //2 clocks and wave size is 1 1/2
-                               if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave
-                                       if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit
-                                               start = i + 3;
-                                               break;
-                                       }
-                               }
-                       }
-               }
-       }
-       // first ST not found - ERROR
-       if (start < 0) {
-               if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting");
-               return false;
-       } else {
-               if (g_debugMode==2) prnt("DEBUG STT: first STT found at: %d, j=%d",start, j);
-       }
-       if (waveLen[i+2] > clk*1+tol)
-               phaseoff = 0;
-       else
-               phaseoff = clk/2;
-       
-       // skip over the remainder of ST
-       skip += clk*7/2; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point
+       uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
+       size_t startIdx = 0;
+       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+       if (errChk == 0) return -4; //preamble not found
+       if (*size != 128) return -3;
+       return (int)startIdx;
+}

 
 

-       // now do it again to find the end
-       end = skip;
-       for (i += 3; i < j - 4; ++i) {
-               end += tmpbuff[i];
-               if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol && waveLen[i] < clk+tol) {           //1 to 2 clocks depending on 2 bits prior
-                       if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) {       //2 clocks and wave size is 1 1/2
-                               if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave
-                                       if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit
-                                               complete = true;
-                                               break;
-                                       }
-                               }
-                       }
-               }
-       }
-       end -= phaseoff;
-       //didn't find second ST - ERROR
-       if (!complete) {
-               if (g_debugMode==2) prnt("DEBUG STT: second STT not found - quitting");
-               return false;
-       }
-       if (g_debugMode==2) prnt("DEBUG STT: start of data: %d end of data: %d, datalen: %d, clk: %d, bits: %d, phaseoff: %d", skip, end, end-skip, clk, (end-skip)/clk, phaseoff);
-       //now begin to trim out ST so we can use normal demod cmds
-       start = skip;
-       size_t datalen = end - start;
-       // check validity of datalen (should be even clock increments)  - use a tolerance of up to 1/8th a clock
-       if ( clk - (datalen % clk) <= clk/8) {
-               // padd the amount off - could be problematic...  but shouldn't happen often
-               datalen += clk - (datalen % clk);
-       } else if ( (datalen % clk) <= clk/8 ) {
-               // padd the amount off - could be problematic...  but shouldn't happen often
-               datalen -= datalen % clk;
-       } else {
-               if (g_debugMode==2) prnt("DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting", datalen, clk, datalen % clk);
-               return false;
-       }
-       // if datalen is less than one t55xx block - ERROR
-       if (datalen/clk < 8*4) {
-               if (g_debugMode==2) prnt("DEBUG STT: datalen is less than 1 full t55xx block - quitting");              
-               return false;
-       }
-       size_t dataloc = start;
-       if (buffer[dataloc-(clk*4)-(clk/8)] <= low && buffer[dataloc] <= low && buffer[dataloc-(clk*4)] >= high) {
-               //we have low drift (and a low just before the ST and a low just after the ST) - compensate by backing up the start 
-               for ( i=0; i <= (clk/8); ++i ) {
-                       if ( buffer[dataloc - (clk*4) - i] <= low ) {
-                               dataloc -= i;
-                               break;
-                       }
-               }
-       }
-       
-       size_t newloc = 0;
-       i=0;
-       if (g_debugMode==2) prnt("DEBUG STT: Starting STT trim - start: %d, datalen: %d ",dataloc, datalen);            
+// by marshmellow
+// find viking preamble 0xF200 in already demoded data
+int VikingDemod_AM(uint8_t *dest, size_t *size) {
+       //make sure buffer has data
+       if (*size < 64*2) return -2;

 
 

-       // warning - overwriting buffer given with raw wave data with ST removed...
-       while ( dataloc < bufsize-(clk/2) ) {
-               //compensate for long high at end of ST not being high due to signal loss... (and we cut out the start of wave high part)
-               if (buffer[dataloc]<high && buffer[dataloc]>low && buffer[dataloc+3]<high && buffer[dataloc+3]>low) {
-                       for(i=0; i < clk/2-tol; ++i) {
-                               buffer[dataloc+i] = high+5;
-                       }
-               }
-               for (i=0; i<datalen; ++i) {
-                       if (i+newloc < bufsize) {
-                               if (i+newloc < dataloc)
-                                       buffer[i+newloc] = buffer[dataloc];
+       size_t startIdx = 0;
+       uint8_t preamble[] = {1,1,1,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+       if (errChk == 0) return -4; //preamble not found
+       uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^ bytebits_to_byte(dest+startIdx+8,8) ^ bytebits_to_byte(dest+startIdx+16,8)
+           ^ bytebits_to_byte(dest+startIdx+24,8) ^ bytebits_to_byte(dest+startIdx+32,8) ^ bytebits_to_byte(dest+startIdx+40,8) 
+           ^ bytebits_to_byte(dest+startIdx+48,8) ^ bytebits_to_byte(dest+startIdx+56,8);
+       if ( checkCalc != 0xA8 ) return -5;
+       if (*size != 64) return -6;
+       //return start position
+       return (int) startIdx;
+}

 
 

-                               dataloc++;
-                       }
-               }
-               newloc += i;
-               //skip next ST  -  we just assume it will be there from now on...
-               if (g_debugMode==2) prnt("DEBUG STT: skipping STT at %d to %d", dataloc, dataloc+(clk*4));
-               dataloc += clk*4;
-       }
-       *size = newloc;
-       return true;
+// by iceman
+// find Visa2000 preamble in already demoded data
+int Visa2kDemod_AM(uint8_t *dest, size_t *size) {
+       if (*size < 96) return -1; //make sure buffer has data
+       size_t startIdx = 0;
+       uint8_t preamble[] = {0,1,0,1,0,1,1,0,0,1,0,0,1,0,0,1,0,1,0,1,0,0,1,1,0,0,1,1,0,0,1,0};
+       if (preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx) == 0)
+               return -2; //preamble not found
+       if (*size != 96) return -3; //wrong demoded size
+       //return start position
+       return (int)startIdx;

 }
 }