FIX: Removed a double const

[proxmark3-svn] / common / lfdemod.c

diff --git a/common/lfdemod.c b/common/lfdemod.c
index ad4721f167a2c592db2962d695b8d919a28e61a0..967a98a88ea4d94733850f088012ee6536fca60f 100644 (file)
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -1,458 +1,490 @@
 //-----------------------------------------------------------------------------
 //-----------------------------------------------------------------------------

-// Copyright (C) 2014 
+// Copyright (C) 2014

 //
 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
 // at your option, any later version. See the LICENSE.txt file for the text of
 // the license.
 //-----------------------------------------------------------------------------
 //
 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
 // at your option, any later version. See the LICENSE.txt file for the text of
 // the license.
 //-----------------------------------------------------------------------------

-// Low frequency commands
+// Low frequency demod/decode commands

 //-----------------------------------------------------------------------------
 
 #include <stdlib.h>
 #include <string.h>
 #include "lfdemod.h"
 //-----------------------------------------------------------------------------
 
 #include <stdlib.h>
 #include <string.h>
 #include "lfdemod.h"

+#include "common.h"
+
+//un_comment to allow debug print calls when used not on device
+void dummy(char *fmt, ...){}
+
+#ifndef ON_DEVICE
+#include "ui.h"
+#include "cmdparser.h"
+#include "cmddata.h"
+#define prnt PrintAndLog
+#else 
+       uint8_t g_debugMode=0;
+#define prnt dummy
+#endif
+
+uint8_t justNoise(uint8_t *BitStream, size_t size)
+{
+       static const uint8_t THRESHOLD = 123;
+       //test samples are not just noise
+       uint8_t justNoise1 = 1;
+       for(size_t idx=0; idx < size && justNoise1 ;idx++){
+               justNoise1 = BitStream[idx] < 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
+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 
+       for (size_t i=0; i < size; i++){
+               if (BitStream[i] > *high) *high = BitStream[i];
+               if (BitStream[i] < *low) *low = BitStream[i];
+       }
+       if (*high < 123) return -1; // just noise
+       *high = ((*high-128)*fuzzHi + 12800)/100;
+       *low = ((*low-128)*fuzzLo + 12800)/100;
+       return 1;
+}
+
+// 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);
+       }
+       //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType);
+       return (ans == pType);
+}
+
+//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 Always 1'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;
+       size_t j = 0, bitCnt = 0;
+       for (int word = 0; word < (bLen); word+=pLen){
+               for (int bit=0; bit < pLen; bit++){
+                       parityWd = (parityWd << 1) | BitStream[startIdx+word+bit];
+                       BitStream[j++] = (BitStream[startIdx+word+bit]);
+               }
+               j--; // overwrite parity with next data
+               // if parity fails then return 0
+               if (pType == 2) { // then marker bit which should be a 1
+                       if (!BitStream[j]) return 0;
+               } else {
+                       if (parityTest(parityWd, pLen, pType) == 0) return 0;                   
+               }
+               bitCnt+=(pLen-1);
+               parityWd = 0;
+       }
+       // if we got here then all the parities passed
+       //return ID start index and size
+       return bitCnt;
+}
+
+// by marshmellow
+// 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), and binary Length (length to run)
+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) {
+               for (int bit=0; bit < pLen-1; bit++){
+                       parityWd = (parityWd << 1) | BitSource[word+bit];
+                       dest[j++] = (BitSource[word+bit]);
+               }
+               // if parity fails then return 0
+               if (pType == 2) { // then marker bit which should be a 1
+                       dest[j++]=1;
+               } else {
+                       dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1;
+               }
+               bitCnt += pLen;
+               parityWd = 0;
+       }
+       // if we got here then all the parities passed
+       //return ID start index and size
+       return bitCnt;
+}
+
+uint32_t bytebits_to_byte(uint8_t *src, size_t numbits)
+{
+       uint32_t num = 0;
+       for(int i = 0 ; i < numbits ; i++)
+       {
+               num = (num << 1) | (*src);
+               src++;
+       }
+       return num;
+}
+
+//least significant bit first
+uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits)
+{
+       uint32_t num = 0;
+       for(int i = 0 ; i < numbits ; i++) {
+               num = (num << 1) | *(src + (numbits-(i+1)));
+       }
+       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)
+{
+       uint8_t foundCnt=0;
+       for (int idx=0; idx < *size - pLen; idx++){
+               if (memcmp(BitStream+idx, preamble, pLen) == 0){
+                       //first index found
+                       foundCnt++;
+                       if (foundCnt == 1){
+                               *startIdx = idx;
+                       }
+                       if (foundCnt == 2){
+                               *size = idx - *startIdx;
+                               return 1;
+                       }
+               }
+       }
+       return 0;
+}

 
 //by marshmellow
 //takes 1s and 0s and searches for EM410x format - output EM ID
 
 //by marshmellow
 //takes 1s and 0s and searches for EM410x format - output EM ID

-uint64_t Em410xDecode(uint8_t *BitStream, int BitLen)
+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
-  int high=0, low=128;
-  uint64_t lo=0; //hi=0,
-
-  uint32_t i = 0;
-  uint32_t initLoopMax = 65;
-  if (initLoopMax>BitLen) initLoopMax=BitLen;
-
-  for (;i < initLoopMax; ++i) //65 samples should be plenty to find high and low values
-  {
-    if (BitStream[i] > high)
-      high = BitStream[i];
-    else if (BitStream[i] < low)
-      low = BitStream[i];
-  }
-  if (((high !=1)||(low !=0))){  //allow only 1s and 0s 
-   // PrintAndLog("no data found"); 
-    return 0;
-  }
-  uint8_t parityTest=0;
-   // 111111111 bit pattern represent start of frame
-  uint8_t frame_marker_mask[] = {1,1,1,1,1,1,1,1,1};
-  uint32_t idx = 0;
-  uint32_t ii=0;
-  uint8_t resetCnt = 0;
-  while( (idx + 64) < BitLen) {
- restart:
-    // search for a start of frame marker
-    if ( memcmp(BitStream+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
-    { // frame marker found
-      idx+=9;//sizeof(frame_marker_mask);
-      for (i=0; i<10;i++){
-        for(ii=0; ii<5; ++ii){
-          parityTest += BitStream[(i*5)+ii+idx];        
-        }
-        if (parityTest== ((parityTest>>1)<<1)){
-          parityTest=0;
-          for (ii=0; ii<4;++ii){
-            //hi = (hi<<1)|(lo>>31);
-            lo=(lo<<1LL)|(BitStream[(i*5)+ii+idx]);
-          }
-          //PrintAndLog("DEBUG: EM parity passed parity val: %d, i:%d, ii:%d,idx:%d, Buffer: %d%d%d%d%d,lo: %d",parityTest,i,ii,idx,BitStream[idx+ii+(i*5)-5],BitStream[idx+ii+(i*5)-4],BitStream[idx+ii+(i*5)-3],BitStream[idx+ii+(i*5)-2],BitStream[idx+ii+(i*5)-1],lo);          
-        }else {//parity failed
-          //PrintAndLog("DEBUG: EM parity failed parity val: %d, i:%d, ii:%d,idx:%d, Buffer: %d%d%d%d%d",parityTest,i,ii,idx,BitStream[idx+ii+(i*5)-5],BitStream[idx+ii+(i*5)-4],BitStream[idx+ii+(i*5)-3],BitStream[idx+ii+(i*5)-2],BitStream[idx+ii+(i*5)-1]);
-          parityTest=0;
-          idx-=8;
-          if (resetCnt>5)return 0;
-          resetCnt++;
-          goto restart;//continue;
-        }
-      }
-      //skip last 5 bit parity test for simplicity.
-      return lo;
-    }else{
-      idx++;
-    }
-  }
-  return 0;
+       //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
+
+       // 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;

 }
 
 //by marshmellow
 }
 
 //by marshmellow

-//takes 2 arguments - clock and invert both as integers
-//attempts to demodulate ask while decoding manchester 
-//prints binary found and saves in graphbuffer for further commands
-int askmandemod(uint8_t * BinStream, int *BitLen,int *clk, int *invert)
+//demodulates strong heavily clipped samples
+int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low)

 {
 {

-  int i;
-  int high = 0, low = 128;
-  *clk=DetectASKClock(BinStream,(size_t)*BitLen,*clk); //clock default
-
-  if (*clk<8) *clk =64;
-  if (*clk<32) *clk=32;
-  if (*invert != 0 && *invert != 1) *invert=0;
-  uint32_t initLoopMax = 200;
-  if (initLoopMax>*BitLen) initLoopMax=*BitLen;
-  // Detect high and lows 
-  for (i = 0; i < initLoopMax; ++i) //200 samples should be enough to find high and low values
-  {
-    if (BinStream[i] > high)
-      high = BinStream[i];
-    else if (BinStream[i] < low)
-      low = BinStream[i];
-  }
-  if ((high < 158) ){  //throw away static 
-    //PrintAndLog("no data found"); 
-    return -2;
-  }
-  //25% fuzz in case highs and lows aren't clipped [marshmellow]
-  high=(int)((high-128)*.75)+128;
-  low= (int)((low-128)*.75)+128;
- 
-  //PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
-  int lastBit = 0;  //set first clock check
-  uint32_t bitnum = 0;     //output counter
-  int 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 
-  int iii = 0;
-  uint32_t gLen = *BitLen;
-  if (gLen > 3000) gLen=3000;
-  uint8_t errCnt =0;
-  uint32_t bestStart = *BitLen;
-  uint32_t bestErrCnt = (*BitLen/1000);
-  uint32_t maxErr = (*BitLen/1000);
-  //PrintAndLog("DEBUG - lastbit - %d",lastBit);
-  //loop to find first wave that works
-  for (iii=0; iii < gLen; ++iii){
-    if ((BinStream[iii]>=high)||(BinStream[iii]<=low)){
-      lastBit=iii-*clk;    
-      errCnt=0;
-      //loop through to see if this start location works
-      for (i = iii; i < *BitLen; ++i) {   
-        if ((BinStream[i] >= high) && ((i-lastBit)>(*clk-tol))){
-          lastBit+=*clk;
-        } else if ((BinStream[i] <= low) && ((i-lastBit)>(*clk-tol))){
-          //low found and we are expecting a bar
-          lastBit+=*clk;
-        } else {
-          //mid value found or no bar supposed to be here
-          if ((i-lastBit)>(*clk+tol)){
-            //should have hit a high or low based on clock!!
-           
-            //debug
-            //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
-            
-            errCnt++;
-            lastBit+=*clk;//skip over until hit too many errors
-            if (errCnt>(maxErr)) break;  //allow 1 error for every 1000 samples else start over
-          }
-        }
-        if ((i-iii) >(400 * *clk)) break; //got plenty of bits
-      }
-      //we got more than 64 good bits and not all errors
-      if ((((i-iii)/ *clk) > (64+errCnt)) && (errCnt<maxErr)) {
-        //possible good read
-        if (errCnt==0){
-                                       bestStart=iii;
-                                       bestErrCnt=errCnt;
-                                       break;  //great read - finish
-        } 
-        if (errCnt<bestErrCnt){  //set this as new best run
-          bestErrCnt=errCnt;
-          bestStart = iii;
-        }
-      }
-    }
-  }
-  if (bestErrCnt<maxErr){
-       //best run is good enough set to best run and set overwrite BinStream
-       iii=bestStart;
-       lastBit=bestStart-*clk;
-       bitnum=0;
-    for (i = iii; i < *BitLen; ++i) {   
-      if ((BinStream[i] >= high) && ((i-lastBit)>(*clk-tol))){
-        lastBit+=*clk;
-        BinStream[bitnum] =  *invert;
-        bitnum++;
-      } else if ((BinStream[i] <= low) && ((i-lastBit)>(*clk-tol))){
-        //low found and we are expecting a bar
-        lastBit+=*clk;
-        BinStream[bitnum] = 1-*invert; 
-        bitnum++;
-      } else {
-        //mid value found or no bar supposed to be here
-        if ((i-lastBit)>(*clk+tol)){
-          //should have hit a high or low based on clock!!
-         
-          //debug
-          //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
-          if (bitnum > 0){
-            BinStream[bitnum]=77;
-            bitnum++;
-          }
-          
-          lastBit+=*clk;//skip over error
-        }
-      }
-      if (bitnum >=400) break;
-    }
-    *BitLen=bitnum;
-       } else{
-       *invert=bestStart;
-       *clk=iii;
-       return -1; 
-  }    
-  return bestErrCnt;
+       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++;
+                                               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;
+}
+
+//by marshmellow
+void askAmp(uint8_t *BitStream, size_t size)
+{
+       for(size_t i = 1; i<size; i++){
+               if (BitStream[i]-BitStream[i-1]>=30) //large jump up
+                       BitStream[i]=127;
+               else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down
+                       BitStream[i]=-127;
+       }
+       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: clk %d, beststart %d", *clk, start);
+
+       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
+
+       size_t errCnt = 0;
+       // if clean clipped waves detected run alternate demod
+       if (DetectCleanAskWave(BinStream, *size, high, low)) {
+               if (g_debugMode==2) prnt("DEBUG: Clean Wave Detected");
+               errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
+               if (askType) //askman
+                       return manrawdecode(BinStream, size, 0);        
+               else //askraw
+                       return errCnt;
+       }
+
+       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;
+       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) {
+                                       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 (bitnum >= MaxBits) break;
+       }
+       *size = bitnum;
+       return errCnt;

 }
 
 //by marshmellow
 //take 10 and 01 and manchester decode
 //run through 2 times and take least errCnt
 }
 
 //by marshmellow
 //take 10 and 01 and manchester decode
 //run through 2 times and take least errCnt

-int manrawdecode(uint8_t * BitStream, int *bitLen)
+int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert)

 {
 {

-  int bitnum=0;
-  int errCnt =0;
-  int i=1;
-  int bestErr = 1000;
-  int bestRun = 0;
-  int ii=1;
-  for (ii=1;ii<3;++ii){
-       i=1;
-               for (i=i+ii;i<*bitLen-2;i+=2){
-                 if(BitStream[i]==1 && (BitStream[i+1]==0)){
-                 } else if((BitStream[i]==0)&& BitStream[i+1]==1){
-           } else {
-                     errCnt++;
-           }
-           if(bitnum>300) break;
-               }
+       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){
                if (bestErr>errCnt){

-                 bestErr=errCnt;
-                 bestRun=ii;
-               }       
+                       bestErr=errCnt;
+                       bestRun=ii;
+               }

                errCnt=0;
                errCnt=0;

-  }
-  errCnt=bestErr;
-  if (errCnt<20){
-       ii=bestRun;
-       i=1;
-               for (i=i+ii;i<*bitLen-2;i+=2){
-                 if(BitStream[i]==1 && (BitStream[i+1]==0)){
-                   BitStream[bitnum++]=0;
-                 } else if((BitStream[i]==0)&& BitStream[i+1]==1){
-                   BitStream[bitnum++]=1;
-           } else {
-             BitStream[bitnum++]=77;
-                     //errCnt++;
-           }
-           if(bitnum>300) break;
+       }
+       //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;

                }
                }

-       *bitLen=bitnum;
-       }   
-  return errCnt;
+               if(bitnum>MaxBits) break;
+       }
+       *size=bitnum;
+       return bestErr;

 }
 
 }
 

+uint32_t manchesterEncode2Bytes(uint16_t datain) {
+       uint32_t output = 0;
+       uint8_t curBit = 0;
+       for (uint8_t i=0; i<16; i++) {
+               curBit = (datain >> (15-i) & 1);
+               output |= (1<<(((15-i)*2)+curBit));
+       }
+       return output;
+}

 
 //by marshmellow
 
 //by marshmellow

-//take 01 or 10 = 0 and 11 or 00 = 1
-int BiphaseRawDecode(uint8_t * BitStream, int *bitLen, int offset)
+//encode binary data into binary manchester 
+int ManchesterEncode(uint8_t *BitStream, size_t size)

 {
 {

-  uint8_t bitnum=0;
-  uint32_t errCnt =0;
-  uint32_t i=1;
-       i=offset;
-       for (;i<*bitLen-2;i+=2){
-         if((BitStream[i]==1 && BitStream[i+1]==0)||(BitStream[i]==0 && BitStream[i+1]==1)){
-           BitStream[bitnum++]=1;
-         } else if((BitStream[i]==0 && BitStream[i+1]==0)||(BitStream[i]==1 && BitStream[i+1]==1)){
-           BitStream[bitnum++]=0;
-    } else {
-           BitStream[bitnum++]=77;
-      errCnt++;
-    }
-    if(bitnum>250) break;
-       }  
-  *bitLen=bitnum;
-  return errCnt;
+       size_t modIdx=20000, i=0;
+       if (size>modIdx) return -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];
+       }
+       return i;

 }
 
 //by marshmellow
 }
 
 //by marshmellow

-//takes 2 arguments - clock and invert both as integers
-//attempts to demodulate ask only
-//prints binary found and saves in graphbuffer for further commands
-int askrawdemod(uint8_t *BinStream, int *bitLen,int *clk, int *invert)
+//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)

 {
 {

-  uint32_t i;
- // int invert=0;  //invert default
-  int high = 0, low = 128;
-  *clk=DetectASKClock(BinStream,*bitLen,*clk); //clock default
-  uint8_t BitStream[502] = {0};
-
-  if (*clk<8) *clk =64;
-  if (*clk<32) *clk=32;
-  if (*invert != 0 && *invert != 1) *invert =0;
-  uint32_t initLoopMax = 200;
-  if (initLoopMax>*bitLen) initLoopMax=*bitLen;
-  // Detect high and lows 
-  for (i = 0; i < initLoopMax; ++i) //200 samples should be plenty to find high and low values
-  {
-    if (BinStream[i] > high)
-      high = BinStream[i];
-    else if (BinStream[i] < low)
-      low = BinStream[i];
-  }
-  if ((high < 158)){  //throw away static
- //   PrintAndLog("no data found"); 
-    return -2;
-  }
-  //25% fuzz in case highs and lows aren't clipped [marshmellow]
-  high=(int)((high-128)*.75)+128;
-  low= (int)((low-128)*.75)+128;
-
-  //PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
-  int lastBit = 0;  //set first clock check
-  uint32_t bitnum = 0;     //output counter
-  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 
-  uint32_t iii = 0;
-  uint32_t gLen = *bitLen;
-  if (gLen > 500) gLen=500;
-  uint8_t errCnt =0;
-  uint32_t bestStart = *bitLen;
-  uint32_t bestErrCnt = (*bitLen/1000);
-  uint8_t midBit=0;
-  //PrintAndLog("DEBUG - lastbit - %d",lastBit);
-  //loop to find first wave that works
-  for (iii=0; iii < gLen; ++iii){
-    if ((BinStream[iii]>=high)||(BinStream[iii]<=low)){
-      lastBit=iii-*clk;    
-      //loop through to see if this start location works
-      for (i = iii; i < *bitLen; ++i) {  
-        if ((BinStream[i] >= high) && ((i-lastBit)>(*clk-tol))){
-          lastBit+=*clk;
-          BitStream[bitnum] =  *invert;
-          bitnum++;
-          midBit=0;
-        } else if ((BinStream[i] <= low) && ((i-lastBit)>(*clk-tol))){
-          //low found and we are expecting a bar
-          lastBit+=*clk;
-          BitStream[bitnum] = 1-*invert; 
-          bitnum++;
-          midBit=0;
-        } else if ((BinStream[i]<=low) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
-          //mid bar?
-          midBit=1;
-          BitStream[bitnum]= 1-*invert;
-          bitnum++;
-        } else if ((BinStream[i]>=high)&&(midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
-          //mid bar?
-          midBit=1;
-          BitStream[bitnum]= *invert;
-          bitnum++;
-        } else if ((i-lastBit)>((*clk/2)+tol)&&(midBit==0)){
-          //no mid bar found
-          midBit=1;
-          BitStream[bitnum]= BitStream[bitnum-1];
-          bitnum++;
-        } else {
-          //mid value found or no bar supposed to be here
-
-          if ((i-lastBit)>(*clk+tol)){
-            //should have hit a high or low based on clock!!
-            //debug
-            //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
-            if (bitnum > 0){
-              BitStream[bitnum]=77;
-              bitnum++;
-            }
-            
-
-            errCnt++;
-            lastBit+=*clk;//skip over until hit too many errors
-            if (errCnt>((*bitLen/1000))){  //allow 1 error for every 1000 samples else start over
-              errCnt=0;
-              bitnum=0;//start over
-              break;
-            }
-          }          
-        }
-        if (bitnum>500) break;
-      }
-      //we got more than 64 good bits and not all errors
-      if ((bitnum > (64+errCnt)) && (errCnt<(*bitLen/1000))) {
-        //possible good read
-        if (errCnt==0) break;  //great read - finish
-        if (bestStart == iii) break;  //if current run == bestErrCnt run (after exhausted testing) then finish 
-        if (errCnt<bestErrCnt){  //set this as new best run
-          bestErrCnt=errCnt;
-          bestStart = iii;
-        }
-      }
-    }
-    if (iii>=gLen){ //exhausted test
-      //if there was a ok test go back to that one and re-run the best run (then dump after that run)
-      if (bestErrCnt < (*bitLen/1000)) iii=bestStart;
-    }
-  }
-  if (bitnum>16){
-    
-   // PrintAndLog("Data start pos:%d, lastBit:%d, stop pos:%d, numBits:%d",iii,lastBit,i,bitnum);
-    //move BitStream back to BinStream
-   // ClearGraph(0);
-    for (i=0; i < bitnum; ++i){
-      BinStream[i]=BitStream[i];
-    }
-    *bitLen=bitnum;
-   // RepaintGraphWindow();
-    //output
-   // if (errCnt>0){
-   //   PrintAndLog("# Errors during Demoding (shown as 77 in bit stream): %d",errCnt);
-   // }
-   // PrintAndLog("ASK decoded bitstream:");
-    // Now output the bitstream to the scrollback by line of 16 bits
-   // printBitStream2(BitStream,bitnum);
-    //int errCnt=0;
-    //errCnt=manrawdemod(BitStream,bitnum);
-
- //   Em410xDecode(Cmd);
-  } else return -1;
-  return errCnt;
+       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;

 }
 }

-//translate wave to 11111100000 (1 for each short wave 0 for each long wave) 
+
+// 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;
+       }
+       return -5;
+}
+
+//translate wave to 11111100000 (1 for each short wave 0 for each long wave)

 size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow)
 {
 size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow)
 {

-       uint32_t last_transition = 0;
-       uint32_t idx = 1;
-       uint32_t maxVal=0;
+       size_t last_transition = 0;
+       size_t idx = 1;
+       //uint32_t maxVal=0;

        if (fchigh==0) fchigh=10;
        if (fclow==0) fclow=8;
        if (fchigh==0) fchigh=10;
        if (fclow==0) fclow=8;

-       // we do care about the actual theshold value as sometimes near the center of the
-       // wave we may get static that changes direction of wave for one value
-       // if our value is too low it might affect the read.  and if our tag or
-       // antenna is weak a setting too high might not see anything. [marshmellow]
-       if (size<100) return 0;
-       for(idx=1; idx<100; idx++){
-    if(maxVal<dest[idx]) maxVal = dest[idx];
-  }
-    // set close to the top of the wave threshold with 25% margin for error
-    // less likely to get a false transition up there. 
-    // (but have to be careful not to go too high and miss some short waves)
-  uint8_t threshold_value = (uint8_t)(((maxVal-128)*.75)+128); 
- //    idx=1;
-               //uint8_t threshold_value = 127;
-       
+       //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;

        // sync to first lo-hi transition, and threshold
 
        // Need to threshold first sample
        // sync to first lo-hi transition, and threshold
 
        // Need to threshold first sample

-       
-       if(dest[0] < threshold_value) dest[0] = 0;
+       // skip 160 samples to allow antenna/samples to settle
+       if(dest[160] < threshold_value) dest[0] = 0;

        else dest[0] = 1;
 
        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 with anywhere
        // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
        else dest[0] = 1;
 
        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 with anywhere
        // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10

-       for(idx = 1; idx < size; idx++) {
+       for(idx = 161; idx < size-20; idx++) {

                // threshold current value
 
                if (dest[idx] < threshold_value) dest[idx] = 0;
                // threshold current value
 
                if (dest[idx] < threshold_value) dest[idx] = 0;


@@ -460,696 +492,1042 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow
 
                // Check for 0->1 transition
                if (dest[idx-1] < dest[idx]) { // 0 -> 1 transition
 
                // Check for 0->1 transition
                if (dest[idx-1] < dest[idx]) { // 0 -> 1 transition

-                       if ((idx-last_transition)<(fclow-2)){            //0-5 = garbage noise
+                       preLastSample = LastSample;
+                       LastSample = currSample;
+                       currSample = idx-last_transition;
+                       if (currSample < (fclow-2)){            //0-5 = garbage noise (or 0-3)

                                //do nothing with extra garbage
                                //do nothing with extra garbage

-                       } else if ((idx-last_transition) < (fchigh-1)) { //6-8 = 8 waves
-                               dest[numBits]=1;
-                       } else {                                                        //9+ = 10 waves
-                               dest[numBits]=0;
+                       } else if (currSample < (fchigh-1)) { //6-8 = 8 sample waves  or 3-6 = 5
+                               if (LastSample > (fchigh-2) && (preLastSample < (fchigh-1) || preLastSample     == 0 )){
+                                       dest[numBits-1]=1;  //correct previous 9 wave surrounded by 8 waves
+                               }
+                               dest[numBits++]=1;
+
+                       } else if (currSample > (fchigh) && !numBits) { //12 + and first bit = garbage 
+                               //do nothing with beginning garbage
+                       } else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's
+                               dest[numBits++]=1;
+                       } else {                                         //9+ = 10 sample waves
+                               dest[numBits++]=0;

                        }
                        last_transition = idx;
                        }
                        last_transition = idx;

-                       numBits++;

                }
        }
        return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
 }
 
                }
        }
        return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
 }
 

-uint32_t myround2(float f)
-{
-  if (f >= 2000) return 2000;//something bad happened
-  return (uint32_t) (f + (float)0.5);
-}
-
-//translate 11111100000 to 10 
-size_t aggregate_bits(uint8_t *dest,size_t size,  uint8_t rfLen, uint8_t maxConsequtiveBits, uint8_t invert,uint8_t fchigh,uint8_t fclow )// uint8_t h2l_crossing_value,uint8_t l2h_crossing_value, 
+//translate 11111100000 to 10
+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];
 {
        uint8_t lastval=dest[0];

-       uint32_t idx=0;
+       size_t idx=0;

        size_t numBits=0;
        uint32_t n=1;
        size_t numBits=0;
        uint32_t n=1;

-

        for( idx=1; idx < size; idx++) {
        for( idx=1; idx < size; idx++) {

-
-               if (dest[idx]==lastval) {
-                       n++;
-                       continue;
-               }
+               n++;
+               if (dest[idx]==lastval) continue; 
+               

                //if lastval was 1, we have a 1->0 crossing
                //if lastval was 1, we have a 1->0 crossing

-               if ( dest[idx-1]==1 ) {
-                       n=myround2((float)(n+1)/((float)(rfLen)/(float)fclow));
-                       //n=(n+1) / h2l_crossing_value;
-               } else {// 0->1 crossing
-                       n=myround2((float)(n+1)/((float)(rfLen-2)/(float)fchigh));  //-2 for fudge factor
-                       //n=(n+1) / l2h_crossing_value;
+               if (dest[idx-1]==1) {
+                       n = (n * fclow + rfLen/2) / rfLen;
+               } else {// 0->1 crossing 
+                       n = (n * fchigh + rfLen/2) / rfLen; 

                }
                if (n == 0) n = 1;
 
                }
                if (n == 0) n = 1;
 

-               if(n < maxConsequtiveBits) //Consecutive 
-               {
-                       if(invert==0){ //invert bits 
-                               memset(dest+numBits, dest[idx-1] , n);
-                       }else{
-                               memset(dest+numBits, dest[idx-1]^1 , n);        
-                       }                       
-                       numBits += n;
-               }
+               memset(dest+numBits, dest[idx-1]^invert , n);
+               numBits += n;

                n=0;
                lastval=dest[idx];
        }//end for
                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 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)
 {
 //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,192,invert,fchigh,fclow);
-  return size;
+       // FSK demodulator
+       size = fsk_wave_demod(dest, size, fchigh, fclow);
+       size = aggregate_bits(dest, size, rfLen, invert, fchigh, fclow);
+       return size;

 }
 }

+

 // loop to get raw HID waveform then FSK demodulate the TAG ID from it
 // 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 HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo)

 {
 {

-       
-       size_t idx=0; //, found=0; //size=0,
+       if (justNoise(dest, *size)) return -1;
+
+       size_t numStart=0, size2=*size, startIdx=0; 

        // FSK demodulator
        // FSK demodulator

-       size = fskdemod(dest, size,50,0,10,8);
-
-       // final loop, go over previously decoded manchester data and decode into usable tag ID
-       // 111000 bit pattern represent start of frame, 01 pattern represents a 1 and 10 represents a 0
-       uint8_t frame_marker_mask[] = {1,1,1,0,0,0};
-       int numshifts = 0;
-       idx = 0;
-       //one scan
-       while( idx + sizeof(frame_marker_mask) < size) {
-       // search for a start of frame marker
-               if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
-               { // frame marker found
-                       idx+=sizeof(frame_marker_mask);
-                       while(dest[idx] != dest[idx+1] && idx < size-2)
-                       {       
-                               // Keep going until next frame marker (or error)
-                               // Shift in a bit. Start by shifting high registers
-                               *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)|0;
-                               else // 0 1
-                                       *lo=(*lo<<1)|1;
-                               numshifts++;
-                               idx += 2;
-                       }
-                       // Hopefully, we read a tag and  hit upon the next frame marker
-                       if(idx + sizeof(frame_marker_mask) < size)
-                       {
-                               if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
-                               {
-                                       //good return 
-                                       return idx;
-                               }
-                       }
-                       // reset
-                       *hi2 = *hi = *lo = 0;
-                       numshifts = 0;
-               }else   {
-                       idx++;
+       *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
+
+       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;

        }
        }

-       return -1;
+       return (int)startIdx;

 }
 
 }
 

-uint32_t bytebits_to_byte(uint8_t* src, int numbits)
+// 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)

 {
 {

-       uint32_t num = 0;
-       for(int i = 0 ; i < numbits ; i++)
-       {
-               num = (num << 1) | (*src);
-               src++;
+       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};
+
+       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
+               *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 num;
+       return (int)startIdx;

 }
 
 int IOdemodFSK(uint8_t *dest, size_t size)
 {
 }
 
 int IOdemodFSK(uint8_t *dest, size_t size)
 {

-  uint32_t idx=0;
+       if (justNoise(dest, size)) return -1;

        //make sure buffer has data
        //make sure buffer has data

-       if (size < 66) return -1;
+       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
+
+       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;
+}
+
+// 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;
+
+       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;
+}
+
+// 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;
+
+       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;
+}
+
+
+// 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
+       return (int)startIdx;
+}
+
+// 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;
+
+       if (justNoise(dest, *size)) return -2;
+
+       // FSK demodulator
+       *size = fskdemod(dest, *size, 50, 1, 10, 8);  // fsk2a RF/50 
+       if (*size < 96) return -3;  //did we get a good demod?
+
+       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
+// 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;
+

        //test samples are not just noise
        //test samples are not just noise

-       uint8_t testMax=0;
-       for(idx=0;idx<65;idx++){
-               if (testMax<dest[idx]) testMax=dest[idx];
+       if (justNoise(dest, *size)) return -1;
+
+       // FSK demodulator
+       *size = fskdemod(dest, *size, 50, 1, 10, 8);  // fsk2a RF/50 
+       if (*size < 128) return -2;  //did we get a good demod?
+
+       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;
+}
+
+// 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;
+       }
+       return allArePeaks;
+}
+// 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;
+
+       // 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];

        }
        }

-       idx=0;
-       //if not just noise
-       if (testMax>170){
-               // FSK demodulator
-               size = fskdemod(dest, size,64,1,10,8);  //  RF/64 and invert
-               if (size < 65) return -1;  //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
-         uint8_t mask[] = {0,0,0,0,0,0,0,0,0,1};
-               for( idx=0; idx < (size - 65); idx++) {
-       if ( memcmp(dest + idx, mask, sizeof(mask))==0) {
-               //frame marker found
-               if (!dest[idx+8] && dest[idx+17]==1 && dest[idx+26]==1 && dest[idx+35]==1 && dest[idx+44]==1 && dest[idx+53]==1){
-                       //confirmed proper separator bits found
-                       //return start position
-                                       return (int) idx;
-                               }
-                       }               
-               }
-       }       

        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 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?

-int DetectASKClock(uint8_t dest[], size_t size, int clock)
+// 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
+
+       //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);
+                       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]
+                               }
+                       }
+               }
+       }
+       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;
+
+       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 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;
+
+                       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;
+                       }
+               }
+       }
+       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];
+}
+
+//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)

 {
 {

-  int i=0;
-  int peak=0;
-  int low=128;
-  int clk[]={16,32,40,50,64,100,128,256};
-  int loopCnt = 256;  //don't need to loop through entire array...
-  if (size<loopCnt) loopCnt = size;
-
-  //if we already have a valid clock quit
-  for (;i<8;++i)
-       if (clk[i]==clock) return clock;
-
-  //get high and low peak
-  for (i=0;i<loopCnt;++i){
-    if(dest[i]>peak){
-      peak = dest[i]; 
-    }
-    if(dest[i]<low){
-      low = dest[i];
-    }
-  }
-  peak=(int)(((peak-128)*.75)+128);
-  low= (int)(((low-128)*.75)+128);
-  int ii;
-  int clkCnt;
-  int tol = 0;
-  int bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000};
-  int errCnt=0;
-  //test each valid clock from smallest to greatest to see which lines up
-  for(clkCnt=0; clkCnt<6;++clkCnt){
-    if (clk[clkCnt]==32){
-      tol=1;
-    }else{
-      tol=0;
-    }
-    bestErr[clkCnt]=1000;
-    //try lining up the peaks by moving starting point (try first 256) 
-    for (ii=0; ii<loopCnt; ++ii){
-      if ((dest[ii]>=peak) || (dest[ii]<=low)){
-        errCnt=0;
-        // now that we have the first one lined up test rest of wave array
-        for (i=0; i<((int)(size/clk[clkCnt])-1); ++i){
-          if (dest[ii+(i*clk[clkCnt])]>=peak || dest[ii+(i*clk[clkCnt])]<=low){
-          }else if(dest[ii+(i*clk[clkCnt])-tol]>=peak || dest[ii+(i*clk[clkCnt])-tol]<=low){
-          }else if(dest[ii+(i*clk[clkCnt])+tol]>=peak || dest[ii+(i*clk[clkCnt])+tol]<=low){
-          }else{  //error no peak detected
-            errCnt++;
-          }    
-        }
-        //if we found no errors this is correct one - return this clock
-        if(errCnt==0) return clk[clkCnt];
-        //if we found errors see if it is lowest so far and save it as best run
-        if(errCnt<bestErr[clkCnt]) bestErr[clkCnt]=errCnt;
-      }
-    } 
-  }
-  int iii=0;
-  int best=0;
-  for (iii=0; iii<7;++iii){
-    if (bestErr[iii]<bestErr[best]){
-      //                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;
-      }
-    }
-  }
-  return clk[best];
+       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;
+
+       //if we already have a valid clock quit
+       size_t i=1;
+       for (; i < 8; ++i)
+               if (clk[i] == clock) return clock;
+
+       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);
+
+       //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;
+                       }
+               }
+       }
+       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);
+
+               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];

 }
 }

-int DetectpskNRZClock(uint8_t dest[], size_t size, int clock)
-{ 
-  int i=0;
-  int peak=0;
-  int low=128;
-  int clk[]={16,32,40,50,64,100,128,256};
-  int loopCnt = 2048;  //don't need to loop through entire array...
-  if (size<loopCnt) loopCnt = size;
-
-  //if we already have a valid clock quit
-  for (;i<8;++i)
-    if (clk[i]==clock) return clock;
-
-  //get high and low peak
-  for (i=0;i<loopCnt;++i){
-    if(dest[i]>peak){
-      peak = dest[i]; 
-    }
-    if(dest[i]<low){
-      low = dest[i];
-    }
-  }
-  peak=(int)(((peak-128)*.90)+128);
-  low= (int)(((low-128)*.90)+128);
-  //PrintAndLog("DEBUG: peak: %d, low: %d",peak,low);
-  int ii;
-  int clkCnt;
-  int tol = 0;
-  int peakcnt=0;
-  int errCnt=0;
-  int bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
-  int peaksdet[]={0,0,0,0,0,0,0,0,0};
-  //test each valid clock from smallest to greatest to see which lines up
-  for(clkCnt=0; clkCnt<6;++clkCnt){
-    if (clk[clkCnt]==32){
-      tol=0;
-    }else{
-      tol=0;
-    }
-    //try lining up the peaks by moving starting point (try first 256) 
-    for (ii=0; ii<loopCnt; ++ii){
-      if ((dest[ii]>=peak) || (dest[ii]<=low)){
-        errCnt=0;
-        peakcnt=0;
-        // now that we have the first one lined up test rest of wave array
-        for (i=0; i<((int)(size/clk[clkCnt])-1); ++i){
-          if (dest[ii+(i*clk[clkCnt])]>=peak || dest[ii+(i*clk[clkCnt])]<=low){
-            peakcnt++;
-          }else if(dest[ii+(i*clk[clkCnt])-tol]>=peak || dest[ii+(i*clk[clkCnt])-tol]<=low){
-            peakcnt++;
-          }else if(dest[ii+(i*clk[clkCnt])+tol]>=peak || dest[ii+(i*clk[clkCnt])+tol]<=low){
-            peakcnt++;
-          }else{  //error no peak detected
-            errCnt++;
-          }    
-        }
-        if(peakcnt>peaksdet[clkCnt]) {
-          peaksdet[clkCnt]=peakcnt;
-          bestErr[clkCnt]=errCnt;
-        } 
-      } 
-    } 
-  }
-  int iii=0;
-  int best=0;
-  //int ratio2;  //debug
-  int ratio;
-  //int bits;
-  for (iii=0; iii<7;++iii){
-    ratio=1000;
-    //ratio2=1000;  //debug
-    //bits=size/clk[iii];  //debug
-    if (peaksdet[iii]>0){
-      ratio=bestErr[iii]/peaksdet[iii];
-      if (((bestErr[best]/peaksdet[best])>(ratio)+1)){
-        best = iii;    
-      }     
-      //ratio2=bits/peaksdet[iii]; //debug
-    } 
-    //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d, ratio: %d, bits: %d, peakbitr: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best],ratio, bits,ratio2);
-  }
-  return clk[best];
+
+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;
+
+       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;
+               }
+       }
+       if (lowestTransition == 255) lowestTransition = 0;
+       if (g_debugMode==2) prnt("DEBUG NRZ: detectstrongNRZclk smallest wave: %d",lowestTransition);
+       return lowestTransition;

 }
 
 }
 

-/*
-int DetectNRZpskClock(uint8_t dest[], size_t size, int clock)
+//by marshmellow
+//detect nrz clock by reading #peaks vs no peaks(or errors)
+int DetectNRZClock(uint8_t dest[], size_t size, int clock)

 {
 {

-       int i=0;
-  int peak=0;
-  int low=128;
-  int clk[]={16,32,40,50,64,100,128,256};
-  int loopCnt = 1500;  //don't need to loop through entire array...
-  if (size<loopCnt) loopCnt = size;
-
-  //if we already have a valid clock quit
-  for (;i<8;++i)
-       if (clk[i]==clock) return clock;
-
-  //get high and low peak
-  for (i=0;i<loopCnt;++i){
-    if(dest[i]>peak){
-      peak = dest[i]; 
-    }
-    if(dest[i]<low){
-      low = dest[i];
-    }
-  }
-  peak=(int)((peak-128)*.75)+128;
-  low= (int)((low-128)*.75)+128;
-  int ii;
-  int clkCnt;
-  int tol = 0;
-  int bestErr=1000;
-  int errCnt[]={0,0,0,0,0,0,0,0};
-  int lastClk = 0;
-  uint8_t bitHigh=0;
-  uint8_t ignorewin;
-  int lowBitCnt[]={0,0,0,0,0,0,0,0};
-  int BestLowBit=0;
-  //test each valid clock from smallest to greatest to see which lines up
-  for(clkCnt=0; clkCnt<6;++clkCnt){
-    if (clk[clkCnt]==32){
-      tol=1;
-    }else{
-      tol=0;
-    }
-    ignorewin = clk[clkCnt]/8;
-    bestErr=1000;
-    //try lining up the peaks by moving starting point (try first 256) 
-    for (ii=1; ii<loopCnt; ++ii){
-      if ((dest[ii]>=peak) || (dest[ii]<=low)){
-       lastClk = ii-*clk;
-        errCnt[clkCnt]=0;
-        // now that we have the first one lined up test rest of wave array
-        for (i=ii; i<size; ++i){
-          if ((dest[i]>=peak || dest[i]<=low) && (i>=lastClk+*clk-tol && i<=lastClk+*clk+tol)){
-               bitHigh=1;
-               lastClk=lastClk+*clk;
-            ignorewin=clk[clkCnt]/8;
-          }else if(dest[i]<peak && dest[i]>low) {
-               if (ignorewin==0){
-              bitHigh=0;  
-            }else ignorewin--;
-            if (i>=lastClk+*clk+tol){ //past possible bar
-              lowBitCnt[clkCnt]++;
-            }
-          }else if ((dest[i]>=peak || dest[i]<=low) && (i<lastClk+*clk-tol || i>=lastClk+*clk+tol) && (bitHigh==0)){
-               //error bar found no clock...
-               errCnt[clkCnt]++;
-          }    
-        }
-        //if we found no errors this is correct one - return this clock
-        if(errCnt[clkCnt]==0 && lowBitCnt[clkCnt]==0) return clk[clkCnt];
-        //if we found errors see if it is lowest so far and save it as best run
-        if(errCnt[clkCnt]<bestErr) bestErr=errCnt[clkCnt];
-        if(lowBitCnt[clkCnt]<BestLowBit && errCnt[clkCnt]==bestErr) BestLowBit=lowBitCnt[clkCnt];
-      }
-    } 
-  }
-  int iii=0;
-  int best=0;
-  int best2=0;
-  //get best run
-  for (iii=0; iii<7;++iii){
-    if (errCnt[iii]<errCnt[best]){
-      best = iii;
-    }
-    if (lowBitCnt[iii]<lowBitCnt[best2]){
-      best2=iii;
-    }
-  }
-  //adjust best to one with least low bit counts (as long as no errors)
-  if (best!=best2){
-    if (errCnt[best]==errCnt[best2]) best = best2;
-  }
-  return clk[best];
+       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;
+
+       //get high and low peak
+       int peak, low;
+       if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return 0;
+
+       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);
+                               }
+                               peakcnt++;
+                               //prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt);
+                               smplCnt=0;
+                       }
+               }
+       }
+       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;
+                               }
+                       }
+               }
+       }
+       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, maxPeak: %d, bestClk: %d, lowestTrs: %d",clk[iii],peaksdet[iii],maxPeak, clk[best], lowestTransition);
+       }
+
+       return clk[best];

 }
 }

-*/

 
 

-//by marshmellow (attempt to get rid of high immediately after a low)
-void pskCleanWave(uint8_t *bitStream, int bitLen)
+// by marshmellow
+// convert psk1 demod to psk2 demod
+// only transition waves are 1s
+void psk1TOpsk2(uint8_t *BitStream, size_t size)

 {
 {

-  int i;
-  int low=128;
-  int high=0;
-  int gap = 4;
- // int loopMax = 2048;
-  int newLow=0;
-  int newHigh=0;
-  for (i=0; i<bitLen; ++i){
-    if (bitStream[i]<low) low=bitStream[i];
-    if (bitStream[i]>high) high=bitStream[i];
-  }
-  high = (int)(((high-128)*.80)+128); 
-  low = (int)(((low-128)*.90)+128); 
-  //low = (uint8_t)(((int)(low)-128)*.80)+128;
-  for (i=0; i<bitLen; ++i){
-    if (newLow==1){
-      bitStream[i]=low+8;
-      gap--;
-      if (gap==0){
-        newLow=0;
-        gap=4;
-      } 
-    }else if (newHigh==1){
-      bitStream[i]=high-8;
-      gap--;
-      if (gap==0){
-        newHigh=0;
-        gap=4;
-      }
-    }
-    if (bitStream[i]<=low) newLow=1;
-    if (bitStream[i]>=high) newHigh=1;
-  }
-  return;
+       size_t i=1;
+       uint8_t lastBit=BitStream[0];
+       for (; i<size; i++){
+               if (BitStream[i]==7){
+                       //ignore errors
+               } else if (lastBit!=BitStream[i]){
+                       lastBit=BitStream[i];
+                       BitStream[i]=1;
+               } else {
+                       BitStream[i]=0;
+               }
+       }
+       return;

 }
 
 }
 

-int indala26decode(uint8_t *bitStream, int *bitLen, uint8_t *invert)
+// 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)

 {
 {

-  //26 bit 40134 format  (don't know other formats)
- // Finding the start of a UID
-  int i;
-  int long_wait;
-    //uidlen = 64;
-    long_wait = 29;//29 leading zeros in format  
-  int start;
-  int first = 0;
-  int first2 = 0;
-  int bitCnt = 0;
-  int ii;
-  for (start = 0; start <= *bitLen - 250; start++) {
-    first = bitStream[start];
-    for (i = start; i < start + long_wait; i++) {
-      if (bitStream[i] != first) {
-        break;
-      }
-    }
-    if (i == (start + long_wait)) {
-      break;
-    }
-  }
-  if (start == *bitLen - 250 + 1) {
-    // did not find start sequence
-    return -1;
-  } 
-  //found start once now test length by finding next one
-  // Inverting signal if needed
-  if (first == 1) {
-    for (i = start; i < *bitLen; i++) {
-      bitStream[i] = !bitStream[i];
-    }
-    *invert = 1;
-  }else *invert=0;
- 
-  int iii;
-  for (ii=start+29; ii <= *bitLen - 250; ii++) {
-    first2 = bitStream[ii];
-    for (iii = ii; iii < ii + long_wait; iii++) {
-      if (bitStream[iii] != first2) {
-        break;
-      }
-    }
-    if (iii == (ii + long_wait)) {
-      break;
-    }
-  }
-  if (ii== *bitLen - 250 + 1){
-    // did not find second start sequence
-    return -2;
-  }
-  bitCnt=ii-start;
-
-  // Dumping UID
-  i = start;
-  for (ii = 0; ii < bitCnt; ii++) {
-    bitStream[ii] = bitStream[i++];
-    //showbits[bit] = '0' + bits[bit];
-  }
-  *bitLen=bitCnt;
-  return 1;
+       uint8_t phase=0;
+       for (size_t i=0; i<size; i++){
+               if (BitStream[i]==1){
+                       phase ^=1;
+               }
+               BitStream[i]=phase;
+       }
+       return;

 }
 
 }
 

-int pskNRZrawDemod(uint8_t *dest, int *bitLen, int *clk, int *invert)
+// 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)

 {
 {

-  pskCleanWave(dest,*bitLen);
-  int clk2 = DetectpskNRZClock(dest, *bitLen, *clk);
-       *clk=clk2;
-  uint32_t i;
-       uint8_t high=0, low=128;
-  uint32_t gLen = *bitLen;
-  if (gLen > 1280) gLen=1280;
-       // get high
-       for (i=0; i<gLen; ++i){
-               if (dest[i]>high) high = dest[i];
-               if (dest[i]<low) low=dest[i];
+       //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 NRZ wave
+// 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 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;

        }
        }

-       //fudge high/low bars by 25%
-       high = (uint8_t)((((int)(high)-128)*.75)+128);
-       low = (uint8_t)((((int)(low)-128)*.80)+128);
-
-       //PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
-  int lastBit = 0;  //set first clock check
-  uint32_t bitnum = 0;     //output counter
-  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=2;    //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely 
-  uint32_t iii = 0;
-  uint8_t errCnt =0;
-  uint32_t bestStart = *bitLen;
-  uint32_t maxErr = (*bitLen/1000);
-  uint32_t bestErrCnt = maxErr;
-  //uint8_t midBit=0;
-  uint8_t curBit=0;
-  uint8_t bitHigh=0;
-  uint8_t ignorewin=*clk/8;
-  //PrintAndLog("DEBUG - lastbit - %d",lastBit);
-  //loop to find first wave that works - align to clock
-  for (iii=0; iii < gLen; ++iii){
-    if ((dest[iii]>=high)||(dest[iii]<=low)){
-      lastBit=iii-*clk;    
-      //loop through to see if this start location works
-      for (i = iii; i < *bitLen; ++i) {
-       //if we found a high bar and we are at a clock bit  
-                               if ((dest[i]>=high ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
-               bitHigh=1;
-               lastBit+=*clk;
-                               //curBit=1-*invert;
-                               //dest[bitnum]=curBit;
-          ignorewin=*clk/8;
-                               bitnum++;
-                       //else if low bar found and we are at a clock point
-       }else if ((dest[i]<=low ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
-               bitHigh=1;
-               lastBit+=*clk;
-          ignorewin=*clk/8;
-               //curBit=*invert;
-               //dest[bitnum]=curBit;
-               bitnum++;
-       //else if no bars found
-        }else if(dest[i]<high && dest[i]>low) {
-          if (ignorewin==0){
-            bitHigh=0;
-          }else ignorewin--;
-                       //if we are past a clock point
-               if (i>=lastBit+*clk+tol){ //clock val
-                                               //dest[bitnum]=curBit;
-                       lastBit+=*clk;
-                               bitnum++;
-               }
-        //else if bar found but we are not at a clock bit and we did not just have a clock bit
-        }else if ((dest[i]>=high || dest[i]<=low) && (i<lastBit+*clk-tol || i>lastBit+*clk+tol) && (bitHigh==0)){
-               //error bar found no clock...
-               errCnt++;
-        }   
-        if (bitnum>=1000) break;
-      }
-      //we got more than 64 good bits and not all errors
-      if ((bitnum > (64+errCnt)) && (errCnt<(maxErr))) {
-        //possible good read
-        if (errCnt==0){
-          bestStart = iii;
-          bestErrCnt=errCnt;
-          break;  //great read - finish 
-        }
-        if (bestStart == iii) break;  //if current run == bestErrCnt run (after exhausted testing) then finish 
-        if (errCnt<bestErrCnt){  //set this as new best run
-          bestErrCnt=errCnt;
-          bestStart = iii;
-        }
-      }
-    }
-  }
-  if (bestErrCnt<maxErr){
-       //best run is good enough set to best run and set overwrite BinStream
-       iii=bestStart;
-       lastBit=bestStart-*clk;
-       bitnum=0;
-    for (i = iii; i < *bitLen; ++i) {   
-           //if we found a high bar and we are at a clock bit  
-                       if ((dest[i]>=high ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
-       bitHigh=1;
-       lastBit+=*clk;
-                               curBit=1-*invert;
-                               dest[bitnum]=curBit;
-        ignorewin=*clk/8;
-       bitnum++;
-                       //else if low bar found and we are at a clock point
-       }else if ((dest[i]<=low ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
-       bitHigh=1;
-       lastBit+=*clk;
-               curBit=*invert;
-               dest[bitnum]=curBit;
-        ignorewin=*clk/8;
-               bitnum++;
-       //else if no bars found
-      }else if(dest[i]<high && dest[i]>low) {
-       if (ignorewin==0){
-          bitHigh=0;
-        }else ignorewin--;
-               //if we are past a clock point
-       if (i>=lastBit+*clk+tol){ //clock val
-                     lastBit+=*clk;
-                       dest[bitnum]=curBit;
-                                       bitnum++;
-       }
-      //else if bar found but we are not at a clock bit and we did not just have a clock bit
-      }else if ((dest[i]>=high || dest[i]<=low) && ((i<lastBit+*clk-tol) || (i>lastBit+*clk+tol)) && (bitHigh==0)){
-       //error bar found no clock...
-       bitHigh=1;
-       dest[bitnum]=77;
-       bitnum++;
-       errCnt++;
-      }
-      if (bitnum >=1000) break;
-    }
-    *bitLen=bitnum;
-       } else{
-    *bitLen=bitnum;
-    *clk=bestStart;
-       return -1; 
-  }
-
-  if (bitnum>16){    
-    *bitLen=bitnum;
-  } else return -1;
-  return errCnt;
+       //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;
+               }
+       }
+       *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;

 
 

-  /*not needed?
-       uint32_t i;
-       uint8_t high=0, low=128;
-       uint32_t loopMax = 1280; //20 raw bits 
+       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;
+                                       }
+                               }
+                               if (rfCounter > 0 && rfLensFnd < 15){
+                                       //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
+                                       rfCnts[rfLensFnd]++;
+                                       rfLens[rfLensFnd++] = rfCounter;
+                               }
+                       } else {
+                               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;
+                               }
+                       }
+               }
+       }
+
+       if (ii<0) return 0; // oops we went too far
+
+       return clk[ii];
+}
+
+//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 == 0) return 0;
+
+       // 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;
+
+       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++;
+               }
+       }

        
        

-       // get high
-       if (size<loopMax) return -1;
-       for (i=0; i<loopMax; ++i){
-               if (dest[i]>high) high = dest[i];
-               if (dest[i]<low) low=dest[i];
+       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[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];

        }
        }

-       //fudge high/low bars by 25%
-  high = (uint8_t)(((int)(high)-128)*.75)+128;
-  low = (uint8_t)(((int)(low)-128)*.75)+128;
-
-       //clean waves
-       for (i=0;i<size; ++i){
-               if (dest[i]>=high) dest[i]=high;
-               else if(dest[i]<=low) dest[i]=low;
-               else dest[i]=0;
+       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
+
+       uint16_t fcs = (((uint16_t)fcH)<<8) | fcL;
+       if (fskAdj) return fcs; 
+       return fcLens[best1];
+}
+
+//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;
+
+       size_t numBits=0;
+       uint8_t curPhase = *invert;
+       size_t i, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0;
+       uint8_t fc=0, fullWaveLen=0, tol=1;
+       uint16_t errCnt=0, waveLenCnt=0;
+       fc = countFC(dest, *size, 0);
+       if (fc!=2 && fc!=4 && fc!=8) return -1;
+       //PrintAndLog("DEBUG: FC: %d",fc);
+       *clock = DetectPSKClock(dest, *size, *clock);
+       if (*clock == 0) return -1;
+       int avgWaveVal=0, lastAvgWaveVal=0;
+       //find first phase shift
+       for (i=0; i<loopCnt; i++){
+               if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
+                       waveEnd = i+1;
+                       //PrintAndLog("DEBUG: waveEnd: %d",waveEnd);
+                       waveLenCnt = waveEnd-waveStart;
+                       if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+2)){ //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
+                               if (lastAvgWaveVal > 123) curPhase ^= 1;  //fudge graph 0 a little 123 vs 128
+                               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;
+       //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);  
+       //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d", *clock, lastClkBit);
+       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;
+                               }
+                               avgWaveVal = 0;
+                               waveStart = i+1;
+                       }
+               }
+               avgWaveVal += dest[i+1];
+       }
+       *size = numBits;
+       return errCnt;
+}