FIX: removing compiler warning about double const.

[proxmark3-svn] / common / lfdemod.c

diff --git a/common/lfdemod.c b/common/lfdemod.c
index a410fd7c3e5ff7d8f68192725c50caccbbaebc87..ca126df32c696f7be98961c642dd0159397e07b7 100644 (file)
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -7,33 +7,29 @@
 //-----------------------------------------------------------------------------
 // Low frequency demod/decode commands
 //-----------------------------------------------------------------------------
 //-----------------------------------------------------------------------------
 // Low frequency demod/decode commands
 //-----------------------------------------------------------------------------

-
-#include <stdlib.h>

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

-#include <string.h>

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

+

 #ifndef ON_DEVICE
 #ifndef ON_DEVICE

-#include "ui.h"
-#include "cmdparser.h"
-#include "cmddata.h"
-#define prnt PrintAndLog
+# include "ui.h"
+# include "cmdparser.h"
+# include "cmddata.h"
+# define prnt PrintAndLog

 #else 
        uint8_t g_debugMode=0;
 #else 
        uint8_t g_debugMode=0;

-#define prnt dummy
+# define prnt dummy

 #endif
 
 #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;
+//test samples are not just noise
+uint8_t justNoise(uint8_t *bits, size_t size) {
+       #define THRESHOLD 123
+       uint8_t val = 1;
+       for(size_t idx=0; idx < size && val ;idx++)
+               val = bits[idx] < THRESHOLD;
+       return val;

 }
 
 //by marshmellow
 }
 
 //by marshmellow


@@ -62,7 +58,7 @@ uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType)
        for (uint8_t i = 0; i < bitLen; i++){
                ans ^= ((bits >> i) & 1);
        }
        for (uint8_t i = 0; i < bitLen; i++){
                ans ^= ((bits >> i) & 1);
        }

-       //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType);
+       if (g_debugMode) prnt("DEBUG: ans: %d, ptype: %d, bits: %08X",ans,pType,bits);

        return (ans == pType);
 }
 
        return (ans == pType);
 }
 


@@ -73,20 +69,21 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p
 {
        uint32_t parityWd = 0;
        size_t j = 0, bitCnt = 0;
 {
        uint32_t parityWd = 0;
        size_t j = 0, bitCnt = 0;

-       for (int word = 0; word < (bLen); word+=pLen){
+       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]);
                }
                for (int bit=0; bit < pLen; bit++){
                        parityWd = (parityWd << 1) | BitStream[startIdx+word+bit];
                        BitStream[j++] = (BitStream[startIdx+word+bit]);
                }

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

                j--; // overwrite parity with next data
                // if parity fails then return 0
                switch (pType) {
                j--; // overwrite parity with next data
                // if parity fails then return 0
                switch (pType) {

-                       case 3: if (BitStream[j]==1) return 0; break; //should be 0 spacer bit
-                       case 2: if (BitStream[j]==0) return 0; break; //should be 1 spacer bit
-                       default: //test parity
-                               if (parityTest(parityWd, pLen, pType) == 0) return 0; break;
+                       case 3:  if (BitStream[j]==1) { return 0; } break; //should be 0 spacer bit
+                       case 2:  if (BitStream[j]==0) { return 0; } break; //should be 1 spacer bit
+                       default: if (parityTest(parityWd, pLen, pType) == 0) { return 0; } break; //test parity

                }
                }

-               bitCnt+=(pLen-1);
+               bitCnt += (pLen-1);

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


@@ -144,64 +141,105 @@ uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits)
        return num;
 }
 
        return num;
 }
 

+//by marshmellow
+// search for given preamble in given BitStream and return success=1 or fail=0 and startIndex (where it was found)
+bool preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx){
+       return preambleSearchEx(BitStream, preamble, pLen, size, startIdx, false);
+}

 //by marshmellow
 //search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length
 //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)
+// param @findone:  look for a repeating preamble or only the first.
+// em4x05/4x69 only sends preamble once, so look for it once in the first pLen bits
+bool preambleSearchEx(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx, bool findone)

 {
 {

-       uint8_t foundCnt=0;
-       for (int idx=0; idx < *size - pLen; idx++){
+       // Sanity check.  If preamble length is bigger than bitstream length.
+       if ( *size <= pLen ) return false;
+       
+       uint8_t foundCnt = 0;
+       for (int idx = 0; idx < *size - pLen; idx++){

                if (memcmp(BitStream+idx, preamble, pLen) == 0){
                if (memcmp(BitStream+idx, preamble, pLen) == 0){

+                       if (g_debugMode) prnt("DEBUG: preamble found at %i", idx);

                        //first index found
                        foundCnt++;
                        if (foundCnt == 1){
                                *startIdx = idx;
                        //first index found
                        foundCnt++;
                        if (foundCnt == 1){
                                *startIdx = idx;

+                               if (findone) return true;

                        }
                        if (foundCnt == 2){
                                *size = idx - *startIdx;
                        }
                        if (foundCnt == 2){
                                *size = idx - *startIdx;

-                               return 1;
+                               return true;

                        }
                }
        }
                        }
                }
        }

-       return 0;
+       return false;
+}
+
+// find start of modulating data (for fsk and psk) in case of beginning noise or slow chip startup.
+size_t findModStart(uint8_t dest[], size_t size, uint8_t threshold_value, uint8_t expWaveSize) {
+       size_t i = 0;
+       size_t waveSizeCnt = 0;
+       uint8_t thresholdCnt = 0;
+       bool isAboveThreshold = dest[i++] >= threshold_value;
+       for (; i < size-20; i++ ) {
+               if(dest[i] < threshold_value && isAboveThreshold) {
+                       thresholdCnt++;
+                       if (thresholdCnt > 2 && waveSizeCnt < expWaveSize+1) break;                     
+                       isAboveThreshold = false;
+                       waveSizeCnt = 0;
+               } else if (dest[i] >= threshold_value && !isAboveThreshold) {
+                       thresholdCnt++;
+                       if (thresholdCnt > 2 && waveSizeCnt < expWaveSize+1) break;                     
+                       isAboveThreshold = true;
+                       waveSizeCnt = 0;
+               } else {
+                       waveSizeCnt++;
+               }
+               if (thresholdCnt > 10) break;
+       }
+       if (g_debugMode == 2) prnt("DEBUG: threshold Count reached at %u, count: %u",i, thresholdCnt);
+       return i;

 }
 
 //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

+// actually, no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future

 uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo)
 {
 uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo)
 {

-       //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
-       //  otherwise could be a void with no arguments
-       //set defaults
-       uint32_t i = 0;
-       if (BitStream[1]>1) return 0;  //allow only 1s and 0s
-
-       // 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;
+       // sanity check
+       if (BitStream[1] > 1) return 0; 
+       
+       uint8_t fmtlen;

        *startIdx = 0;
        *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]);
-               }
+       
+       // preamble 0111111111
+       // include 0 in front to help get start pos
+       uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1};
+       if (!preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx)) 
+               return 0;
+       if (*size < 64) return 0;
+       
+       fmtlen = (*size == 110) ? 22 : 10;
+
+       //skip last 4bit parity row for simplicity
+       *size = removeParity(BitStream, *startIdx + sizeof(preamble), 5, 0, fmtlen * 5);  
+       
+       switch (*size) {
+          case 40: { 
+           // std em410x format
+               *hi = 0;
+               *lo = ((uint64_t)(bytebits_to_byte(BitStream, 8)) << 32) | (bytebits_to_byte(BitStream + 8, 32));
+               break;
+           } 
+           case 88:  { 
+           // long em format
+               *hi = (bytebits_to_byte(BitStream, 24)); 
+               *lo = ((uint64_t)(bytebits_to_byte(BitStream + 24, 32)) << 32) | (bytebits_to_byte(BitStream + 24 + 32, 32));
+               break;
+           } 
+           default: return 0;
+       

        }
        }

-       if (errChk != 0) return 1;
-       //skip last 5 bit parity test for simplicity.
-       // *size = 64 | 128;
-       return 0;
+       return 1;

 }
 
 //by marshmellow
 }
 
 //by marshmellow


@@ -217,11 +255,12 @@ int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int
                        smplCnt++;
                } else { //transition
                        if ((BinStream[i] >= high && !waveHigh) || (BinStream[i] <= low && waveHigh)){
                        smplCnt++;
                } else { //transition
                        if ((BinStream[i] >= high && !waveHigh) || (BinStream[i] <= low && waveHigh)){

+

                                if (smplCnt > clk-(clk/4)-1) { //full clock
                                        if (smplCnt > clk + (clk/4)+1) { //too many samples
                                                errCnt++;
                                                if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
                                if (smplCnt > clk-(clk/4)-1) { //full clock
                                        if (smplCnt > clk + (clk/4)+1) { //too many samples
                                                errCnt++;
                                                if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);

-                                               BinStream[bitCnt++]=7;
+                                               BinStream[bitCnt++] = 7;

                                        } else if (waveHigh) {
                                                BinStream[bitCnt++] = invert;
                                                BinStream[bitCnt++] = invert;
                                        } else if (waveHigh) {
                                                BinStream[bitCnt++] = invert;
                                                BinStream[bitCnt++] = invert;


@@ -276,10 +315,11 @@ int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr
 {
        if (*size==0) return -1;
        int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default
 {
        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 (*clk==0 || start < 0) return -3;
        if (*invert != 1) *invert = 0;
        if (amp==1) askAmp(BinStream, *size);

-       if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d", *clk, start);
+       if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d, amp %d", *clk, start, amp);

 
        uint8_t initLoopMax = 255;
        if (initLoopMax > *size) initLoopMax = *size;
 
        uint8_t initLoopMax = 255;
        if (initLoopMax > *size) initLoopMax = *size;


@@ -296,8 +336,8 @@ int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr
                errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
                if (askType) //askman
                        return manrawdecode(BinStream, size, 0);        
                errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
                if (askType) //askman
                        return manrawdecode(BinStream, size, 0);        

-               else //askraw
-                       return errCnt;
+               //askraw
+               return errCnt;

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


@@ -344,38 +384,36 @@ int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr
        *size = bitnum;
        return errCnt;
 }
        *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, size_t *size, uint8_t invert)
-{
-       uint16_t bitnum=0, MaxBits = 512, errCnt = 0;
-       size_t i, ii;
-       uint16_t bestErr = 1000, bestRun = 0;
+int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert){
+       int errCnt = 0, bestErr = 1000;
+       uint16_t bitnum = 0, MaxBits = 512, bestRun = 0;
+       size_t i, k;

        if (*size < 16) return -1;
        //find correct start position [alignment]
        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])
+       for (k=0; k < 2; ++k){
+               for (i=k; i<*size-3; i += 2)
+                       if (BitStream[i] == BitStream[i+1])

                                errCnt++;
 
                                errCnt++;
 

-               if (bestErr>errCnt){
-                       bestErr=errCnt;
-                       bestRun=ii;
+               if (bestErr > errCnt){
+                       bestErr = errCnt;
+                       bestRun = k;

                }
                errCnt=0;
        }
        //decode
                }
                errCnt=0;
        }
        //decode

-       for (i=bestRun; i < *size-3; i+=2){
-               if(BitStream[i] == 1 && (BitStream[i+1] == 0)){
-                       BitStream[bitnum++]=invert;
-               } else if((BitStream[i] == 0) && BitStream[i+1] == 1){
-                       BitStream[bitnum++]=invert^1;
+       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 {
                } else {

-                       BitStream[bitnum++]=7;
+                       BitStream[bitnum++] = 7;

                }
                }

-               if(bitnum>MaxBits) break;
+               if (bitnum>MaxBits) break;

        }
        *size=bitnum;
        return bestErr;
        }
        *size=bitnum;
        return bestErr;


@@ -456,9 +494,11 @@ int gProxII_Demod(uint8_t BitStream[], size_t *size)
        size_t startIdx=0;
        uint8_t preamble[] = {1,1,1,1,1,0};
 
        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 (!preambleSearch(BitStream, preamble, sizeof(preamble), size, &startIdx)) 
+               return -3; //preamble not found
+

        if (*size != 96) return -2; //should have found 96 bits
        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
        //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


@@ -473,7 +513,6 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow
 {
        size_t last_transition = 0;
        size_t idx = 1;
 {
        size_t last_transition = 0;
        size_t idx = 1;

-       //uint32_t maxVal=0;

        if (fchigh==0) fchigh=10;
        if (fclow==0) fclow=8;
        //set the threshold close to 0 (graph) or 128 std to avoid static
        if (fchigh==0) fchigh=10;
        if (fclow==0) fclow=8;
        //set the threshold close to 0 (graph) or 128 std to avoid static


@@ -481,19 +520,22 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow
        size_t preLastSample = 0;
        size_t LastSample = 0;
        size_t currSample = 0;
        size_t preLastSample = 0;
        size_t LastSample = 0;
        size_t currSample = 0;

-       // sync to first lo-hi transition, and threshold
+       if ( size < 1024 ) return 0; // not enough samples
+
+       //find start of modulating data in trace 
+       idx = findModStart(dest, size, threshold_value, fchigh);

 
        // Need to threshold first sample
 
        // Need to threshold first sample

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

        else dest[0] = 1;
        else dest[0] = 1;

+       idx++;

 
        size_t numBits = 0;
        // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
        // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere
        // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
        //  (could also be fc/5 && fc/7 for fsk1 = 4-9)
 
        size_t numBits = 0;
        // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
        // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere
        // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
        //  (could also be fc/5 && fc/7 for fsk1 = 4-9)

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


@@ -508,13 +550,14 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow
                                //do nothing with extra garbage
                        } else if (currSample < (fchigh-1)) {           //6-8 = 8 sample waves  (or 3-6 = 5)
                                //correct previous 9 wave surrounded by 8 waves (or 6 surrounded by 5)
                                //do nothing with extra garbage
                        } else if (currSample < (fchigh-1)) {           //6-8 = 8 sample waves  (or 3-6 = 5)
                                //correct previous 9 wave surrounded by 8 waves (or 6 surrounded by 5)

-                               if (LastSample > (fchigh-2) && (preLastSample < (fchigh-1) || preLastSample     == 0 )){
+                               if (LastSample > (fchigh-2) && (preLastSample < (fchigh-1))){

                                        dest[numBits-1]=1;
                                }
                                dest[numBits++]=1;
 
                                        dest[numBits-1]=1;
                                }
                                dest[numBits++]=1;
 

-                       } else if (currSample > (fchigh) && !numBits) { //12 + and first bit = unusable garbage 
-                               //do nothing with beginning garbage
+                       } else if (currSample > (fchigh+1) && numBits < 3) { //12 + and first two bit = unusable garbage
+                               //do nothing with beginning garbage and reset..  should be rare..
+                               numBits = 0; 

                        } else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's (or 4 then a 6 should be two 5's)
                                dest[numBits++]=1;
                        } else {                                        //9+ = 10 sample waves (or 6+ = 7)
                        } else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's (or 4 then a 6 should be two 5's)
                                dest[numBits++]=1;
                        } else {                                        //9+ = 10 sample waves (or 6+ = 7)


@@ -537,7 +580,7 @@ size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen,
        uint32_t n=1;
        for( idx=1; idx < size; idx++) {
                n++;
        uint32_t n=1;
        for( idx=1; idx < size; idx++) {
                n++;

-               if (dest[idx]==lastval) continue; 
+               if (dest[idx]==lastval) continue; //skip until we hit a transition

                
                //find out how many bits (n) we collected
                //if lastval was 1, we have a 1->0 crossing
                
                //find out how many bits (n) we collected
                //if lastval was 1, we have a 1->0 crossing


@@ -582,15 +625,14 @@ int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32
 {
        if (justNoise(dest, *size)) return -1;
 
 {
        if (justNoise(dest, *size)) return -1;
 

-       size_t numStart=0, size2=*size, startIdx=0; 
+       size_t numStart=0, size2 = *size, startIdx=0; 

        // FSK demodulator
        *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
        if (*size < 96*2) return -2;
        // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
        uint8_t preamble[] = {0,0,0,1,1,1,0,1};
        // FSK demodulator
        *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
        if (*size < 96*2) return -2;
        // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
        uint8_t preamble[] = {0,0,0,1,1,1,0,1};

-       // find bitstring in array  
-       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
-       if (errChk == 0) return -3; //preamble not found
+       if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx)) 
+               return -3; //preamble not found

 
        numStart = startIdx + sizeof(preamble);
        // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
 
        numStart = startIdx + sizeof(preamble);
        // final loop, go over previously decoded FSK data and manchester decode into usable tag ID


@@ -601,10 +643,11 @@ int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32
                *hi2 = (*hi2<<1)|(*hi>>31);
                *hi = (*hi<<1)|(*lo>>31);
                //Then, shift in a 0 or one into low
                *hi2 = (*hi2<<1)|(*hi>>31);
                *hi = (*hi<<1)|(*lo>>31);
                //Then, shift in a 0 or one into low

+               *lo <<= 1;

                if (dest[idx] && !dest[idx+1])  // 1 0
                if (dest[idx] && !dest[idx+1])  // 1 0

-                       *lo=(*lo<<1)|1;
+                       *lo |= 1;

                else // 0 1
                else // 0 1

-                       *lo=(*lo<<1)|0;
+                       *lo |= 0;

        }
        return (int)startIdx;
 }
        }
        return (int)startIdx;
 }


@@ -614,16 +657,15 @@ int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, ui
 {
        if (justNoise(dest, *size)) return -1;
        
 {
        if (justNoise(dest, *size)) return -1;
        

-       size_t numStart=0, size2=*size, startIdx=0;
+       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};
        // 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
+       if (preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx)) 
+               return -3; //preamble not found

 
        numStart = startIdx + sizeof(preamble);
        // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
 
        numStart = startIdx + sizeof(preamble);
        // final loop, go over previously decoded FSK data and manchester decode into usable tag ID


@@ -660,8 +702,8 @@ int IOdemodFSK(uint8_t *dest, size_t size)
        //Handle the data
        size_t startIdx = 0;
        uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,1};
        //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 (! preambleSearch(dest, preamble, sizeof(preamble), &size, &startIdx))
+               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
 
        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


@@ -676,11 +718,11 @@ int IOdemodFSK(uint8_t *dest, size_t size)
 int VikingDemod_AM(uint8_t *dest, size_t *size) {
        //make sure buffer has data
        if (*size < 64*2) return -2;
 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};
        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
+       if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx)) 
+               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) ^ 
        uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^ 
                                                 bytebits_to_byte(dest+startIdx+8,8) ^ 
                                                 bytebits_to_byte(dest+startIdx+16,8) ^ 


@@ -692,34 +734,77 @@ int VikingDemod_AM(uint8_t *dest, size_t *size) {
        if ( checkCalc != 0xA8 ) return -5;     
        if (*size != 64) return -6;
        //return start position
        if ( checkCalc != 0xA8 ) return -5;     
        if (*size != 64) return -6;
        //return start position

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

 }
 
 }
 

+// by iceman
+// find Visa2000 preamble in already demoded data
+int Visa2kDemod_AM(uint8_t *dest, size_t *size) {
+       if (*size < 96) return -1; //make sure buffer has data
+       size_t startIdx = 0;
+       uint8_t preamble[] = {0,1,0,1,0,1,1,0,0,1,0,0,1,0,0,1,0,1,0,1,0,0,1,1,0,0,1,1,0,0,1,0};
+       if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
+               return -2; //preamble not found
+       if (*size != 96) return -3; //wrong demoded size
+       //return start position
+       return (int)startIdx;
+}
+// by iceman
+// find Noralsy preamble in already demoded data
+int NoralsyDemod_AM(uint8_t *dest, size_t *size) {
+       if (*size < 96) return -1; //make sure buffer has data
+       size_t startIdx = 0;
+       uint8_t preamble[] = {1,0,1,1,1,0,1,1,0,0,0,0};
+       if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
+               return -2; //preamble not found
+       if (*size != 96) return -3; //wrong demoded size
+       //return start position
+       return (int)startIdx;
+}

 // find presco preamble 0x10D in already demoded data
 int PrescoDemod(uint8_t *dest, size_t *size) {
 // find presco preamble 0x10D in already demoded data
 int PrescoDemod(uint8_t *dest, size_t *size) {

-       //make sure buffer has data
-       if (*size < 64*2) return -2;
-
+       if (*size < 128*2) return -1; //make sure buffer has data

        size_t startIdx = 0;
        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
+       uint8_t preamble[] = {0,0,0,1,0,0,0,0,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0};
+       if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
+               return -2; //preamble not found
+       if (*size != 128) return -3; //wrong demoded size

        //return start position
        //return start position

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

 }
 
 // Ask/Biphase Demod then try to locate an ISO 11784/85 ID
 // BitStream must contain previously askrawdemod and biphasedemoded data
 }
 
 // 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;
-
+int FDXBdemodBI(uint8_t *dest, size_t *size) {
+       if (*size < 128*2) return -1;   //make sure buffer has enough data

        size_t startIdx = 0;
        uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,1};
        size_t startIdx = 0;
        uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,1};

+       if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
+               return -2; //preamble not found
+       if (*size != 128) return -3; //wrong demoded size
+       //return start position
+       return (int)startIdx;
+}

 
 

-       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
-       if (errChk == 0) return -2; //preamble not found
+// ASK/Diphase fc/64 (inverted Biphase)
+// Note: this i s not a demod, this is only a detection
+// the parameter *dest needs to be demoded before call
+// 0xFFFF preamble, 64bits
+int JablotronDemod(uint8_t *dest, size_t *size){
+       if (*size < 64*2) return -1;    //make sure buffer has enough data
+       size_t startIdx = 0;
+       uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0};
+       if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx)) 
+               return -2; //preamble not found
+       if (*size != 64) return -3; // wrong demoded size
+       
+       uint8_t checkchksum = 0;
+       for (int i=16; i < 56; i += 8) {
+               checkchksum += bytebits_to_byte(dest+startIdx+i,8);
+       }
+       checkchksum ^= 0x3A;
+       uint8_t crc = bytebits_to_byte(dest+startIdx+56, 8);
+       if ( checkchksum != crc ) return -5;

        return (int)startIdx;
 }
 
        return (int)startIdx;
 }
 


@@ -738,8 +823,8 @@ int AWIDdemodFSK(uint8_t *dest, size_t *size)
 
        uint8_t preamble[] = {0,0,0,0,0,0,0,1};
        size_t startIdx = 0;
 
        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 (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
+               return -4; //preamble not found

        if (*size != 96) return -5;
        return (int)startIdx;
 }
        if (*size != 96) return -5;
        return (int)startIdx;
 }


@@ -757,16 +842,15 @@ int PyramiddemodFSK(uint8_t *dest, size_t *size)
        // FSK demodulator
        *size = fskdemod(dest, *size, 50, 1, 10, 8);  // fsk2a RF/50 
        if (*size < 128) return -2;  //did we get a good demod?
        // 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;
        size_t startIdx = 0;

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

        if (*size != 128) return -3;
        return (int)startIdx;
 }
 
        if (*size != 128) return -3;
        return (int)startIdx;
 }
 

-// find presco preamble 0x10D in already demoded data
+// find nedap preamble in already demoded data

 int NedapDemod(uint8_t *dest, size_t *size) {
        //make sure buffer has data
        if (*size < 128) return -3;
 int NedapDemod(uint8_t *dest, size_t *size) {
        //make sure buffer has data
        if (*size < 128) return -3;


@@ -774,8 +858,21 @@ int NedapDemod(uint8_t *dest, size_t *size) {
        size_t startIdx = 0;
        //uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,0,0,0,1};
        uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,0};
        size_t startIdx = 0;
        //uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,0,0,0,1};
        uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,0};

-       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
-       if (errChk == 0) return -4; //preamble not found
+       if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
+               return -4; //preamble not found
+       return (int) startIdx;
+}
+
+// Find IDTEC PSK1, RF  Preamble == 0x4944544B, Demodsize 64bits
+// by iceman
+int IdteckDemodPSK(uint8_t *dest, size_t *size) {
+       //make sure buffer has data
+       if (*size < 64*2) return -1;    
+       size_t startIdx = 0;
+       uint8_t preamble[] = {0,1,0,0,1,0,0,1,0,1,0,0,0,1,0,0,0,1,0,1,0,1,0,0,0,1,0,0,1,0,1,1};
+       if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
+               return -2; //preamble not found
+       if (*size != 64) return -3; // wrong demoded size

        return (int) startIdx;
 }
 
        return (int) startIdx;
 }
 


@@ -883,24 +980,28 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
        if (clockFnd>0) {
                clkCnt = clockFnd;
                clkEnd = clockFnd+1;
        if (clockFnd>0) {
                clkCnt = clockFnd;
                clkEnd = clockFnd+1;

+       } else {
+               clkCnt=1;

        }
        }

-       else clkCnt=1;

 
        //test each valid clock from smallest to greatest to see which lines up
 
        //test each valid clock from smallest to greatest to see which lines up

-       for(; clkCnt < clkEnd; clkCnt++){
-               if (clk[clkCnt] <= 32){
+       for(; clkCnt < clkEnd; clkCnt++) {
+               if (clk[clkCnt] <= 32) {

                        tol=1;
                        tol=1;

-               }else{
+               } else {

                        tol=0;
                }
                //if no errors allowed - keep start within the first clock
                        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;
+               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;
 
                //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;
+                       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){
                        // 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){


@@ -914,29 +1015,29 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
                        }
                        //if we found no errors then we can stop here and a low clock (common clocks)
                        //  this is correct one - return this clock
                        }
                        //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 (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 (!clockFnd) *clock = clk[clkCnt];
                                return ii;
                        }
                        //if we found errors see if it is lowest so far and save it as best run

-                       if(errCnt<bestErr[clkCnt]){
-                               bestErr[clkCnt]=errCnt;
-                               bestStart[clkCnt]=ii;
+                       if (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;
+       uint8_t k;
+       uint8_t best = 0;
+       for (k=1; k < clkEnd; ++k){
+               if (bestErr[k] < bestErr[best]){
+                       if (bestErr[k] == 0) bestErr[k]=1;

                        // current best bit to error ratio     vs  new bit to error ratio
                        // 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 ( (size/clk[best])/bestErr[best] < (size/clk[k])/bestErr[k] ){
+                               best = k;

                        }
                }
                        }
                }

-               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 (g_debugMode == 2) prnt("DEBUG ASK: clk %d, # Errors %d, Current Best Clk %d, bestStart %d", clk[k], bestErr[k], clk[best], bestStart[best]);

        }
        if (!clockFnd) *clock = clk[best];
        return bestStart[best];
        }
        if (!clockFnd) *clock = clk[best];
        return bestStart[best];


@@ -1189,36 +1290,32 @@ int DetectNRZClock(uint8_t dest[], size_t size, int clock)
 // by marshmellow
 // convert psk1 demod to psk2 demod
 // only transition waves are 1s
 // by marshmellow
 // convert psk1 demod to psk2 demod
 // only transition waves are 1s

-void psk1TOpsk2(uint8_t *BitStream, size_t size)
-{
-       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;
+void psk1TOpsk2(uint8_t *bits, size_t size) {
+       uint8_t lastBit = bits[0];
+       for (size_t i = 1; i < size; i++){
+               //ignore errors         
+               if (bits[i] == 7) continue;
+                       
+               if (lastBit != bits[i]){
+                       lastBit = bits[i];
+                       bits[i] = 1;

                } else {
                } else {

-                       BitStream[i]=0;
+                       bits[i] = 0;

                }
        }
                }
        }

-       return;

 }
 
 // by marshmellow
 // convert psk2 demod to psk1 demod
 // from only transition waves are 1s to phase shifts change bit
 }
 
 // by marshmellow
 // convert psk2 demod to psk1 demod
 // from only transition waves are 1s to phase shifts change bit

-void psk2TOpsk1(uint8_t *BitStream, size_t size)
-{
-       uint8_t phase=0;
-       for (size_t i=0; i<size; i++){
-               if (BitStream[i]==1){
-                       phase ^=1;
+void psk2TOpsk1(uint8_t *bits, size_t size) {
+       uint8_t phase = 0;
+       for (size_t i = 0; i < size; i++){
+               if (bits[i] == 1){
+                       phase ^= 1;

                }
                }

-               BitStream[i]=phase;
+               bits[i] = phase;

        }
        }

-       return;

 }
 
 // redesigned by marshmellow adjusted from existing decode functions
 }
 
 // redesigned by marshmellow adjusted from existing decode functions


@@ -1295,7 +1392,7 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc
        fcCounter=0;
        rfCounter=0;
        firstBitFnd=0;
        fcCounter=0;
        rfCounter=0;
        firstBitFnd=0;

-       //PrintAndLog("DEBUG: fcTol: %d",fcTol);
+       //prnt("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])
        // 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])


@@ -1309,7 +1406,10 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc
                        continue;               
                // else new peak 
                // if we got less than the small fc + tolerance then set it to the small fc
                        continue;               
                // else new peak 
                // if we got less than the small fc + tolerance then set it to the small fc

-               if (fcCounter < fcLow+fcTol) 
+               // if it is inbetween set it to the last counter
+               if (fcCounter < fcHigh && fcCounter > fcLow)
+                       fcCounter = lastFCcnt;
+               else if (fcCounter < fcLow+fcTol) 

                        fcCounter = fcLow;
                else //set it to the large fc
                        fcCounter = fcHigh;
                        fcCounter = fcLow;
                else //set it to the large fc
                        fcCounter = fcHigh;


@@ -1326,7 +1426,7 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc
                                        }
                                }
                                if (rfCounter > 0 && rfLensFnd < 15){
                                        }
                                }
                                if (rfCounter > 0 && rfLensFnd < 15){

-                                       //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
+                                       //prnt("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);

                                        rfCnts[rfLensFnd]++;
                                        rfLens[rfLensFnd++] = rfCounter;
                                }
                                        rfCnts[rfLensFnd]++;
                                        rfLens[rfLensFnd++] = rfCounter;
                                }


@@ -1375,7 +1475,7 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc
                }
        }
 
                }
        }
 

-       if (ii<0) return 0; // oops we went too far
+       if (ii<2) return 0; // oops we went too far

 
        return clk[ii];
 }
 
        return clk[ii];
 }


@@ -1389,10 +1489,10 @@ 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 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 lastFCcnt = 0;

        uint8_t fcCounter = 0;
        size_t i;
        uint8_t fcCounter = 0;
        size_t i;

-       if (size == 0) return 0;
+       if (size < 180) return 0;

 
        // prime i to first up transition
        for (i = 160; i < size-20; i++)
 
        // prime i to first up transition
        for (i = 160; i < size-20; i++)


@@ -1479,27 +1579,37 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
 
        size_t numBits=0;
        uint8_t curPhase = *invert;
 
        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);
+       size_t i=0, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0;
+       uint16_t fc=0, fullWaveLen=0, tol=1;
+       uint16_t errCnt=0, waveLenCnt=0, errCnt2=0;
+       fc = countFC(dest, *size, 1);
+       uint8_t fc2 = fc >> 8;
+       if (fc2 == 10) return -1; //fsk found - quit
+       fc = fc & 0xFF;

        if (fc!=2 && fc!=4 && fc!=8) return -1;
        if (fc!=2 && fc!=4 && fc!=8) return -1;

-       //PrintAndLog("DEBUG: FC: %d",fc);
+       //prnt("DEBUG: FC: %d",fc);

        *clock = DetectPSKClock(dest, *size, *clock);
        if (*clock == 0) return -1;
        *clock = DetectPSKClock(dest, *size, *clock);
        if (*clock == 0) return -1;

-       int avgWaveVal=0, lastAvgWaveVal=0;
+
+       //find start of modulating data in trace 
+       uint8_t threshold_value = 123; //-5
+       i = findModStart(dest, *size, threshold_value, fc);
+

        //find first phase shift
        //find first phase shift

-       for (i=0; i<loopCnt; i++){
+       int avgWaveVal=0, lastAvgWaveVal=0;
+       waveStart = i;
+       for (; i<loopCnt; i++){
+               // find peak 

                if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
                        waveEnd = i+1;
                if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
                        waveEnd = i+1;

-                       //PrintAndLog("DEBUG: waveEnd: %d",waveEnd);
+                       if (g_debugMode == 2) prnt("DEBUG PSK: waveEnd: %u, waveStart: %u",waveEnd, waveStart);

                        waveLenCnt = waveEnd-waveStart;
                        waveLenCnt = waveEnd-waveStart;

-                       if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+2)){ //not first peak and is a large wave but not out of whack
+                       if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+3)){ //not first peak and is a large wave but not out of whack

                                lastAvgWaveVal = avgWaveVal/(waveLenCnt);
                                firstFullWave = waveStart;
                                fullWaveLen=waveLenCnt;
                                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
+                               //if average wave value is > graph 0 then it is an up wave or a 1 (could cause inverting)
+                               if (lastAvgWaveVal > threshold_value) curPhase ^= 1;

                                break;
                        } 
                        waveStart = i+1;
                                break;
                        } 
                        waveStart = i+1;


@@ -1520,7 +1630,7 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
        //set start of wave as clock align
        lastClkBit = firstFullWave;
        if (g_debugMode==2) prnt("DEBUG PSK: firstFullWave: %u, waveLen: %u",firstFullWave,fullWaveLen);  
        //set start of wave as clock align
        lastClkBit = firstFullWave;
        if (g_debugMode==2) prnt("DEBUG PSK: firstFullWave: %u, waveLen: %u",firstFullWave,fullWaveLen);  

-       if (g_debugMode==2) prnt("DEBUG: clk: %d, lastClkBit: %u, fc: %u", *clock, lastClkBit,(unsigned int) fc);
+       if (g_debugMode==2) prnt("DEBUG PSK: clk: %d, lastClkBit: %u, fc: %u", *clock, lastClkBit,(unsigned int) fc);

        waveStart = 0;
        dest[numBits++] = curPhase; //set first read bit
        for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){
        waveStart = 0;
        dest[numBits++] = curPhase; //set first read bit
        for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){


@@ -1535,9 +1645,9 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
                                waveLenCnt = waveEnd-waveStart;
                                lastAvgWaveVal = avgWaveVal/waveLenCnt;
                                if (waveLenCnt > fc){  
                                waveLenCnt = waveEnd-waveStart;
                                lastAvgWaveVal = avgWaveVal/waveLenCnt;
                                if (waveLenCnt > fc){  

-                                       //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);
+                                       //prnt("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);

                                        //this wave is a phase shift
                                        //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);
+                                       //prnt("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;
                                        if (i+1 >= lastClkBit + *clock - tol){ //should be a clock bit
                                                curPhase ^= 1;
                                                dest[numBits++] = curPhase;


@@ -1551,6 +1661,9 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
                                } else if (i+1 > lastClkBit + *clock + tol + fc){
                                        lastClkBit += *clock; //no phase shift but clock bit
                                        dest[numBits++] = curPhase;
                                } else if (i+1 > lastClkBit + *clock + tol + fc){
                                        lastClkBit += *clock; //no phase shift but clock bit
                                        dest[numBits++] = curPhase;

+                               } else if (waveLenCnt < fc - 1) { //wave is smaller than field clock (shouldn't happen often)
+                                       errCnt2++;
+                                       if(errCnt2 > 101) return errCnt2;

                                }
                                avgWaveVal = 0;
                                waveStart = i+1;
                                }
                                avgWaveVal = 0;
                                waveStart = i+1;


@@ -1572,13 +1685,15 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
        int tol = 0;
        int i, j, skip, start, end, low, high, minClk, waveStart;
        bool complete = false;
        int tol = 0;
        int i, j, skip, start, end, low, high, minClk, waveStart;
        bool complete = false;

-       int tmpbuff[bufsize / 64];
-       int waveLen[bufsize / 64];
+       int tmpbuff[bufsize / 32]; //guess rf/32 clock, if click is smaller we will only have room for a fraction of the samples captured
+       int waveLen[bufsize / 32]; //  if clock is larger then we waste memory in array size that is not needed...

        size_t testsize = (bufsize < 512) ? bufsize : 512;
        int phaseoff = 0;
        high = low = 128;
        memset(tmpbuff, 0, sizeof(tmpbuff));
        size_t testsize = (bufsize < 512) ? bufsize : 512;
        int phaseoff = 0;
        high = low = 128;
        memset(tmpbuff, 0, sizeof(tmpbuff));

+       memset(waveLen, 0, sizeof(waveLen));

 
 

+       

        if ( getHiLo(buffer, testsize, &high, &low, 80, 80) == -1 ) {
                if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting");
                return false; //just noise
        if ( getHiLo(buffer, testsize, &high, &low, 80, 80) == -1 ) {
                if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting");
                return false; //just noise


@@ -1605,7 +1720,7 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
                waveStart = i;
                while ((buffer[i] > low) && (i < bufsize))
                        ++i;
                waveStart = i;
                while ((buffer[i] > low) && (i < bufsize))
                        ++i;

-               if (j >= (bufsize/64)) {
+               if (j >= (bufsize/32)) {

                        break;
                }
                waveLen[j] = i - waveStart; //first high to first low
                        break;
                }
                waveLen[j] = i - waveStart; //first high to first low


@@ -1651,6 +1766,8 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
        if (start < 0) {
                if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting");
                return false;
        if (start < 0) {
                if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting");
                return false;

+       } else {
+               if (g_debugMode==2) prnt("DEBUG STT: first STT found at: %d, j=%d",start, j);

        }
        if (waveLen[i+2] > clk*1+tol)
                phaseoff = 0;
        }
        if (waveLen[i+2] > clk*1+tol)
                phaseoff = 0;


@@ -1664,7 +1781,7 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
        end = skip;
        for (i += 3; i < j - 4; ++i) {
                end += tmpbuff[i];
        end = skip;
        for (i += 3; i < j - 4; ++i) {
                end += tmpbuff[i];

-               if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol) {           //1 to 2 clocks depending on 2 bits prior
+               if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol && waveLen[i] < clk+tol) {           //1 to 2 clocks depending on 2 bits prior

                        if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) {       //2 clocks and wave size is 1 1/2
                                if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave
                                        if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit
                        if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) {       //2 clocks and wave size is 1 1/2
                                if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave
                                        if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit


@@ -1686,12 +1803,15 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
        start = skip;
        size_t datalen = end - start;
        // check validity of datalen (should be even clock increments)  - use a tolerance of up to 1/8th a clock
        start = skip;
        size_t datalen = end - start;
        // check validity of datalen (should be even clock increments)  - use a tolerance of up to 1/8th a clock

-       if (datalen % clk > clk/8) {
+       if ( clk - (datalen % clk) <= clk/8) {
+               // padd the amount off - could be problematic...  but shouldn't happen often
+               datalen += clk - (datalen % clk);
+       } else if ( (datalen % clk) <= clk/8 ) {
+               // padd the amount off - could be problematic...  but shouldn't happen often
+               datalen -= datalen % clk;
+       } else {

                if (g_debugMode==2) prnt("DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting", datalen, clk, datalen % clk);
                return false;
                if (g_debugMode==2) prnt("DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting", datalen, clk, datalen % clk);
                return false;

-       } else {
-               // padd the amount off - could be problematic...  but shouldn't happen often
-               datalen += datalen % clk;

        }
        // if datalen is less than one t55xx block - ERROR
        if (datalen/clk < 8*4) {
        }
        // if datalen is less than one t55xx block - ERROR
        if (datalen/clk < 8*4) {


@@ -1699,8 +1819,20 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
                return false;
        }
        size_t dataloc = start;
                return false;
        }
        size_t dataloc = start;

+       if (buffer[dataloc-(clk*4)-(clk/8)] <= low && buffer[dataloc] <= low && buffer[dataloc-(clk*4)] >= high) {
+               //we have low drift (and a low just before the ST and a low just after the ST) - compensate by backing up the start 
+               for ( i=0; i <= (clk/8); ++i ) {
+                       if ( buffer[dataloc - (clk*4) - i] <= low ) {
+                               dataloc -= i;
+                               break;
+                       }
+               }
+       }
+       

        size_t newloc = 0;
        i=0;
        size_t newloc = 0;
        i=0;

+       if (g_debugMode==2) prnt("DEBUG STT: Starting STT trim - start: %d, datalen: %d ",dataloc, datalen);            
+

        // warning - overwriting buffer given with raw wave data with ST removed...
        while ( dataloc < bufsize-(clk/2) ) {
                //compensate for long high at end of ST not being high due to signal loss... (and we cut out the start of wave high part)
        // warning - overwriting buffer given with raw wave data with ST removed...
        while ( dataloc < bufsize-(clk/2) ) {
                //compensate for long high at end of ST not being high due to signal loss... (and we cut out the start of wave high part)


@@ -1719,6 +1851,7 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
                }
                newloc += i;
                //skip next ST  -  we just assume it will be there from now on...
                }
                newloc += i;
                //skip next ST  -  we just assume it will be there from now on...

+               if (g_debugMode==2) prnt("DEBUG STT: skipping STT at %d to %d", dataloc, dataloc+(clk*4));

                dataloc += clk*4;
        }
        *size = newloc;
                dataloc += clk*4;
        }
        *size = newloc;