CHG: `data plot`- the marking of clock, looks better without borders. It only connec...

[proxmark3-svn] / common / lfdemod.c

diff --git a/common/lfdemod.c b/common/lfdemod.c
index 21695ec16136959ffed4bd4c87a3044548a01a1d..61d01c27588f93bdeab20ef70a5e1b77d6b91dec 100644 (file)
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -74,7 +74,7 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p
                        parityWd = (parityWd << 1) | BitStream[startIdx+word+bit];
                        BitStream[j++] = (BitStream[startIdx+word+bit]);
                }
                        parityWd = (parityWd << 1) | BitStream[startIdx+word+bit];
                        BitStream[j++] = (BitStream[startIdx+word+bit]);
                }

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

 
                j--; // overwrite parity with next data
                // if parity fails then return 0
 
                j--; // overwrite parity with next data
                // if parity fails then return 0


@@ -158,7 +158,7 @@ bool preambleSearchEx(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t
        uint8_t foundCnt = 0;
        for (int idx = 0; idx < *size - pLen; idx++){
                if (memcmp(BitStream+idx, preamble, pLen) == 0){
        uint8_t foundCnt = 0;
        for (int idx = 0; idx < *size - pLen; idx++){
                if (memcmp(BitStream+idx, preamble, pLen) == 0){

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

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


@@ -203,45 +203,50 @@ size_t findModStart(uint8_t dest[], size_t size, uint8_t threshold_value, uint8_
 //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
 //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)
+int Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo)

 {
 {

-       //allow only 1s and 0s
-       // only checking first bitvalue?!
-       if (BitStream[1] > 1) return 0; 
+       // sanity check
+       if (*size < 64) return -3;      
+       if (BitStream[1] > 1) return -1; 

        
        

-       uint32_t i = 0, idx = 0, parityBits = 0;
-       uint8_t fmtlen = 0;
+       uint8_t fmtlen;

        *startIdx = 0;
        
        // preamble 0111111111
        // include 0 in front to help get start pos
        uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1};
        *startIdx = 0;
        
        // 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;
+       if (!preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx))
+               return -2;
+
+       //XL and normal size.
+       if (*size != 64 && *size != 128) return -3;

        
        

-       fmtlen = (*size > 64) ? 22 : 10;
+       fmtlen = (*size == 128) ? 22 : 10;

 
 

-       idx = *startIdx + sizeof(preamble);
+       //skip last 4bit parity row for simplicity
+       *size = removeParity(BitStream, *startIdx + sizeof(preamble), 5, 0, fmtlen * 5);  

        
        

-       //loop through 10 or 22 sets of 5 bits (50-10p = 40 bits or 88 bits)
-       for (i=0; i < fmtlen; i++){ 
-               parityBits = bytebits_to_byte(BitStream + (i*5) + idx, 5);
-               //check even parity
-               if (parityTest(parityBits, 5, 0) == 0) return 0;
-               //set uint64 with ID from BitStream
-               for (uint8_t j = 0; j < 4; j++){
-                       *hi = (*hi << 1) | (*lo >> 63);
-                       *lo = (*lo << 1) | (BitStream[(i*5) + j + idx]);
-               }
+       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 -4; 

        }
        }

-       //skip last 5 bit parity test for simplicity.
-       // *size = 64 | 128;

        return 1;
 }
 
 //by marshmellow
 //demodulates strong heavily clipped samples
        return 1;
 }
 
 //by marshmellow
 //demodulates strong heavily clipped samples

+//RETURN: num of errors.  if 0, is ok.

 int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low)
 {
        size_t bitCnt=0, smplCnt=0, errCnt=0;
 int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low)
 {
        size_t bitCnt=0, smplCnt=0, errCnt=0;


@@ -385,25 +390,30 @@ int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr
 //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){
+int manrawdecode(uint8_t *BitStream, size_t *size, uint8_t invert){
+
+       // sanity check
+       if (*size < 16) return -1;
+       

        int errCnt = 0, bestErr = 1000;
        uint16_t bitnum = 0, MaxBits = 512, bestRun = 0;
        size_t i, k;
        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]
        //find correct start position [alignment]

-       for (k=0; k < 2; ++k){
-               for (i=k; i<*size-3; i += 2)
+       for (k = 0; k < 2; ++k){
+               for (i = k; i < *size-3; i += 2) {

                        if (BitStream[i] == BitStream[i+1])
                                errCnt++;
                        if (BitStream[i] == BitStream[i+1])
                                errCnt++;

-
+               }

                if (bestErr > errCnt){
                        bestErr = errCnt;
                        bestRun = k;
                }
                if (bestErr > errCnt){
                        bestErr = errCnt;
                        bestRun = k;
                }

-               errCnt=0;
+               errCnt = 0;

        }
        }

+       

        //decode
        //decode

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


@@ -411,9 +421,9 @@ int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert){
                } else {
                        BitStream[bitnum++] = 7;
                }
                } else {
                        BitStream[bitnum++] = 7;
                }

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

        }
        }

-       *size=bitnum;
+       *size = bitnum;

        return bestErr;
 }
 
        return bestErr;
 }
 


@@ -930,6 +940,10 @@ int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low)
        }
        return 0;
 }
        }
        return 0;
 }

+void SetGraphClock( int clock, int startidx){
+       PlotClock = clock;
+       PlockClockStartIndex = startidx;        
+}

 
 // by marshmellow
 // not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)
 
 // by marshmellow
 // not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)


@@ -937,15 +951,15 @@ int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low)
 // 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)
 {
 // 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;
+       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...
        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
+       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
        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)
+       uint8_t clockFnd = 0;
+       for (; i < clkEnd; ++i)

                if (clk[i] == *clock) clockFnd = i;
                //clock found but continue to find best startpos
 
                if (clk[i] == *clock) clockFnd = i;
                //clock found but continue to find best startpos
 


@@ -975,15 +989,15 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
        size_t errCnt = 0;
        size_t arrLoc, loopEnd;
 
        size_t errCnt = 0;
        size_t arrLoc, loopEnd;
 

-       if (clockFnd>0) {
+       if (clockFnd > 0) {

                clkCnt = clockFnd;
                clkEnd = clockFnd+1;
        } else {
                clkCnt = clockFnd;
                clkEnd = clockFnd+1;
        } else {

-               clkCnt=1;
+               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++) {
+       for (; clkCnt < clkEnd; clkCnt++) {

                if (clk[clkCnt] <= 32) {
                        tol=1;
                } else {
                if (clk[clkCnt] <= 32) {
                        tol=1;
                } else {


@@ -1016,6 +1030,8 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
                        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];
                        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];

+                               
+                               SetGraphClock(*clock, ii);

                                return ii;
                        }
                        //if we found errors see if it is lowest so far and save it as best run
                                return ii;
                        }
                        //if we found errors see if it is lowest so far and save it as best run


@@ -1038,6 +1054,8 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
                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];
                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];

+       
+       SetGraphClock(*clock, bestStart[best]);

        return bestStart[best];
 }
 
        return bestStart[best];
 }
 


@@ -1046,27 +1064,30 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
 // a phase shift is determined by measuring the sample length of each wave
 int DetectPSKClock(uint8_t dest[], size_t size, int clock)
 {
 // a phase shift is determined by measuring the sample length of each wave
 int DetectPSKClock(uint8_t dest[], size_t size, int clock)
 {

-       uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock
+       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...
        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;
 
        //if we already have a valid clock quit
        size_t i=1;
        for (; i < 8; ++i)
                if (clk[i] == clock) return clock;

+       
+       if (size < 160+20) return 0;
+       
+       // size must be larger than 20 here, and 160 later on.
+       if (size < loopCnt) loopCnt = size-20;

 
        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;
 
        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};
+       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
        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++){
+       for (i=160; i < loopCnt; i++){

                if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
                        if (waveStart == 0) {
                                waveStart = i+1;
                if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
                        if (waveStart == 0) {
                                waveStart = i+1;


@@ -1084,10 +1105,10 @@ int DetectPSKClock(uint8_t dest[], size_t size, int clock)
                        }
                }
        }
                        }
                }
        }

-       if (g_debugMode ==2) prnt("DEBUG PSK: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);
+       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
        
        //test each valid clock from greatest to smallest to see which lines up

-       for(clkCnt=7; clkCnt >= 1 ; clkCnt--){
+       for (clkCnt=7; clkCnt >= 1 ; clkCnt--){

                lastClkBit = firstFullWave; //set end of wave as clock align
                waveStart = 0;
                errCnt=0;
                lastClkBit = firstFullWave; //set end of wave as clock align
                waveStart = 0;
                errCnt=0;


@@ -1121,19 +1142,17 @@ int DetectPSKClock(uint8_t dest[], size_t size, int clock)
                                }
                        }
                }
                                }
                        }
                }

-               if (errCnt == 0){
-                       return clk[clkCnt];
-               }
-               if (errCnt <= bestErr[clkCnt]) bestErr[clkCnt]=errCnt;
-               if (peakcnt > peaksdet[clkCnt]) peaksdet[clkCnt]=peakcnt;
+               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
        } 
        //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]) {
+       uint8_t best = 7;
+       for (i=7; i >= 1; i--){
+               if (peaksdet[i] > peaksdet[best])

                        best = i;
                        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];
                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];


@@ -1170,16 +1189,20 @@ int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low){
 
 //by marshmellow
 //detect nrz clock by reading #peaks vs no peaks(or errors)
 
 //by marshmellow
 //detect nrz clock by reading #peaks vs no peaks(or errors)

+//iceman: shouldn't param clock be reference?  like DetectASKClock

 int DetectNRZClock(uint8_t dest[], size_t size, int clock)
 {
 int DetectNRZClock(uint8_t dest[], size_t size, int clock)
 {

-       size_t i=0;
-       uint8_t clk[]={8,16,32,40,50,64,100,128,255};
+       size_t 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...
        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;
        //if we already have a valid clock quit
        for (; i < 8; ++i)
                if (clk[i] == clock) return clock;

+       
+       if (size < 20) return 0;
+       // size must be larger than 20 here
+       if (size < loopCnt) loopCnt = size-20;

 
        //get high and low peak
        int peak, low;
 
        //get high and low peak
        int peak, low;


@@ -1200,7 +1223,7 @@ int DetectNRZClock(uint8_t dest[], size_t size, int clock)
                        if (!firstpeak) continue;
                        smplCnt++;
                } else {
                        if (!firstpeak) continue;
                        smplCnt++;
                } else {

-                       firstpeak=true;
+                       firstpeak = true;

                        if (smplCnt > 6 ){
                                if (maxPeak > smplCnt){
                                        maxPeak = smplCnt;
                        if (smplCnt > 6 ){
                                if (maxPeak > smplCnt){
                                        maxPeak = smplCnt;


@@ -1208,7 +1231,7 @@ int DetectNRZClock(uint8_t dest[], size_t size, int clock)
                                }
                                peakcnt++;
                                //prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt);
                                }
                                peakcnt++;
                                //prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt);

-                               smplCnt=0;
+                               smplCnt = 0;

                        }
                }
        }
                        }
                }
        }


@@ -1218,7 +1241,7 @@ int DetectNRZClock(uint8_t dest[], size_t size, int clock)
        uint8_t ignoreWindow = 4;
        bool lastPeakHigh = 0;
        int lastBit = 0; 
        uint8_t ignoreWindow = 4;
        bool lastPeakHigh = 0;
        int lastBit = 0; 

-       peakcnt=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
        //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


@@ -1238,7 +1261,7 @@ int DetectNRZClock(uint8_t dest[], size_t size, int clock)
                                                if (dest[i] >= peak || dest[i] <= low) {
                                                        //if same peak don't count it
                                                        if ((dest[i] >= peak && !lastPeakHigh) || (dest[i] <= low && lastPeakHigh)) {
                                                if (dest[i] >= peak || dest[i] <= low) {
                                                        //if same peak don't count it
                                                        if ((dest[i] >= peak && !lastPeakHigh) || (dest[i] <= low && lastPeakHigh)) {

-                                               peakcnt++;
+                                                               peakcnt++;

                                                        }
                                                        lastPeakHigh = (dest[i] >= peak);
                                                        bitHigh = true;
                                                        }
                                                        lastPeakHigh = (dest[i] >= peak);
                                                        bitHigh = true;


@@ -1250,9 +1273,10 @@ int DetectNRZClock(uint8_t dest[], size_t size, int clock)
                                                }
                                        //else if not a clock bit and no peaks
                                        } else if (dest[i] < peak && dest[i] > low){
                                                }
                                        //else if not a clock bit and no peaks
                                        } else if (dest[i] < peak && dest[i] > low){

-                                               if (ignoreCnt==0){
+                                               if (ignoreCnt == 0){

                                                        bitHigh=false;
                                                        bitHigh=false;

-                                                       if (errBitHigh==true) peakcnt--;
+                                                       if (errBitHigh==true) 
+                                                               peakcnt--;

                                                        errBitHigh=false;
                                                } else {
                                                        ignoreCnt--;
                                                        errBitHigh=false;
                                                } else {
                                                        ignoreCnt--;


@@ -1263,23 +1287,23 @@ int DetectNRZClock(uint8_t dest[], size_t size, int clock)
                                                errBitHigh=true;
                                        }
                                }
                                                errBitHigh=true;
                                        }
                                }

-                               if(peakcnt>peaksdet[clkCnt]) {
-                                       peaksdet[clkCnt]=peakcnt;
+                               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;
+
+       uint8_t best = 0;
+       for (int m = 7; m > 0; m--){
+               if ((peaksdet[m] >= (peaksdet[best]-1)) && (peaksdet[m] <= peaksdet[best]+1) && lowestTransition) {
+                       if (clk[m] > (lowestTransition - (clk[m]/8)) && clk[m] < (lowestTransition + (clk[m]/8))) {
+                               best = m;
+                       }
+               } else if (peaksdet[m] > peaksdet[best]){
+                       best = m;

                }
                }

-               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);
+               if (g_debugMode==2) prnt("DEBUG NRZ: Clk: %d, peaks: %d, maxPeak: %d, bestClk: %d, lowestTrs: %d", clk[m], peaksdet[m], maxPeak, clk[best], lowestTransition);

        }
 
        return clk[best];
        }
 
        return clk[best];


@@ -1673,9 +1697,14 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
        return errCnt;
 }
 
        return errCnt;
 }
 

+bool DetectST(uint8_t  buffer[], size_t *size, int *foundclock) {
+       size_t ststart = 0, stend = 0;
+       return DetectST_ext(buffer, size, foundclock, &ststart, &stend);
+}
+

 //by marshmellow
 //attempt to identify a Sequence Terminator in ASK modulated raw wave
 //by marshmellow
 //attempt to identify a Sequence Terminator in ASK modulated raw wave

-bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
+bool DetectST_ext(uint8_t buffer[], size_t *size, int *foundclock, size_t *ststart, size_t *stend) {

        size_t bufsize = *size;
        //need to loop through all samples and identify our clock, look for the ST pattern
        uint8_t fndClk[] = {8,16,32,40,50,64,128};
        size_t bufsize = *size;
        //need to loop through all samples and identify our clock, look for the ST pattern
        uint8_t fndClk[] = {8,16,32,40,50,64,128};


@@ -1830,7 +1859,7 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
        size_t newloc = 0;
        i=0;
        if (g_debugMode==2) prnt("DEBUG STT: Starting STT trim - start: %d, datalen: %d ",dataloc, datalen);            
        size_t newloc = 0;
        i=0;
        if (g_debugMode==2) prnt("DEBUG STT: Starting STT trim - start: %d, datalen: %d ",dataloc, datalen);            

-
+       bool firstrun = true;

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


@@ -1838,6 +1867,15 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
                        for(i=0; i < clk/2-tol; ++i) {
                                buffer[dataloc+i] = high+5;
                        }
                        for(i=0; i < clk/2-tol; ++i) {
                                buffer[dataloc+i] = high+5;
                        }

+               } //test for single sample outlier (high between two lows) in the case of very strong waves
+               if (buffer[dataloc] >= high && buffer[dataloc+2] <= low) {
+                       buffer[dataloc] = buffer[dataloc+2];
+                       buffer[dataloc+1] = buffer[dataloc+2];
+               }
+               if (firstrun) {
+                       *stend = dataloc;
+                       *ststart = dataloc-(clk*4);
+                       firstrun=false;

                }
                for (i=0; i<datalen; ++i) {
                        if (i+newloc < bufsize) {
                }
                for (i=0; i<datalen; ++i) {
                        if (i+newloc < bufsize) {