ADD: `analyse nuid` - generates NUID 4byte from a UID 7byte. Mifare Classic Ev1...

[proxmark3-svn] / common / lfdemod.c

diff --git a/common/lfdemod.c b/common/lfdemod.c
index ca126df32c696f7be98961c642dd0159397e07b7..797bce40638e805cbffd55ec43a7da312b52b187 100644 (file)
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -11,23 +11,29 @@
 
 //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, ...){}

-
+void dummy_sgc (int clock, int startidx) {}

 
 #ifndef ON_DEVICE
 
 #ifndef ON_DEVICE

-# include "ui.h"
+# include "ui.h"                // plotclock, plotclockstartindex

 # include "cmdparser.h"
 # include "cmddata.h"
 # define prnt PrintAndLog
 # include "cmdparser.h"
 # include "cmddata.h"
 # define prnt PrintAndLog

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

 #else 
 #else 

-       uint8_t g_debugMode=0;
+  uint8_t g_debugMode = 0;

 # define prnt dummy
 # define prnt dummy

+# define sgc dummy_sgc

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

                val = bits[idx] < THRESHOLD;
        return val;
 }
                val = bits[idx] < THRESHOLD;
        return val;
 }


@@ -203,10 +209,11 @@ 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)

 {
        // sanity check
 {
        // sanity check

-       if (BitStream[1] > 1) return 0; 
+       if (*size < 64) return -3;      
+       if (BitStream[1] > 1) return -1; 

        
        uint8_t fmtlen;
        *startIdx = 0;
        
        uint8_t fmtlen;
        *startIdx = 0;


@@ -214,11 +221,13 @@ uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_
        // preamble 0111111111
        // include 0 in front to help get start pos
        uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1};
        // 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 == 110) ? 22 : 10;
+       fmtlen = (*size == 128) ? 22 : 10;

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


@@ -236,14 +245,14 @@ uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_
                *lo = ((uint64_t)(bytebits_to_byte(BitStream + 24, 32)) << 32) | (bytebits_to_byte(BitStream + 24 + 32, 32));
                break;
            } 
                *lo = ((uint64_t)(bytebits_to_byte(BitStream + 24, 32)) << 32) | (bytebits_to_byte(BitStream + 24 + 32, 32));
                break;
            } 

-           default: return 0;
-       
+           default: return -4; 

        }
        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;


@@ -315,12 +324,13 @@ 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 (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d, amp %d", *clk, start, amp);
 
        if (*clk==0 || start < 0) return -3;
        if (*invert != 1) *invert = 0;
        if (amp==1) askAmp(BinStream, *size);
        if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d, amp %d", *clk, start, amp);
 

+       sgc(*clk, start);
+               

        uint8_t initLoopMax = 255;
        if (initLoopMax > *size) initLoopMax = *size;
        // Detect high and lows
        uint8_t initLoopMax = 255;
        if (initLoopMax > *size) initLoopMax = *size;
        // Detect high and lows


@@ -387,25 +397,30 @@ 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){


@@ -413,9 +428,9 @@ 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;
 }
 


@@ -898,13 +913,14 @@ uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t lo
 // by marshmellow
 // to help detect clocks on heavily clipped samples
 // based on count of low to low
 // by marshmellow
 // to help detect clocks on heavily clipped samples
 // based on count of low to low

-int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low)
+int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low, int *clock)

 {
 {

-       uint8_t fndClk[] = {8,16,32,40,50,64,128};
+       uint8_t clocks[] = {8,16,32,40,50,64,128};

        size_t startwave;
        size_t i = 100;
        size_t minClk = 255;
        size_t startwave;
        size_t i = 100;
        size_t minClk = 255;

-               // get to first full low to prime loop and skip incomplete first pulse
+       int shortestWaveIdx = 0;
+       // get to first full low to prime loop and skip incomplete first pulse

        while ((dest[i] < high) && (i < size))
                ++i;
        while ((dest[i] > low) && (i < size))
        while ((dest[i] < high) && (i < size))
                ++i;
        while ((dest[i] > low) && (i < size))


@@ -921,14 +937,18 @@ int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low)
                while ((dest[i] > low) && (i < size))
                        ++i;
                //get minimum measured distance
                while ((dest[i] > low) && (i < size))
                        ++i;
                //get minimum measured distance

-               if (i-startwave < minClk && i < size)
+               if (i-startwave < minClk && i < size) {

                        minClk = i - startwave;
                        minClk = i - startwave;

+                       shortestWaveIdx = startwave;
+               }

        }
        // set clock
        if (g_debugMode==2) prnt("DEBUG ASK: detectstrongASKclk smallest wave: %d",minClk);
        for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
        }
        // set clock
        if (g_debugMode==2) prnt("DEBUG ASK: detectstrongASKclk smallest wave: %d",minClk);
        for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {

-               if (minClk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1)
-                       return fndClk[clkCnt];
+               if (minClk >= clocks[clkCnt]-(clocks[clkCnt]/8) && minClk <= clocks[clkCnt]+1) {
+                       *clock = clocks[clkCnt];
+                       return shortestWaveIdx;
+               }

        }
        return 0;
 }
        }
        return 0;
 }


@@ -939,15 +959,15 @@ 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
 


@@ -958,15 +978,10 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
        //test for large clean peaks
        if (!clockFnd){
                if (DetectCleanAskWave(dest, size, peak, low)==1){
        //test for large clean peaks
        if (!clockFnd){
                if (DetectCleanAskWave(dest, size, peak, low)==1){

-                       int ans = DetectStrongAskClock(dest, size, peak, low);
-                       if (g_debugMode==2) prnt("DEBUG ASK: detectaskclk Clean Ask Wave Detected: clk %d",ans);
-                       for (i=clkEnd-1; i>0; i--){
-                               if (clk[i] == ans) {
-                                       *clock = ans;
-                                       //clockFnd = i;
-                                       return 0;  // for strong waves i don't use the 'best start position' yet...
-                                       //break; //clock found but continue to find best startpos [not yet]
-                               }
+                       int ans = DetectStrongAskClock(dest, size, peak, low, clock);
+                       if (g_debugMode==2) prnt("DEBUG ASK: detectaskclk Clean Ask Wave Detected: clk %i, ShortestWave: %i", clock ,ans);
+                       if (ans > 0){
+                                       return ans;  // return shortest wave start pos

                        }
                }
        }
                        }
                }
        }


@@ -977,15 +992,15 @@ 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 {


@@ -1040,35 +1055,42 @@ 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];

+       

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

+int DetectPSKClock(uint8_t dest[], size_t size, int clock) {
+       int firstPhaseShift = 0;
+       return DetectPSKClock_ext(dest, size, clock, &firstPhaseShift);
+}
+

 //by marshmellow
 //detect psk clock by reading each phase shift
 // a phase shift is determined by measuring the sample length of each wave
 //by marshmellow
 //detect psk clock by reading each phase shift
 // a phase shift is determined by measuring the sample length of each wave

-int DetectPSKClock(uint8_t dest[], size_t size, int clock)
-{
-       uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock
+int DetectPSKClock_ext(uint8_t dest[], size_t size, int clock, int *firstPhaseShift) {
+       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;


@@ -1086,10 +1108,11 @@ int DetectPSKClock(uint8_t dest[], size_t size, int clock)
                        }
                }
        }
                        }
                }
        }

-       if (g_debugMode ==2) prnt("DEBUG PSK: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);
+       *firstPhaseShift = firstFullWave;
+       if (g_debugMode == 2) prnt("DEBUG PSK: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);

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


@@ -1123,19 +1146,17 @@ 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];


@@ -1170,18 +1191,25 @@ int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low){
        return lowestTransition;
 }
 
        return lowestTransition;
 }
 

+int DetectNRZClock(uint8_t dest[], size_t size, int clock) {
+       int bestStart = 0;
+       return DetectNRZClock_ext(dest, size, clock, &bestStart);
+}
+

 //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)

-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};
+int DetectNRZClock_ext(uint8_t dest[], size_t size, int clock, int *clockStartIdx) {
+       size_t i = 0;
+       uint8_t clk[] = {8,16,32,40,50,64,100,128,255};

        size_t loopCnt = 4096;  //don't need to loop through entire array...
        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;


@@ -1202,7 +1230,7 @@ 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;


@@ -1210,7 +1238,7 @@ 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;

                        }
                }
        }
                        }
                }
        }


@@ -1220,7 +1248,8 @@ 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;
+       int bestStart[] = {0,0,0,0,0,0,0,0,0};
+       peakcnt = 0;

        //test each valid clock from smallest to greatest to see which lines up
        for(clkCnt=0; clkCnt < 8; ++clkCnt){
                //ignore clocks smaller than smallest peak
        //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


@@ -1240,7 +1269,7 @@ 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;


@@ -1252,9 +1281,10 @@ 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--;


@@ -1265,25 +1295,26 @@ 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]) {
+                                       bestStart[clkCnt]=ii;
+                                       peaksdet[clkCnt] = peakcnt;

                                }
                        }
                }
        }
                                }
                        }
                }
        }

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

        }
        }

-
+       *clockStartIdx  = bestStart[best];

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


@@ -1372,10 +1403,14 @@ int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert){
        return 0;
 }
 
        return 0;
 }
 

+uint8_t        detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow) {
+       int firstClockEdge = 0;
+       return detectFSKClk_ext(BitStream, size, fcHigh, fcLow, &firstClockEdge);
+}
+

 //by marshmellow
 //detects the bit clock for FSK given the high and low Field Clocks
 //by marshmellow
 //detects the bit clock for FSK given the high and low Field Clocks

-uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow)
-{
+uint8_t detectFSKClk_ext(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow, int *firstClockEdge) {

        uint8_t clk[] = {8,16,32,40,50,64,100,128,0};
        uint16_t rfLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
        uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
        uint8_t clk[] = {8,16,32,40,50,64,100,128,0};
        uint16_t rfLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
        uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};


@@ -1431,6 +1466,7 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc
                                        rfLens[rfLensFnd++] = rfCounter;
                                }
                        } else {
                                        rfLens[rfLensFnd++] = rfCounter;
                                }
                        } else {

+                               *firstClockEdge = i;

                                firstBitFnd++;
                        }
                        rfCounter=0;
                                firstBitFnd++;
                        }
                        rfCounter=0;


@@ -1675,9 +1711,14 @@ 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};


@@ -1832,7 +1873,7 @@ 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)


@@ -1840,6 +1881,15 @@ 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) {