X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/b2c330b36778471de73683ca779d4850556db895..a75d63f19b93f22faeff886f9f2568f3d7531d55:/common/lfdemod.c diff --git a/common/lfdemod.c b/common/lfdemod.c index f13a567c..306f3626 100644 --- a/common/lfdemod.c +++ b/common/lfdemod.c @@ -9,8 +9,22 @@ //----------------------------------------------------------------------------- #include -#include #include "lfdemod.h" +#include + +//un_comment to allow debug print calls when used not on device +void dummy(char *fmt, ...){} + +#ifndef ON_DEVICE +#include "ui.h" +#include "cmdparser.h" +#include "cmddata.h" +#define prnt PrintAndLog +#else + uint8_t g_debugMode=0; +#define prnt dummy +#endif + uint8_t justNoise(uint8_t *BitStream, size_t size) { static const uint8_t THRESHOLD = 123; @@ -52,6 +66,80 @@ uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType) return (ans == pType); } +//by marshmellow +// takes a array of binary values, start position, length of bits per parity (includes parity bit), +// Parity Type (1 for odd; 0 for even; 2 Always 1's), and binary Length (length to run) +size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen) +{ + uint32_t parityWd = 0; + size_t j = 0, bitCnt = 0; + for (int word = 0; word < (bLen); word+=pLen){ + for (int bit=0; bit < pLen; bit++){ + parityWd = (parityWd << 1) | BitStream[startIdx+word+bit]; + BitStream[j++] = (BitStream[startIdx+word+bit]); + } + j--; // overwrite parity with next data + // if parity fails then return 0 + if (pType == 2) { // then marker bit which should be a 1 + if (!BitStream[j]) return 0; + } else { + if (parityTest(parityWd, pLen, pType) == 0) return 0; + } + bitCnt+=(pLen-1); + parityWd = 0; + } + // if we got here then all the parities passed + //return ID start index and size + return bitCnt; +} + +// by marshmellow +// takes a array of binary values, length of bits per parity (includes parity bit), +// Parity Type (1 for odd; 0 for even; 2 Always 1's), and binary Length (length to run) +size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t pLen, uint8_t pType) +{ + uint32_t parityWd = 0; + size_t j = 0, bitCnt = 0; + for (int word = 0; word < sourceLen; word+=pLen-1) { + for (int bit=0; bit < pLen-1; bit++){ + parityWd = (parityWd << 1) | BitSource[word+bit]; + dest[j++] = (BitSource[word+bit]); + } + // if parity fails then return 0 + if (pType == 2) { // then marker bit which should be a 1 + dest[j++]=1; + } else { + dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1; + } + bitCnt += pLen; + parityWd = 0; + } + // if we got here then all the parities passed + //return ID start index and size + return bitCnt; +} + +uint32_t bytebits_to_byte(uint8_t *src, size_t numbits) +{ + uint32_t num = 0; + for(int i = 0 ; i < numbits ; i++) + { + num = (num << 1) | (*src); + src++; + } + return num; +} + +//least significant bit first +uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits) +{ + uint32_t num = 0; + for(int i = 0 ; i < numbits ; i++) { + num = (num << 1) | *(src + (numbits-(i+1))); + } + return num; +} + //by marshmellow //search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx) @@ -128,6 +216,7 @@ int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int if (smplCnt > clk-(clk/4)-1) { //full clock if (smplCnt > clk + (clk/4)+1) { //too many samples errCnt++; + if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i); BinStream[bitCnt++]=7; } else if (waveHigh) { BinStream[bitCnt++] = invert; @@ -184,6 +273,7 @@ int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr 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); uint8_t initLoopMax = 255; if (initLoopMax > *size) initLoopMax = *size; @@ -196,19 +286,21 @@ int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr size_t errCnt = 0; // if clean clipped waves detected run alternate demod if (DetectCleanAskWave(BinStream, *size, high, low)) { + if (g_debugMode==2) prnt("DEBUG ASK: Clean Wave Detected - using clean wave demod"); errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low); if (askType) //askman return manrawdecode(BinStream, size, 0); else //askraw return errCnt; } + if (g_debugMode==2) prnt("DEBUG ASK: Weak Wave Detected - using weak wave demod"); int lastBit; //set first clock check - can go negative size_t i, bitnum = 0; //output counter uint8_t midBit = 0; uint8_t tol = 0; //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave if (*clk <= 32) tol = 1; //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely - size_t MaxBits = 1024; + size_t MaxBits = 3072; //max bits to collect lastBit = start - *clk; for (i = start; i < *size; ++i) { @@ -219,6 +311,7 @@ int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr BinStream[bitnum++] = *invert ^ 1; } else if (i-lastBit >= *clk+tol) { if (bitnum > 0) { + if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i); BinStream[bitnum++]=7; errCnt++; } @@ -282,6 +375,16 @@ int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert) return bestErr; } +uint32_t manchesterEncode2Bytes(uint16_t datain) { + uint32_t output = 0; + uint8_t curBit = 0; + for (uint8_t i=0; i<16; i++) { + curBit = (datain >> (15-i) & 1); + output |= (1<<(((15-i)*2)+curBit)); + } + return output; +} + //by marshmellow //encode binary data into binary manchester int ManchesterEncode(uint8_t *BitStream, size_t size) @@ -369,19 +472,21 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow if (fclow==0) fclow=8; //set the threshold close to 0 (graph) or 128 std to avoid static uint8_t threshold_value = 123; - + size_t preLastSample = 0; + size_t LastSample = 0; + size_t currSample = 0; // sync to first lo-hi transition, and threshold // Need to threshold first sample - - if(dest[0] < threshold_value) dest[0] = 0; + // skip 160 samples to allow antenna/samples to settle + if(dest[160] < threshold_value) dest[0] = 0; else dest[0] = 1; size_t numBits = 0; // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8) // or 10 (fc/10) cycles but in practice due to noise etc we may end up with with anywhere // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10 - for(idx = 1; idx < size; idx++) { + for(idx = 161; idx < size-20; idx++) { // threshold current value if (dest[idx] < threshold_value) dest[idx] = 0; @@ -389,13 +494,22 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow // Check for 0->1 transition if (dest[idx-1] < dest[idx]) { // 0 -> 1 transition - if ((idx-last_transition)<(fclow-2)){ //0-5 = garbage noise + preLastSample = LastSample; + LastSample = currSample; + currSample = idx-last_transition; + if (currSample < (fclow-2)){ //0-5 = garbage noise (or 0-3) //do nothing with extra garbage - } else if ((idx-last_transition) < (fchigh-1)) { //6-8 = 8 waves + } else if (currSample < (fchigh-1)) { //6-8 = 8 sample waves or 3-6 = 5 + if (LastSample > (fchigh-2) && (preLastSample < (fchigh-1) || preLastSample == 0 )){ + dest[numBits-1]=1; //correct previous 9 wave surrounded by 8 waves + } dest[numBits++]=1; - } else if ((idx-last_transition) > (fchigh+1) && !numBits) { //12 + and first bit = garbage + + } else if (currSample > (fchigh) && !numBits) { //12 + and first bit = garbage //do nothing with beginning garbage - } else { //9+ = 10 waves + } else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's + dest[numBits++]=1; + } else { //9+ = 10 sample waves dest[numBits++]=0; } last_transition = idx; @@ -418,19 +532,8 @@ size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, //if lastval was 1, we have a 1->0 crossing if (dest[idx-1]==1) { - if (!numBits && n < rfLen/fclow) { - n=0; - lastval = dest[idx]; - continue; - } n = (n * fclow + rfLen/2) / rfLen; } else {// 0->1 crossing - //test first bitsample too small - if (!numBits && n < rfLen/fchigh) { - n=0; - lastval = dest[idx]; - continue; - } n = (n * fchigh + rfLen/2) / rfLen; } if (n == 0) n = 1; @@ -452,6 +555,7 @@ size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, } return numBits; } + //by marshmellow (from holiman's base) // full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod) int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow) @@ -526,28 +630,6 @@ int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, ui return (int)startIdx; } -uint32_t bytebits_to_byte(uint8_t *src, size_t numbits) -{ - uint32_t num = 0; - for(int i = 0 ; i < numbits ; i++) - { - num = (num << 1) | (*src); - src++; - } - return num; -} - -//least significant bit first -uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits) -{ - uint32_t num = 0; - for(int i = 0 ; i < numbits ; i++) - { - num = (num << 1) | *(src + (numbits-(i+1))); - } - return num; -} - int IOdemodFSK(uint8_t *dest, size_t size) { if (justNoise(dest, size)) return -1; @@ -579,30 +661,38 @@ int IOdemodFSK(uint8_t *dest, size_t size) } // by marshmellow -// takes a array of binary values, start position, length of bits per parity (includes parity bit), -// Parity Type (1 for odd; 0 for even; 2 for just drop it), and binary Length (length to run) -size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen) -{ - uint32_t parityWd = 0; - size_t j = 0, bitCnt = 0; - for (int word = 0; word < (bLen); word+=pLen){ - for (int bit=0; bit < pLen; bit++){ - parityWd = (parityWd << 1) | BitStream[startIdx+word+bit]; - BitStream[j++] = (BitStream[startIdx+word+bit]); - } - j--; - // if parity fails then return 0 - if (pType != 2) { - if (parityTest(parityWd, pLen, pType) == 0) return -1; - } - bitCnt+=(pLen-1); - parityWd = 0; - } - // if we got here then all the parities passed - //return ID start index and size - return bitCnt; +// find viking preamble 0xF200 in already demoded data +int VikingDemod_AM(uint8_t *dest, size_t *size) { + //make sure buffer has data + if (*size < 64*2) return -2; + + size_t startIdx = 0; + uint8_t preamble[] = {1,1,1,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; + uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); + if (errChk == 0) return -4; //preamble not found + uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^ bytebits_to_byte(dest+startIdx+8,8) ^ bytebits_to_byte(dest+startIdx+16,8) + ^ bytebits_to_byte(dest+startIdx+24,8) ^ bytebits_to_byte(dest+startIdx+32,8) ^ bytebits_to_byte(dest+startIdx+40,8) + ^ bytebits_to_byte(dest+startIdx+48,8) ^ bytebits_to_byte(dest+startIdx+56,8); + if ( checkCalc != 0xA8 ) return -5; + if (*size != 64) return -6; + //return start position + return (int) startIdx; } +// find presco preamble 0x10D in already demoded data +int PrescoDemod(uint8_t *dest, size_t *size) { + //make sure buffer has data + if (*size < 64*2) return -2; + + size_t startIdx = 0; + uint8_t preamble[] = {1,0,0,0,0,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0}; + uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); + if (errChk == 0) return -4; //preamble not found + //return start position + return (int) startIdx; +} + + // Ask/Biphase Demod then try to locate an ISO 11784/85 ID // BitStream must contain previously askrawdemod and biphasedemoded data int FDXBdemodBI(uint8_t *dest, size_t *size) @@ -640,7 +730,7 @@ int AWIDdemodFSK(uint8_t *dest, size_t *size) } // by marshmellow -// FSK Demod then try to locate an Farpointe Data (pyramid) ID +// FSK Demod then try to locate a Farpointe Data (pyramid) ID int PyramiddemodFSK(uint8_t *dest, size_t *size) { //make sure buffer has data @@ -665,22 +755,21 @@ int PyramiddemodFSK(uint8_t *dest, size_t *size) // to detect a wave that has heavily clipped (clean) samples uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low) { - uint16_t allPeaks=1; + bool allArePeaks = true; uint16_t cntPeaks=0; - size_t loopEnd = 512+60; + size_t loopEnd = 512+160; if (loopEnd > size) loopEnd = size; - for (size_t i=60; ilow && dest[i] 300) return 1; + if (!allArePeaks){ + if (cntPeaks > 300) return true; } - return allPeaks; + return allArePeaks; } - // by marshmellow // to help detect clocks on heavily clipped samples // based on count of low to low @@ -688,7 +777,7 @@ int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low) { uint8_t fndClk[] = {8,16,32,40,50,64,128}; size_t startwave; - size_t i = 0; + size_t i = 100; size_t minClk = 255; // get to first full low to prime loop and skip incomplete first pulse while ((dest[i] < high) && (i < size)) @@ -711,6 +800,7 @@ int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low) minClk = i - startwave; } // set clock + if (g_debugMode==2) prnt("DEBUG ASK: detectstrongASKclk smallest wave: %d",minClk); for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) { if (minClk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1) return fndClk[clkCnt]; @@ -728,8 +818,8 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr) 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) 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 uint8_t clockFnd=0; for (;i0; i--){ if (clk[i] == ans) { *clock = ans; @@ -754,7 +845,6 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr) } } } - uint8_t ii; uint8_t clkCnt, tol = 0; uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000}; @@ -796,7 +886,7 @@ 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 - //PrintAndLog("DEBUG: clk %d, err %d, ii %d, i %d",clk[clkCnt],errCnt,ii,i); + 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; @@ -818,8 +908,8 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr) best = iii; } } + if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, # Errors %d, Current Best Clk %d, bestStart %d",clk[iii],bestErr[iii],clk[best],bestStart[best]); } - //if (bestErr[best] > maxErr) return -1; if (!clockFnd) *clock = clk[best]; return bestStart[best]; } @@ -832,7 +922,7 @@ 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 uint16_t loopCnt = 4096; //don't need to loop through entire array... if (size == 0) return 0; - if (size= dest[i+2]){ if (waveStart == 0) { waveStart = i+1; - //PrintAndLog("DEBUG: waveStart: %d",waveStart); + //prnt("DEBUG: waveStart: %d",waveStart); } else { waveEnd = i+1; - //PrintAndLog("DEBUG: waveEnd: %d",waveEnd); + //prnt("DEBUG: waveEnd: %d",waveEnd); waveLenCnt = waveEnd-waveStart; if (waveLenCnt > fc){ firstFullWave = waveStart; @@ -867,7 +957,7 @@ int DetectPSKClock(uint8_t dest[], size_t size, int clock) } } } - //PrintAndLog("DEBUG: 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 for(clkCnt=7; clkCnt >= 1 ; clkCnt--){ @@ -875,7 +965,7 @@ int DetectPSKClock(uint8_t dest[], size_t size, int clock) waveStart = 0; errCnt=0; peakcnt=0; - //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit); + if (g_debugMode == 2) prnt("DEBUG PSK: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit); for (i = firstFullWave+fullWaveLen-1; i < loopCnt-2; i++){ //top edge of wave = start of new wave @@ -888,7 +978,7 @@ int DetectPSKClock(uint8_t dest[], size_t size, int clock) waveLenCnt = waveEnd-waveStart; if (waveLenCnt > fc){ //if this wave is a phase shift - //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, ii: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+clk[clkCnt]-tol,ii+1,fc); + if (g_debugMode == 2) prnt("DEBUG PSK: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+clk[clkCnt]-tol,i+1,fc); if (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit peakcnt++; lastClkBit+=clk[clkCnt]; @@ -917,11 +1007,40 @@ int DetectPSKClock(uint8_t dest[], size_t size, int clock) if (peaksdet[i] > peaksdet[best]) { best = i; } - //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],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]; } +int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low){ + //find shortest transition from high to low + size_t i = 0; + size_t transition1 = 0; + int lowestTransition = 255; + bool lastWasHigh = false; + + //find first valid beginning of a high or low wave + while ((dest[i] >= peak || dest[i] <= low) && (i < size)) + ++i; + while ((dest[i] < peak && dest[i] > low) && (i < size)) + ++i; + lastWasHigh = (dest[i] >= peak); + + if (i==size) return 0; + transition1 = i; + + for (;i < size; i++) { + if ((dest[i] >= peak && !lastWasHigh) || (dest[i] <= low && lastWasHigh)) { + lastWasHigh = (dest[i] >= peak); + if (i-transition1 < lowestTransition) lowestTransition = i-transition1; + transition1 = i; + } + } + if (lowestTransition == 255) lowestTransition = 0; + if (g_debugMode==2) prnt("DEBUG NRZ: detectstrongNRZclk smallest wave: %d",lowestTransition); + return lowestTransition; +} + //by marshmellow //detect nrz clock by reading #peaks vs no peaks(or errors) int DetectNRZClock(uint8_t dest[], size_t size, int clock) @@ -930,8 +1049,7 @@ int DetectNRZClock(uint8_t dest[], size_t size, int clock) uint8_t clk[]={8,16,32,40,50,64,100,128,255}; size_t loopCnt = 4096; //don't need to loop through entire array... if (size == 0) return 0; - if (size= peak || dest[i] <= low){ - peakcnt++; + if (!firstpeak) continue; + smplCnt++; } else { - if (peakcnt>0 && maxPeak < peakcnt){ - maxPeak = peakcnt; + firstpeak=true; + if (smplCnt > 6 ){ + if (maxPeak > smplCnt){ + maxPeak = smplCnt; + //prnt("maxPk: %d",maxPeak); + } + peakcnt++; + //prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt); + smplCnt=0; } - peakcnt=0; } } + bool errBitHigh = 0; + bool bitHigh = 0; + uint8_t ignoreCnt = 0; + uint8_t ignoreWindow = 4; + bool lastPeakHigh = 0; + int lastBit = 0; peakcnt=0; //test each valid clock from smallest to greatest to see which lines up for(clkCnt=0; clkCnt < 8; ++clkCnt){ - //ignore clocks smaller than largest peak - if (clk[clkCnt]= peak) || (dest[ii] <= low)){ peakcnt=0; - // now that we have the first one lined up test rest of wave array - for (i=0; i < ((int)((size-ii-tol)/clk[clkCnt])-1); ++i){ - if (dest[ii+(i*clk[clkCnt])]>=peak || dest[ii+(i*clk[clkCnt])]<=low){ + bitHigh = false; + ignoreCnt = 0; + lastBit = ii-clk[clkCnt]; + //loop through to see if this start location works + for (i = ii; i < size-20; ++i) { + //if we are at a clock bit + if ((i >= lastBit + clk[clkCnt] - tol) && (i <= lastBit + clk[clkCnt] + tol)) { + //test high/low + if (dest[i] >= peak || dest[i] <= low) { + //if same peak don't count it + if ((dest[i] >= peak && !lastPeakHigh) || (dest[i] <= low && lastPeakHigh)) { peakcnt++; + } + lastPeakHigh = (dest[i] >= peak); + bitHigh = true; + errBitHigh = false; + ignoreCnt = ignoreWindow; + lastBit += clk[clkCnt]; + } else if (i == lastBit + clk[clkCnt] + tol) { + lastBit += clk[clkCnt]; + } + //else if not a clock bit and no peaks + } else if (dest[i] < peak && dest[i] > low){ + if (ignoreCnt==0){ + bitHigh=false; + if (errBitHigh==true) peakcnt--; + errBitHigh=false; + } else { + ignoreCnt--; + } + // else if not a clock bit but we have a peak + } else if ((dest[i]>=peak || dest[i]<=low) && (!bitHigh)) { + //error bar found no clock... + errBitHigh=true; } } if(peakcnt>peaksdet[clkCnt]) { @@ -983,11 +1145,16 @@ int DetectNRZClock(uint8_t dest[], size_t size, int clock) int iii=7; uint8_t best=0; for (iii=7; iii > 0; iii--){ - if (peaksdet[iii] > peaksdet[best]){ + 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; } - //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]); + } else if (peaksdet[iii] > peaksdet[best]){ + best = iii; + } + if (g_debugMode==2) prnt("DEBUG NRZ: Clk: %d, peaks: %d, maxPeak: %d, bestClk: %d, lowestTrs: %d",clk[iii],peaksdet[iii],maxPeak, clk[best], lowestTransition); } + return clk[best]; } @@ -1031,182 +1198,53 @@ void psk2TOpsk1(uint8_t *BitStream, size_t size) int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert) { //26 bit 40134 format (don't know other formats) - int i; - int long_wait=29;//29 leading zeros in format - int start; - int first = 0; - int first2 = 0; - int bitCnt = 0; - int ii; - // Finding the start of a UID - for (start = 0; start <= *size - 250; start++) { - first = bitStream[start]; - for (i = start; i < start + long_wait; i++) { - if (bitStream[i] != first) { - break; - } - } - if (i == (start + long_wait)) { - break; - } - } - if (start == *size - 250 + 1) { - // did not find start sequence - return -1; - } - // Inverting signal if needed - if (first == 1) { - for (i = start; i < *size; i++) { - bitStream[i] = !bitStream[i]; - } - *invert = 1; - }else *invert=0; - - int iii; - //found start once now test length by finding next one - for (ii=start+29; ii <= *size - 250; ii++) { - first2 = bitStream[ii]; - for (iii = ii; iii < ii + long_wait; iii++) { - if (bitStream[iii] != first2) { - break; - } - } - if (iii == (ii + long_wait)) { - break; - } - } - if (ii== *size - 250 + 1){ - // did not find second start sequence - return -2; - } - bitCnt=ii-start; + uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1}; + uint8_t preamble_i[] = {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0}; + size_t startidx = 0; + if (!preambleSearch(bitStream, preamble, sizeof(preamble), size, &startidx)){ + // if didn't find preamble try again inverting + if (!preambleSearch(bitStream, preamble_i, sizeof(preamble_i), size, &startidx)) return -1; + *invert ^= 1; + } + if (*size != 64 && *size != 224) return -2; + if (*invert==1) + for (size_t i = startidx; i < *size; i++) + bitStream[i] ^= 1; - // Dumping UID - i = start; - for (ii = 0; ii < bitCnt; ii++) { - bitStream[ii] = bitStream[i++]; - } - *size=bitCnt; - return 1; + return (int) startidx; } -// by marshmellow - demodulate NRZ wave (both similar enough) +// by marshmellow - demodulate NRZ wave - requires a read with strong signal // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak -// there probably is a much simpler way to do this.... -int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert, int maxErr) -{ +int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert){ if (justNoise(dest, *size)) return -1; *clk = DetectNRZClock(dest, *size, *clk); if (*clk==0) return -2; size_t i, gLen = 4096; - if (gLen>*size) gLen = *size; + if (gLen>*size) gLen = *size-20; int high, low; if (getHiLo(dest, gLen, &high, &low, 75, 75) < 1) return -3; //25% fuzz on high 25% fuzz on low - int lastBit = 0; //set first clock check - size_t iii = 0, bitnum = 0; //bitnum counter - uint16_t errCnt = 0, MaxBits = 1000; - size_t bestErrCnt = maxErr+1; - size_t bestPeakCnt = 0, bestPeakStart = 0; - uint8_t bestFirstPeakHigh=0, firstPeakHigh=0, curBit=0, bitHigh=0, errBitHigh=0; - uint8_t tol = 1; //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave - uint16_t peakCnt=0; - uint8_t ignoreWindow=4; - uint8_t ignoreCnt=ignoreWindow; //in case of noise near peak - //loop to find first wave that works - align to clock - for (iii=0; iii < gLen; ++iii){ - if ((dest[iii]>=high) || (dest[iii]<=low)){ - if (dest[iii]>=high) firstPeakHigh=1; - else firstPeakHigh=0; - lastBit=iii-*clk; - peakCnt=0; - errCnt=0; - //loop through to see if this start location works - for (i = iii; i < *size; ++i) { - // if we are at a clock bit - if ((i >= lastBit + *clk - tol) && (i <= lastBit + *clk + tol)) { - //test high/low - if (dest[i] >= high || dest[i] <= low) { - bitHigh = 1; - peakCnt++; - errBitHigh = 0; - ignoreCnt = ignoreWindow; - lastBit += *clk; - } else if (i == lastBit + *clk + tol) { - lastBit += *clk; - } - //else if no bars found - } else if (dest[i] < high && dest[i] > low){ - if (ignoreCnt==0){ - bitHigh=0; - if (errBitHigh==1) errCnt++; - errBitHigh=0; - } else { - ignoreCnt--; - } - } else if ((dest[i]>=high || dest[i]<=low) && (bitHigh==0)) { - //error bar found no clock... - errBitHigh=1; - } - if (((i-iii) / *clk)>=MaxBits) break; - } - //we got more than 64 good bits and not all errors - if (((i-iii) / *clk) > 64 && (errCnt <= (maxErr))) { - //possible good read - if (!errCnt || peakCnt > bestPeakCnt){ - bestFirstPeakHigh=firstPeakHigh; - bestErrCnt = errCnt; - bestPeakCnt = peakCnt; - bestPeakStart = iii; - if (!errCnt) break; //great read - finish - } - } - } + + uint8_t bit=0; + //convert wave samples to 1's and 0's + for(i=20; i < *size-20; i++){ + if (dest[i] >= high) bit = 1; + if (dest[i] <= low) bit = 0; + dest[i] = bit; } - //PrintAndLog("DEBUG: bestErrCnt: %d, maxErr: %d, bestStart: %d, bestPeakCnt: %d, bestPeakStart: %d",bestErrCnt,maxErr,bestStart,bestPeakCnt,bestPeakStart); - if (bestErrCnt > maxErr) return bestErrCnt; - - //best run is good enough set to best run and set overwrite BinStream - lastBit = bestPeakStart - *clk; - memset(dest, bestFirstPeakHigh^1, bestPeakStart / *clk); - bitnum += (bestPeakStart / *clk); - for (i = bestPeakStart; i < *size; ++i) { - // if expecting a clock bit - if ((i >= lastBit + *clk - tol) && (i <= lastBit + *clk + tol)) { - // test high/low - if (dest[i] >= high || dest[i] <= low) { - peakCnt++; - bitHigh = 1; - errBitHigh = 0; - ignoreCnt = ignoreWindow; - curBit = *invert; - if (dest[i] >= high) curBit ^= 1; - dest[bitnum++] = curBit; - lastBit += *clk; - //else no bars found in clock area - } else if (i == lastBit + *clk + tol) { - dest[bitnum++] = curBit; - lastBit += *clk; - } - //else if no bars found - } else if (dest[i] < high && dest[i] > low){ - if (ignoreCnt == 0){ - bitHigh = 0; - if (errBitHigh == 1){ - dest[bitnum++] = 7; - errCnt++; - } - errBitHigh=0; - } else { - ignoreCnt--; - } - } else if ((dest[i] >= high || dest[i] <= low) && (bitHigh == 0)) { - //error bar found no clock... - errBitHigh=1; + //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit) + size_t lastBit = 0; + size_t numBits = 0; + for(i=21; i < *size-20; i++) { + //if transition detected or large number of same bits - store the passed bits + if (dest[i] != dest[i-1] || (i-lastBit) == (10 * *clk)) { + memset(dest+numBits, dest[i-1] ^ *invert, (i - lastBit + (*clk/4)) / *clk); + numBits += (i - lastBit + (*clk/4)) / *clk; + lastBit = i-1; } - if (bitnum >= MaxBits) break; } - *size = bitnum; - return bestErrCnt; + *size = numBits; + return 0; } //by marshmellow @@ -1224,18 +1262,18 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc size_t i; if (size == 0) return 0; - uint8_t fcTol = (uint8_t)(0.5+(float)(fcHigh-fcLow)/2); + uint8_t fcTol = ((fcHigh*100 - fcLow*100)/2 + 50)/100; //(uint8_t)(0.5+(float)(fcHigh-fcLow)/2); rfLensFnd=0; fcCounter=0; rfCounter=0; firstBitFnd=0; //PrintAndLog("DEBUG: fcTol: %d",fcTol); - // prime i to first up transition - for (i = 1; i < size-1; i++) + // prime i to first peak / up transition + for (i = 160; i < size-20; i++) if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1]) break; - for (; i < size-1; i++){ + for (; i < size-20; i++){ fcCounter++; rfCounter++; @@ -1253,7 +1291,7 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc //not the same size as the last wave - start of new bit sequence if (firstBitFnd > 1){ //skip first wave change - probably not a complete bit for (int ii=0; ii<15; ii++){ - if (rfLens[ii] == rfCounter){ + if (rfLens[ii] >= (rfCounter-4) && rfLens[ii] <= (rfCounter+4)){ rfCnts[ii]++; rfCounter = 0; break; @@ -1275,7 +1313,6 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15; for (i=0; i<15; i++){ - //PrintAndLog("DEBUG: RF %d, cnts %d",rfLens[i], rfCnts[i]); //get highest 2 RF values (might need to get more values to compare or compare all?) if (rfCnts[i]>rfCnts[rfHighest]){ rfHighest3=rfHighest2; @@ -1287,20 +1324,23 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc } else if(rfCnts[i]>rfCnts[rfHighest3]){ rfHighest3=i; } + if (g_debugMode==2) prnt("DEBUG FSK: RF %d, cnts %d",rfLens[i], rfCnts[i]); } // set allowed clock remainder tolerance to be 1 large field clock length+1 // we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off uint8_t tol1 = fcHigh+1; - //PrintAndLog("DEBUG: hightest: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]); + if (g_debugMode==2) prnt("DEBUG FSK: most counted rf values: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]); // loop to find the highest clock that has a remainder less than the tolerance // compare samples counted divided by + // test 128 down to 32 (shouldn't be possible to have fc/10 & fc/8 and rf/16 or less) int ii=7; - for (; ii>=0; ii--){ + for (; ii>=2; ii--){ if (rfLens[rfHighest] % clk[ii] < tol1 || rfLens[rfHighest] % clk[ii] > clk[ii]-tol1){ if (rfLens[rfHighest2] % clk[ii] < tol1 || rfLens[rfHighest2] % clk[ii] > clk[ii]-tol1){ if (rfLens[rfHighest3] % clk[ii] < tol1 || rfLens[rfHighest3] % clk[ii] > clk[ii]-tol1){ + if (g_debugMode==2) prnt("DEBUG FSK: clk %d divides into the 3 most rf values within tolerance",clk[ii]); break; } } @@ -1318,8 +1358,8 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc //mainly used for FSK field clock detection uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj) { - uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0}; - uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0}; + 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 fcCounter = 0; @@ -1327,11 +1367,11 @@ uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj) if (size == 0) return 0; // prime i to first up transition - for (i = 1; i < size-1; i++) + for (i = 160; i < size-20; i++) if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]) break; - for (; i < size-1; i++){ + for (; i < size-20; i++){ if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){ // new up transition fcCounter++; @@ -1344,14 +1384,14 @@ uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj) lastFCcnt = fcCounter; } // find which fcLens to save it to: - for (int ii=0; ii<10; ii++){ + for (int ii=0; ii<15; ii++){ if (fcLens[ii]==fcCounter){ fcCnts[ii]++; fcCounter=0; break; } } - if (fcCounter>0 && fcLensFnd<10){ + if (fcCounter>0 && fcLensFnd<15){ //add new fc length fcCnts[fcLensFnd]++; fcLens[fcLensFnd++]=fcCounter; @@ -1363,11 +1403,10 @@ uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj) } } - uint8_t best1=9, best2=9, best3=9; + uint8_t best1=14, best2=14, best3=14; uint16_t maxCnt1=0; // go through fclens and find which ones are bigest 2 - for (i=0; i<10; i++){ - // PrintAndLog("DEBUG: FC %d, Cnt %d, Errs %d",fcLens[i],fcCnts[i],errCnt); + for (i=0; i<15; i++){ // get the 3 best FC values if (fcCnts[i]>maxCnt1) { best3=best2; @@ -1380,7 +1419,9 @@ uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj) } else if(fcCnts[i]>fcCnts[best3]){ best3=i; } + if (g_debugMode==2) prnt("DEBUG countfc: FC %u, Cnt %u, best fc: %u, best2 fc: %u",fcLens[i],fcCnts[i],fcLens[best1],fcLens[best2]); } + if (fcLens[best1]==0) return 0; uint8_t fcH=0, fcL=0; if (fcLens[best1]>fcLens[best2]){ fcH=fcLens[best1]; @@ -1389,11 +1430,13 @@ uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj) fcH=fcLens[best2]; fcL=fcLens[best1]; } - + if ((size-180)/fcH/3 > fcCnts[best1]+fcCnts[best2]) { + if (g_debugMode==2) prnt("DEBUG countfc: fc is too large: %u > %u. Not psk or fsk",(size-180)/fcH/3,fcCnts[best1]+fcCnts[best2]); + return 0; //lots of waves not psk or fsk + } // TODO: take top 3 answers and compare to known Field clocks to get top 2 uint16_t fcs = (((uint16_t)fcH)<<8) | fcL; - // PrintAndLog("DEBUG: Best %d best2 %d best3 %d",fcLens[best1],fcLens[best2],fcLens[best3]); if (fskAdj) return fcs; return fcLens[best1]; } @@ -1406,6 +1449,7 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) uint16_t loopCnt = 4096; //don't need to loop through entire array... if (*size fc && waveStart > fc){ //not first peak and is a large wave + if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+2)){ //not first peak and is a large wave but not out of whack lastAvgWaveVal = avgWaveVal/(waveLenCnt); firstFullWave = waveStart; fullWaveLen=waveLenCnt; @@ -1435,14 +1479,21 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) } avgWaveVal += dest[i+2]; } + if (firstFullWave == 0) { + // no phase shift detected - could be all 1's or 0's - doesn't matter where we start + // so skip a little to ensure we are past any Start Signal + firstFullWave = 160; + memset(dest, curPhase, firstFullWave / *clock); + } else { + memset(dest, curPhase^1, firstFullWave / *clock); + } + //advance bits + numBits += (firstFullWave / *clock); + //set start of wave as clock align + lastClkBit = firstFullWave; //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen); - lastClkBit = firstFullWave; //set start of wave as clock align //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d", *clock, lastClkBit); waveStart = 0; - size_t numBits=0; - //set skipped bits - memset(dest, curPhase^1, firstFullWave / *clock); - numBits += (firstFullWave / *clock); dest[numBits++] = curPhase; //set first read bit for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){ //top edge of wave = start of new wave @@ -1482,3 +1533,166 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) *size = numBits; return errCnt; } + +//by marshmellow +//attempt to identify a Sequence Terminator in ASK modulated raw wave +bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) { + size_t bufsize = *size; + //need to loop through all samples and identify our clock, look for the ST pattern + uint8_t fndClk[] = {8,16,32,40,50,64,128}; + int clk = 0; + int tol = 0; + int i, j, skip, start, end, low, high, minClk, waveStart; + bool complete = false; + int tmpbuff[bufsize / 64]; + int waveLen[bufsize / 64]; + size_t testsize = (bufsize < 512) ? bufsize : 512; + int phaseoff = 0; + high = low = 128; + memset(tmpbuff, 0, sizeof(tmpbuff)); + + if ( getHiLo(buffer, testsize, &high, &low, 80, 80) == -1 ) { + if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting"); + return false; //just noise + } + i = 0; + j = 0; + minClk = 255; + // get to first full low to prime loop and skip incomplete first pulse + while ((buffer[i] < high) && (i < bufsize)) + ++i; + while ((buffer[i] > low) && (i < bufsize)) + ++i; + skip = i; + + // populate tmpbuff buffer with pulse lengths + while (i < bufsize) { + // measure from low to low + while ((buffer[i] > low) && (i < bufsize)) + ++i; + start= i; + while ((buffer[i] < high) && (i < bufsize)) + ++i; + //first high point for this wave + waveStart = i; + while ((buffer[i] > low) && (i < bufsize)) + ++i; + if (j >= (bufsize/64)) { + break; + } + waveLen[j] = i - waveStart; //first high to first low + tmpbuff[j++] = i - start; + if (i-start < minClk && i < bufsize) { + minClk = i - start; + } + } + // set clock - might be able to get this externally and remove this work... + if (!clk) { + for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) { + tol = fndClk[clkCnt]/8; + if (minClk >= fndClk[clkCnt]-tol && minClk <= fndClk[clkCnt]+1) { + clk=fndClk[clkCnt]; + break; + } + } + // clock not found - ERROR + if (!clk) { + if (g_debugMode==2) prnt("DEBUG STT: clock not found - quitting"); + return false; + } + } else tol = clk/8; + + *foundclock = clk; + + // look for Sequence Terminator - should be pulses of clk*(1 or 1.5), clk*2, clk*(1.5 or 2) + start = -1; + for (i = 0; i < j - 4; ++i) { + skip += tmpbuff[i]; + if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol && waveLen[i] < clk+tol) { //1 to 2 clocks depending on 2 bits prior + if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) { //2 clocks and wave size is 1 1/2 + if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave + if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit + start = i + 3; + break; + } + } + } + } + } + // first ST not found - ERROR + if (start < 0) { + if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting"); + return false; + } + if (waveLen[i+2] > clk*1+tol) + phaseoff = 0; + else + phaseoff = clk/2; + + // skip over the remainder of ST + skip += clk*7/2; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point + + // now do it again to find the end + end = skip; + for (i += 3; i < j - 4; ++i) { + end += tmpbuff[i]; + if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol) { //1 to 2 clocks depending on 2 bits prior + if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) { //2 clocks and wave size is 1 1/2 + if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave + if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit + complete = true; + break; + } + } + } + } + } + end -= phaseoff; + //didn't find second ST - ERROR + if (!complete) { + if (g_debugMode==2) prnt("DEBUG STT: second STT not found - quitting"); + return false; + } + if (g_debugMode==2) prnt("DEBUG STT: start of data: %d end of data: %d, datalen: %d, clk: %d, bits: %d, phaseoff: %d", skip, end, end-skip, clk, (end-skip)/clk, phaseoff); + //now begin to trim out ST so we can use normal demod cmds + start = skip; + size_t datalen = end - start; + // check validity of datalen (should be even clock increments) - use a tolerance of up to 1/8th a clock + if (datalen % clk > clk/8) { + 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 (g_debugMode==2) prnt("DEBUG STT: datalen is less than 1 full t55xx block - quitting"); + return false; + } + size_t dataloc = start; + size_t newloc = 0; + i=0; + // 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... (we cut out the high part) + if (buffer[dataloc]low && buffer[dataloc+3]low) { + for(i=0; i < clk/2-tol; ++i) { + buffer[dataloc+i] = high+5; + } + } + for (i=0; i