X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/2dcf60f3df145625781982040ae9c80d30e40482..9bef1216b98ab37573afa24195fe61f46e076232:/common/lfdemod.c diff --git a/common/lfdemod.c b/common/lfdemod.c index 5fec933f..4b17c6fd 100644 --- a/common/lfdemod.c +++ b/common/lfdemod.c @@ -7,22 +7,20 @@ //----------------------------------------------------------------------------- // Low frequency demod/decode commands //----------------------------------------------------------------------------- - -#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 +# include "ui.h" +# include "cmdparser.h" +# include "cmddata.h" +# define prnt PrintAndLog #else uint8_t g_debugMode=0; -#define prnt dummy +# define prnt dummy #endif //test samples are not just noise @@ -60,7 +58,7 @@ uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType) for (uint8_t i = 0; i < bitLen; i++){ ans ^= ((bits >> i) & 1); } - //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType); + if (g_debugMode) prnt("DEBUG: ans: %d, ptype: %d, bits: %08X",ans,pType,bits); return (ans == pType); } @@ -71,11 +69,13 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p { uint32_t parityWd = 0; size_t j = 0, bitCnt = 0; - for (int word = 0; word < (bLen); word+=pLen){ + for (int word = 0; word < (bLen); word += pLen){ for (int bit=0; bit < pLen; bit++){ parityWd = (parityWd << 1) | BitStream[startIdx+word+bit]; BitStream[j++] = (BitStream[startIdx+word+bit]); } + if (word+pLen >= bLen) break; + j--; // overwrite parity with next data // if parity fails then return 0 switch (pType) { @@ -83,7 +83,7 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p case 2: if (BitStream[j]==0) { return 0; } break; //should be 1 spacer bit default: if (parityTest(parityWd, pLen, pType) == 0) { return 0; } break; //test parity } - bitCnt+=(pLen-1); + bitCnt += (pLen-1); parityWd = 0; } // if we got here then all the parities passed @@ -218,11 +218,12 @@ int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int smplCnt++; } else { //transition if ((BinStream[i] >= high && !waveHigh) || (BinStream[i] <= low && waveHigh)){ + if (smplCnt > clk-(clk/4)-1) { //full clock if (smplCnt > clk + (clk/4)+1) { //too many samples errCnt++; if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i); - BinStream[bitCnt++]=7; + BinStream[bitCnt++] = 7; } else if (waveHigh) { BinStream[bitCnt++] = invert; BinStream[bitCnt++] = invert; @@ -277,10 +278,11 @@ int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr { if (*size==0) return -1; int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default + if (*clk==0 || start < 0) return -3; if (*invert != 1) *invert = 0; if (amp==1) askAmp(BinStream, *size); - if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d", *clk, start); + if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d, amp %d", *clk, start, amp); uint8_t initLoopMax = 255; if (initLoopMax > *size) initLoopMax = *size; @@ -297,8 +299,8 @@ int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low); if (askType) //askman return manrawdecode(BinStream, size, 0); - else //askraw - return errCnt; + //askraw + return errCnt; } if (g_debugMode==2) prnt("DEBUG ASK: Weak Wave Detected - using weak wave demod"); @@ -345,38 +347,36 @@ int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr *size = bitnum; return errCnt; } - //by marshmellow //take 10 and 01 and manchester decode //run through 2 times and take least errCnt -int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert) -{ - uint16_t bitnum=0, MaxBits = 512, errCnt = 0; - size_t i, ii; - uint16_t bestErr = 1000, bestRun = 0; +int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert){ + int errCnt = 0, bestErr = 1000; + uint16_t bitnum = 0, MaxBits = 512, bestRun = 0; + size_t i, k; if (*size < 16) return -1; //find correct start position [alignment] - for (ii=0;ii<2;++ii){ - for (i=ii; i<*size-3; i+=2) - if (BitStream[i]==BitStream[i+1]) + for (k=0; k < 2; ++k){ + for (i=k; i<*size-3; i += 2) + if (BitStream[i] == BitStream[i+1]) errCnt++; - if (bestErr>errCnt){ - bestErr=errCnt; - bestRun=ii; + if (bestErr > errCnt){ + bestErr = errCnt; + bestRun = k; } errCnt=0; } //decode - for (i=bestRun; i < *size-3; i+=2){ - if(BitStream[i] == 1 && (BitStream[i+1] == 0)){ - BitStream[bitnum++]=invert; - } else if((BitStream[i] == 0) && BitStream[i+1] == 1){ - BitStream[bitnum++]=invert^1; + for (i=bestRun; i < *size-3; i += 2){ + if (BitStream[i] == 1 && (BitStream[i+1] == 0)){ + BitStream[bitnum++] = invert; + } else if ((BitStream[i] == 0) && BitStream[i+1] == 1){ + BitStream[bitnum++] = invert^1; } else { - BitStream[bitnum++]=7; + BitStream[bitnum++] = 7; } - if(bitnum>MaxBits) break; + if (bitnum>MaxBits) break; } *size=bitnum; return bestErr; @@ -482,19 +482,42 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow size_t preLastSample = 0; size_t LastSample = 0; size_t currSample = 0; - // sync to first lo-hi transition, and threshold + if ( size < 1024 ) return 0; // not enough samples + + // jump to modulating data by finding the first 4 threshold crossings (or first 2 waves) + // in case you have junk or noise at the beginning of the trace... + uint8_t thresholdCnt = 0; + size_t waveSizeCnt = 0; + bool isAboveThreshold = dest[idx++] >= threshold_value; + for (; idx < size-20; idx++ ) { + if(dest[idx] < threshold_value && isAboveThreshold) { + thresholdCnt++; + if (thresholdCnt > 2 && waveSizeCnt < fchigh+1) break; + isAboveThreshold = false; + waveSizeCnt = 0; + } else if (dest[idx] >= threshold_value && !isAboveThreshold) { + thresholdCnt++; + if (thresholdCnt > 2 && waveSizeCnt < fchigh+1) break; + isAboveThreshold = true; + waveSizeCnt = 0; + } else { + waveSizeCnt++; + } + if (thresholdCnt > 10) break; + } + if (g_debugMode == 2) prnt("threshold Count reached at %u",idx); // Need to threshold first sample - // skip 160 samples to allow antenna/samples to settle - if(dest[160] < threshold_value) dest[0] = 0; + if(dest[idx] < threshold_value) dest[0] = 0; else dest[0] = 1; + idx++; size_t numBits = 0; // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8) // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10 // (could also be fc/5 && fc/7 for fsk1 = 4-9) - for(idx = 161; idx < size-20; idx++) { + for(; idx < size-20; idx++) { // threshold current value if (dest[idx] < threshold_value) dest[idx] = 0; @@ -509,13 +532,14 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow //do nothing with extra garbage } else if (currSample < (fchigh-1)) { //6-8 = 8 sample waves (or 3-6 = 5) //correct previous 9 wave surrounded by 8 waves (or 6 surrounded by 5) - if (LastSample > (fchigh-2) && (preLastSample < (fchigh-1) || preLastSample == 0 )){ + if (LastSample > (fchigh-2) && (preLastSample < (fchigh-1))){ dest[numBits-1]=1; } dest[numBits++]=1; - } else if (currSample > (fchigh) && !numBits) { //12 + and first bit = unusable garbage - //do nothing with beginning garbage + } else if (currSample > (fchigh+1) && numBits < 3) { //12 + and first two bit = unusable garbage + //do nothing with beginning garbage and reset.. should be rare.. + numBits = 0; } else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's (or 4 then a 6 should be two 5's) dest[numBits++]=1; } else { //9+ = 10 sample waves (or 6+ = 7) @@ -538,7 +562,7 @@ size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, uint32_t n=1; for( idx=1; idx < size; idx++) { n++; - if (dest[idx]==lastval) continue; + if (dest[idx]==lastval) continue; //skip until we hit a transition //find out how many bits (n) we collected //if lastval was 1, we have a 1->0 crossing @@ -602,10 +626,11 @@ int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32 *hi2 = (*hi2<<1)|(*hi>>31); *hi = (*hi<<1)|(*lo>>31); //Then, shift in a 0 or one into low + *lo <<= 1; if (dest[idx] && !dest[idx+1]) // 1 0 - *lo=(*lo<<1)|1; + *lo |= 1; else // 0 1 - *lo=(*lo<<1)|0; + *lo |= 0; } return (int)startIdx; } @@ -677,7 +702,6 @@ int IOdemodFSK(uint8_t *dest, size_t size) int VikingDemod_AM(uint8_t *dest, size_t *size) { //make sure buffer has data if (*size < 64*2) return -2; - 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); @@ -693,67 +717,77 @@ int VikingDemod_AM(uint8_t *dest, size_t *size) { if ( checkCalc != 0xA8 ) return -5; if (*size != 64) return -6; //return start position - return (int) startIdx; + return (int)startIdx; } +// by iceman +// find Visa2000 preamble in already demoded data +int Visa2kDemod_AM(uint8_t *dest, size_t *size) { + if (*size < 96) return -1; //make sure buffer has data + size_t startIdx = 0; + uint8_t preamble[] = {0,1,0,1,0,1,1,0,0,1,0,0,1,0,0,1,0,1,0,1,0,0,1,1,0,0,1,1,0,0,1,0}; + uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); + if (errChk == 0) return -2; //preamble not found + if (*size != 96) return -3; //wrong demoded size + //return start position + return (int)startIdx; +} +// by iceman +// find Noralsy preamble in already demoded data +int NoralsyDemod_AM(uint8_t *dest, size_t *size) { + if (*size < 96) return -1; //make sure buffer has data + size_t startIdx = 0; + uint8_t preamble[] = {1,0,1,1,1,0,1,1,0,0,0,0}; + uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); + if (errChk == 0) return -2; //preamble not found + if (*size != 96) return -3; //wrong demoded size + //return start position + return (int)startIdx; +} // find presco preamble 0x10D in already demoded data int PrescoDemod(uint8_t *dest, size_t *size) { - //make sure buffer has data - if (*size < 64*2) return -2; - + if (*size < 128*2) return -1; //make sure buffer has data size_t startIdx = 0; - 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 preamble[] = {0,0,0,1,0,0,0,0,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0}; uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); - if (errChk == 0) return -4; //preamble not found + if (errChk == 0) return -2; //preamble not found + if (*size != 128) return -3; //wrong demoded size //return start position - return (int) startIdx; + return (int)startIdx; } // Ask/Biphase Demod then try to locate an ISO 11784/85 ID // BitStream must contain previously askrawdemod and biphasedemoded data -int FDXBdemodBI(uint8_t *dest, size_t *size) -{ - //make sure buffer has enough data - if (*size < 128) return -1; - +int FDXBdemodBI(uint8_t *dest, size_t *size) { + if (*size < 128*2) return -1; //make sure buffer has enough data size_t startIdx = 0; uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,1}; - uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); if (errChk == 0) return -2; //preamble not found + if (*size != 128) return -3; //wrong demoded size + //return start position return (int)startIdx; } // ASK/Diphase fc/64 (inverted Biphase) // Note: this i s not a demod, this is only a detection // the parameter *dest needs to be demoded before call +// 0xFFFF preamble, 64bits int JablotronDemod(uint8_t *dest, size_t *size){ - //make sure buffer has enough data - if (*size < 64) return -1; - + if (*size < 64*2) return -1; //make sure buffer has enough data size_t startIdx = 0; - // 0xFFFF preamble, 64bits - uint8_t preamble[] = { - 1,1,1,1, - 1,1,1,1, - 1,1,1,1, - 1,1,1,1, - 0 - }; - + uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0}; uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); - if (errChk == 0) return -4; //preamble not found - if (*size != 64) return -3; + if (errChk == 0) return -2; //preamble not found + if (*size != 64) return -3; // wrong demoded size uint8_t checkchksum = 0; for (int i=16; i < 56; i += 8) { checkchksum += bytebits_to_byte(dest+startIdx+i,8); } checkchksum ^= 0x3A; - uint8_t crc = bytebits_to_byte(dest+startIdx+56, 8); - - if ( checkchksum != crc ) return -5; + if ( checkchksum != crc ) return -5; return (int)startIdx; } @@ -792,7 +826,7 @@ int PyramiddemodFSK(uint8_t *dest, size_t *size) *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50 if (*size < 128) return -2; //did we get a good demod? - uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1}; + uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1}; size_t startIdx = 0; uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); if (errChk == 0) return -4; //preamble not found @@ -813,6 +847,19 @@ int NedapDemod(uint8_t *dest, size_t *size) { return (int) startIdx; } +// Find IDTEC PSK1, RF Preamble == 0x4944544B, Demodsize 64bits +// by iceman +int IdteckDemodPSK(uint8_t *dest, size_t *size) { + //make sure buffer has data + if (*size < 64*2) return -1; + size_t startIdx = 0; + uint8_t preamble[] = {0,1,0,0,1,0,0,1,0,1,0,0,0,1,0,0,0,1,0,1,0,1,0,0,0,1,0,0,1,0,1,1}; + uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); + if (errChk == 0) return -2; //preamble not found + if (*size != 64) return -3; // wrong demoded size + return (int) startIdx; +} + // by marshmellow // to detect a wave that has heavily clipped (clean) samples uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low) @@ -917,24 +964,28 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr) if (clockFnd>0) { clkCnt = clockFnd; clkEnd = clockFnd+1; + } else { + clkCnt=1; } - else clkCnt=1; //test each valid clock from smallest to greatest to see which lines up - for(; clkCnt < clkEnd; clkCnt++){ - if (clk[clkCnt] <= 32){ + for(; clkCnt < clkEnd; clkCnt++) { + if (clk[clkCnt] <= 32) { tol=1; - }else{ + } else { tol=0; } //if no errors allowed - keep start within the first clock - if (!maxErr && size > clk[clkCnt]*2 + tol && clk[clkCnt]<128) loopCnt=clk[clkCnt]*2; - bestErr[clkCnt]=1000; + if (!maxErr && size > clk[clkCnt]*2 + tol && clk[clkCnt]<128) + loopCnt = clk[clkCnt] * 2; + + bestErr[clkCnt] = 1000; + //try lining up the peaks by moving starting point (try first few clocks) for (ii=0; ii < loopCnt; ii++){ if (dest[ii] < peak && dest[ii] > low) continue; - errCnt=0; + errCnt = 0; // now that we have the first one lined up test rest of wave array loopEnd = ((size-ii-tol) / clk[clkCnt]) - 1; for (i=0; i < loopEnd; ++i){ @@ -948,29 +999,29 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr) } //if we found no errors then we can stop here and a low clock (common clocks) // this is correct one - return this clock - if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, err %d, startpos %d, endpos %d",clk[clkCnt],errCnt,ii,i); - if(errCnt==0 && clkCnt<7) { + if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, err %d, startpos %d, endpos %d", clk[clkCnt], errCnt, ii, i); + if (errCnt==0 && clkCnt<7) { if (!clockFnd) *clock = clk[clkCnt]; return ii; } //if we found errors see if it is lowest so far and save it as best run - if(errCnt BitStream[i-1] && BitStream[i]>=BitStream[i+1]) @@ -1360,7 +1407,7 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc } } if (rfCounter > 0 && rfLensFnd < 15){ - //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter); + //prnt("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter); rfCnts[rfLensFnd]++; rfLens[rfLensFnd++] = rfCounter; } @@ -1423,10 +1470,10 @@ uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj) uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; uint8_t fcLensFnd = 0; - uint8_t lastFCcnt=0; + uint8_t lastFCcnt = 0; uint8_t fcCounter = 0; size_t i; - if (size == 0) return 0; + if (size < 180) return 0; // prime i to first up transition for (i = 160; i < size-20; i++) @@ -1513,27 +1560,53 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) size_t numBits=0; uint8_t curPhase = *invert; - size_t i, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0; + size_t i=0, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0; uint8_t fc=0, fullWaveLen=0, tol=1; uint16_t errCnt=0, waveLenCnt=0; fc = countFC(dest, *size, 0); if (fc!=2 && fc!=4 && fc!=8) return -1; - //PrintAndLog("DEBUG: FC: %d",fc); + //prnt("DEBUG: FC: %d",fc); *clock = DetectPSKClock(dest, *size, *clock); if (*clock == 0) return -1; + // jump to modulating data by finding the first 2 threshold crossings (or first 1 waves) + // in case you have junk or noise at the beginning of the trace... + uint8_t thresholdCnt = 0; + size_t waveSizeCnt = 0; + uint8_t threshold_value = 123; //-5 + bool isAboveThreshold = dest[i++] >= threshold_value; + for (; i < *size-20; i++ ) { + if(dest[i] < threshold_value && isAboveThreshold) { + thresholdCnt++; + if (thresholdCnt > 2 && waveSizeCnt < fc+1) break; + isAboveThreshold = false; + waveSizeCnt = 0; + } else if (dest[i] >= threshold_value && !isAboveThreshold) { + thresholdCnt++; + if (thresholdCnt > 2 && waveSizeCnt < fc+1) break; + isAboveThreshold = true; + waveSizeCnt = 0; + } else { + waveSizeCnt++; + } + if (thresholdCnt > 10) break; + } + if (g_debugMode == 2) prnt("DEBUG PSK: threshold Count reached at %u, count: %u",i, thresholdCnt); + + int avgWaveVal=0, lastAvgWaveVal=0; + waveStart = i+1; //find first phase shift - for (i=0; i= dest[i+2]){ waveEnd = i+1; - //PrintAndLog("DEBUG: waveEnd: %d",waveEnd); + if (g_debugMode == 2) prnt("DEBUG PSK: waveEnd: %u, waveStart: %u",waveEnd, waveStart); waveLenCnt = waveEnd-waveStart; - if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+2)){ //not first peak and is a large wave but not out of whack + if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+3)){ //not first peak and is a large wave but not out of whack lastAvgWaveVal = avgWaveVal/(waveLenCnt); firstFullWave = waveStart; fullWaveLen=waveLenCnt; //if average wave value is > graph 0 then it is an up wave or a 1 - if (lastAvgWaveVal > 123) curPhase ^= 1; //fudge graph 0 a little 123 vs 128 + if (lastAvgWaveVal > threshold_value) curPhase ^= 1; //fudge graph 0 a little 123 vs 128 break; } waveStart = i+1; @@ -1569,9 +1642,9 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) waveLenCnt = waveEnd-waveStart; lastAvgWaveVal = avgWaveVal/waveLenCnt; if (waveLenCnt > fc){ - //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal); + //prnt("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal); //this wave is a phase shift - //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc); + //prnt("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc); if (i+1 >= lastClkBit + *clock - tol){ //should be a clock bit curPhase ^= 1; dest[numBits++] = curPhase; @@ -1606,13 +1679,15 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) { int tol = 0; int i, j, skip, start, end, low, high, minClk, waveStart; bool complete = false; - int tmpbuff[bufsize / 64]; - int waveLen[bufsize / 64]; + int tmpbuff[bufsize / 32]; //guess rf/32 clock, if click is smaller we will only have room for a fraction of the samples captured + int waveLen[bufsize / 32]; // if clock is larger then we waste memory in array size that is not needed... size_t testsize = (bufsize < 512) ? bufsize : 512; int phaseoff = 0; high = low = 128; memset(tmpbuff, 0, sizeof(tmpbuff)); + memset(waveLen, 0, sizeof(waveLen)); + if ( getHiLo(buffer, testsize, &high, &low, 80, 80) == -1 ) { if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting"); return false; //just noise @@ -1639,7 +1714,7 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) { waveStart = i; while ((buffer[i] > low) && (i < bufsize)) ++i; - if (j >= (bufsize/64)) { + if (j >= (bufsize/32)) { break; } waveLen[j] = i - waveStart; //first high to first low @@ -1685,6 +1760,8 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) { if (start < 0) { if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting"); return false; + } else { + if (g_debugMode==2) prnt("DEBUG STT: first STT found at: %d, j=%d",start, j); } if (waveLen[i+2] > clk*1+tol) phaseoff = 0; @@ -1698,7 +1775,7 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) { end = skip; for (i += 3; i < j - 4; ++i) { end += tmpbuff[i]; - if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol) { //1 to 2 clocks depending on 2 bits prior + if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol && waveLen[i] < clk+tol) { //1 to 2 clocks depending on 2 bits prior if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) { //2 clocks and wave size is 1 1/2 if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit @@ -1720,12 +1797,15 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) { start = skip; size_t datalen = end - start; // check validity of datalen (should be even clock increments) - use a tolerance of up to 1/8th a clock - if (datalen % clk > clk/8) { + if ( clk - (datalen % clk) <= clk/8) { + // padd the amount off - could be problematic... but shouldn't happen often + datalen += clk - (datalen % clk); + } else if ( (datalen % clk) <= clk/8 ) { + // padd the amount off - could be problematic... but shouldn't happen often + datalen -= datalen % clk; + } else { if (g_debugMode==2) prnt("DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting", datalen, clk, datalen % clk); return false; - } 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) { @@ -1733,8 +1813,20 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) { return false; } size_t dataloc = start; + if (buffer[dataloc-(clk*4)-(clk/8)] <= low && buffer[dataloc] <= low && buffer[dataloc-(clk*4)] >= high) { + //we have low drift (and a low just before the ST and a low just after the ST) - compensate by backing up the start + for ( i=0; i <= (clk/8); ++i ) { + if ( buffer[dataloc - (clk*4) - i] <= low ) { + dataloc -= i; + break; + } + } + } + size_t newloc = 0; i=0; + if (g_debugMode==2) prnt("DEBUG STT: Starting STT trim - start: %d, datalen: %d ",dataloc, datalen); + // warning - overwriting buffer given with raw wave data with ST removed... while ( dataloc < bufsize-(clk/2) ) { //compensate for long high at end of ST not being high due to signal loss... (and we cut out the start of wave high part) @@ -1753,6 +1845,7 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) { } newloc += i; //skip next ST - we just assume it will be there from now on... + if (g_debugMode==2) prnt("DEBUG STT: skipping STT at %d to %d", dataloc, dataloc+(clk*4)); dataloc += clk*4; } *size = newloc;