X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/a3abb028978d98bf28676d3b4a98083db3b2912a..db8296025f78251ffa2c28d6fe995bbb0a386c77:/common/lfdemod.c diff --git a/common/lfdemod.c b/common/lfdemod.c index 7d40d22e..063c8a74 100644 --- a/common/lfdemod.c +++ b/common/lfdemod.c @@ -282,6 +282,16 @@ 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) @@ -369,7 +379,9 @@ 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 @@ -389,13 +401,22 @@ 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 //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 + if (LastSample > (fchigh-2) && (preLastSample < (fchigh-1) || preLastSample == 0 )){ + dest[numBits-1]=1; //correct last 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; @@ -418,12 +439,16 @@ 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; + if (!numBits) { + if (n < rfLen/fclow) { + n=0; + lastval = dest[idx]; + continue; + } + n = (n * fclow + rfLen/4) / rfLen; + } else { + n = (n * fclow + rfLen/2) / rfLen; } - n = (n * fclow + rfLen/2) / rfLen; } else {// 0->1 crossing //test first bitsample too small if (!numBits && n < rfLen/fchigh) { @@ -526,7 +551,7 @@ 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 bytebits_to_byte(uint8_t *src, size_t numbits) { uint32_t num = 0; for(int i = 0 ; i < numbits ; i++) @@ -537,6 +562,17 @@ uint32_t bytebits_to_byte(uint8_t* src, size_t numbits) 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; @@ -565,11 +601,30 @@ int IOdemodFSK(uint8_t *dest, size_t size) return (int) startIdx; } return -5; +} + +// by marshmellow +// 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; } // 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), and binary Length (length to run) +// 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; @@ -579,9 +634,13 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p parityWd = (parityWd << 1) | BitStream[startIdx+word+bit]; BitStream[j++] = (BitStream[startIdx+word+bit]); } - j--; + j--; // overwrite parity with next data // if parity fails then return 0 - if (parityTest(parityWd, pLen, pType) == 0) return -1; + 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; } @@ -590,6 +649,21 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p return bitCnt; } +// 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; + + 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 + return (int)startIdx; +} + // by marshmellow // FSK Demod then try to locate an AWID ID int AWIDdemodFSK(uint8_t *dest, size_t *size) @@ -633,15 +707,26 @@ int PyramiddemodFSK(uint8_t *dest, size_t *size) return (int)startIdx; } +/* +void dummy(char *fmt, ...){} + +#ifndef ON_DEVICE +#include "ui.h" +#define prnt PrintAndLog +#else + +#define prnt dummy +#endif +*/ // 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) { uint16_t allPeaks=1; 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]= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1) return fndClk[clkCnt]; @@ -700,8 +785,8 @@ 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 (;i= 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; @@ -839,7 +923,7 @@ int DetectPSKClock(uint8_t dest[], size_t size, int clock) } } } - //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen); + //prnt("DEBUG: 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--){ @@ -847,7 +931,7 @@ 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); + //prnt("DEBUG: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit); for (i = firstFullWave+fullWaveLen-1; i < loopCnt-2; i++){ //top edge of wave = start of new wave @@ -860,7 +944,7 @@ 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); + //prnt("DEBUG: phase shift at: %d, len: %d, nextClk: %d, ii: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+clk[clkCnt]-tol,ii+1,fc); if (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit peakcnt++; lastClkBit+=clk[clkCnt]; @@ -889,11 +973,50 @@ 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]); + //prnt("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],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; + uint8_t lastWasHigh=0; + //find first valid beginning of a high/low wave + if (dest[i] >= peak) { + for (; i < size; i++) { + if (dest[i] <= low) break; + } + lastWasHigh=0; + } else if (dest[i] <= low) { + for (; i < size; i++) { + if (dest[i] >= peak) break; + } + lastWasHigh=1; + } else { + for (; i < size; i++) { + if (dest[i] >= peak || dest[i] <= low) { + lastWasHigh = (dest[i] >= peak); + break; + } + } + } + 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; + 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) @@ -902,8 +1025,7 @@ 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=1; + 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; } } + uint8_t samePeak=0; + uint8_t errBitHigh=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){ - peakcnt++; + uint8_t bitHigh =0; + uint8_t ignoreCnt = 0; + uint8_t ignoreWindow = 4; + int 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 (samePeak) peakcnt--; + bitHigh=1; + peakcnt++; + errBitHigh = 0; + ignoreCnt = ignoreWindow; + lastBit += clk[clkCnt]; + samePeak = 1; + } else if (i == lastBit + clk[clkCnt] + tol) { + lastBit += clk[clkCnt]; + samePeak = 0; + } + //else if not a clock bit and no peaks + } else if (dest[i] < peak && dest[i] > low){ + samePeak = 0; + if (ignoreCnt==0){ + bitHigh=0; + if (errBitHigh==1) peakcnt--; + errBitHigh=0; + } else { + ignoreCnt--; + } + // else if not a clock bit but we have a peak + } else if ((dest[i]>=peak || dest[i]<=low) && (bitHigh==0)) { + //error bar found no clock... + errBitHigh=1; } } if(peakcnt>peaksdet[clkCnt]) { @@ -957,9 +1121,14 @@ int DetectNRZClock(uint8_t dest[], size_t size, int clock) for (iii=7; iii > 0; iii--){ if (peaksdet[iii] > peaksdet[best]){ best = iii; + } else if (peaksdet[iii] == peaksdet[best] && 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]); + //prnt("DEBUG: Clk: %d, peaks: %d, maxPeak: %d, bestClk: %d, lowestTrs: %d",clk[iii],peaksdet[iii],maxPeak, clk[best], lowestTransition); } + return clk[best]; } @@ -1003,182 +1172,53 @@ 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 // 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 @@ -1378,6 +1418,7 @@ 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; @@ -1407,14 +1448,21 @@ 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