X-Git-Url: http://cvs.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/13d77ef964cefe68750873d5268299a53c9e22a5..7666f4608e8ade0ada08777d1cc33469c5d9471d:/common/lfdemod.c diff --git a/common/lfdemod.c b/common/lfdemod.c index 5b0bc29d..8324c440 100644 --- a/common/lfdemod.c +++ b/common/lfdemod.c @@ -9,9 +9,21 @@ //----------------------------------------------------------------------------- #include -#include #include "lfdemod.h" +#include +//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) { @@ -31,13 +43,13 @@ int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi *high=0; *low=255; // get high and low thresholds - for (int i=0; i < size; i++){ + for (size_t i=0; i < size; i++){ if (BitStream[i] > *high) *high = BitStream[i]; if (BitStream[i] < *low) *low = BitStream[i]; } if (*high < 123) return -1; // just noise - *high = (int)(((*high-128)*(((float)fuzzHi)/100))+128); - *low = (int)(((*low-128)*(((float)fuzzLo)/100))+128); + *high = ((*high-128)*fuzzHi + 12800)/100; + *low = ((*low-128)*fuzzLo + 12800)/100; return 1; } @@ -54,254 +66,346 @@ 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 for Always 1's; 3 for Always 0'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 + switch (pType) { + case 3: if (BitStream[j]==1) {return 0;} break; //should be 0 spacer bit + 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); + 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; 3 Always 0's), and binary Length (length to run) +// Make sure *dest is long enough to store original sourceLen + #_of_parities_to_be_added +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 + switch (pType) { + case 3: dest[j++]=0; break; // marker bit which should be a 0 + case 2: dest[j++]=1; break; // marker bit which should be a 1 + default: + dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1; + break; + } + 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) { - uint8_t foundCnt=0; - for (int idx=0; idx < *size - pLen; idx++){ - if (memcmp(BitStream+idx, preamble, pLen) == 0){ - //first index found - foundCnt++; - if (foundCnt == 1){ - *startIdx = idx; - } - if (foundCnt == 2){ - *size = idx - *startIdx; - return 1; - } - } - } - return 0; + uint8_t foundCnt=0; + for (int idx=0; idx < *size - pLen; idx++){ + if (memcmp(BitStream+idx, preamble, pLen) == 0){ + //first index found + foundCnt++; + if (foundCnt == 1){ + *startIdx = idx; + } + if (foundCnt == 2){ + *size = idx - *startIdx; + return 1; + } + } + } + return 0; } //by marshmellow //takes 1s and 0s and searches for EM410x format - output EM ID uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo) { - //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future - // otherwise could be a void with no arguments - //set defaults - uint32_t i = 0; - if (BitStream[1]>1){ //allow only 1s and 0s - // PrintAndLog("no data found"); - return 0; - } - // 111111111 bit pattern represent start of frame - uint8_t preamble[] = {1,1,1,1,1,1,1,1,1}; - uint32_t idx = 0; - uint32_t parityBits = 0; - uint8_t errChk = 0; - uint8_t FmtLen = 10; - *startIdx = 0; - for (uint8_t extraBitChk=0; extraBitChk<5; extraBitChk++){ - errChk = preambleSearch(BitStream+extraBitChk+*startIdx, preamble, sizeof(preamble), size, startIdx); - if (errChk == 0) return 0; - if (*size>64) FmtLen = 22; - if (*size<64) return 0; - idx = *startIdx + 9; - for (i=0; i> 63); - *lo = (*lo << 1) | (BitStream[(i*5)+ii+idx]); - } - } - if (errChk != 0) return 1; - //skip last 5 bit parity test for simplicity. - // *size = 64 | 128; - } - return 0; + //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future + // otherwise could be a void with no arguments + //set defaults + uint32_t i = 0; + if (BitStream[1]>1) return 0; //allow only 1s and 0s + + // 111111111 bit pattern represent start of frame + // include 0 in front to help get start pos + uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1}; + uint32_t idx = 0; + uint32_t parityBits = 0; + uint8_t errChk = 0; + uint8_t FmtLen = 10; + *startIdx = 0; + errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx); + if (errChk == 0 || *size < 64) return 0; + if (*size > 64) FmtLen = 22; + *startIdx += 1; //get rid of 0 from preamble + idx = *startIdx + 9; + for (i=0; i> 63); + *lo = (*lo << 1) | (BitStream[(i*5)+ii+idx]); + } + } + if (errChk != 0) return 1; + //skip last 5 bit parity test for simplicity. + // *size = 64 | 128; + return 0; } //by marshmellow -//takes 3 arguments - clock, invert, maxErr as integers -//attempts to demodulate ask while decoding manchester -//prints binary found and saves in graphbuffer for further commands -int askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr) +//demodulates strong heavily clipped samples +int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low) { - int i; - //int clk2=*clk; - int start = DetectASKClock(BinStream, *size, clk, 20); //clock default - if (*clk==0) return -3; - if (start < 0) return -3; - // if autodetected too low then adjust //MAY NEED ADJUSTMENT - //if (clk2==0 && *clk<8) *clk =64; - //if (clk2==0 && *clk<32) *clk=32; - if (*invert != 0 && *invert != 1) *invert=0; - uint32_t initLoopMax = 200; - if (initLoopMax > *size) initLoopMax=*size; - // Detect high and lows - // 25% fuzz in case highs and lows aren't clipped [marshmellow] - int high, low, ans; - ans = getHiLo(BinStream, initLoopMax, &high, &low, 75, 75); - if (ans<1) return -2; //just noise - - // PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low); - int lastBit = 0; //set first clock check - uint32_t bitnum = 0; //output counter - int 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 - int iii = 0; - uint32_t gLen = *size; - if (gLen > 3000) gLen=3000; - //if 0 errors allowed then only try first 2 clock cycles as we want a low tolerance - if (!maxErr) gLen=*clk*2; - uint8_t errCnt =0; - uint16_t MaxBits = 500; - uint32_t bestStart = *size; - int bestErrCnt = maxErr+1; - // PrintAndLog("DEBUG - lastbit - %d",lastBit); - // loop to find first wave that works - for (iii=0; iii < gLen; ++iii){ - if ((BinStream[iii] >= high) || (BinStream[iii] <= low)){ - lastBit=iii-*clk; - errCnt=0; - // loop through to see if this start location works - for (i = iii; i < *size; ++i) { - if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){ - lastBit+=*clk; - } else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){ - //low found and we are expecting a bar - lastBit+=*clk; - } else { - //mid value found or no bar supposed to be here - if ((i-lastBit)>(*clk+tol)){ - //should have hit a high or low based on clock!! - - //debug - //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit); - + size_t bitCnt=0, smplCnt=0, errCnt=0; + uint8_t waveHigh = 0; + for (size_t i=0; i < *size; i++){ + if (BinStream[i] >= high && waveHigh){ + smplCnt++; + } else if (BinStream[i] <= low && !waveHigh){ + 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++; - lastBit+=*clk;//skip over until hit too many errors - if (errCnt>(maxErr)) break; //allow 1 error for every 1000 samples else start over + if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i); + BinStream[bitCnt++]=7; + } else if (waveHigh) { + BinStream[bitCnt++] = invert; + BinStream[bitCnt++] = invert; + } else if (!waveHigh) { + BinStream[bitCnt++] = invert ^ 1; + BinStream[bitCnt++] = invert ^ 1; } - } - if ((i-iii) >(MaxBits * *clk)) break; //got plenty of bits - } - //we got more than 64 good bits and not all errors - if ((((i-iii)/ *clk) > (64)) && (errCnt<=maxErr)) { - //possible good read - if (errCnt==0){ - bestStart=iii; - bestErrCnt=errCnt; - break; //great read - finish - } - if (errCnt= high) && ((i-lastBit) > (*clk-tol))){ - lastBit += *clk; - BinStream[bitnum] = *invert; - bitnum++; - } else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){ - //low found and we are expecting a bar - lastBit+=*clk; - BinStream[bitnum] = 1-*invert; - bitnum++; - } else { - //mid value found or no bar supposed to be here - if ((i-lastBit)>(*clk+tol)){ - //should have hit a high or low based on clock!! - - //debug - //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit); - if (bitnum > 0){ - BinStream[bitnum]=77; - bitnum++; + waveHigh ^= 1; + smplCnt = 0; + } else if (smplCnt > (clk/2) - (clk/4)-1) { + if (waveHigh) { + BinStream[bitCnt++] = invert; + } else if (!waveHigh) { + BinStream[bitCnt++] = invert ^ 1; } - - lastBit+=*clk;//skip over error + waveHigh ^= 1; + smplCnt = 0; + } else if (!bitCnt) { + //first bit + waveHigh = (BinStream[i] >= high); + smplCnt = 1; + } else { + smplCnt++; + //transition bit oops } + } else { //haven't hit new high or new low yet + smplCnt++; } - if (bitnum >=MaxBits) break; } - *size=bitnum; - } else{ - *invert=bestStart; - *clk=iii; - return -1; } - return bestErrCnt; + *size = bitCnt; + return errCnt; } //by marshmellow -//encode binary data into binary manchester -int ManchesterEncode(uint8_t *BitStream, size_t size) +void askAmp(uint8_t *BitStream, size_t size) { - size_t modIdx=20000, i=0; - if (size>modIdx) return -1; - for (size_t idx=0; idx < size; idx++){ - BitStream[idx+modIdx++] = BitStream[idx]; - BitStream[idx+modIdx++] = BitStream[idx]^1; + uint8_t Last = 128; + for(size_t i = 1; i=30) //large jump up + Last = 255; + else if(BitStream[i-1]-BitStream[i]>=20) //large jump down + Last = 0; + + BitStream[i-1] = Last; } - for (; i<(size*2); i++){ - BitStream[i] = BitStream[i+20000]; + return; +} + +//by marshmellow +//attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester +int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType) +{ + 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); + + uint8_t initLoopMax = 255; + if (initLoopMax > *size) initLoopMax = *size; + // Detect high and lows + //25% clip in case highs and lows aren't clipped [marshmellow] + int high, low; + if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1) + return -2; //just noise + + 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; } - return i; + 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 = 3072; //max bits to collect + lastBit = start - *clk; + + for (i = start; i < *size; ++i) { + if (i-lastBit >= *clk-tol){ + if (BinStream[i] >= high) { + BinStream[bitnum++] = *invert; + } else if (BinStream[i] <= low) { + 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++; + } + } else { //in tolerance - looking for peak + continue; + } + midBit = 0; + lastBit += *clk; + } else if (i-lastBit >= (*clk/2-tol) && !midBit && !askType){ + if (BinStream[i] >= high) { + BinStream[bitnum++] = *invert; + } else if (BinStream[i] <= low) { + BinStream[bitnum++] = *invert ^ 1; + } else if (i-lastBit >= *clk/2+tol) { + BinStream[bitnum] = BinStream[bitnum-1]; + bitnum++; + } else { //in tolerance - looking for peak + continue; + } + midBit = 1; + } + if (bitnum >= MaxBits) break; + } + *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) +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; - if (size == 0) return -1; + if (*size < 16) return -1; + //find correct start position [alignment] for (ii=0;ii<2;++ii){ - i=0; - for (i=i+ii;i<*size-2;i+=2){ - if(BitStream[i]==1 && (BitStream[i+1]==0)){ - } else if((BitStream[i]==0)&& BitStream[i+1]==1){ - } else { + for (i=ii; i<*size-3; i+=2) + if (BitStream[i]==BitStream[i+1]) errCnt++; - } - if(bitnum>MaxBits) break; - } + if (bestErr>errCnt){ bestErr=errCnt; bestRun=ii; } errCnt=0; } - errCnt=bestErr; - if (errCnt<20){ - ii=bestRun; - i=0; - for (i=i+ii; i < *size-2; i+=2){ - if(BitStream[i] == 1 && (BitStream[i+1] == 0)){ - BitStream[bitnum++]=0; - } else if((BitStream[i] == 0) && BitStream[i+1] == 1){ - BitStream[bitnum++]=1; - } else { - BitStream[bitnum++]=77; - //errCnt++; - } - if(bitnum>MaxBits) break; + //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; + } else { + BitStream[bitnum++]=7; } - *size=bitnum; + if(bitnum>MaxBits) break; } - return errCnt; + *size=bitnum; + 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) +{ + size_t modIdx=20000, i=0; + if (size>modIdx) return -1; + for (size_t idx=0; idx < size; idx++){ + BitStream[idx+modIdx++] = BitStream[idx]; + BitStream[idx+modIdx++] = BitStream[idx]^1; + } + for (; i<(size*2); i++){ + BitStream[i] = BitStream[i+20000]; + } + return i; } //by marshmellow @@ -310,9 +414,9 @@ int manrawdecode(uint8_t * BitStream, size_t *size) //decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert) { - uint16_t bitnum=0; - uint32_t errCnt =0; - size_t i=offset; + uint16_t bitnum = 0; + uint16_t errCnt = 0; + size_t i = offset; uint16_t MaxBits=512; //if not enough samples - error if (*size < 51) return -1; @@ -326,7 +430,7 @@ int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert) for (i=offset; i<*size-3; i+=2){ //check for phase error if (BitStream[i+1]==BitStream[i+2]) { - BitStream[bitnum++]=77; + BitStream[bitnum++]=7; errCnt++; } if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){ @@ -334,7 +438,7 @@ int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert) } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){ BitStream[bitnum++]=invert; } else { - BitStream[bitnum++]=77; + BitStream[bitnum++]=7; errCnt++; } if(bitnum>MaxBits) break; @@ -343,233 +447,7 @@ int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert) return errCnt; } -//by marshmellow -void askAmp(uint8_t *BitStream, size_t size) -{ - int shift = 127; - int shiftedVal=0; - for(int i = 1; i=30) //large jump up - shift=127; - else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down - shift=-127; - - shiftedVal=BitStream[i]+shift; - - if (shiftedVal>255) - shiftedVal=255; - else if (shiftedVal<0) - shiftedVal=0; - BitStream[i-1] = shiftedVal; - } - return; -} - -int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low) -{ - size_t bitCnt=0, smplCnt=0, errCnt=0; - uint8_t waveHigh = 0; - //PrintAndLog("clk: %d", clk); - for (size_t i=0; i < *size; i++){ - if (BinStream[i] >= high && waveHigh){ - smplCnt++; - } else if (BinStream[i] <= low && !waveHigh){ - smplCnt++; - } else { //not high or low or a transition - if (smplCnt > clk-(clk/4)) { //full clock - if (smplCnt > clk + (clk/4)) { //too many samples - errCnt++; - BinStream[bitCnt++]=77; - } else if (waveHigh) { - BinStream[bitCnt++] = invert; - BinStream[bitCnt++] = invert; - } else if (!waveHigh) { - BinStream[bitCnt++] = invert ^ 1; - BinStream[bitCnt++] = invert ^ 1; - } - waveHigh ^= 1; - smplCnt = 0; - } else if (smplCnt > (clk/2) - (clk/5)) { - if (waveHigh) { - BinStream[bitCnt++] = invert; - } else if (!waveHigh) { - BinStream[bitCnt++] = invert ^ 1; - } - waveHigh ^= 1; - smplCnt = 0; - } else if (!bitCnt) { - //first bit - waveHigh = (BinStream[i] >= high); - smplCnt = 1; - } else { - //transition bit? ignore - } - } - } - *size = bitCnt; - return errCnt; -} - -//by marshmellow -//takes 3 arguments - clock, invert and maxErr as integers -//attempts to demodulate ask only -int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp) -{ - uint32_t i; - if (*size==0) return -1; - int start = DetectASKClock(BinStream, *size, clk, 20); //clock default - if (*clk==0) return -1; - if (start<0) return -1; - if (*invert != 0 && *invert != 1) *invert =0; - if (amp==1) askAmp(BinStream, *size); - - uint32_t initLoopMax = 200; - if (initLoopMax > *size) initLoopMax=*size; - // Detect high and lows - //25% clip in case highs and lows aren't clipped [marshmellow] - uint8_t clip = 75; - int high, low, ans; - ans = getHiLo(BinStream, initLoopMax, &high, &low, clip, clip); - if (ans<1) return -1; //just noise - - if (DetectCleanAskWave(BinStream, *size, high, low)) { - //PrintAndLog("Clean"); - return cleanAskRawDemod(BinStream, size, *clk, *invert, high, low); - } - - //PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low); - int lastBit = 0; //set first clock check - uint32_t bitnum = 0; //output counter - 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=0; //clock tolerance may not be needed anymore currently set to - // + or - 1 but could be increased for poor waves or removed entirely - uint32_t iii = 0; - uint32_t gLen = *size; - if (gLen > 500) gLen=500; - //if 0 errors allowed then only try first 2 clock cycles as we want a low tolerance - if (!maxErr) gLen = *clk * 2; - uint8_t errCnt =0; - uint32_t bestStart = *size; - uint32_t bestErrCnt = maxErr; //(*size/1000); - uint8_t midBit=0; - uint16_t MaxBits=1000; - - //PrintAndLog("DEBUG - lastbit - %d",lastBit); - //loop to find first wave that works - for (iii=start; iii < gLen; ++iii){ - if ((BinStream[iii]>=high) || (BinStream[iii]<=low)){ - lastBit=iii-*clk; - errCnt=0; - //loop through to see if this start location works - for (i = iii; i < *size; ++i) { - if ((BinStream[i] >= high) && ((i-lastBit)>(*clk-tol))){ - lastBit+=*clk; - midBit=0; - } else if ((BinStream[i] <= low) && ((i-lastBit)>(*clk-tol))){ - //low found and we are expecting a bar - lastBit+=*clk; - midBit=0; - } else if ((BinStream[i]<=low) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){ - //mid bar? - midBit=1; - } else if ((BinStream[i]>=high) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){ - //mid bar? - midBit=1; - } else if ((i-lastBit)>((*clk/2)+tol) && (midBit==0)){ - //no mid bar found - midBit=1; - } else { - //mid value found or no bar supposed to be here - - if ((i-lastBit)>(*clk+tol)){ - //should have hit a high or low based on clock!! - //debug - //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit); - - errCnt++; - lastBit+=*clk;//skip over until hit too many errors - if (errCnt > maxErr){ - //errCnt=0; - break; - } - } - } - if ((i-iii)>(MaxBits * *clk)) break; //got enough bits - } - //we got more than 64 good bits and not all errors - if ((((i-iii)/ *clk) > (64)) && (errCnt<=maxErr)) { - //possible good read - if (errCnt==0){ - bestStart=iii; - bestErrCnt=errCnt; - break; //great read - finish - } - if (errCnt= high) && ((i-lastBit) > (*clk-tol))){ - lastBit += *clk; - BinStream[bitnum] = *invert; - bitnum++; - midBit=0; - } else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){ - //low found and we are expecting a bar - lastBit+=*clk; - BinStream[bitnum] = 1 - *invert; - bitnum++; - midBit=0; - } else if ((BinStream[i]<=low) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){ - //mid bar? - midBit=1; - BinStream[bitnum] = 1 - *invert; - bitnum++; - } else if ((BinStream[i]>=high) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){ - //mid bar? - midBit=1; - BinStream[bitnum] = *invert; - bitnum++; - } else if ((i-lastBit)>((*clk/2)+tol) && (midBit==0)){ - //no mid bar found - midBit=1; - if (bitnum!=0) BinStream[bitnum] = BinStream[bitnum-1]; - bitnum++; - - } else { - //mid value found or no bar supposed to be here - if ((i-lastBit)>(*clk+tol)){ - //should have hit a high or low based on clock!! - - //debug - //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit); - if (bitnum > 0){ - BinStream[bitnum]=77; - bitnum++; - } - lastBit+=*clk;//skip over error - } - } - if (bitnum >= MaxBits) break; - } - *size=bitnum; - } else{ - *invert=bestStart; - *clk=iii; - return -1; - } - return bestErrCnt; -} - +// by marshmellow // demod gProxIIDemod // error returns as -x // success returns start position in BitStream @@ -588,162 +466,148 @@ int gProxII_Demod(uint8_t BitStream[], size_t *size) //return start position return (int) startIdx; } - return -5; + return -5; //spacer bits not found - not a valid gproxII } -//translate wave to 11111100000 (1 for each short wave 0 for each long wave) +//translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq]) size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow) { - uint32_t last_transition = 0; - uint32_t idx = 1; + size_t last_transition = 0; + size_t idx = 1; //uint32_t maxVal=0; if (fchigh==0) fchigh=10; 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 + // 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 - for(idx = 1; idx < size; idx++) { + // (could also be fc/5 && fc/7 for fsk1 = 4-9) + for(idx = 161; idx < size-20; idx++) { // threshold current value if (dest[idx] < threshold_value) dest[idx] = 0; else dest[idx] = 1; // Check for 0->1 transition - if (dest[idx-1] < dest[idx]) { // 0 -> 1 transition - if ((idx-last_transition)<(fclow-2)){ //0-5 = garbage noise + if (dest[idx-1] < dest[idx]) { + 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 - dest[numBits]=1; - } else if ((idx-last_transition) > (fchigh+1) && !numBits) { //12 + and first bit = 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 )){ + dest[numBits-1]=1; + } + dest[numBits++]=1; + + } else if (currSample > (fchigh) && !numBits) { //12 + and first bit = unusable garbage //do nothing with beginning garbage - } else { //9+ = 10 waves - dest[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) + dest[numBits++]=0; } last_transition = idx; - numBits++; } } return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0 } -uint32_t myround2(float f) -{ - if (f >= 2000) return 2000;//something bad happened - return (uint32_t) (f + (float)0.5); -} - //translate 11111100000 to 10 -size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t maxConsequtiveBits, - uint8_t invert, uint8_t fchigh, uint8_t fclow) +//rfLen = clock, fchigh = larger field clock, fclow = smaller field clock +size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, + uint8_t invert, uint8_t fchigh, uint8_t fclow) { uint8_t lastval=dest[0]; - uint32_t idx=0; + size_t idx=0; size_t numBits=0; uint32_t n=1; - float lowWaves = (((float)(rfLen))/((float)fclow)); - float highWaves = (((float)(rfLen))/((float)fchigh)); for( idx=1; idx < size; idx++) { - - if (dest[idx]==lastval) { - n++; - continue; - } n++; + 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 if (dest[idx-1]==1) { - if (!numBits && n < (uint8_t)lowWaves) { - n=0; - lastval = dest[idx]; - continue; - } - n=myround2(((float)n)/lowWaves); + n = (n * fclow + rfLen/2) / rfLen; } else {// 0->1 crossing - //test first bitsample too small - if (!numBits && n < (uint8_t)highWaves) { - n=0; - lastval = dest[idx]; - continue; - } - n = myround2(((float)n)/highWaves); //-1 for fudge factor + n = (n * fchigh + rfLen/2) / rfLen; } if (n == 0) n = 1; - if(n < maxConsequtiveBits) //Consecutive - { - if(invert==0){ //invert bits - memset(dest+numBits, dest[idx-1] , n); - }else{ - memset(dest+numBits, dest[idx-1]^1 , n); - } - numBits += n; - } + //add to our destination the bits we collected + memset(dest+numBits, dest[idx-1]^invert , n); + numBits += n; n=0; lastval=dest[idx]; }//end for - // if valid extra bits at the end were all the same frequency - add them in - if (n > lowWaves && n > highWaves) { + if (n > rfLen/fchigh) { if (dest[idx-2]==1) { - n=myround2((float)(n+1)/((float)(rfLen)/(float)fclow)); + n = (n * fclow + rfLen/2) / rfLen; } else { - n=myround2((float)(n+1)/((float)(rfLen-1)/(float)fchigh)); //-1 for fudge factor + n = (n * fchigh + rfLen/2) / rfLen; } - memset(dest, dest[idx-1]^invert , n); + memset(dest+numBits, dest[idx-1]^invert , n); numBits += n; } 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) { // FSK demodulator size = fsk_wave_demod(dest, size, fchigh, fclow); - size = aggregate_bits(dest, size, rfLen, 192, invert, fchigh, fclow); + size = aggregate_bits(dest, size, rfLen, invert, fchigh, fclow); return size; } // loop to get raw HID waveform then FSK demodulate the TAG ID from it int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo) { - if (justNoise(dest, *size)) return -1; - - size_t numStart=0, size2=*size, startIdx=0; - // FSK demodulator - *size = fskdemod(dest, size2,50,1,10,8); //fsk2a - if (*size < 96) return -2; - // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1 - uint8_t preamble[] = {0,0,0,1,1,1,0,1}; - // find bitstring in array - uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); - if (errChk == 0) return -3; //preamble not found - - numStart = startIdx + sizeof(preamble); - // final loop, go over previously decoded FSK data and manchester decode into usable tag ID - for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){ - if (dest[idx] == dest[idx+1]){ - return -4; //not manchester data - } - *hi2 = (*hi2<<1)|(*hi>>31); - *hi = (*hi<<1)|(*lo>>31); - //Then, shift in a 0 or one into low - if (dest[idx] && !dest[idx+1]) // 1 0 - *lo=(*lo<<1)|1; - else // 0 1 - *lo=(*lo<<1)|0; - } - return (int)startIdx; + if (justNoise(dest, *size)) return -1; + + size_t numStart=0, size2=*size, startIdx=0; + // FSK demodulator + *size = fskdemod(dest, size2,50,1,10,8); //fsk2a + if (*size < 96*2) return -2; + // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1 + uint8_t preamble[] = {0,0,0,1,1,1,0,1}; + // find bitstring in array + uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); + if (errChk == 0) return -3; //preamble not found + + numStart = startIdx + sizeof(preamble); + // final loop, go over previously decoded FSK data and manchester decode into usable tag ID + for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){ + if (dest[idx] == dest[idx+1]){ + return -4; //not manchester data + } + *hi2 = (*hi2<<1)|(*hi>>31); + *hi = (*hi<<1)|(*lo>>31); + //Then, shift in a 0 or one into low + if (dest[idx] && !dest[idx+1]) // 1 0 + *lo=(*lo<<1)|1; + else // 0 1 + *lo=(*lo<<1)|0; + } + return (int)startIdx; } // loop to get raw paradox waveform then FSK demodulate the TAG ID from it @@ -778,17 +642,6 @@ 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; -} - int IOdemodFSK(uint8_t *dest, size_t size) { if (justNoise(dest, size)) return -1; @@ -817,29 +670,53 @@ int IOdemodFSK(uint8_t *dest, size_t size) return (int) startIdx; } return -5; -} +} // 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) -size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen) +// 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) { - 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 (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; + //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 @@ -864,7 +741,7 @@ 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 @@ -885,67 +762,61 @@ int PyramiddemodFSK(uint8_t *dest, size_t *size) return (int)startIdx; } - -uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, int high, int low) +// 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) { - uint8_t allPeaks=1; + bool allArePeaks = true; uint16_t cntPeaks=0; - for (size_t i=30; i<255; i++){ + size_t loopEnd = 512+160; + if (loopEnd > size) loopEnd = size; + for (size_t i=160; ilow && dest[i]210) return 1; + if (!allArePeaks){ + if (cntPeaks > 300) return true; } - return allPeaks; + return allArePeaks; } - -int DetectStrongAskClock(uint8_t dest[], size_t size) +// 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 clk[]={0,8,16,32,40,50,64,100,128,256}; - size_t idx = 40; - uint8_t high=0; - size_t cnt = 0; - size_t highCnt = 0; - size_t highCnt2 = 0; - for (;idx < size; idx++){ - if (dest[idx]>128) { - if (!high){ - high=1; - if (cnt > highCnt){ - if (highCnt != 0) highCnt2 = highCnt; - highCnt = cnt; - } else if (cnt > highCnt2) { - highCnt2 = cnt; - } - cnt=1; - } else { - cnt++; - } - } else if (dest[idx] <= 128){ - if (high) { - high=0; - if (cnt > highCnt) { - if (highCnt != 0) highCnt2 = highCnt; - highCnt = cnt; - } else if (cnt > highCnt2) { - highCnt2 = cnt; - } - cnt=1; - } else { - cnt++; - } - } + uint8_t fndClk[] = {8,16,32,40,50,64,128}; + size_t startwave; + 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)) + ++i; + while ((dest[i] > low) && (i < size)) + ++i; + + // loop through all samples + while (i < size) { + // measure from low to low + while ((dest[i] > low) && (i < size)) + ++i; + startwave= i; + while ((dest[i] < high) && (i < size)) + ++i; + while ((dest[i] > low) && (i < size)) + ++i; + //get minimum measured distance + if (i-startwave < minClk && i < size) + minClk = i - startwave; } - for (idx=8; idx>0; idx--){ - if (clk[idx] >= highCnt && clk[idx] <= highCnt+2) - return clk[idx]; - if (clk[idx] >= highCnt2 && clk[idx] <= highCnt2+2) - return clk[idx]; + // 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]; } - return -1; + return 0; } // by marshmellow @@ -954,87 +825,104 @@ int DetectStrongAskClock(uint8_t dest[], size_t size) // 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) { - int i=0; - int clk[]={8,16,32,40,50,64,100,128,256}; - int loopCnt = 256; //don't need to loop through entire array... - if (size == 0) return -1; - if (size0; i--){ - if (clk[i] == ans) { - *clock=ans; - return 0; - } - } - } - int ii; - int clkCnt; - int tol = 0; - int bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000}; - int bestStart[]={0,0,0,0,0,0,0,0,0}; - int errCnt=0; - //test each valid clock from smallest to greatest to see which lines up - for(clkCnt=0; clkCnt < 8; clkCnt++){ - if (clk[clkCnt] == 32){ - tol=1; - }else{ - tol=0; - } - if (!maxErr) loopCnt=clk[clkCnt]*2; - bestErr[clkCnt]=1000; - //try lining up the peaks by moving starting point (try first 256) - for (ii=0; ii < loopCnt; ii++){ - if ((dest[ii] >= peak) || (dest[ii] <= low)){ - errCnt=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){ - }else if(dest[ii+(i*clk[clkCnt])-tol]>=peak || dest[ii+(i*clk[clkCnt])-tol]<=low){ - }else if(dest[ii+(i*clk[clkCnt])+tol]>=peak || dest[ii+(i*clk[clkCnt])+tol]<=low){ - }else{ //error no peak detected - errCnt++; - } - } - //if we found no errors then we can stop here - // this is correct one - return this clock - //PrintAndLog("DEBUG: clk %d, err %d, ii %d, i %d",clk[clkCnt],errCnt,ii,i); - if(errCnt==0 && clkCnt<6) { - *clock = clk[clkCnt]; - return ii; - } - //if we found errors see if it is lowest so far and save it as best run - if(errCntmaxErr) return -1; - *clock=clk[best]; - return bestStart[best]; + 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... + 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; + //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] + } + } + } + } + uint8_t ii; + uint8_t clkCnt, tol = 0; + uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000}; + uint8_t bestStart[]={0,0,0,0,0,0,0,0,0}; + size_t errCnt = 0; + size_t arrLoc, loopEnd; + + if (clockFnd>0) { + clkCnt = clockFnd; + clkEnd = clockFnd+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){ + tol=1; + }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; + //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; + // 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){ + arrLoc = ii + (i * clk[clkCnt]); + if (dest[arrLoc] >= peak || dest[arrLoc] <= low){ + }else if (dest[arrLoc-tol] >= peak || dest[arrLoc-tol] <= low){ + }else if (dest[arrLoc+tol] >= peak || dest[arrLoc+tol] <= low){ + }else{ //error no peak detected + errCnt++; + } + } + //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 (!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= dest[i+2]){ - if (waveStart == 0) { - waveStart = i+1; - //PrintAndLog("DEBUG: waveStart: %d",waveStart); - } else { - waveEnd = i+1; - //PrintAndLog("DEBUG: waveEnd: %d",waveEnd); - waveLenCnt = waveEnd-waveStart; - if (waveLenCnt > fc){ - firstFullWave = waveStart; - fullWaveLen=waveLenCnt; - break; - } - waveStart=0; - } - } - } - //PrintAndLog("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--){ - lastClkBit = firstFullWave; //set end of wave as clock align - waveStart = 0; - errCnt=0; - peakcnt=0; - //PrintAndLog("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 - if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){ - if (waveStart == 0) { - waveStart = i+1; - waveLenCnt=0; - } else { //waveEnd - waveEnd = i+1; - 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 (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit - peakcnt++; - lastClkBit+=clk[clkCnt]; - } else if (i lastClkBit + clk[clkCnt] + tol + fc){ - lastClkBit+=clk[clkCnt]; //no phase shift but clock bit - } - waveStart=i+1; - } - } - } - 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 - uint8_t best=7; - for (i=7; i>=1; i--){ - 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]); - } - return clk[best]; + 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; + //prnt("DEBUG: waveStart: %d",waveStart); + } else { + waveEnd = i+1; + //prnt("DEBUG: waveEnd: %d",waveEnd); + waveLenCnt = waveEnd-waveStart; + if (waveLenCnt > fc){ + firstFullWave = waveStart; + fullWaveLen=waveLenCnt; + break; + } + waveStart=0; + } + } + } + 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--){ + lastClkBit = firstFullWave; //set end of wave as clock align + waveStart = 0; + errCnt=0; + peakcnt=0; + 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 + if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){ + if (waveStart == 0) { + waveStart = i+1; + waveLenCnt=0; + } else { //waveEnd + waveEnd = i+1; + waveLenCnt = waveEnd-waveStart; + if (waveLenCnt > fc){ + //if this wave is a phase shift + 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]; + } else if (i lastClkBit + clk[clkCnt] + tol + fc){ + lastClkBit+=clk[clkCnt]; //no phase shift but clock bit + } + waveStart=i+1; + } + } + } + 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 + uint8_t best=7; + for (i=7; i>=1; i--){ + if (peaksdet[i] > peaksdet[best]) { + 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]; +} + +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) { - int i=0; - int clk[]={8,16,32,40,50,64,100,128,256}; - int loopCnt = 4096; //don't need to loop through entire array... - if (size == 0) return 0; - if (size= peak || dest[i] <= low){ - peakcnt++; - } else { - if (peakcnt>0 && maxPeak < peakcnt){ - maxPeak = peakcnt; - } - peakcnt=0; - } - } - peakcnt=0; - //test each valid clock from smallest to greatest to see which lines up - for(clkCnt=0; clkCnt < 8; ++clkCnt){ - //ignore clocks smaller than 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++; - } - } - if(peakcnt>peaksdet[clkCnt]) { - peaksdet[clkCnt]=peakcnt; - } - } - } - } - int iii=7; - int best=0; - for (iii=7; iii > 0; iii--){ - if (peaksdet[iii] > peaksdet[best]){ - best = iii; - } - //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]); - } - return clk[best]; + 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... + if (size == 0) return 0; + if (size= peak || dest[i] <= low){ + if (!firstpeak) continue; + smplCnt++; + } else { + 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; + } + } + } + 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 smallest peak + if (clk[clkCnt] < maxPeak - (clk[clkCnt]/4)) continue; + //try lining up the peaks by moving starting point (try first 256) + for (ii=20; ii < loopCnt; ++ii){ + if ((dest[ii] >= peak) || (dest[ii] <= low)){ + peakcnt = 0; + 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]) { + 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; + } + 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]; } // by marshmellow @@ -1211,7 +1177,7 @@ void psk1TOpsk2(uint8_t *BitStream, size_t size) size_t i=1; uint8_t lastBit=BitStream[0]; for (; i*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 + + 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; + } + //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 (i == (start + long_wait)) { + } + *size = numBits; + return 0; +} + +//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 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 rfLensFnd = 0; + uint8_t lastFCcnt = 0; + uint16_t fcCounter = 0; + uint16_t rfCounter = 0; + uint8_t firstBitFnd = 0; + size_t i; + if (size == 0) return 0; + + 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 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-20; i++){ + fcCounter++; + rfCounter++; + + if (BitStream[i] <= BitStream[i-1] || BitStream[i] < BitStream[i+1]) + continue; + // else new peak + // if we got less than the small fc + tolerance then set it to the small fc + if (fcCounter < fcLow+fcTol) + fcCounter = fcLow; + else //set it to the large fc + fcCounter = fcHigh; + + //look for bit clock (rf/xx) + if ((fcCounter < lastFCcnt || fcCounter > lastFCcnt)){ + //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-4) && rfLens[ii] <= (rfCounter+4)){ + rfCnts[ii]++; + rfCounter = 0; + break; + } + } + if (rfCounter > 0 && rfLensFnd < 15){ + //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter); + rfCnts[rfLensFnd]++; + rfLens[rfLensFnd++] = rfCounter; + } + } else { + firstBitFnd++; + } + rfCounter=0; + lastFCcnt=fcCounter; } + fcCounter=0; } - 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]; + uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15; + + for (i=0; i<15; i++){ + //get highest 2 RF values (might need to get more values to compare or compare all?) + if (rfCnts[i]>rfCnts[rfHighest]){ + rfHighest3=rfHighest2; + rfHighest2=rfHighest; + rfHighest=i; + } else if(rfCnts[i]>rfCnts[rfHighest2]){ + rfHighest3=rfHighest2; + rfHighest2=i; + } else if(rfCnts[i]>rfCnts[rfHighest3]){ + rfHighest3=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 (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; + + 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>=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; + } } } - if (iii == (ii + long_wait)) { - break; - } } - if (ii== *size - 250 + 1){ - // did not find second start sequence - return -2; - } - bitCnt=ii-start; - // Dumping UID - i = start; - for (ii = 0; ii < bitCnt; ii++) { - bitStream[ii] = bitStream[i++]; - } - *size=bitCnt; - return 1; -} + if (ii<0) return 0; // oops we went too far -// by marshmellow - demodulate NRZ wave (both similar enough) -// 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) -{ - if (justNoise(dest, *size)) return -1; - *clk = DetectNRZClock(dest, *size, *clk); - if (*clk==0) return -2; - uint32_t i; - uint32_t gLen = 4096; - if (gLen>*size) gLen = *size; - 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 - uint32_t bitnum = 0; //output counter - 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 - uint32_t iii = 0; - uint16_t errCnt =0; - uint16_t MaxBits = 1000; - uint32_t bestErrCnt = maxErr+1; - uint32_t bestPeakCnt = 0; - uint32_t bestPeakStart=0; - uint8_t bestFirstPeakHigh=0; - uint8_t firstPeakHigh=0; - uint8_t curBit=0; - uint8_t bitHigh=0; - uint8_t errBitHigh=0; - uint16_t peakCnt=0; - uint8_t ignoreWindow=4; - uint8_t ignoreCnt=ignoreWindow; //in case of noice 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; - bitnum=0; - //loop through to see if this start location works - for (i = iii; i < *size; ++i) { - //if we found a high bar and we are at a clock bit - if ((dest[i]>=high ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){ - bitHigh=1; - lastBit+=*clk; - bitnum++; - peakCnt++; - errBitHigh=0; - ignoreCnt=ignoreWindow; - //else if low bar found and we are at a clock point - }else if ((dest[i]<=low ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){ - bitHigh=1; - lastBit+=*clk; - bitnum++; - peakCnt++; - errBitHigh=0; - ignoreCnt=ignoreWindow; - //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--; - } - //if we are past a clock point - if (i >= lastBit+*clk+tol){ //clock val - lastBit+=*clk; - bitnum++; - } - //else if bar found but we are not at a clock bit and we did not just have a clock bit - }else if ((dest[i]>=high || dest[i]<=low) && (ilastBit+*clk+tol) && (bitHigh==0)){ - //error bar found no clock... - errBitHigh=1; - } - if (bitnum>=MaxBits) break; - } - //we got more than 64 good bits and not all errors - if (bitnum > (64) && (errCnt <= (maxErr))) { - //possible good read - if (errCnt == 0){ - //bestStart = iii; - bestFirstPeakHigh=firstPeakHigh; - bestErrCnt = errCnt; - bestPeakCnt = peakCnt; - bestPeakStart = iii; - break; //great read - finish - } - if (errCnt < bestErrCnt){ //set this as new best run - bestErrCnt = errCnt; - //bestStart = iii; - } - if (peakCnt > bestPeakCnt){ - bestFirstPeakHigh=firstPeakHigh; - bestPeakCnt=peakCnt; - bestPeakStart=iii; - } - } - } - } - //PrintAndLog("DEBUG: bestErrCnt: %d, maxErr: %d, bestStart: %d, bestPeakCnt: %d, bestPeakStart: %d",bestErrCnt,maxErr,bestStart,bestPeakCnt,bestPeakStart); - if (bestErrCnt <= maxErr){ - //best run is good enough set to best run and set overwrite BinStream - iii=bestPeakStart; - lastBit=bestPeakStart-*clk; - bitnum=0; - memset(dest, bestFirstPeakHigh^1, bestPeakStart / *clk); - bitnum += (bestPeakStart / *clk); - for (i = iii; i < *size; ++i) { - //if we found a high bar and we are at a clock bit - if ((dest[i] >= high ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){ - bitHigh=1; - lastBit+=*clk; - curBit=1-*invert; - dest[bitnum]=curBit; - bitnum++; - errBitHigh=0; - ignoreCnt=ignoreWindow; - //else if low bar found and we are at a clock point - }else if ((dest[i]<=low ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){ - bitHigh=1; - lastBit+=*clk; - curBit=*invert; - dest[bitnum]=curBit; - bitnum++; - errBitHigh=0; - ignoreCnt=ignoreWindow; - //else if no bars found - }else if(dest[i]low) { - if (ignoreCnt==0){ - bitHigh=0; - //if peak is done was it an error peak? - if (errBitHigh==1){ - dest[bitnum]=77; - bitnum++; - errCnt++; - } - errBitHigh=0; - } else { - ignoreCnt--; - } - //if we are past a clock point - if (i>=lastBit+*clk+tol){ //clock val - lastBit+=*clk; - dest[bitnum]=curBit; - bitnum++; - } - //else if bar found but we are not at a clock bit and we did not just have a clock bit - }else if ((dest[i]>=high || dest[i]<=low) && ((ilastBit+*clk+tol)) && (bitHigh==0)){ - //error bar found no clock... - errBitHigh=1; - } - if (bitnum >= MaxBits) break; - } - *size=bitnum; - } else{ - *size=bitnum; - return bestErrCnt; - } - - if (bitnum>16){ - *size=bitnum; - } else return -5; - return errCnt; -} - -//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 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 rfLensFnd = 0; - uint8_t lastFCcnt=0; - uint32_t fcCounter = 0; - uint16_t rfCounter = 0; - uint8_t firstBitFnd = 0; - size_t i; - if (size == 0) return 0; - - uint8_t fcTol = (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++) - if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1]) - break; - - for (; i < size-1; i++){ - if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1]){ - // new peak - fcCounter++; - rfCounter++; - // if we got less than the small fc + tolerance then set it to the small fc - if (fcCounter < fcLow+fcTol) - fcCounter = fcLow; - else //set it to the large fc - fcCounter = fcHigh; - - //look for bit clock (rf/xx) - if ((fcCounterlastFCcnt)){ - //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){ - rfCnts[ii]++; - rfCounter=0; - break; - } - } - if (rfCounter>0 && rfLensFnd<15){ - //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter); - rfCnts[rfLensFnd]++; - rfLens[rfLensFnd++]=rfCounter; - } - } else { - firstBitFnd++; - } - rfCounter=0; - lastFCcnt=fcCounter; - } - fcCounter=0; - } else { - // count sample - fcCounter++; - rfCounter++; - } - } - 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; - rfHighest2=rfHighest; - rfHighest=i; - } else if(rfCnts[i]>rfCnts[rfHighest2]){ - rfHighest3=rfHighest2; - rfHighest2=i; - } else if(rfCnts[i]>rfCnts[rfHighest3]){ - rfHighest3=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]); - - // loop to find the highest clock that has a remainder less than the tolerance - // compare samples counted divided by - int ii=7; - for (; ii>=0; 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){ - break; - } - } - } - } - - if (ii<0) return 0; // oops we went too far - - return clk[ii]; + return clk[ii]; } //by marshmellow //countFC is to detect the field clock lengths. //counts and returns the 2 most common wave lengths //mainly used for FSK field clock detection -uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t *mostFC) +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 fcLensFnd = 0; - uint8_t lastFCcnt=0; - uint32_t fcCounter = 0; - size_t i; - if (size == 0) return 0; - - // prime i to first up transition - for (i = 1; i < size-1; i++) - if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]) - break; - - for (; i < size-1; i++){ - if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){ - // new up transition - fcCounter++; - - //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8) - if (lastFCcnt==5 && fcCounter==9) fcCounter--; - //if odd and not rc/5 add one (for when we get a fc 9 instead of 10) - if ((fcCounter==9 && fcCounter & 1) || fcCounter==4) fcCounter++; - - // save last field clock count (fc/xx) - // find which fcLens to save it to: - for (int ii=0; ii<10; ii++){ - if (fcLens[ii]==fcCounter){ - fcCnts[ii]++; - fcCounter=0; - break; - } - } - if (fcCounter>0 && fcLensFnd<10){ - //add new fc length - fcCnts[fcLensFnd]++; - fcLens[fcLensFnd++]=fcCounter; - } - fcCounter=0; - } else { - // count sample - fcCounter++; - } - } - - uint8_t best1=9, best2=9, best3=9; - 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); - // get the 3 best FC values - if (fcCnts[i]>maxCnt1) { - best3=best2; - best2=best1; - maxCnt1=fcCnts[i]; - best1=i; - } else if(fcCnts[i]>fcCnts[best2]){ - best3=best2; - best2=i; - } else if(fcCnts[i]>fcCnts[best3]){ - best3=i; - } - } - uint8_t fcH=0, fcL=0; - if (fcLens[best1]>fcLens[best2]){ - fcH=fcLens[best1]; - fcL=fcLens[best2]; - } else{ - fcH=fcLens[best2]; - fcL=fcLens[best1]; - } - - *mostFC=fcLens[best1]; - // 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]); - - return fcs; -} + 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; + size_t i; + if (size == 0) return 0; + + // prime i to first up transition + for (i = 160; i < size-20; i++) + if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]) + break; -//by marshmellow -//countPSK_FC is to detect the psk carrier clock length. -//counts and returns the 1 most common wave length -uint8_t countPSK_FC(uint8_t *BitStream, size_t size) -{ - 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 fcLensFnd = 0; - uint32_t fcCounter = 0; - size_t i; - if (size == 0) return 0; - - // prime i to first up transition - for (i = 1; i < size-1; i++) - if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]) - break; - - for (; i < size-1; i++){ - if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){ - // new up transition - fcCounter++; - - // save last field clock count (fc/xx) - // find which fcLens to save it to: - for (int ii=0; ii<10; ii++){ - if (fcLens[ii]==fcCounter){ - fcCnts[ii]++; - fcCounter=0; - break; - } - } - if (fcCounter>0 && fcLensFnd<10){ - //add new fc length - fcCnts[fcLensFnd]++; - fcLens[fcLensFnd++]=fcCounter; - } - fcCounter=0; - } else { - // count sample - fcCounter++; - } - } - - uint8_t best1=9; - uint16_t maxCnt1=0; - // go through fclens and find which ones are bigest - for (i=0; i<10; i++){ - //PrintAndLog("DEBUG: FC %d, Cnt %d",fcLens[i],fcCnts[i]); - // get the best FC value - if (fcCnts[i]>maxCnt1) { - maxCnt1=fcCnts[i]; - best1=i; - } - } - return fcLens[best1]; + for (; i < size-20; i++){ + if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){ + // new up transition + fcCounter++; + if (fskAdj){ + //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8) + if (lastFCcnt==5 && fcCounter==9) fcCounter--; + //if fc=9 or 4 add one (for when we get a fc 9 instead of 10 or a 4 instead of a 5) + if ((fcCounter==9) || fcCounter==4) fcCounter++; + // save last field clock count (fc/xx) + lastFCcnt = fcCounter; + } + // find which fcLens to save it to: + for (int ii=0; ii<15; ii++){ + if (fcLens[ii]==fcCounter){ + fcCnts[ii]++; + fcCounter=0; + break; + } + } + if (fcCounter>0 && fcLensFnd<15){ + //add new fc length + fcCnts[fcLensFnd]++; + fcLens[fcLensFnd++]=fcCounter; + } + fcCounter=0; + } else { + // count sample + fcCounter++; + } + } + + 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<15; i++){ + // get the 3 best FC values + if (fcCnts[i]>maxCnt1) { + best3=best2; + best2=best1; + maxCnt1=fcCnts[i]; + best1=i; + } else if(fcCnts[i]>fcCnts[best2]){ + best3=best2; + best2=i; + } 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]; + fcL=fcLens[best2]; + } else{ + 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; + if (fskAdj) return fcs; + return fcLens[best1]; } //by marshmellow - demodulate PSK1 wave //uses wave lengths (# Samples) 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 == 0) return -1; - if (*size= dest[i+2]){ - waveEnd = i+1; - //PrintAndLog("DEBUG: waveEnd: %d",waveEnd); - waveLenCnt = waveEnd-waveStart; - if (waveLenCnt > fc && waveStart > fc){ //not first peak and is a large wave - 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 - break; - } - waveStart = i+1; - avgWaveVal = 0; - } - avgWaveVal+=dest[i+2]; - } - //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; - errCnt=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 - if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){ - if (waveStart == 0) { - waveStart = i+1; - waveLenCnt=0; - avgWaveVal = dest[i+1]; - } else { //waveEnd - waveEnd = i+1; - waveLenCnt = waveEnd-waveStart; - lastAvgWaveVal = avgWaveVal/waveLenCnt; - if (waveLenCnt > fc){ - //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal); - //if 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); - if (i+1 >= lastClkBit + *clock - tol){ //should be a clock bit - curPhase^=1; - dest[numBits++] = curPhase; - lastClkBit += *clock; - } else if (i lastClkBit + *clock + tol + fc){ - lastClkBit += *clock; //no phase shift but clock bit - dest[numBits++] = curPhase; - } - avgWaveVal=0; - waveStart=i+1; - } - } - avgWaveVal+=dest[i+1]; - } - *size = numBits; - return errCnt; + if (size == 0) return -1; + uint16_t loopCnt = 4096; //don't need to loop through entire array... + if (*size= dest[i+2]){ + waveEnd = i+1; + //PrintAndLog("DEBUG: waveEnd: %d",waveEnd); + waveLenCnt = waveEnd-waveStart; + 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; + //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 + break; + } + waveStart = i+1; + avgWaveVal = 0; + } + 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; + if (g_debugMode==2) prnt("DEBUG PSK: firstFullWave: %u, waveLen: %u",firstFullWave,fullWaveLen); + if (g_debugMode==2) prnt("DEBUG: clk: %d, lastClkBit: %u, fc: %u", *clock, lastClkBit,(unsigned int) fc); + waveStart = 0; + dest[numBits++] = curPhase; //set first read bit + for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){ + //top edge of wave = start of new wave + if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){ + if (waveStart == 0) { + waveStart = i+1; + waveLenCnt = 0; + avgWaveVal = dest[i+1]; + } else { //waveEnd + waveEnd = i+1; + waveLenCnt = waveEnd-waveStart; + lastAvgWaveVal = avgWaveVal/waveLenCnt; + if (waveLenCnt > fc){ + //PrintAndLog("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); + if (i+1 >= lastClkBit + *clock - tol){ //should be a clock bit + curPhase ^= 1; + dest[numBits++] = curPhase; + lastClkBit += *clock; + } else if (i < lastClkBit+10+fc){ + //noise after a phase shift - ignore + } else { //phase shift before supposed to based on clock + errCnt++; + dest[numBits++] = 7; + } + } else if (i+1 > lastClkBit + *clock + tol + fc){ + lastClkBit += *clock; //no phase shift but clock bit + dest[numBits++] = curPhase; + } + avgWaveVal = 0; + waveStart = i+1; + } + } + avgWaveVal += dest[i+1]; + } + *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 / 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)); + + 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/32)) { + 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; + } 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; + 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 && 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 + 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 ( 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; + } + // 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; + 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) + 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