From 8ad1e731c8561ba050db2e80daff7b1e97e575ca Mon Sep 17 00:00:00 2001 From: iceman1001 Date: Thu, 23 Feb 2017 00:52:40 +0100 Subject: [PATCH] chg: @marshmellow42 's changes. --- common/lfdemod.c | 244 ++++++++++++++++++++++++----------------------- common/lfdemod.h | 5 +- 2 files changed, 127 insertions(+), 122 deletions(-) diff --git a/common/lfdemod.c b/common/lfdemod.c index 4b17c6fd..21695ec1 100644 --- a/common/lfdemod.c +++ b/common/lfdemod.c @@ -141,68 +141,103 @@ uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits) return num; } +//by marshmellow +// search for given preamble in given BitStream and return success=1 or fail=0 and startIndex (where it was found) +bool preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx){ + return preambleSearchEx(BitStream, preamble, pLen, size, startIdx, false); +} //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) +// param @findone: look for a repeating preamble or only the first. +// em4x05/4x69 only sends preamble once, so look for it once in the first pLen bits +bool preambleSearchEx(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx, bool findone) { // Sanity check. If preamble length is bigger than bitstream length. - if ( *size <= pLen ) return 0; + if ( *size <= pLen ) return false; uint8_t foundCnt = 0; for (int idx = 0; idx < *size - pLen; idx++){ if (memcmp(BitStream+idx, preamble, pLen) == 0){ + if (g_debugMode) prnt("DEBUG: preamble found at %u", idx); //first index found foundCnt++; if (foundCnt == 1){ *startIdx = idx; + if (findone) return true; } if (foundCnt == 2){ *size = idx - *startIdx; - return 1; + return true; } } } - return 0; + return false; +} + +// find start of modulating data (for fsk and psk) in case of beginning noise or slow chip startup. +size_t findModStart(uint8_t dest[], size_t size, uint8_t threshold_value, uint8_t expWaveSize) { + size_t i = 0; + size_t waveSizeCnt = 0; + uint8_t thresholdCnt = 0; + bool isAboveThreshold = dest[i++] >= threshold_value; + for (; i < size-20; i++ ) { + if(dest[i] < threshold_value && isAboveThreshold) { + thresholdCnt++; + if (thresholdCnt > 2 && waveSizeCnt < expWaveSize+1) break; + isAboveThreshold = false; + waveSizeCnt = 0; + } else if (dest[i] >= threshold_value && !isAboveThreshold) { + thresholdCnt++; + if (thresholdCnt > 2 && waveSizeCnt < expWaveSize+1) break; + isAboveThreshold = true; + waveSizeCnt = 0; + } else { + waveSizeCnt++; + } + if (thresholdCnt > 10) break; + } + if (g_debugMode == 2) prnt("DEBUG: threshold Count reached at %u, count: %u",i, thresholdCnt); + return i; } //by marshmellow //takes 1s and 0s and searches for EM410x format - output EM ID -int Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo) +// actually, no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future +uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo) { - //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 -1; //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; + //allow only 1s and 0s + // only checking first bitvalue?! + if (BitStream[1] > 1) return 0; + + uint32_t i = 0, idx = 0, parityBits = 0; + uint8_t fmtlen = 0; *startIdx = 0; - errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx); - if (errChk == 0 ) return -4; - if (*size < 64) return -3; - if (*size > 64) FmtLen = 22; - *startIdx += 1; //get rid of 0 from preamble - idx = *startIdx + 9; - for (i=0; i 64) ? 22 : 10; + + idx = *startIdx + sizeof(preamble); + + //loop through 10 or 22 sets of 5 bits (50-10p = 40 bits or 88 bits) + for (i=0; i < fmtlen; i++){ + parityBits = bytebits_to_byte(BitStream + (i*5) + idx, 5); + //check even parity + if (parityTest(parityBits, 5, 0) == 0) return 0; //set uint64 with ID from BitStream - for (uint8_t ii=0; ii<4; ii++){ + for (uint8_t j = 0; j < 4; j++){ *hi = (*hi << 1) | (*lo >> 63); - *lo = (*lo << 1) | (BitStream[(i*5)+ii+idx]); + *lo = (*lo << 1) | (BitStream[(i*5) + j + idx]); } } - if (errChk != 0) return 1; //skip last 5 bit parity test for simplicity. // *size = 64 | 128; - return 0; + return 1; } //by marshmellow @@ -457,9 +492,11 @@ int gProxII_Demod(uint8_t BitStream[], size_t *size) size_t startIdx=0; uint8_t preamble[] = {1,1,1,1,1,0}; - uint8_t errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, &startIdx); - if (errChk == 0) return -3; //preamble not found + if (!preambleSearch(BitStream, preamble, sizeof(preamble), size, &startIdx)) + return -3; //preamble not found + if (*size != 96) return -2; //should have found 96 bits + //check first 6 spacer bits to verify format if (!BitStream[startIdx+5] && !BitStream[startIdx+10] && !BitStream[startIdx+15] && !BitStream[startIdx+20] && !BitStream[startIdx+25] && !BitStream[startIdx+30]){ //confirmed proper separator bits found @@ -474,7 +511,6 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow { 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 @@ -484,28 +520,8 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow size_t currSample = 0; if ( size < 1024 ) return 0; // not enough samples - // jump to modulating data by finding the first 4 threshold crossings (or first 2 waves) - // in case you have junk or noise at the beginning of the trace... - uint8_t thresholdCnt = 0; - size_t waveSizeCnt = 0; - bool isAboveThreshold = dest[idx++] >= threshold_value; - for (; idx < size-20; idx++ ) { - if(dest[idx] < threshold_value && isAboveThreshold) { - thresholdCnt++; - if (thresholdCnt > 2 && waveSizeCnt < fchigh+1) break; - isAboveThreshold = false; - waveSizeCnt = 0; - } else if (dest[idx] >= threshold_value && !isAboveThreshold) { - thresholdCnt++; - if (thresholdCnt > 2 && waveSizeCnt < fchigh+1) break; - isAboveThreshold = true; - waveSizeCnt = 0; - } else { - waveSizeCnt++; - } - if (thresholdCnt > 10) break; - } - if (g_debugMode == 2) prnt("threshold Count reached at %u",idx); + //find start of modulating data in trace + idx = findModStart(dest, size, threshold_value, fchigh); // Need to threshold first sample if(dest[idx] < threshold_value) dest[0] = 0; @@ -613,9 +629,8 @@ int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32 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 + if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx)) + return -3; //preamble not found numStart = startIdx + sizeof(preamble); // final loop, go over previously decoded FSK data and manchester decode into usable tag ID @@ -647,9 +662,8 @@ int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, ui // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1 uint8_t preamble[] = {0,0,0,0,1,1,1,1}; - - uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); - if (errChk == 0) return -3; //preamble not found + if (preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx)) + return -3; //preamble not found numStart = startIdx + sizeof(preamble); // final loop, go over previously decoded FSK data and manchester decode into usable tag ID @@ -686,8 +700,8 @@ int IOdemodFSK(uint8_t *dest, size_t size) //Handle the data size_t startIdx = 0; uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,1}; - uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), &size, &startIdx); - if (errChk == 0) return -4; //preamble not found + if (! preambleSearch(dest, preamble, sizeof(preamble), &size, &startIdx)) + return -4; //preamble not found if (!dest[startIdx+8] && dest[startIdx+17]==1 && dest[startIdx+26]==1 && dest[startIdx+35]==1 && dest[startIdx+44]==1 && dest[startIdx+53]==1){ //confirmed proper separator bits found @@ -704,8 +718,9 @@ int VikingDemod_AM(uint8_t *dest, size_t *size) { 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 + if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx)) + 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) ^ @@ -726,8 +741,8 @@ int Visa2kDemod_AM(uint8_t *dest, size_t *size) { if (*size < 96) return -1; //make sure buffer has data size_t startIdx = 0; uint8_t preamble[] = {0,1,0,1,0,1,1,0,0,1,0,0,1,0,0,1,0,1,0,1,0,0,1,1,0,0,1,1,0,0,1,0}; - uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); - if (errChk == 0) return -2; //preamble not found + if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx)) + return -2; //preamble not found if (*size != 96) return -3; //wrong demoded size //return start position return (int)startIdx; @@ -738,8 +753,8 @@ int NoralsyDemod_AM(uint8_t *dest, size_t *size) { if (*size < 96) return -1; //make sure buffer has data size_t startIdx = 0; uint8_t preamble[] = {1,0,1,1,1,0,1,1,0,0,0,0}; - uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); - if (errChk == 0) return -2; //preamble not found + if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx)) + return -2; //preamble not found if (*size != 96) return -3; //wrong demoded size //return start position return (int)startIdx; @@ -749,8 +764,8 @@ int PrescoDemod(uint8_t *dest, size_t *size) { if (*size < 128*2) return -1; //make sure buffer has data size_t startIdx = 0; uint8_t preamble[] = {0,0,0,1,0,0,0,0,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0}; - uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); - if (errChk == 0) return -2; //preamble not found + if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx)) + return -2; //preamble not found if (*size != 128) return -3; //wrong demoded size //return start position return (int)startIdx; @@ -762,8 +777,8 @@ int FDXBdemodBI(uint8_t *dest, size_t *size) { if (*size < 128*2) return -1; //make sure buffer has enough data size_t startIdx = 0; uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,1}; - uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); - if (errChk == 0) return -2; //preamble not found + if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx)) + return -2; //preamble not found if (*size != 128) return -3; //wrong demoded size //return start position return (int)startIdx; @@ -777,8 +792,8 @@ int JablotronDemod(uint8_t *dest, size_t *size){ if (*size < 64*2) return -1; //make sure buffer has enough data size_t startIdx = 0; uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0}; - uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); - if (errChk == 0) return -2; //preamble not found + if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx)) + return -2; //preamble not found if (*size != 64) return -3; // wrong demoded size uint8_t checkchksum = 0; @@ -806,8 +821,8 @@ int AWIDdemodFSK(uint8_t *dest, size_t *size) uint8_t preamble[] = {0,0,0,0,0,0,0,1}; size_t startIdx = 0; - uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); - if (errChk == 0) return -4; //preamble not found + if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx)) + return -4; //preamble not found if (*size != 96) return -5; return (int)startIdx; } @@ -825,11 +840,10 @@ int PyramiddemodFSK(uint8_t *dest, size_t *size) // FSK demodulator *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50 if (*size < 128) return -2; //did we get a good demod? - - uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1}; size_t startIdx = 0; - uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); - if (errChk == 0) return -4; //preamble not found + uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1}; + if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx)) + return -4; //preamble not found if (*size != 128) return -3; return (int)startIdx; } @@ -842,8 +856,8 @@ int NedapDemod(uint8_t *dest, size_t *size) { size_t startIdx = 0; //uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,0,0,0,1}; uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,0}; - uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); - if (errChk == 0) return -4; //preamble not found + if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx)) + return -4; //preamble not found return (int) startIdx; } @@ -854,8 +868,8 @@ int IdteckDemodPSK(uint8_t *dest, size_t *size) { if (*size < 64*2) return -1; size_t startIdx = 0; uint8_t preamble[] = {0,1,0,0,1,0,0,1,0,1,0,0,0,1,0,0,0,1,0,1,0,1,0,0,0,1,0,0,1,0,1,1}; - uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); - if (errChk == 0) return -2; //preamble not found + if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx)) + return -2; //preamble not found if (*size != 64) return -3; // wrong demoded size return (int) startIdx; } @@ -1390,7 +1404,10 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc continue; // else new peak // if we got less than the small fc + tolerance then set it to the small fc - if (fcCounter < fcLow+fcTol) + // if it is inbetween set it to the last counter + if (fcCounter < fcHigh && fcCounter > fcLow) + fcCounter = lastFCcnt; + else if (fcCounter < fcLow+fcTol) fcCounter = fcLow; else //set it to the large fc fcCounter = fcHigh; @@ -1456,7 +1473,7 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc } } - if (ii<0) return 0; // oops we went too far + if (ii<2) return 0; // oops we went too far return clk[ii]; } @@ -1561,42 +1578,26 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) size_t numBits=0; uint8_t curPhase = *invert; size_t i=0, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0; - uint8_t fc=0, fullWaveLen=0, tol=1; - uint16_t errCnt=0, waveLenCnt=0; - fc = countFC(dest, *size, 0); + uint16_t fc=0, fullWaveLen=0, tol=1; + uint16_t errCnt=0, waveLenCnt=0, errCnt2=0; + fc = countFC(dest, *size, 1); + uint8_t fc2 = fc >> 8; + if (fc2 == 10) return -1; //fsk found - quit + fc = fc & 0xFF; if (fc!=2 && fc!=4 && fc!=8) return -1; //prnt("DEBUG: FC: %d",fc); *clock = DetectPSKClock(dest, *size, *clock); if (*clock == 0) return -1; - // jump to modulating data by finding the first 2 threshold crossings (or first 1 waves) - // in case you have junk or noise at the beginning of the trace... - uint8_t thresholdCnt = 0; - size_t waveSizeCnt = 0; - uint8_t threshold_value = 123; //-5 - bool isAboveThreshold = dest[i++] >= threshold_value; - for (; i < *size-20; i++ ) { - if(dest[i] < threshold_value && isAboveThreshold) { - thresholdCnt++; - if (thresholdCnt > 2 && waveSizeCnt < fc+1) break; - isAboveThreshold = false; - waveSizeCnt = 0; - } else if (dest[i] >= threshold_value && !isAboveThreshold) { - thresholdCnt++; - if (thresholdCnt > 2 && waveSizeCnt < fc+1) break; - isAboveThreshold = true; - waveSizeCnt = 0; - } else { - waveSizeCnt++; - } - if (thresholdCnt > 10) break; - } - if (g_debugMode == 2) prnt("DEBUG PSK: threshold Count reached at %u, count: %u",i, thresholdCnt); + //find start of modulating data in trace + uint8_t threshold_value = 123; //-5 + i = findModStart(dest, *size, threshold_value, fc); - int avgWaveVal=0, lastAvgWaveVal=0; - waveStart = i+1; //find first phase shift + int avgWaveVal=0, lastAvgWaveVal=0; + waveStart = i; for (; i= dest[i+2]){ waveEnd = i+1; if (g_debugMode == 2) prnt("DEBUG PSK: waveEnd: %u, waveStart: %u",waveEnd, waveStart); @@ -1605,8 +1606,8 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) 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 > threshold_value) curPhase ^= 1; //fudge graph 0 a little 123 vs 128 + //if average wave value is > graph 0 then it is an up wave or a 1 (could cause inverting) + if (lastAvgWaveVal > threshold_value) curPhase ^= 1; break; } waveStart = i+1; @@ -1627,7 +1628,7 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) //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); + if (g_debugMode==2) prnt("DEBUG PSK: 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++){ @@ -1658,6 +1659,9 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) } else if (i+1 > lastClkBit + *clock + tol + fc){ lastClkBit += *clock; //no phase shift but clock bit dest[numBits++] = curPhase; + } else if (waveLenCnt < fc - 1) { //wave is smaller than field clock (shouldn't happen often) + errCnt2++; + if(errCnt2 > 101) return errCnt2; } avgWaveVal = 0; waveStart = i+1; diff --git a/common/lfdemod.h b/common/lfdemod.h index 86ae7bc2..4c2cb9fb 100644 --- a/common/lfdemod.h +++ b/common/lfdemod.h @@ -41,7 +41,8 @@ int ManchesterEncode(uint8_t *BitStream, size_t size); int manrawdecode(uint8_t *BitStream, size_t *size, uint8_t invert); int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert); uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType); -uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx); +bool preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx); +bool preambleSearchEx(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx, bool findone); int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert); void psk2TOpsk1(uint8_t *BitStream, size_t size); void psk1TOpsk2(uint8_t *BitStream, size_t size); @@ -49,7 +50,7 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t //tag specific int AWIDdemodFSK(uint8_t *dest, size_t *size); -int Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo); +uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo); int FDXBdemodBI(uint8_t *dest, size_t *size); int gProxII_Demod(uint8_t BitStream[], size_t *size); int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo); -- 2.39.2