From: marshmellow42 Date: Tue, 27 Jan 2015 19:51:12 +0000 (-0500) Subject: lf demod bug fix & refactor X-Git-Tag: v2.0.0-rc1~41^2~6 X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/commitdiff_plain/a1d17964a218f65acb20b3ff4c651a228d54c7b4 lf demod bug fix & refactor fixed bug in lfops.c in hid fskdemod refactored data fskXXXDemods for specific tags to use more common code. --- diff --git a/armsrc/lfops.c b/armsrc/lfops.c index 8ea9b317..3cc98446 100644 --- a/armsrc/lfops.c +++ b/armsrc/lfops.c @@ -633,9 +633,9 @@ void CmdHIDdemodFSK(int findone, int *high, int *low, int ledcontrol) { uint8_t *dest = (uint8_t *)BigBuf; - size_t size=sizeof(BigBuf), idx=0; //, found=0; + size_t size=sizeof(BigBuf); uint32_t hi2=0, hi=0, lo=0; - + int idx=0; // Configure to go in 125Khz listen mode LFSetupFPGAForADC(95, true); @@ -646,10 +646,11 @@ void CmdHIDdemodFSK(int findone, int *high, int *low, int ledcontrol) DoAcquisition125k_internal(-1,true); // FSK demodulator - idx = HIDdemodFSK(dest, &size, &hi2, &hi, &lo); - WDT_HIT(); + size = sizeof(BigBuf); + idx = HIDdemodFSK(dest, &size, &hi2, &hi, &lo); + if (idx>0 && lo>0){ // final loop, go over previously decoded manchester data and decode into usable tag ID // 111000 bit pattern represent start of frame, 01 pattern represents a 1 and 10 represents a 0 diff --git a/client/cmddata.c b/client/cmddata.c index 9ed228a4..79ff93be 100644 --- a/client/cmddata.c +++ b/client/cmddata.c @@ -659,9 +659,21 @@ int CmdFSKdemodHID(const char *Cmd) uint8_t BitStream[MAX_GRAPH_TRACE_LEN]={0}; size_t BitLen = getFromGraphBuf(BitStream); //get binary from fsk wave - size_t idx = HIDdemodFSK(BitStream,&BitLen,&hi2,&hi,&lo); + int idx = HIDdemodFSK(BitStream,&BitLen,&hi2,&hi,&lo); if (idx<0){ - if (g_debugMode) PrintAndLog("DEBUG: Error demoding fsk"); + if (g_debugMode){ + if (idx==-1){ + PrintAndLog("DEBUG: Just Noise Detected"); + } else if (idx == -2) { + PrintAndLog("DEBUG: Error demoding fsk"); + } else if (idx == -3) { + PrintAndLog("DEBUG: Preamble not found"); + } else if (idx == -4) { + PrintAndLog("DEBUG: Error in Manchester data, SIZE: %d", BitLen); + } else { + PrintAndLog("DEBUG: Error demoding fsk %d", idx); + } + } return 0; } if (hi2==0 && hi==0 && lo==0) { @@ -732,9 +744,21 @@ int CmdFSKdemodParadox(const char *Cmd) uint8_t BitStream[MAX_GRAPH_TRACE_LEN]={0}; size_t BitLen = getFromGraphBuf(BitStream); //get binary from fsk wave - size_t idx = ParadoxdemodFSK(BitStream,&BitLen,&hi2,&hi,&lo); + int idx = ParadoxdemodFSK(BitStream,&BitLen,&hi2,&hi,&lo); if (idx<0){ - if (g_debugMode) PrintAndLog("DEBUG: Error demoding fsk"); + if (g_debugMode){ + if (idx==-1){ + PrintAndLog("DEBUG: Just Noise Detected"); + } else if (idx == -2) { + PrintAndLog("DEBUG: Error demoding fsk"); + } else if (idx == -3) { + PrintAndLog("DEBUG: Preamble not found"); + } else if (idx == -4) { + PrintAndLog("DEBUG: Error in Manchester data"); + } else { + PrintAndLog("DEBUG: Error demoding fsk %d", idx); + } + } return 0; } if (hi2==0 && hi==0 && lo==0){ @@ -774,7 +798,21 @@ int CmdFSKdemodIO(const char *Cmd) //get binary from fsk wave idx = IOdemodFSK(BitStream,BitLen); if (idx<0){ - if (g_debugMode==1) PrintAndLog("DEBUG: demoding fsk error: %d", idx); + if (g_debugMode){ + if (idx==-1){ + PrintAndLog("DEBUG: Just Noise Detected"); + } else if (idx == -2) { + PrintAndLog("DEBUG: not enough samples"); + } else if (idx == -3) { + PrintAndLog("DEBUG: error during fskdemod"); + } else if (idx == -4) { + PrintAndLog("DEBUG: Preamble not found"); + } else if (idx == -5) { + PrintAndLog("DEBUG: Separator bits not found"); + } else { + PrintAndLog("DEBUG: Error demoding fsk %d", idx); + } + } return 0; } if (idx==0){ @@ -834,13 +872,13 @@ int CmdFSKdemodAWID(const char *Cmd) size_t size = getFromGraphBuf(BitStream); //get binary from fsk wave - int idx = AWIDdemodFSK(BitStream, size); + int idx = AWIDdemodFSK(BitStream, &size); if (idx<=0){ if (g_debugMode==1){ if (idx == -1) PrintAndLog("DEBUG: Error - not enough samples"); else if (idx == -2) - PrintAndLog("DEBUG: Error - only noise found - no waves"); + PrintAndLog("DEBUG: Error - only noise found"); else if (idx == -3) PrintAndLog("DEBUG: Error - problem during FSK demod"); // else if (idx == -3) @@ -848,7 +886,7 @@ int CmdFSKdemodAWID(const char *Cmd) else if (idx == -4) PrintAndLog("DEBUG: Error - AWID preamble not found"); else if (idx == -5) - PrintAndLog("DEBUG: Error - Second AWID preamble not found"); + PrintAndLog("DEBUG: Error - Size not correct: %d", size); else PrintAndLog("DEBUG: Error %d",idx); } @@ -933,17 +971,17 @@ int CmdFSKdemodPyramid(const char *Cmd) size_t size = getFromGraphBuf(BitStream); //get binary from fsk wave - int idx = PyramiddemodFSK(BitStream, size); + int idx = PyramiddemodFSK(BitStream, &size); if (idx < 0){ if (g_debugMode==1){ if (idx == -5) PrintAndLog("DEBUG: Error - not enough samples"); else if (idx == -1) - PrintAndLog("DEBUG: Error - only noise found - no waves"); + PrintAndLog("DEBUG: Error - only noise found"); else if (idx == -2) PrintAndLog("DEBUG: Error - problem during FSK demod"); else if (idx == -3) - PrintAndLog("DEBUG: Error - Second Pyramid preamble not found"); + PrintAndLog("DEBUG: Error - Size not correct: %d", size); else if (idx == -4) PrintAndLog("DEBUG: Error - Pyramid preamble not found"); else @@ -1039,7 +1077,6 @@ int CmdFSKdemodPyramid(const char *Cmd) PrintAndLog("Pyramid ID Found - BitLength: %d -unknown BitLength- (%d), Raw: %x%08x%08x%08x", fmtLen, cardnum, rawHi3, rawHi2, rawHi, rawLo); } } - //todo - convert hi2, hi, lo to demodbuffer for future sim/clone commands if (g_debugMode){ PrintAndLog("DEBUG: idx: %d, Len: %d, Printing Demod Buffer:", idx, 128); printDemodBuff(); @@ -1248,7 +1285,7 @@ int CmdIndalaDecode(const char *Cmd) PrintAndLog("Error2: %d",ans); return -1; } - char showbits[251]; + char showbits[251]={0x00}; if (invert) if (g_debugMode==1) PrintAndLog("Had to invert bits"); @@ -1298,6 +1335,10 @@ int CmdIndalaDecode(const char *Cmd) showbits[idx]='\0'; PrintAndLog("Indala UID=%s (%x%08x%08x%08x%08x%08x%08x)", showbits, uid1, uid2, uid3, uid4, uid5, uid6, uid7); } + if (g_debugMode){ + PrintAndLog("DEBUG: printing demodbuffer:"); + printDemodBuff(); + } return 1; } diff --git a/common/lfdemod.c b/common/lfdemod.c index 1b499158..88a250d8 100644 --- a/common/lfdemod.c +++ b/common/lfdemod.c @@ -12,6 +12,18 @@ #include #include "lfdemod.h" + +uint8_t justNoise(uint8_t *BitStream, size_t size) +{ + static const uint8_t THRESHOLD = 123; + //test samples are not just noise + uint8_t justNoise1 = 1; + for(size_t idx=0; idx < size && justNoise1 ;idx++){ + justNoise1 = BitStream[idx] < THRESHOLD; + } + return justNoise1; +} + //by marshmellow //get high and low with passed in fuzz factor. also return noise test = 1 for passed or 0 for only noise int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi, uint8_t fuzzLo) @@ -29,59 +41,82 @@ int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi return 1; } +// by marshmellow +// pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType +// returns 1 if passed +uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType) +{ + uint8_t ans = 0; + for (uint8_t i = 0; i < bitLen; i++){ + ans ^= ((bits >> i) & 1); + } + //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType); + return (ans == pType); +} + +//by marshmellow +//search for given preamble in given BitStream and return 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; +} + + //by marshmellow //takes 1s and 0s and searches for EM410x format - output EM ID uint64_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx) { - //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 - uint64_t lo=0; - uint32_t i = 0; - if (BitStream[10]>1){ //allow only 1s and 0s - // PrintAndLog("no data found"); - return 0; - } - uint8_t parityTest=0; - // 111111111 bit pattern represent start of frame - uint8_t frame_marker_mask[] = {1,1,1,1,1,1,1,1,1}; - uint32_t idx = 0; - uint32_t ii=0; - uint8_t resetCnt = 0; - while( (idx + 64) < *size) { - restart: - // search for a start of frame marker - if ( memcmp(BitStream+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0) - { // frame marker found - *startIdx=idx; - idx+=9; - for (i=0; i<10;i++){ - for(ii=0; ii<5; ++ii){ - parityTest ^= BitStream[(i*5)+ii+idx]; - } - if (!parityTest){ //even parity - parityTest=0; - for (ii=0; ii<4;++ii){ - lo=(lo<<1LL)|(BitStream[(i*5)+ii+idx]); - } - //PrintAndLog("DEBUG: EM parity passed parity val: %d, i:%d, ii:%d,idx:%d, Buffer: %d%d%d%d%d,lo: %d",parityTest,i,ii,idx,BitStream[idx+ii+(i*5)-5],BitStream[idx+ii+(i*5)-4],BitStream[idx+ii+(i*5)-3],BitStream[idx+ii+(i*5)-2],BitStream[idx+ii+(i*5)-1],lo); - }else {//parity failed - //PrintAndLog("DEBUG: EM parity failed parity val: %d, i:%d, ii:%d,idx:%d, Buffer: %d%d%d%d%d",parityTest,i,ii,idx,BitStream[idx+ii+(i*5)-5],BitStream[idx+ii+(i*5)-4],BitStream[idx+ii+(i*5)-3],BitStream[idx+ii+(i*5)-2],BitStream[idx+ii+(i*5)-1]); - parityTest=0; - idx-=8; - if (resetCnt>5)return 0; //try 5 times - resetCnt++; - goto restart;//continue; - } - } - //skip last 5 bit parity test for simplicity. - *size = 64; - return lo; - }else{ - idx++; - } - } - 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 + uint64_t lo=0; + 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; + *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; + idx = *startIdx + 9; + for (i=0; i<10;i++){ //loop through 10 sets of 5 bits (50-10p = 40 bits) + parityBits = bytebits_to_byte(BitStream+(i*5)+idx,5); + //check even parity + if (parityTest(parityBits, 5, 0) == 0){ + //parity failed try next bit (in the case of 1111111111) but last 9 = preamble + startIdx++; + errChk = 0; + break; + } + for (uint8_t ii=0; ii<4; ii++){ + lo = (lo << 1LL) | (BitStream[(i*5)+ii+idx]); + } + } + if (errChk != 0) return lo; + //skip last 5 bit parity test for simplicity. + // *size = 64; + } + return 0; } //by marshmellow @@ -537,114 +572,69 @@ int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t size = aggregate_bits(dest, size, rfLen, 192, 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 idx=0, size2=*size, startIdx=0; - // FSK demodulator - - *size = fskdemod(dest, size2,50,0,10,8); - - // final loop, go over previously decoded manchester data and decode into usable tag ID - // 111000 bit pattern represent start of frame, 01 pattern represents a 1 and 10 represents a 0 - uint8_t frame_marker_mask[] = {1,1,1,0,0,0}; - int numshifts = 0; - idx = 0; - //one scan - while( idx + sizeof(frame_marker_mask) < *size) { - // search for a start of frame marker - if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0) - { // frame marker found - startIdx=idx; - idx+=sizeof(frame_marker_mask); - while(dest[idx] != dest[idx+1] && idx < *size-2) - { - // Keep going until next frame marker (or error) - // Shift in a bit. Start by shifting high registers - *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)|0; - else // 0 1 - *lo=(*lo<<1)|1; - numshifts++; - idx += 2; - } - // Hopefully, we read a tag and hit upon the next frame marker - if(idx + sizeof(frame_marker_mask) < *size) - { - if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0) - { - //good return - *size=idx-startIdx; - return startIdx; - } - } - // reset - *hi2 = *hi = *lo = 0; - numshifts = 0; - }else { - idx++; - } - } - 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; } // loop to get raw paradox waveform then FSK demodulate the TAG ID from it -size_t ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo) +int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo) { - - size_t idx=0, size2=*size; + if (justNoise(dest, *size)) return -1; + + size_t numStart=0, size2=*size, startIdx=0; // FSK demodulator - - *size = fskdemod(dest, size2,50,1,10,8); - - // final loop, go over previously decoded manchester data and decode into usable tag ID - // 00001111 bit pattern represent start of frame, 01 pattern represents a 1 and 10 represents a 0 - uint8_t frame_marker_mask[] = {0,0,0,0,1,1,1,1}; - uint16_t numshifts = 0; - idx = 0; - //one scan - while( idx + sizeof(frame_marker_mask) < *size) { - // search for a start of frame marker - if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0) - { // frame marker found - size2=idx; - idx+=sizeof(frame_marker_mask); - while(dest[idx] != dest[idx+1] && idx < *size-2) - { - // Keep going until next frame marker (or error) - // Shift in a bit. Start by shifting high registers - *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; - numshifts++; - idx += 2; - } - // Hopefully, we read a tag and hit upon the next frame marker and got enough bits - if(idx + sizeof(frame_marker_mask) < *size && numshifts > 40) - { - if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0) - { - //good return - return start grid position and bits found - *size = ((numshifts*2)+8); - return size2; - } - } - // reset - *hi2 = *hi = *lo = 0; - numshifts = 0; - }else { - idx++; - } + *size = fskdemod(dest, size2,50,1,10,8); //fsk2a + if (*size < 96) return -2; + + // 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 + + 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 0; + return (int)startIdx; } uint32_t bytebits_to_byte(uint8_t* src, size_t numbits) @@ -660,20 +650,12 @@ uint32_t bytebits_to_byte(uint8_t* src, size_t numbits) int IOdemodFSK(uint8_t *dest, size_t size) { - static const uint8_t THRESHOLD = 129; - uint32_t idx=0; + if (justNoise(dest, size)) return -1; //make sure buffer has data - if (size < 66) return -1; - //test samples are not just noise - uint8_t justNoise = 1; - for(idx=0;idx< size && justNoise ;idx++){ - justNoise = dest[idx] < THRESHOLD; - } - if(justNoise) return 0; - + if (size < 66*64) return -2; // FSK demodulator - size = fskdemod(dest, size, 64, 1, 10, 8); // RF/64 and invert - if (size < 65) return -1; //did we get a good demod? + size = fskdemod(dest, size, 64, 1, 10, 8); // FSK2a RF/64 + if (size < 65) return -3; //did we get a good demod? //Index map //0 10 20 30 40 50 60 //| | | | | | | @@ -683,31 +665,17 @@ int IOdemodFSK(uint8_t *dest, size_t size) // //XSF(version)facility:codeone+codetwo //Handle the data - uint8_t mask[] = {0,0,0,0,0,0,0,0,0,1}; - for( idx=0; idx < (size - 65); idx++) { - if ( memcmp(dest + idx, mask, sizeof(mask))==0) { - //frame marker found - if (!dest[idx+8] && dest[idx+17]==1 && dest[idx+26]==1 && dest[idx+35]==1 && dest[idx+44]==1 && dest[idx+53]==1){ - //confirmed proper separator bits found - //return start position - return (int) idx; - } - } - } - return 0; -} - -// by marshmellow -// pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType -// returns 1 if passed -uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType) -{ - uint8_t ans = 0; - for (uint8_t i = 0; i < bitLen; i++){ - ans ^= ((bits >> i) & 1); + 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 (!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 + //return start position + return (int) startIdx; } - //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType); - return (ans == pType); + return -5; } // by marshmellow @@ -735,70 +703,45 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p // by marshmellow // FSK Demod then try to locate an AWID ID -int AWIDdemodFSK(uint8_t *dest, size_t size) +int AWIDdemodFSK(uint8_t *dest, size_t *size) { - static const uint8_t THRESHOLD = 123; - uint32_t idx=0, idx2=0; - //make sure buffer has data - if (size < 96*50) return -1; - //test samples are not just noise - uint8_t justNoise = 1; - for(idx=0; idx < size && justNoise ;idx++){ - justNoise = dest[idx] < THRESHOLD; - } - if(justNoise) return -2; + //make sure buffer has enough data + if (*size < 96*50) return -1; + + if (justNoise(dest, *size)) return -2; // FSK demodulator - size = fskdemod(dest, size, 50, 1, 10, 8); // RF/64 and invert - if (size < 96) return -3; //did we get a good demod? - - uint8_t mask[] = {0,0,0,0,0,0,0,1}; - for( idx=0; idx < (size - 96); idx++) { - if ( memcmp(dest + idx, mask, sizeof(mask))==0) { - // frame marker found - //return ID start index - if (idx2 == 0) idx2=idx; - else if(idx-idx2==96) return idx2; - else return -5; - - // should always get 96 bits if it is awid - } - } - //never found mask - return -4; + *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50 + if (*size < 96) return -3; //did we get a good demod? + + 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 (*size != 96) return -5; + return (int)startIdx; } // by marshmellow // FSK Demod then try to locate an Farpointe Data (pyramid) ID -int PyramiddemodFSK(uint8_t *dest, size_t size) +int PyramiddemodFSK(uint8_t *dest, size_t *size) { - static const uint8_t THRESHOLD = 123; - uint32_t idx=0, idx2=0; - // size_t size2 = size; //make sure buffer has data - if (size < 128*50) return -5; + if (*size < 128*50) return -5; + //test samples are not just noise - uint8_t justNoise = 1; - for(idx=0; idx < size && justNoise ;idx++){ - justNoise = dest[idx] < THRESHOLD; - } - if(justNoise) return -1; + if (justNoise(dest, *size)) return -1; // FSK demodulator - size = fskdemod(dest, size, 50, 1, 10, 8); // RF/64 and invert - if (size < 128) return -2; //did we get a good demod? - - uint8_t mask[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1}; - for( idx=0; idx < (size - 128); idx++) { - if ( memcmp(dest + idx, mask, sizeof(mask))==0) { - // frame marker found - if (idx2==0) idx2=idx; - else if (idx-idx2==128) return idx2; - else return -3; - } - } - //never found mask - return -4; + *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}; + size_t startIdx = 0; + uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); + if (errChk == 0) return -4; //preamble not found + if (*size != 128) return -3; + return (int)startIdx; } // by marshmellow @@ -1068,6 +1011,7 @@ int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert) // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak int pskNRZrawDemod(uint8_t *dest, size_t *size, int *clk, int *invert) { + if (justNoise(dest, *size)) return -1; pskCleanWave(dest,*size); int clk2 = DetectpskNRZClock(dest, *size, *clk); *clk=clk2; diff --git a/common/lfdemod.h b/common/lfdemod.h index a2eb2c78..dbeab0f7 100644 --- a/common/lfdemod.h +++ b/common/lfdemod.h @@ -31,12 +31,15 @@ void psk1TOpsk2(uint8_t *BitStream, size_t size); int DetectpskNRZClock(uint8_t dest[], size_t size, int clock); int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert); void pskCleanWave(uint8_t *bitStream, size_t size); -int PyramiddemodFSK(uint8_t *dest, size_t size); -int AWIDdemodFSK(uint8_t *dest, size_t size); +int PyramiddemodFSK(uint8_t *dest, size_t *size); +int AWIDdemodFSK(uint8_t *dest, size_t *size); size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen); uint16_t countFC(uint8_t *BitStream, size_t size); uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow); int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi, uint8_t fuzzLo); -size_t ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo); +int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo); +uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx); +uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType); +uint8_t justNoise(uint8_t *BitStream, size_t size); #endif