X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/d3a22c7dfa87bf5e21d228849a602194be4a0895..5a08545794cefc9fd9450707e739784c8c84839e:/common/lfdemod.c diff --git a/common/lfdemod.c b/common/lfdemod.c index eb5a4d95..d9a87583 100644 --- a/common/lfdemod.c +++ b/common/lfdemod.c @@ -1,532 +1,571 @@ //----------------------------------------------------------------------------- -// Copyright (C) 2014 +// Copyright (C) 2014 // // This code is licensed to you under the terms of the GNU GPL, version 2 or, // at your option, any later version. See the LICENSE.txt file for the text of // the license. //----------------------------------------------------------------------------- -// Low frequency commands +// Low frequency demod/decode commands //----------------------------------------------------------------------------- -#include #include -#include #include "lfdemod.h" +#include + +//un_comment to allow debug print calls when used not on device +void dummy(char *fmt, ...){} + +#ifndef ON_DEVICE +#include "ui.h" +#include "cmdparser.h" +#include "cmddata.h" +#define prnt PrintAndLog +#else + uint8_t g_debugMode=0; +#define prnt dummy +#endif + +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 -//takes 1s and 0s and searches for EM410x format - output EM ID -uint64_t Em410xDecode(uint8_t *BitStream, uint32_t BitLen) +//get high and low values of a wave 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) { - //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 - int high = 0, low = 128; - uint64_t lo = 0; - uint32_t i = 0; - uint32_t initLoopMax = 65; + *high=0; + *low=255; + // get high and low thresholds + 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 = ((*high-128)*fuzzHi + 12800)/100; + *low = ((*low-128)*fuzzLo + 12800)/100; + 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 +// 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; +} - if (initLoopMax > BitLen) - initLoopMax = BitLen; +// 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; +} - for (; i < initLoopMax; ++i) //65 samples should be plenty to find high and low values - { - if (BitStream[i] > high) - high = BitStream[i]; - else if (BitStream[i] < low) - low = BitStream[i]; +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; +} - if (((high !=1)||(low !=0))){ //allow only 1s and 0s - return 0; +//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; +} - 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 j = 0; - uint8_t resetCnt = 0; - while( (idx + 64) < BitLen) { - - restart: - - // search for a start of frame marker - if ( memcmp(BitStream+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0) { - // frame marker found - idx += 9;//sizeof(frame_marker_mask); - for ( i = 0; i < 10; ++i){ - for( j = 0; j < 5; ++j){ - parityTest += BitStream[(i*5) + j + idx]; +//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) +{ + // Sanity check. If preamble length is bigger than bitstream length. + if ( *size <= pLen ) 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 (parityTest == ( (parityTest >> 1) << 1)){ - parityTest = 0; - for (j = 0; j < 4; ++j){ - lo = ( lo << 1LL)|( BitStream[( i * 5 ) + j + idx]); - } - } else { - //parity failed - parityTest = 0; - idx -= 8; - if (resetCnt > 5) return 0; - resetCnt++; - goto restart;//continue; + if (foundCnt == 2){ + *size = idx - *startIdx; + return 1; } } - //skip last 5 bit parity test for simplicity. - return lo; - } else { - idx++; + } + 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) 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 2 arguments - clock and invert both as integers -//attempts to demodulate ask while decoding manchester -//prints binary found and saves in graphbuffer for further commands -int askmandemod(uint8_t *BinStream, uint32_t *BitLen, int *clk, int *invert) -{ - int i; - int high = 0, low = 128; - *clk = DetectASKClock(BinStream, (size_t)*BitLen, *clk); //clock default - - if (*clk < 8 ) *clk = 64; - if (*clk < 32 ) *clk = 32; - if (*invert != 1) *invert = 0; - - uint32_t initLoopMax = 200; - if (initLoopMax > *BitLen) - initLoopMax = *BitLen; - - // Detect high and lows - // 200 samples should be enough to find high and low values - for (i = 0; i < initLoopMax; ++i) { - if (BinStream[i] > high) - high = BinStream[i]; - else if (BinStream[i] < low) - low = BinStream[i]; - } - - //throw away static - if ((high < 158) ) - return -2; - - //25% fuzz in case highs and lows aren't clipped [marshmellow] - high = (int)(high * .75); - low = (int)(low+128 * .25); - - int lastBit = 0; // set first clock check - uint32_t bitnum = 0; // output counter - - // clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave - //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely - int tol = ( *clk == 32 ) ? 1 : 0; - - int j = 0; - uint32_t gLen = *BitLen; - - if (gLen > 3000) gLen = 3000; - - uint8_t errCnt = 0; - uint32_t bestStart = *BitLen; - uint32_t bestErrCnt = (*BitLen/1000); - uint32_t maxErr = bestErrCnt; - - //loop to find first wave that works - for (j=0; j < gLen; ++j){ - - if ((BinStream[j] >= high)||(BinStream[j] <= low)){ - lastBit = j - *clk; - errCnt = 0; - - //loop through to see if this start location works - for (i = j; i < *BitLen; ++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!! - - 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 ((i-j) >(400 * *clk)) break; //got plenty of bits - } - //we got more than 64 good bits and not all errors - if ((((i-j)/ *clk) > (64 + errCnt)) && (errCnt < maxErr)) { - //possible good read - if (errCnt == 0){ - bestStart = j; - bestErrCnt = errCnt; - break; //great read - finish - } - if (errCnt < bestErrCnt){ //set this as new best run - bestErrCnt = errCnt; - bestStart = j; - } - } - } - } - if (bestErrCnt < maxErr){ - //best run is good enough set to best run and set overwrite BinStream - j = bestStart; - lastBit = bestStart - *clk; - bitnum = 0; - for (i = j; i < *BitLen; ++i) { - if ((BinStream[i] >= 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!! - if (bitnum > 0){ - BinStream[bitnum] = 77; - bitnum++; +//demodulates strong heavily clipped samples +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; + 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++; + 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; + } + waveHigh ^= 1; + smplCnt = 0; + } else if (smplCnt > (clk/2) - (clk/4)-1) { + 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 { + smplCnt++; + //transition bit oops } - lastBit += *clk;//skip over error + } else { //haven't hit new high or new low yet + smplCnt++; } } - if (bitnum >= 400) break; + } + *size = bitCnt; + return errCnt; +} + +//by marshmellow +void askAmp(uint8_t *BitStream, size_t size) +{ + uint8_t last = 128; + for(size_t i = 1; i < size; ++i){ + if (BitStream[i]-BitStream[i-1] >= 30) //large jump up + last = 255; + else if(BitStream[i-1] - BitStream[i] >= 20) //large jump down + last = 0; + + BitStream[i] = last; + } +} + +//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", *clk, start); + + 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; + } + 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; } - *BitLen = bitnum; - } else { - *invert = bestStart; - *clk = j; - return -1; - } - return bestErrCnt; + 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 * bits, int *bitlen) -{ - int bitnum = 0; - int errCnt = 0; - int bestErr = 1000; - int bestRun = 0; - int i = 1; - int j = 1; - - for (; j < 3; ++j){ - i = 1; - for ( i = i + j; i < *bitlen-2; i += 2){ - if ( bits[i]==1 && (bits[i+1]==0)){ - } else if ((bits[i]==0)&& bits[i+1]==1){ - } else { +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 < 16) return -1; + //find correct start position [alignment] + for (ii=0;ii<2;++ii){ + for (i=ii; i<*size-3; i+=2) + if (BitStream[i]==BitStream[i+1]) errCnt++; - } - if(bitnum > 300) break; - } - if (bestErr > errCnt){ - bestErr = errCnt; - bestRun = j; - } - errCnt = 0; - } - errCnt = bestErr; - if (errCnt < 20){ - j = bestRun; - i = 1; - for ( i = i+j; i < *bitlen-2; i += 2){ - if ( bits[i] == 1 && bits[i + 1] == 0 ){ - bits[bitnum++] = 0; - } else if ( bits[i] == 0 && bits[i + 1] == 1 ){ - bits[bitnum++] = 1; - } else { - bits[bitnum++] = 77; - } - if ( bitnum > 300 ) break; + + if (bestErr>errCnt){ + bestErr=errCnt; + bestRun=ii; } - *bitlen = bitnum; - } - return errCnt; + errCnt=0; + } + //decode + for (i=bestRun; i < *size-3; i+=2){ + if(BitStream[i] == 1 && (BitStream[i+1] == 0)){ + BitStream[bitnum++]=invert; + } else if((BitStream[i] == 0) && BitStream[i+1] == 1){ + BitStream[bitnum++]=invert^1; + } else { + BitStream[bitnum++]=7; + } + if(bitnum>MaxBits) break; + } + *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 -//take 01 or 10 = 0 and 11 or 00 = 1 -int BiphaseRawDecode(uint8_t * bits, int *bitlen, int offset) +//encode binary data into binary manchester +int ManchesterEncode(uint8_t *BitStream, size_t size) { - uint8_t bitnum = 0; - uint32_t errCnt = 0; - uint32_t i = offset; - - for (; i < *bitlen-2; i += 2 ){ - if ( (bits[i]==1 && bits[i+1]==0)|| - (bits[i]==0 && bits[i+1]==1)){ - bits[bitnum++] = 1; - } else if ( (bits[i]==0 && bits[i+1]==0)|| - (bits[i]==1 && bits[i+1]==1)){ - bits[bitnum++] = 0; + 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 +//take 01 or 10 = 1 and 11 or 00 = 0 +//check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010 +//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; + uint16_t errCnt = 0; + size_t i = offset; + uint16_t MaxBits=512; + //if not enough samples - error + if (*size < 51) return -1; + //check for phase change faults - skip one sample if faulty + uint8_t offsetA = 1, offsetB = 1; + for (; i<48; i+=2){ + if (BitStream[i+1]==BitStream[i+2]) offsetA=0; + if (BitStream[i+2]==BitStream[i+3]) offsetB=0; + } + if (!offsetA && offsetB) offset++; + for (i=offset; i<*size-3; i+=2){ + //check for phase error + if (BitStream[i+1]==BitStream[i+2]) { + BitStream[bitnum++]=7; + errCnt++; + } + if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){ + BitStream[bitnum++]=1^invert; + } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){ + BitStream[bitnum++]=invert; } else { - bits[bitnum++] = 77; + BitStream[bitnum++]=7; errCnt++; } - if ( bitnum > 250) break; - } - *bitlen = bitnum; + if(bitnum>MaxBits) break; + } + *size=bitnum; return errCnt; } -//by marshmellow -//takes 2 arguments - clock and invert both as integers -//attempts to demodulate ask only -//prints binary found and saves in graphbuffer for further commands -int askrawdemod(uint8_t *BinStream, int *bitLen, int *clk, int *invert) -{ - uint32_t i; - uint32_t initLoopMax = 200; - int high = 0, low = 128; - uint8_t BitStream[502] = {0x00}; - - *clk = DetectASKClock(BinStream, *bitLen, *clk); //clock default - - if (*clk < 8) *clk = 64; - if (*clk < 32) *clk = 32; - if (*invert != 1) *invert = 0; - - if (initLoopMax > *bitLen) - initLoopMax = *bitLen; - - // Detect high and lows - for (i = 0; i < initLoopMax; ++i) //200 samples should be plenty to find high and low values - { - if (BinStream[i] > high) - high = BinStream[i]; - else if (BinStream[i] < low) - low = BinStream[i]; - } - - //throw away static - if ((high < 158)){ - return -2; - } - - //25% fuzz in case highs and lows aren't clipped [marshmellow] - high = (int)(high * .75); - low = (int)(low+128 * .25); - - 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 = 1; //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely - - uint32_t gLen = *bitLen; - if (gLen > 500) gLen = 500; - - uint32_t j = 0; - uint8_t errCnt = 0; - uint32_t bestStart = *bitLen; - uint32_t bestErrCnt = (*bitLen / 1000); - uint32_t errCntLimit = bestErrCnt; - uint8_t midBit = 0; - - //loop to find first wave that works - for (j = 0; j < gLen; ++j){ - - if ((BinStream[j] >= high)||(BinStream[j] <= low)){ - lastBit = j - *clk; - //loop through to see if this start location works - for (i = j; i < *bitLen; ++i) { - if ((BinStream[i] >= high) && ((i-lastBit)>(*clk-tol))){ - lastBit += *clk; - BitStream[bitnum] = *invert; - bitnum++; - midBit = 0; - } else if ((BinStream[i] <= low) && ((i-lastBit)>(*clk-tol))){ - //low found and we are expecting a bar - lastBit += *clk; - BitStream[bitnum] = 1-*invert; - bitnum++; - midBit=0; - } else if ((BinStream[i]<=low) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){ - //mid bar? - midBit = 1; - BitStream[bitnum] = 1 - *invert; - bitnum++; - } else if ((BinStream[i]>=high)&&(midBit==0) && ((i-lastBit)>((*clk/2)-tol))){ - //mid bar? - midBit = 1; - BitStream[bitnum] = *invert; - bitnum++; - } else if ((i-lastBit)>((*clk/2)+tol)&&(midBit==0)){ - //no mid bar found - midBit = 1; - BitStream[bitnum] = BitStream[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!! - - if (bitnum > 0){ - BitStream[bitnum] = 77; - bitnum++; - } - - errCnt++; - lastBit += *clk;//skip over until hit too many errors - if (errCnt > errCntLimit){ //allow 1 error for every 1000 samples else start over - errCnt = 0; - bitnum = 0;//start over - break; - } - } - } - if (bitnum > 500) break; - } - //we got more than 64 good bits and not all errors - //possible good read - if ((bitnum > (64 + errCnt)) && (errCnt < errCntLimit)) { - - //great read - finish - if (errCnt == 0) break; - - //if current run == bestErrCnt run (after exhausted testing) then finish - if (bestStart == j) break; - - //set this as new best run - if (errCnt < bestErrCnt){ - bestErrCnt = errCnt; - bestStart = j; - } - } - } - if (j >= gLen){ //exhausted test - //if there was a ok test go back to that one and re-run the best run (then dump after that run) - if (bestErrCnt < errCntLimit) - j = bestStart; - } - } - if (bitnum > 16){ - - for (i = 0; i < bitnum; ++i){ - BinStream[i] = BitStream[i]; - } - *bitLen = bitnum; - } else { - return -1; +// by marshmellow +// demod gProxIIDemod +// error returns as -x +// success returns start position in BitStream +// BitStream must contain previously askrawdemod and biphasedemoded data +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 (*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 + //return start position + return (int) startIdx; } - return errCnt; + 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; - uint32_t maxVal = 0; - - if (fchigh == 0) fchigh = 10; - if (fclow == 0) fclow = 8; - - // we do care about the actual theshold value as sometimes near the center of the - // wave we may get static that changes direction of wave for one value - // if our value is too low it might affect the read. and if our tag or - // antenna is weak a setting too high might not see anything. [marshmellow] - if ( size < 100) - return 0; - - // Find high from first 100 samples - for ( idx = 1; idx < 100; idx++ ){ - if ( maxVal < dest[idx]) - maxVal = dest[idx]; - } - - // set close to the top of the wave threshold with 25% margin for error - // less likely to get a false transition up there. - // (but have to be careful not to go too high and miss some short waves) - uint8_t threshold_value = (uint8_t)(maxVal * .75); - + 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 - - dest[0] = (dest[0] < threshold_value) ? 0 : 1; + // 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 - dest[idx] = (dest[idx] < threshold_value) ? 0 : 1; + + 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 { //9+ = 10 waves - dest[numBits]=0; + } 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 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++; } } - //it returns the number of bytes, but each byte represents a bit: 1 or 0 - return numBits; + return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0 } -uint32_t myround2(float f) +//translate 11111100000 to 10 +//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) { - 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 ) -{ - uint8_t lastval = dest[0]; - uint32_t idx = 0; - uint32_t n = 1; - size_t numBits = 0; - - for( idx = 1; idx < size; idx++) { - - if (dest[idx] == lastval) { - n++; - continue; - } + uint8_t lastval=dest[0]; + size_t idx=0; + size_t numBits=0; + uint32_t n=1; + for( idx=1; idx < size; idx++) { + n++; + if (dest[idx]==lastval) continue; + + //find out how many bits (n) we collected //if lastval was 1, we have a 1->0 crossing - if ( dest[idx-1] == 1 ) { - n = myround2( (float)( n + 1 ) / ((float)(rfLen)/(float)fclow)); - } else { // 0->1 crossing - n = myround2( (float)( n + 1 ) / ((float)(rfLen-2)/(float)fchigh)); //-2 for fudge factor + if (dest[idx-1]==1) { + n = (n * fclow + rfLen/2) / rfLen; + } else {// 0->1 crossing + 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; - } - n = 0; - lastval = dest[idx]; + //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 > rfLen/fchigh) { + if (dest[idx-2]==1) { + n = (n * fclow + rfLen/2) / rfLen; + } else { + n = (n * fchigh + rfLen/2) / rfLen; + } + memset(dest+numBits, dest[idx-1]^invert , n); + numBits += n; + } return numBits; } @@ -536,100 +575,82 @@ int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t { // FSK demodulator size = fsk_wave_demod(dest, size, fchigh, fclow); - if ( size > 0 ) - 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) +int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo) { - size_t idx = 0; - int numshifts = 0; + if (justNoise(dest, *size)) return -1; + size_t numStart=0, size2 = *size, startIdx=0; // FSK demodulator - size = fskdemod(dest, size, 50, 0, 10, 8); + *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 - // 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}; - - uint8_t mask_len = sizeof frame_marker_mask / sizeof frame_marker_mask[0]; - - //one scan - while( idx + mask_len < size) { - // search for a start of frame marker - if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0) - { // frame marker found - idx += mask_len; - 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 + mask_len < size) - { - if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0) - { - //good return - return idx; - } - } - // reset - *hi2 = *hi = *lo = 0; - numshifts = 0; - }else { - idx++; + 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 -1; + return (int)startIdx; } -uint32_t bytebits_to_byte(uint8_t *src, int numbits) +// loop to get raw paradox waveform then FSK demodulate the TAG ID from it +int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo) { - //HACK: potential overflow in numbits is larger then uint32 bits. + if (justNoise(dest, *size)) return -1; - uint32_t num = 0; - for(int i = 0 ; i < numbits ; ++i) { - num = (num << 1) | (*src); - src++; + size_t numStart=0, size2 = *size, startIdx=0; + // FSK demodulator + *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 num; + return (int)startIdx; } int IOdemodFSK(uint8_t *dest, size_t size) { + if (justNoise(dest, size)) return -1; //make sure buffer has data - if (size < 100) return -1; - - uint32_t idx = 0; - uint8_t testMax = 0; - - //test samples are not just noise - for (; idx < 65; ++idx ){ - if (testMax < dest[idx]) - testMax = dest[idx]; - } - - //if not, just noise - if (testMax < 20) return -2; - + if (size < 66*64) return -2; // FSK demodulator - size = fskdemod(dest, size, 64, 1, 10, 8); // RF/64 and invert - - //did we get a good demod? - if (size < 65) return -3; - + 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 //| | | | | | | @@ -639,23 +660,213 @@ int IOdemodFSK(uint8_t *dest, size_t size) // //XSF(version)facility:codeone+codetwo //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 (!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; + } + return -5; +} + +// by marshmellow +// find viking preamble 0xF200 in already demoded data +int VikingDemod_AM(uint8_t *dest, size_t *size) { + //make sure buffer has data + if (*size < 64*2) return -2; + + size_t startIdx = 0; + uint8_t preamble[] = {1,1,1,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; + uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); + if (errChk == 0) return -4; //preamble not found + uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^ + bytebits_to_byte(dest+startIdx+8,8) ^ + bytebits_to_byte(dest+startIdx+16,8) ^ + bytebits_to_byte(dest+startIdx+24,8) ^ + bytebits_to_byte(dest+startIdx+32,8) ^ + bytebits_to_byte(dest+startIdx+40,8) ^ + bytebits_to_byte(dest+startIdx+48,8) ^ + bytebits_to_byte(dest+startIdx+56,8); + if ( checkCalc != 0xA8 ) return -5; + if (*size != 64) return -6; + //return start position + return (int) startIdx; +} + +// 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) +{ + //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; +} + +// ASK/Diphase fc/64 (inverted Biphase) +// Note: this i s not a demod, this is only a detection +// the parameter *dest needs to be demoded before call +int JablotronDemod(uint8_t *dest, size_t *size){ + //make sure buffer has enough data + if (*size < 64) return -1; + + size_t startIdx = 0; + // 0xFFFF preamble, 64bits + uint8_t preamble[] = { + 1,1,1,1, + 1,1,1,1, + 1,1,1,1, + 1,1,1,1, + 0 + }; + + uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); + if (errChk == 0) return -4; //preamble not found + if (*size != 64) return -3; - uint8_t mask[] = {0,0,0,0,0,0,0,0,0,1}; + uint8_t checkchksum = 0; + for (int i=16; i < 56; i += 8) { + checkchksum += bytebits_to_byte(dest+startIdx+i,8); + } + checkchksum ^= 0x3A; + + uint8_t crc = bytebits_to_byte(dest+startIdx+56, 8); - 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; - } - } + if ( checkchksum != crc ) return -5; + return (int)startIdx; +} + +// by marshmellow +// FSK Demod then try to locate an AWID ID +int AWIDdemodFSK(uint8_t *dest, size_t *size) +{ + //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); // 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 a Farpointe Data (pyramid) ID +int PyramiddemodFSK(uint8_t *dest, size_t *size) +{ + //make sure buffer has data + if (*size < 128*50) return -5; + + //test samples are not just noise + if (justNoise(dest, *size)) return -1; + + // 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}; + 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; +} + +// find nedap preamble in already demoded data +int NedapDemod(uint8_t *dest, size_t *size) { + //make sure buffer has data + if (*size < 128) return -3; + + 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 + return (int) startIdx; +} + +// by marshmellow +// to detect a wave that has heavily clipped (clean) samples +uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low) +{ + bool allArePeaks = true; + uint16_t cntPeaks=0; + size_t loopEnd = 512+160; + if (loopEnd > size) loopEnd = size; + for (size_t i=160; ilow && dest[i] 300) return true; + } + return allArePeaks; +} +// 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) +{ + 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; + } + // 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 0; } @@ -663,88 +874,888 @@ int IOdemodFSK(uint8_t *dest, size_t size) // by marshmellow // not perfect especially with lower clocks or VERY good antennas (heavy wave clipping) // maybe somehow adjust peak trimming value based on samples to fix? -int DetectASKClock(uint8_t dest[], size_t size, int clock) +// 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[] = {16,32,40,50,64,100,128,256}; - uint8_t clkLen = sizeof clk / sizeof clk[0]; + 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; + //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) +{ + 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) - peak = dest[i]; - if(dest[i] < low) - low = dest[i]; - } - - peak = (int)(peak * .75); - low = (int)(low+128 * .25); - - int ii, cnt, bestErr, tol = 0; - int errCnt[clkLen]; - memset(errCnt, 0x00, clkLen); - - int tmpIndex, tmphigh, tmplow; - + int peak, low; + if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return 0; + + int lowestTransition = DetectStrongNRZClk(dest, size-20, peak, low); + size_t ii; + uint8_t clkCnt; + uint8_t tol = 0; + uint16_t smplCnt = 0; + int16_t peakcnt = 0; + int16_t peaksdet[] = {0,0,0,0,0,0,0,0}; + uint16_t maxPeak = 255; + bool firstpeak = false; + //test for large clipped waves + for (i=0; i= 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( cnt = 0; cnt < clkLen; ++cnt ){ + 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); + } - tol = (clk[cnt] == 32) ? 1 : 0; - bestErr = 1000; - tmpIndex = tmphigh = tmplow = 0; + return clk[best]; +} - //try lining up the peaks by moving starting point (try first 256) - for (ii=0; ii < loopCnt; ++ii){ - - // not a peak? continue - if ( (dest[ii] < peak) && (dest[ii] > low)) - continue; +// by marshmellow +// convert psk1 demod to psk2 demod +// only transition waves are 1s +void psk1TOpsk2(uint8_t *BitStream, size_t size) +{ + size_t i=1; + uint8_t lastBit=BitStream[0]; + for (; i= peak || dest[tmpIndex] <= low ) { +// by marshmellow +// convert psk2 demod to psk1 demod +// from only transition waves are 1s to phase shifts change bit +void psk2TOpsk1(uint8_t *BitStream, size_t size) +{ + uint8_t phase=0; + for (size_t i=0; 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; + } + } + *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; + } } - else if ( tmplow >= peak || tmplow <= low){ - } - else if ( tmphigh >= peak || tmphigh <= low){ + if (rfCounter > 0 && rfLensFnd < 15){ + //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter); + rfCnts[rfLensFnd]++; + rfLens[rfLensFnd++] = rfCounter; } - else - errCnt[cnt]++; //error no peak detected + } else { + firstBitFnd++; } + rfCounter=0; + lastFCcnt=fcCounter; + } + fcCounter=0; + } + 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; + } + 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 we found no errors this is correct one - return this clock - if ( errCnt[cnt] == 0 ) - return clk[cnt]; + if (ii<0) return 0; // oops we went too far - if ( errCnt[cnt] < bestErr) - bestErr = errCnt[cnt]; + 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 fskAdj) +{ + uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; + uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; + uint8_t fcLensFnd = 0; + uint8_t lastFCcnt=0; + uint8_t 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; + + 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++; } - // save the least error. - errCnt[cnt] = bestErr; } - // find best clock which has lowest number of errors - int j = 0, bestIndex = 0; - for (; j < clkLen; ++j){ - if ( errCnt[j] < errCnt[bestIndex] ) - bestIndex = j; + + 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) +{ + 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 / 64]; + int waveLen[bufsize / 64]; + 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/64)) { + 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; + } + 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) { //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 (datalen % clk > clk/8) { + if (g_debugMode==2) prnt("DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting", datalen, clk, datalen % clk); + return false; + } else { + // padd the amount off - could be problematic... but shouldn't happen often + datalen += datalen % clk; + } + // if datalen is less than one t55xx block - ERROR + if (datalen/clk < 8*4) { + if (g_debugMode==2) prnt("DEBUG STT: datalen is less than 1 full t55xx block - quitting"); + return false; + } + size_t dataloc = start; + size_t newloc = 0; + i=0; + // 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