X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/549daaf7784e74a8da886e0c32d947d4128ffa1c..69f42a0593bcb5b52fabe358668358390b4af056:/common/lfdemod.c?ds=inline diff --git a/common/lfdemod.c b/common/lfdemod.c index 750dbf1b..880e2c2b 100644 --- a/common/lfdemod.c +++ b/common/lfdemod.c @@ -33,12 +33,16 @@ //----------------------------------------------------------------------------- #include // for memset, memcmp and size_t +#include "lfdemod.h" #include // for uint_32+ #include // for bool +#include "parity.h" // for parity test //********************************************************************************************** //---------------------------------Utilities Section-------------------------------------------- //********************************************************************************************** +#define LOWEST_DEFAULT_CLOCK 32 +#define FSK_PSK_THRESHOLD 123 //to allow debug print calls when used not on device void dummy(char *fmt, ...){} @@ -53,11 +57,10 @@ void dummy(char *fmt, ...){} #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; + justNoise1 = BitStream[idx] < FSK_PSK_THRESHOLD; } return justNoise1; } @@ -72,7 +75,7 @@ int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi if (BitStream[i] > *high) *high = BitStream[i]; if (BitStream[i] < *low) *low = BitStream[i]; } - if (*high < 123) return -1; // just noise + if (*high < FSK_PSK_THRESHOLD) return -1; // just noise *high = ((*high-128)*fuzzHi + 12800)/100; *low = ((*low-128)*fuzzLo + 12800)/100; return 1; @@ -81,40 +84,35 @@ int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi // 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); - } - if (g_debugMode) prnt("DEBUG: ans: %d, ptype: %d, bits: %08X",ans,pType,bits); - return (ans == pType); +bool parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType) { + return oddparity32(bits) ^ 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) +// takes a array of binary values, start position, length of bits per parity (includes parity bit - MAX 32), +// 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; + size_t bitCnt = 0; for (int word = 0; word < (bLen); word+=pLen) { for (int bit=0; bit < pLen; bit++) { + if (word+bit >= bLen) break; parityWd = (parityWd << 1) | BitStream[startIdx+word+bit]; - BitStream[j++] = (BitStream[startIdx+word+bit]); + BitStream[bitCnt++] = (BitStream[startIdx+word+bit]); } if (word+pLen > bLen) break; - j--; // overwrite parity with next data + bitCnt--; // 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 + case 3: if (BitStream[bitCnt]==1) {return 0;} break; //should be 0 spacer bit + case 2: if (BitStream[bitCnt]==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 size return bitCnt; } @@ -197,18 +195,18 @@ uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_ } // 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 findModStart(uint8_t dest[], size_t size, uint8_t expWaveSize) { size_t i = 0; size_t waveSizeCnt = 0; uint8_t thresholdCnt = 0; - bool isAboveThreshold = dest[i++] >= threshold_value; + bool isAboveThreshold = dest[i++] >= FSK_PSK_THRESHOLD; for (; i < size-20; i++ ) { - if(dest[i] < threshold_value && isAboveThreshold) { + if(dest[i] < FSK_PSK_THRESHOLD && isAboveThreshold) { thresholdCnt++; if (thresholdCnt > 2 && waveSizeCnt < expWaveSize+1) break; isAboveThreshold = false; waveSizeCnt = 0; - } else if (dest[i] >= threshold_value && !isAboveThreshold) { + } else if (dest[i] >= FSK_PSK_THRESHOLD && !isAboveThreshold) { thresholdCnt++; if (thresholdCnt > 2 && waveSizeCnt < expWaveSize+1) break; isAboveThreshold = true; @@ -222,6 +220,91 @@ size_t findModStart(uint8_t dest[], size_t size, uint8_t threshold_value, uint8_ return i; } +int getClosestClock(int testclk) { + uint8_t fndClk[] = {8,16,32,40,50,64,128}; + + for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) + if (testclk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && testclk <= fndClk[clkCnt]+1) + return fndClk[clkCnt]; + + return 0; +} + +void getNextLow(uint8_t samples[], size_t size, int low, size_t *i) { + while ((samples[*i] > low) && (*i < size)) + *i+=1; +} + +void getNextHigh(uint8_t samples[], size_t size, int high, size_t *i) { + while ((samples[*i] < high) && (*i < size)) + *i+=1; +} + +// load wave counters +bool loadWaveCounters(uint8_t samples[], size_t size, int lowToLowWaveLen[], int highToLowWaveLen[], int *waveCnt, int *skip, int *minClk, int *high, int *low) { + size_t i=0, firstLow, firstHigh; + size_t testsize = (size < 512) ? size : 512; + + if ( getHiLo(samples, testsize, high, low, 80, 80) == -1 ) { + if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting"); + return false; //just noise + } + + // get to first full low to prime loop and skip incomplete first pulse + getNextHigh(samples, size, *high, &i); + getNextLow(samples, size, *low, &i); + *skip = i; + + // populate tmpbuff buffer with pulse lengths + while (i < size) { + // measure from low to low + firstLow = i; + //find first high point for this wave + getNextHigh(samples, size, *high, &i); + firstHigh = i; + + getNextLow(samples, size, *low, &i); + + if (*waveCnt >= (size/LOWEST_DEFAULT_CLOCK)) + break; + + highToLowWaveLen[*waveCnt] = i - firstHigh; //first high to first low + lowToLowWaveLen[*waveCnt] = i - firstLow; + *waveCnt += 1; + if (i-firstLow < *minClk && i < size) { + *minClk = i - firstLow; + } + } + return true; +} + +size_t pskFindFirstPhaseShift(uint8_t samples[], size_t size, uint8_t *curPhase, size_t waveStart, uint16_t fc, uint16_t *fullWaveLen) { + uint16_t loopCnt = (size+3 < 4096) ? size : 4096; //don't need to loop through entire array... + + uint16_t avgWaveVal=0, lastAvgWaveVal=0; + size_t i = waveStart, waveEnd, waveLenCnt, firstFullWave; + for (; i= samples[i+2]){ + waveEnd = i+1; + if (g_debugMode == 2) prnt("DEBUG PSK: waveEnd: %u, waveStart: %u", waveEnd, waveStart); + waveLenCnt = waveEnd-waveStart; + if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+8)){ //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 (could cause inverting) + if (lastAvgWaveVal > FSK_PSK_THRESHOLD) *curPhase ^= 1; + return firstFullWave; + } + waveStart = i+1; + avgWaveVal = 0; + } + avgWaveVal += samples[i+2]; + } + return 0; +} + //by marshmellow //amplify based on ask edge detection - not accurate enough to use all the time void askAmp(uint8_t *BitStream, size_t size) { @@ -249,15 +332,17 @@ uint32_t manchesterEncode2Bytes(uint16_t datain) { //by marshmellow //encode binary data into binary manchester -//NOTE: BitStream must have double the size available in memory to do the swap +//NOTE: BitStream must have triple the size of "size" available in memory to do the swap int ManchesterEncode(uint8_t *BitStream, size_t size) { - size_t modIdx=size, i=0; - if (size>modIdx) return -1; + //allow up to 4K out (means BitStream must be at least 2048+4096 to handle the swap) + size = (size>2048) ? 2048 : size; + size_t modIdx = size; + size_t i; for (size_t idx=0; idx < size; idx++){ BitStream[idx+modIdx++] = BitStream[idx]; BitStream[idx+modIdx++] = BitStream[idx]^1; } - for (; i<(size*2); i++){ + for (i=0; i<(size*2); i++){ BitStream[i] = BitStream[i+size]; } return i; @@ -289,28 +374,22 @@ uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t lo // by marshmellow // to help detect clocks on heavily clipped samples // based on count of low to low -int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low, int *clock) { - uint8_t fndClk[] = {8,16,32,40,50,64,128}; +int DetectStrongAskClock(uint8_t dest[], size_t size, int high, int low, int *clock) { size_t startwave; size_t i = 100; size_t minClk = 255; int shortestWaveIdx = 0; // 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; + getNextHigh(dest, size, high, &i); + getNextLow(dest, size, low, &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; + + getNextHigh(dest, size, high, &i); + getNextLow(dest, size, low, &i); //get minimum measured distance if (i-startwave < minClk && i < size) { minClk = i - startwave; @@ -318,14 +397,12 @@ int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low, } } // 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) { - *clock = fndClk[clkCnt]; - return shortestWaveIdx; - } - } - return 0; + if (g_debugMode==2) prnt("DEBUG ASK: DetectStrongAskClock smallest wave: %d",minClk); + *clock = getClosestClock(minClk); + if (*clock == 0) + return 0; + + return shortestWaveIdx; } // by marshmellow @@ -428,13 +505,14 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr) { return bestStart[best]; } -int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low){ +int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low, bool *strong) { //find shortest transition from high to low + *strong = false; size_t i = 0; size_t transition1 = 0; int lowestTransition = 255; bool lastWasHigh = false; - + size_t transitionSampleCount = 0; //find first valid beginning of a high or low wave while ((dest[i] >= peak || dest[i] <= low) && (i < size)) ++i; @@ -450,16 +528,23 @@ int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low){ lastWasHigh = (dest[i] >= peak); if (i-transition1 < lowestTransition) lowestTransition = i-transition1; transition1 = i; + } else if (dest[i] < peak && dest[i] > low) { + transitionSampleCount++; } } if (lowestTransition == 255) lowestTransition = 0; if (g_debugMode==2) prnt("DEBUG NRZ: detectstrongNRZclk smallest wave: %d",lowestTransition); + // if less than 10% of the samples were not peaks (or 90% were peaks) then we have a strong wave + if (transitionSampleCount / size < 10) { + *strong = true; + lowestTransition = getClosestClock(lowestTransition); + } return lowestTransition; } //by marshmellow //detect nrz clock by reading #peaks vs no peaks(or errors) -int DetectNRZClock_ext(uint8_t dest[], size_t size, int clock, size_t *clockStartIdx) { +int DetectNRZClock(uint8_t dest[], size_t size, int clock, size_t *clockStartIdx) { 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... @@ -471,35 +556,35 @@ int DetectNRZClock_ext(uint8_t dest[], size_t size, int clock, size_t *clockStar //get high and low peak int peak, low; - if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return 0; + if (getHiLo(dest, loopCnt, &peak, &low, 90, 90) < 1) return 0; - int lowestTransition = DetectStrongNRZClk(dest, size-20, peak, low); + bool strong = false; + int lowestTransition = DetectStrongNRZClk(dest, size-20, peak, low, &strong); + if (strong) return lowestTransition; 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; + uint16_t minPeak = 255; + bool firstpeak = true; + //test for large clipped waves - ignore first peak + 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); - } + firstpeak = false; + if (smplCnt > 0) { + if (minPeak > smplCnt && smplCnt > 7) minPeak = smplCnt; peakcnt++; - //prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt); - smplCnt=0; + if (g_debugMode == 2) prnt("DEBUG NRZ: minPeak: %d, smplCnt: %d, peakcnt: %d",minPeak,smplCnt,peakcnt); + smplCnt = 0; } } } + if (minPeak < 8) return 0; bool errBitHigh = 0; bool bitHigh = 0; uint8_t ignoreCnt = 0; @@ -509,12 +594,12 @@ int DetectNRZClock_ext(uint8_t dest[], size_t size, int clock, size_t *clockStar size_t bestStart[]={0,0,0,0,0,0,0,0,0}; peakcnt=0; //test each valid clock from smallest to greatest to see which lines up - for(clkCnt=0; clkCnt < 8; ++clkCnt){ + for(clkCnt=0; clkCnt < 8; ++clkCnt) { //ignore clocks smaller than smallest peak - if (clk[clkCnt] < maxPeak - (clk[clkCnt]/4)) continue; + if (clk[clkCnt] < minPeak - (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)){ + for (ii=20; ii < loopCnt; ++ii) { + if ((dest[ii] >= peak) || (dest[ii] <= low)) { peakcnt = 0; bitHigh = false; ignoreCnt = 0; @@ -538,8 +623,8 @@ int DetectNRZClock_ext(uint8_t dest[], size_t size, int clock, size_t *clockStar lastBit += clk[clkCnt]; } //else if not a clock bit and no peaks - } else if (dest[i] < peak && dest[i] > low){ - if (ignoreCnt==0){ + } else if (dest[i] < peak && dest[i] > low) { + if (ignoreCnt==0) { bitHigh=false; if (errBitHigh==true) peakcnt--; errBitHigh=false; @@ -561,25 +646,20 @@ int DetectNRZClock_ext(uint8_t dest[], size_t size, int clock, size_t *clockStar } int iii=7; uint8_t best=0; - for (iii=7; iii > 0; iii--){ + 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]){ + } 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); + if (g_debugMode==2) prnt("DEBUG NRZ: Clk: %d, peaks: %d, minPeak: %d, bestClk: %d, lowestTrs: %d",clk[iii],peaksdet[iii],minPeak, clk[best], lowestTransition); } *clockStartIdx = bestStart[best]; return clk[best]; } -int DetectNRZClock(uint8_t dest[], size_t size, int clock) { - size_t bestStart=0; - return DetectNRZClock_ext(dest, size, clock, &bestStart); -} - //by marshmellow //countFC is to detect the field clock lengths. //counts and returns the 2 most common wave lengths @@ -647,6 +727,7 @@ uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj) { 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[i]==0) break; } if (fcLens[best1]==0) return 0; uint8_t fcH=0, fcL=0; @@ -664,18 +745,24 @@ uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj) { // 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]; + if (fskAdj) return fcs; + return (uint16_t)fcLens[best2] << 8 | fcLens[best1]; } //by marshmellow //detect psk clock by reading each phase shift // a phase shift is determined by measuring the sample length of each wave -int DetectPSKClock_ext(uint8_t dest[], size_t size, int clock, int *firstPhaseShift) { +int DetectPSKClock(uint8_t dest[], size_t size, int clock, size_t *firstPhaseShift, uint8_t *curPhase, uint8_t *fc) { uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock uint16_t loopCnt = 4096; //don't need to loop through entire array... if (size == 0) return 0; - if (size>8); + if ((fcs>>8) == 10 && *fc == 8) return 0; + if (*fc!=2 && *fc!=4 && *fc!=8) return 0; //if we already have a valid clock quit size_t i=1; @@ -683,37 +770,28 @@ int DetectPSKClock_ext(uint8_t dest[], size_t size, int clock, int *firstPhaseSh if (clk[i] == clock) return clock; size_t waveStart=0, waveEnd=0, firstFullWave=0, lastClkBit=0; - uint8_t clkCnt, fc=0, fullWaveLen=0, tol=1; - uint16_t peakcnt=0, errCnt=0, waveLenCnt=0; + + uint8_t clkCnt, tol=1; + uint16_t peakcnt=0, errCnt=0, waveLenCnt=0, fullWaveLen=0; uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000}; uint16_t peaksdet[]={0,0,0,0,0,0,0,0,0}; - fc = countFC(dest, size, 0); - if (fc!=2 && fc!=4 && fc!=8) return -1; - if (g_debugMode==2) prnt("DEBUG PSK: FC: %d",fc); - //find first full wave - for (i=160; i= 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; - } - } + //find start of modulating data in trace + i = findModStart(dest, size, *fc); + + firstFullWave = pskFindFirstPhaseShift(dest, size, curPhase, i, *fc, &fullWaveLen); + 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; + fullWaveLen = 0; } + *firstPhaseShift = firstFullWave; 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--){ + for(clkCnt=7; clkCnt >= 1 ; clkCnt--) { + tol = *fc/2; lastClkBit = firstFullWave; //set end of wave as clock align waveStart = 0; errCnt=0; @@ -729,9 +807,9 @@ int DetectPSKClock_ext(uint8_t dest[], size_t size, int clock, int *firstPhaseSh } else { //waveEnd waveEnd = i+1; waveLenCnt = waveEnd-waveStart; - if (waveLenCnt > fc){ + 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 (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]; @@ -740,7 +818,7 @@ int DetectPSKClock_ext(uint8_t dest[], size_t size, int clock, int *firstPhaseSh } else { //phase shift before supposed to based on clock errCnt++; } - } else if (i+1 > lastClkBit + clk[clkCnt] + tol + fc){ + } else if (i+1 > lastClkBit + clk[clkCnt] + tol + *fc){ lastClkBit+=clk[clkCnt]; //no phase shift but clock bit } waveStart=i+1; @@ -765,14 +843,9 @@ int DetectPSKClock_ext(uint8_t dest[], size_t size, int clock, int *firstPhaseSh return clk[best]; } -int DetectPSKClock(uint8_t dest[], size_t size, int clock) { - int firstPhaseShift = 0; - return DetectPSKClock_ext(dest, size, clock, &firstPhaseShift); -} - //by marshmellow //detects the bit clock for FSK given the high and low Field Clocks -uint8_t detectFSKClk_ext(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow, int *firstClockEdge) { +uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow, int *firstClockEdge) { 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}; @@ -878,17 +951,14 @@ uint8_t detectFSKClk_ext(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_ return clk[ii]; } -uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow) { - int firstClockEdge = 0; - return detectFSKClk_ext(BitStream, size, fcHigh, fcLow, &firstClockEdge); -} - //********************************************************************************************** //--------------------Modulation Demods &/or Decoding Section----------------------------------- //********************************************************************************************** // look for Sequence Terminator - should be pulses of clk*(1 or 2), clk*2, clk*(1.5 or 2), by idx we mean graph position index... -bool findST(int *stStopLoc, int *stStartIdx, int lowToLowWaveLen[], int highToLowWaveLen[], int clk, int tol, int buffSize, int *i) { +bool findST(int *stStopLoc, int *stStartIdx, int lowToLowWaveLen[], int highToLowWaveLen[], int clk, int tol, int buffSize, size_t *i) { + if (buffSize < *i+4) return false; + for (; *i < buffSize - 4; *i+=1) { *stStartIdx += lowToLowWaveLen[*i]; //caution part of this wave may be data and part may be ST.... to be accounted for in main function for now... if (lowToLowWaveLen[*i] >= clk*1-tol && lowToLowWaveLen[*i] <= (clk*2)+tol && highToLowWaveLen[*i] < clk+tol) { //1 to 2 clocks depending on 2 bits prior @@ -906,75 +976,33 @@ bool findST(int *stStopLoc, int *stStartIdx, int lowToLowWaveLen[], int highToLo } //by marshmellow //attempt to identify a Sequence Terminator in ASK modulated raw wave -bool DetectST_ext(uint8_t buffer[], size_t *size, int *foundclock, size_t *ststart, size_t *stend) { +bool DetectST(uint8_t buffer[], size_t *size, int *foundclock, size_t *ststart, size_t *stend) { 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; + int j=0, high, low, skip=0, start=0, end=0, minClk=255; + size_t i = 0; //probably should malloc... || test if memory is available ... handle device side? memory danger!!! [marshmellow] - int tmpbuff[bufsize / 32]; // low to low wave count //guess rf/32 clock, if click is smaller we will only have room for a fraction of the samples captured - int waveLen[bufsize / 32]; // high to low wave count //if clock is larger then we waste memory in array size that is not needed... - size_t testsize = (bufsize < 512) ? bufsize : 512; + int tmpbuff[bufsize / LOWEST_DEFAULT_CLOCK]; // low to low wave count //guess rf/32 clock, if click is smaller we will only have room for a fraction of the samples captured + int waveLen[bufsize / LOWEST_DEFAULT_CLOCK]; // high to low wave count //if clock is larger then we waste memory in array size that is not needed... + //size_t testsize = (bufsize < 512) ? bufsize : 512; int phaseoff = 0; high = low = 128; memset(tmpbuff, 0, sizeof(tmpbuff)); memset(waveLen, 0, sizeof(waveLen)); - if ( getHiLo(buffer, testsize, &high, &low, 80, 80) == -1 ) { - if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting"); - return false; //just noise - } - i = 0; - j = 0; - minClk = 255; - // get to first full low to prime loop and skip incomplete first pulse - while ((buffer[i] < high) && (i < bufsize)) - ++i; - while ((buffer[i] > low) && (i < bufsize)) - ++i; - skip = i; - - // populate tmpbuff buffer with pulse lengths - while (i < bufsize) { - // measure from low to low - while ((buffer[i] > low) && (i < bufsize)) - ++i; - start= i; - while ((buffer[i] < high) && (i < bufsize)) - ++i; - //first high point for this wave - waveStart = i; - while ((buffer[i] > low) && (i < bufsize)) - ++i; - if (j >= (bufsize/32)) { - break; - } - waveLen[j] = i - waveStart; //first high to first low - tmpbuff[j++] = i - start; - if (i-start < minClk && i < bufsize) { - minClk = i - start; - } - } + if (!loadWaveCounters(buffer, bufsize, tmpbuff, waveLen, &j, &skip, &minClk, &high, &low)) return false; // 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; - + clk = getClosestClock(minClk); + // clock not found - ERROR + if (clk == 0) { + if (g_debugMode==2) prnt("DEBUG STT: clock not found - quitting"); + return false; + } *foundclock = clk; - i=0; + + tol = clk/8; if (!findST(&start, &skip, tmpbuff, waveLen, clk, tol, j, &i)) { // first ST not found - ERROR if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting"); @@ -1021,9 +1049,9 @@ bool DetectST_ext(uint8_t buffer[], size_t *size, int *foundclock, size_t *ststa return false; } size_t dataloc = start; - if (buffer[dataloc-(clk*4)-(clk/8)] <= low && buffer[dataloc] <= low && buffer[dataloc-(clk*4)] >= high) { + if (buffer[dataloc-(clk*4)-(clk/4)] <= low && buffer[dataloc] <= low && buffer[dataloc-(clk*4)] >= high) { //we have low drift (and a low just before the ST and a low just after the ST) - compensate by backing up the start - for ( i=0; i <= (clk/8); ++i ) { + for ( i=0; i <= (clk/4); ++i ) { if ( buffer[dataloc - (clk*4) - i] <= low ) { dataloc -= i; break; @@ -1038,14 +1066,15 @@ bool DetectST_ext(uint8_t buffer[], size_t *size, int *foundclock, size_t *ststa // 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) { + if (buffer[dataloc]low && buffer[dataloc+clk/4]low) { for(i=0; i < clk/2-tol; ++i) { buffer[dataloc+i] = high+5; } - } //test for single sample outlier (high between two lows) in the case of very strong waves - if (buffer[dataloc] >= high && buffer[dataloc+2] <= low) { - buffer[dataloc] = buffer[dataloc+2]; - buffer[dataloc+1] = buffer[dataloc+2]; + } //test for small spike outlier (high between two lows) in the case of very strong waves + if (buffer[dataloc] > low && buffer[dataloc+clk/4] <= low) { + for(i=0; i < clk/4; ++i) { + buffer[dataloc+i] = buffer[dataloc+clk/4]; + } } if (firstrun) { *stend = dataloc; @@ -1068,23 +1097,20 @@ bool DetectST_ext(uint8_t buffer[], size_t *size, int *foundclock, size_t *ststa *size = newloc; return true; } -bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) { - size_t ststart = 0, stend = 0; - return DetectST_ext(buffer, size, foundclock, &ststart, &stend); -} //by marshmellow -//take 11 10 01 11 00 and make 01100 ... miller decoding +//take 11 10 01 11 00 and make 01100 ... miller decoding //check for phase errors - should never have half a 1 or 0 by itself and should never exceed 1111 or 0000 in a row //decodes miller encoded binary //NOTE askrawdemod will NOT demod miller encoded ask unless the clock is manually set to 1/2 what it is detected as! -/*int millerRawDecode(uint8_t *BitStream, size_t *size, int invert) { +int millerRawDecode(uint8_t *BitStream, size_t *size, int invert) { if (*size < 16) return -1; - uint16_t MaxBits = 512, errCnt = 0, bestErr = 1000, bestRun = 0; - size_t i, ii, bitCnt=0; - uint8_t alignCnt = 0, curBit = BitStream[0]; + uint16_t MaxBits = 512, errCnt = 0; + size_t i, bitCnt=0; + uint8_t alignCnt = 0, curBit = BitStream[0], alignedIdx = 0; + uint8_t halfClkErr = 0; //find alignment, needs 4 1s or 0s to properly align - for (i=1; i < *size; i++) { + for (i=1; i < *size-1; i++) { alignCnt = (BitStream[i] == curBit) ? alignCnt+1 : 0; curBit = BitStream[i]; if (alignCnt == 4) break; @@ -1094,17 +1120,30 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) { if (g_debugMode) prnt("ERROR MillerDecode: alignment not found so either your bitstream is not miller or your data does not have a 101 in it"); return -1; } + alignedIdx = (i-1) % 2; + for (i=alignedIdx; i < *size-3; i+=2) { + halfClkErr = (uint8_t)((halfClkErr << 1 | BitStream[i]) & 0xFF); + if ( (halfClkErr & 0x7) == 5 || (halfClkErr & 0x7) == 2 || (i > 2 && (halfClkErr & 0x7) == 0) || (halfClkErr & 0x1F) == 0x1F) { + errCnt++; + BitStream[bitCnt++] = 7; + continue; + } + BitStream[bitCnt++] = BitStream[i] ^ BitStream[i+1] ^ invert; -}*/ + if (bitCnt > MaxBits) break; + } + *size = bitCnt; + return errCnt; +} //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) { +int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int *offset, int invert) { uint16_t bitnum = 0; uint16_t errCnt = 0; - size_t i = offset; + size_t i = *offset; uint16_t MaxBits=512; //if not enough samples - error if (*size < 51) return -1; @@ -1114,8 +1153,8 @@ int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert) { 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){ + if (!offsetA && offsetB) *offset+=1; + for (i=*offset; i<*size-3; i+=2){ //check for phase error if (BitStream[i+1]==BitStream[i+2]) { BitStream[bitnum++]=7; @@ -1312,9 +1351,10 @@ int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr // by marshmellow - demodulate NRZ wave - requires a read with strong signal // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak -int nrzRawDemod_ext(uint8_t *dest, size_t *size, int *clk, int *invert, int *startIdx) { +int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert, int *startIdx) { if (justNoise(dest, *size)) return -1; - *clk = DetectNRZClock(dest, *size, *clk); + size_t clkStartIdx = 0; + *clk = DetectNRZClock(dest, *size, *clk, &clkStartIdx); if (*clk==0) return -2; size_t i, gLen = 4096; if (gLen>*size) gLen = *size-20; @@ -1346,10 +1386,6 @@ int nrzRawDemod_ext(uint8_t *dest, size_t *size, int *clk, int *invert, int *sta *size = numBits; return 0; } -int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert) { - int startIdx = 0; - return nrzRawDemod_ext(dest, size, clk, invert, &startIdx); -} //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, int *startIdx) { @@ -1358,16 +1394,15 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow 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; if ( size < 1024 ) return 0; // not enough samples //find start of modulating data in trace - idx = findModStart(dest, size, threshold_value, fchigh); + idx = findModStart(dest, size, fchigh); // Need to threshold first sample - if(dest[idx] < threshold_value) dest[0] = 0; + if(dest[idx] < FSK_PSK_THRESHOLD) dest[0] = 0; else dest[0] = 1; last_transition = idx; @@ -1379,7 +1414,7 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow // (could also be fc/5 && fc/7 for fsk1 = 4-9) for(; idx < size; idx++) { // threshold current value - if (dest[idx] < threshold_value) dest[idx] = 0; + if (dest[idx] < FSK_PSK_THRESHOLD) dest[idx] = 0; else dest[idx] = 1; // Check for 0->1 transition @@ -1464,18 +1499,14 @@ size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, //by marshmellow (from holiman's base) // full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod) -int fskdemod_ext(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow, int *startIdx) { +int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow, int *startIdx) { + if (justNoise(dest, size)) return 0; // FSK demodulator size = fsk_wave_demod(dest, size, fchigh, fclow, startIdx); size = aggregate_bits(dest, size, rfLen, invert, fchigh, fclow, startIdx); return size; } -int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow) { - int startIdx=0; - return fskdemod_ext(dest, size, rfLen, invert, fchigh, fclow, &startIdx); -} - // by marshmellow // convert psk1 demod to psk2 demod // only transition waves are 1s @@ -1512,56 +1543,31 @@ void psk2TOpsk1(uint8_t *BitStream, size_t size) { //by marshmellow - demodulate PSK1 wave //uses wave lengths (# Samples) int pskRawDemod_ext(uint8_t dest[], size_t *size, int *clock, int *invert, int *startIdx) { - if (size == 0) return -1; - uint16_t loopCnt = 4096; //don't need to loop through entire array... - if (*size> 8; - if (fc2 == 10) return -1; //fsk found - quit - fc = fc & 0xFF; - if (fc!=2 && fc!=4 && fc!=8) return -1; - //PrintAndLog("DEBUG: FC: %d",fc); - *clock = DetectPSKClock(dest, *size, *clock); - if (*clock == 0) return -1; - - //find start of modulating data in trace - uint8_t threshold_value = 123; //-5 - i = findModStart(dest, *size, threshold_value, fc); - - //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); - waveLenCnt = waveEnd-waveStart; - if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+3)){ //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 (could cause inverting) - if (lastAvgWaveVal > threshold_value) curPhase ^= 1; - break; - } - - waveStart = i+1; - avgWaveVal = 0; - } - avgWaveVal += dest[i+2]; - } + uint8_t fc=0; + size_t i=0, numBits=0, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0; + uint16_t fullWaveLen=0, waveLenCnt=0, avgWaveVal; + uint16_t errCnt=0, errCnt2=0; + + *clock = DetectPSKClock(dest, *size, *clock, &firstFullWave, &curPhase, &fc); + if (*clock <= 0) return -1; + //if clock detect found firstfullwave... + uint16_t tol = fc/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); + //find start of modulating data in trace + i = findModStart(dest, *size, fc); + //find first phase shift + firstFullWave = pskFindFirstPhaseShift(dest, *size, &curPhase, i, fc, &fullWaveLen); + 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); + } } else { memset(dest, curPhase^1, firstFullWave / *clock); } @@ -1574,9 +1580,9 @@ int pskRawDemod_ext(uint8_t dest[], size_t *size, int *clock, int *invert, int * 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++){ + 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 (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]) { if (waveStart == 0) { waveStart = i+1; waveLenCnt = 0; @@ -1584,27 +1590,27 @@ int pskRawDemod_ext(uint8_t dest[], size_t *size, int *clock, int *invert, int * } else { //waveEnd waveEnd = i+1; waveLenCnt = waveEnd-waveStart; - lastAvgWaveVal = avgWaveVal/waveLenCnt; - if (waveLenCnt > fc){ - //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal); + if (waveLenCnt > fc) { //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 + if (i+1 >= lastClkBit + *clock - tol) { //should be a clock bit curPhase ^= 1; dest[numBits++] = curPhase; lastClkBit += *clock; - } else if (i < lastClkBit+10+fc){ + } 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){ + } 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 += dest[i+1]; + continue; } avgWaveVal = 0; waveStart = i+1; @@ -1627,14 +1633,12 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) { // 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, int *waveStartIdx) { //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 + *size = fskdemod(dest, *size, 50, 1, 10, 8, waveStartIdx); // 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}; @@ -1672,6 +1676,7 @@ uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_ *hi = (bytebits_to_byte(BitStream, 24)); *lo = ((uint64_t)(bytebits_to_byte(BitStream + 24, 32)) << 32) | (bytebits_to_byte(BitStream + 24 + 32, 32)); } else { + if (g_debugMode) prnt("Error removing parity: %u", *size); return 0; } return 1; @@ -1688,6 +1693,8 @@ int FDXBdemodBI(uint8_t *dest, size_t *size) { uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); if (errChk == 0) return -2; //preamble not found + if (*size != 128) return -3; //wrong size for fdxb + //return start position return (int)startIdx; } @@ -1713,12 +1720,10 @@ int gProxII_Demod(uint8_t BitStream[], size_t *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; - +int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo, int *waveStartIdx) { size_t numStart=0, size2=*size, startIdx=0; - // FSK demodulator - *size = fskdemod(dest, size2,50,1,10,8); //fsk2a + // FSK demodulator fsk2a so invert and fc/10/8 + *size = fskdemod(dest, size2, 50, 1, 10, 8, waveStartIdx); 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}; @@ -1743,12 +1748,11 @@ int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32 return (int)startIdx; } -int IOdemodFSK(uint8_t *dest, size_t size) { - if (justNoise(dest, size)) return -1; +int IOdemodFSK(uint8_t *dest, size_t size, int *waveStartIdx) { //make sure buffer has data if (size < 66*64) return -2; - // FSK demodulator - size = fskdemod(dest, size, 64, 1, 10, 8); // FSK2a RF/64 + // FSK demodulator RF/64, fsk2a so invert, and fc/10/8 + size = fskdemod(dest, size, 64, 1, 10, 8, waveStartIdx); if (size < 65) return -3; //did we get a good demod? //Index map //0 10 20 30 40 50 60 @@ -1786,19 +1790,17 @@ int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert) { } if (*size != 64 && *size != 224) return -2; if (*invert==1) - for (size_t i = startidx; i < *size; i++) + for (size_t i = startidx; i < *size + startidx; i++) bitStream[i] ^= 1; return (int) startidx; } // 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) { - if (justNoise(dest, *size)) return -1; - +int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo, int *waveStartIdx) { size_t numStart=0, size2=*size, startIdx=0; // FSK demodulator - *size = fskdemod(dest, size2,50,1,10,8); //fsk2a + *size = fskdemod(dest, size2,50,1,10,8,waveStartIdx); //fsk2a if (*size < 96) return -2; // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1 @@ -1838,15 +1840,12 @@ int PrescoDemod(uint8_t *dest, size_t *size) { // by marshmellow // FSK Demod then try to locate a Farpointe Data (pyramid) ID -int PyramiddemodFSK(uint8_t *dest, size_t *size) { +int PyramiddemodFSK(uint8_t *dest, size_t *size, int *waveStartIdx) { //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 + *size = fskdemod(dest, *size, 50, 1, 10, 8, waveStartIdx); // 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}; @@ -1876,7 +1875,6 @@ int VikingDemod_AM(uint8_t *dest, size_t *size) { return (int) startIdx; } - // by iceman // find Visa2000 preamble in already demoded data int Visa2kDemod_AM(uint8_t *dest, size_t *size) {