From: marshmellow42 Date: Mon, 13 Mar 2017 03:11:52 +0000 (-0400) Subject: meant to put clock detection before demods X-Git-Tag: v3.0.0~45^2~9 X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/commitdiff_plain/d5051b981792695644f17f86cf4ed49bac2b5ff0?ds=sidebyside meant to put clock detection before demods ... fixing that. no code changed here... --- diff --git a/common/lfdemod.c b/common/lfdemod.c index 721c9d1c..fdcb475b 100644 --- a/common/lfdemod.c +++ b/common/lfdemod.c @@ -22,21 +22,23 @@ // There are 4 main sections of code below: // Utilities Section: // for general utilities used by multiple other functions -// Modulation Demods &/or Decoding Section: -// for main general modulation demodulating and encoding decoding code. // Clock / Bitrate Detection Section: // for clock detection functions for each modulation +// Modulation Demods &/or Decoding Section: +// for main general modulation demodulating and encoding decoding code. // Tag format detection section: // for detection of specific tag formats within demodulated data // // marshmellow //----------------------------------------------------------------------------- -#include -#include "lfdemod.h" -#include +#include // for memset, memcmp and size_t +#include // for uint_32+ +#include // for bool -//---------------------------------Utilities Section-------------------------------------------------- +//********************************************************************************************** +//---------------------------------Utilities Section-------------------------------------------- +//********************************************************************************************** //to allow debug print calls when used not on device void dummy(char *fmt, ...){} @@ -261,1335 +263,1341 @@ int ManchesterEncode(uint8_t *BitStream, size_t size) { return i; } -//------------------------------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) { - for (; i < buffSize - 4; ++i) { - *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 - if (lowToLowWaveLen[i+1] >= clk*2-tol && lowToLowWaveLen[i+1] <= clk*2+tol && highToLowWaveLen[i+1] > clk*3/2-tol) { //2 clocks and wave size is 1 1/2 - if (lowToLowWaveLen[i+2] >= (clk*3)/2-tol && lowToLowWaveLen[i+2] <= clk*2+tol && highToLowWaveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave - if (lowToLowWaveLen[i+3] >= clk*1-tol && lowToLowWaveLen[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit - *stStopLoc = i + 3; - return true; - } - } - } - } +// 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 -//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) { - 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; - //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 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)) +//********************************************************************************************** +//-------------------Clock / Bitrate Detection Section------------------------------------------ +//********************************************************************************************** + +// 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}; + 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 ((buffer[i] > low) && (i < bufsize)) + while ((dest[i] > low) && (i < size)) ++i; - skip = i; - // populate tmpbuff buffer with pulse lengths - while (i < bufsize) { + // loop through all samples + while (i < size) { // measure from low to low - while ((buffer[i] > low) && (i < bufsize)) + while ((dest[i] > low) && (i < size)) ++i; - start= i; - while ((buffer[i] < high) && (i < bufsize)) + startwave = i; + while ((dest[i] < high) && (i < size)) ++i; - //first high point for this wave - waveStart = i; - while ((buffer[i] > low) && (i < bufsize)) + while ((dest[i] > low) && (i < size)) ++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; + //get minimum measured distance + if (i-startwave < minClk && i < size) { + minClk = i - startwave; + shortestWaveIdx = startwave; } } - // 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; + // 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; } - } else tol = clk/8; - - *foundclock = clk; - i=0; - 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"); - return false; - } else { - if (g_debugMode==2) prnt("DEBUG STT: first STT found at: %d, j=%d",start, j); } - if (waveLen[i+2] > clk*1+tol) - phaseoff = 0; - else - phaseoff = clk/2; - - // skip over the remainder of ST - skip += clk*7/2; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point + return 0; +} - // now do it again to find the end - int dummy1 = 0; - end = skip; - if (!findST(&dummy1, &end, tmpbuff, waveLen, clk, tol, j, i+3)) { - //didn't find second ST - ERROR - if (g_debugMode==2) prnt("DEBUG STT: second STT not found - quitting"); - return false; - } - end -= phaseoff; - if (g_debugMode==2) prnt("DEBUG STT: start of data: %d end of data: %d, datalen: %d, clk: %d, bits: %d, phaseoff: %d", skip, end, end-skip, clk, (end-skip)/clk, phaseoff); - //now begin to trim out ST so we can use normal demod cmds - start = skip; - size_t datalen = end - start; - // check validity of datalen (should be even clock increments) - use a tolerance of up to 1/8th a clock - if ( clk - (datalen % clk) <= clk/8) { - // padd the amount off - could be problematic... but shouldn't happen often - datalen += clk - (datalen % clk); - } else if ( (datalen % clk) <= clk/8 ) { - // padd the amount off - could be problematic... but shouldn't happen often - datalen -= datalen % clk; - } else { - if (g_debugMode==2) prnt("DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting", datalen, clk, datalen % clk); - return false; - } - // if datalen is less than one t55xx block - ERROR - if (datalen/clk < 8*4) { - if (g_debugMode==2) prnt("DEBUG STT: datalen is less than 1 full t55xx block - quitting"); - return false; - } - size_t dataloc = start; - if (buffer[dataloc-(clk*4)-(clk/8)] <= low && buffer[dataloc] <= low && buffer[dataloc-(clk*4)] >= high) { - //we have low drift (and a low just before the ST and a low just after the ST) - compensate by backing up the start - for ( i=0; i <= (clk/8); ++i ) { - if ( buffer[dataloc - (clk*4) - i] <= low ) { - dataloc -= i; - break; - } - } - } +// 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? +// 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) { + 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 (;ilow && buffer[dataloc+3]low) { - for(i=0; i < clk/2-tol; ++i) { - buffer[dataloc+i] = high+5; + //test for large clean peaks + if (!clockFnd){ + if (DetectCleanAskWave(dest, size, peak, low)==1){ + int ans = DetectStrongAskClock(dest, size, peak, low, clock); + if (g_debugMode==2) prnt("DEBUG ASK: detectaskclk Clean Ask Wave Detected: clk %i, ShortestWave: %i",clock, ans); + if (ans > 0) { + return ans; //return shortest wave start position } - } //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]; - } - if (firstrun) { - *stend = dataloc; - *ststart = dataloc-(clk*4); - firstrun=false; } - for (i=0; i0) { + clkCnt = clockFnd; + clkEnd = clockFnd+1; } - *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); -} + else clkCnt=1; -//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 { - BitStream[bitnum++]=7; - errCnt++; + //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(bitnum>MaxBits) break; - } - *size=bitnum; - return errCnt; -} - -//by marshmellow -//take 10 and 01 and manchester decode -//run through 2 times and take least errCnt -int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert, uint8_t *alignPos) { - 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 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; - if (bestErr>errCnt){ - bestErr=errCnt; - bestRun=ii; + 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(errCntMaxBits) break; + if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, # Errors %d, Current Best Clk %d, bestStart %d",clk[iii],bestErr[iii],clk[best],bestStart[best]); } - *size=bitnum; - return bestErr; + if (!clockFnd) *clock = clk[best]; + return bestStart[best]; } -// 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; +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; + } } - return allArePeaks; + if (lowestTransition == 255) lowestTransition = 0; + if (g_debugMode==2) prnt("DEBUG NRZ: detectstrongNRZclk smallest wave: %d",lowestTransition); + return lowestTransition; } //by marshmellow -//demodulates strong heavily clipped samples -int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low, int *startIdx) -{ - *startIdx=0; - size_t bitCnt=0, smplCnt=1, errCnt=0; - bool waveHigh = (BinStream[0] >= high); - for (size_t i=1; i < *size; i++){ - if (BinStream[i] >= high && waveHigh){ - smplCnt++; - } else if (BinStream[i] <= low && !waveHigh){ +//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) { + size_t i=0; + uint8_t clk[]={8,16,32,40,50,64,100,128,255}; + size_t loopCnt = 4096; //don't need to loop through entire array... + if (size == 0) return 0; + if (size= peak || dest[i] <= low){ + if (!firstpeak) continue; smplCnt++; - } else { //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; - } - if (*startIdx==0) *startIdx = i-clk; - waveHigh = !waveHigh; - smplCnt = 0; - } else if (smplCnt > (clk/2) - (clk/4)-1) { //half clock - if (waveHigh) { - BinStream[bitCnt++] = invert; - } else if (!waveHigh) { - BinStream[bitCnt++] = invert ^ 1; - } - if (*startIdx==0) *startIdx = i-(clk/2); - waveHigh = !waveHigh; - smplCnt = 0; - } else { - smplCnt++; - //transition bit oops + } else { + firstpeak=true; + if (smplCnt > 6 ){ + if (maxPeak > smplCnt){ + maxPeak = smplCnt; + //prnt("maxPk: %d",maxPeak); } - } else { //haven't hit new high or new low yet - smplCnt++; + peakcnt++; + //prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt); + smplCnt=0; } } } - *size = bitCnt; - return errCnt; -} - -//by marshmellow -//attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester -int askdemod_ext(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType, int *startIdx) { - if (*size==0) return -1; - int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default - if (*clk==0 || start < 0) return -3; - if (*invert != 1) *invert = 0; - if (amp==1) askAmp(BinStream, *size); - if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d, amp %d", *clk, start, amp); - - //start pos from detect ask clock is 1/2 clock offset - // NOTE: can be negative (demod assumes rest of wave was there) - *startIdx = start - (*clk/2); - 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, startIdx); - if (askType) { //askman - uint8_t alignPos = 0; - errCnt = manrawdecode(BinStream, size, 0, &alignPos); - *startIdx += *clk/2 * alignPos; - if (g_debugMode) prnt("DEBUG ASK CLEAN: startIdx %i, alignPos %u", *startIdx, alignPos); - return errCnt; - } else { //askraw - return errCnt; - } - } - if (g_debugMode) prnt("DEBUG ASK WEAK: startIdx %i", *startIdx); - 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; + bool errBitHigh = 0; + bool bitHigh = 0; + uint8_t ignoreCnt = 0; + uint8_t ignoreWindow = 4; + bool lastPeakHigh = 0; + int lastBit = 0; + 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){ + //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]) { + bestStart[clkCnt]=ii; + peaksdet[clkCnt]=peakcnt; + } } - midBit = 1; } - if (bitnum >= MaxBits) break; } - *size = bitnum; - return errCnt; -} - -int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType) { - int start = 0; - return askdemod_ext(BinStream, size, clk, invert, maxErr, amp, askType, &start); -} - -// 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) { - if (justNoise(dest, *size)) return -1; - *clk = DetectNRZClock(dest, *size, *clk); - if (*clk==0) return -2; - size_t i, gLen = 4096; - if (gLen>*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; - if (lastBit == 0) { - *startIdx = i - (numBits * *clk); - if (g_debugMode==2) prnt("DEBUG NRZ: startIdx %i", *startIdx); + 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; } - lastBit = i-1; + } 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); } - *size = numBits; - return 0; + *clockStartIdx = bestStart[best]; + return clk[best]; } -int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert) { - int startIdx = 0; - return nrzRawDemod_ext(dest, size, clk, invert, &startIdx); + +int DetectNRZClock(uint8_t dest[], size_t size, int clock) { + size_t bestStart=0; + return DetectNRZClock_ext(dest, size, clock, &bestStart); } -//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) { - size_t last_transition = 0; - size_t idx = 1; - 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 +//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 < 180) return 0; - //find start of modulating data in trace - idx = findModStart(dest, size, threshold_value, fchigh); - // Need to threshold first sample - if(dest[idx] < threshold_value) dest[0] = 0; - else dest[0] = 1; - - last_transition = idx; - idx++; - 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 anywhere - // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10 - // (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; - else dest[idx] = 1; + // 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; - // Check for 0->1 transition - 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 (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 (numBits > 1 && LastSample > (fchigh-2) && (preLastSample < (fchigh-1))){ - dest[numBits-1]=1; + 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; } - dest[numBits++]=1; - if (numBits > 0 && *startIdx==0) *startIdx = idx - fclow; - } else if (currSample > (fchigh+1) && numBits < 3) { //12 + and first two bit = unusable garbage - //do nothing with beginning garbage and reset.. should be rare.. - numBits = 0; - } else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's (or 4 then a 6 should be two 5's) - dest[numBits++]=1; - if (numBits > 0 && *startIdx==0) *startIdx = idx - fclow; - } else { //9+ = 10 sample waves (or 6+ = 7) - dest[numBits++]=0; - if (numBits > 0 && *startIdx==0) *startIdx = idx - fchigh; } - last_transition = idx; + if (fcCounter>0 && fcLensFnd<15){ + //add new fc length + fcCnts[fcLensFnd]++; + fcLens[fcLensFnd++]=fcCounter; + } + fcCounter=0; + } else { + // count sample + fcCounter++; } } - return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0 + + 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]; } -//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, int *startIdx) { - 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; //skip until we hit a transition - - //find out how many bits (n) we collected (use 1/2 clk tolerance) - //if lastval was 1, we have a 1->0 crossing - 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; - - //first transition - save startidx - if (numBits == 0) { - if (lastval == 1) { //high to low - *startIdx += (fclow * idx) - (n*rfLen); - if (g_debugMode==2) prnt("DEBUG FSK: startIdx %i, fclow*idx %i, n*rflen %u", *startIdx, fclow*(idx), n*rfLen); +//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) { + uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock + uint16_t loopCnt = 4096; //don't need to loop through entire array... + if (size == 0) return 0; + if (size= dest[i+2]){ + if (waveStart == 0) { + waveStart = i+1; + //prnt("DEBUG: waveStart: %d",waveStart); } else { - *startIdx += (fchigh * idx) - (n*rfLen); - if (g_debugMode==2) prnt("DEBUG FSK: startIdx %i, fchigh*idx %i, n*rflen %u", *startIdx, fchigh*(idx), n*rfLen); + waveEnd = i+1; + //prnt("DEBUG: waveEnd: %d",waveEnd); + waveLenCnt = waveEnd-waveStart; + if (waveLenCnt > fc){ + firstFullWave = waveStart; + fullWaveLen=waveLenCnt; + break; + } + waveStart=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--){ + 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); - //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; + 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; + } + } } - memset(dest+numBits, dest[idx-1]^invert , n); - numBits += n; + 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 numBits; + return clk[best]; } -//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) { - // FSK demodulator - size = fsk_wave_demod(dest, size, fchigh, fclow, startIdx); - size = aggregate_bits(dest, size, rfLen, invert, fchigh, fclow, startIdx); - return size; +int DetectPSKClock(uint8_t dest[], size_t size, int clock) { + int firstPhaseShift = 0; + return DetectPSKClock_ext(dest, size, clock, &firstPhaseShift); } -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 +//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 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; -// 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 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 it is inbetween set it to the last counter + if (fcCounter < fcHigh && fcCounter > fcLow) + fcCounter = lastFCcnt; + else if (fcCounter < fcLow+fcTol) + fcCounter = fcLow; + else //set it to the large fc + fcCounter = fcHigh; + + //look for bit clock (rf/xx) + if ((fcCounter < lastFCcnt || fcCounter > lastFCcnt)){ + //not the same size as the last wave - start of new bit sequence + if (firstBitFnd > 1){ //skip first wave change - probably not a complete bit + for (int ii=0; ii<15; ii++){ + if (rfLens[ii] >= (rfCounter-4) && rfLens[ii] <= (rfCounter+4)){ + rfCnts[ii]++; + rfCounter = 0; + break; + } + } + if (rfCounter > 0 && rfLensFnd < 15){ + //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter); + rfCnts[rfLensFnd]++; + rfLens[rfLensFnd++] = rfCounter; + } + } else { + *firstClockEdge = i; + firstBitFnd++; + } + rfCounter=0; + lastFCcnt=fcCounter; } + fcCounter=0; } - return; -} + 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]); -// 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=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; + } + } } - BitStream[i]=phase; } - return; -} -//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; + return clk[ii]; +} - //find start of modulating data in trace - uint8_t threshold_value = 123; //-5 - i = findModStart(dest, *size, threshold_value, fc); +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); +} - //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; - } +//********************************************************************************************** +//--------------------Modulation Demods &/or Decoding Section----------------------------------- +//********************************************************************************************** - 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); - *startIdx = firstFullWave - (*clock * numBits)+2; - //set start of wave as clock align - lastClkBit = firstFullWave; - if (g_debugMode==2) prnt("DEBUG PSK: firstFullWave: %u, waveLen: %u, startIdx %i",firstFullWave,fullWaveLen, *startIdx); - 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++){ - //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; +// 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) { + for (; i < buffSize - 4; ++i) { + *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 + if (lowToLowWaveLen[i+1] >= clk*2-tol && lowToLowWaveLen[i+1] <= clk*2+tol && highToLowWaveLen[i+1] > clk*3/2-tol) { //2 clocks and wave size is 1 1/2 + if (lowToLowWaveLen[i+2] >= (clk*3)/2-tol && lowToLowWaveLen[i+2] <= clk*2+tol && highToLowWaveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave + if (lowToLowWaveLen[i+3] >= clk*1-tol && lowToLowWaveLen[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit + *stStopLoc = i + 3; + return true; } - } else if (i+1 > lastClkBit + *clock + tol + fc){ - lastClkBit += *clock; //no phase shift but clock bit - dest[numBits++] = curPhase; - } else if (waveLenCnt < fc - 1) { //wave is smaller than field clock (shouldn't happen often) - errCnt2++; - if(errCnt2 > 101) return errCnt2; } - avgWaveVal = 0; - waveStart = i+1; } } - avgWaveVal += dest[i+1]; } - *size = numBits; - return errCnt; -} - -int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) { - int startIdx = 0; - return pskRawDemod_ext(dest, size, clock, invert, &startIdx); + return false; } - -//-------------------Clock / Bitrate Detection Section------------------------------------------------------------------------------------ - -// 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) { +//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) { + 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}; - 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)) + int clk = 0; + int tol = 0; + int i, j, skip, start, end, low, high, minClk, waveStart; + //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 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 ((dest[i] > low) && (i < size)) + while ((buffer[i] > low) && (i < bufsize)) ++i; + skip = i; - // loop through all samples - while (i < size) { + // populate tmpbuff buffer with pulse lengths + while (i < bufsize) { // measure from low to low - while ((dest[i] > low) && (i < size)) + while ((buffer[i] > low) && (i < bufsize)) ++i; - startwave = i; - while ((dest[i] < high) && (i < size)) + start= i; + while ((buffer[i] < high) && (i < bufsize)) ++i; - while ((dest[i] > low) && (i < size)) + //first high point for this wave + waveStart = i; + while ((buffer[i] > low) && (i < bufsize)) ++i; - //get minimum measured distance - if (i-startwave < minClk && i < size) { - minClk = i - startwave; - shortestWaveIdx = startwave; + if (j >= (bufsize/32)) { + break; } - } - // 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; + waveLen[j] = i - waveStart; //first high to first low + tmpbuff[j++] = i - start; + if (i-start < minClk && i < bufsize) { + minClk = i - start; } } - return 0; -} - -// 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? -// 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) { - 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 (;i 0) { - return ans; //return shortest wave start position + // 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; } } - } - 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; + // clock not found - ERROR + if (!clk) { + if (g_debugMode==2) prnt("DEBUG STT: clock not found - quitting"); + return false; + } + } else tol = clk/8; - if (clockFnd>0) { - clkCnt = clockFnd; - clkEnd = clockFnd+1; + *foundclock = clk; + i=0; + 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"); + return false; + } else { + if (g_debugMode==2) prnt("DEBUG STT: first STT found at: %d, j=%d",start, j); } - 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; + 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 - 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= high) { + //we have low drift (and a low just before the ST and a low just after the ST) - compensate by backing up the start + for ( i=0; i <= (clk/8); ++i ) { + if ( buffer[dataloc - (clk*4) - i] <= low ) { + dataloc -= i; + break; } } } - uint8_t iii; - uint8_t best=0; - for (iii=1; iiilow && buffer[dataloc+3]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]; + } + if (firstrun) { + *stend = dataloc; + *ststart = dataloc-(clk*4); + firstrun=false; + } + for (i=0; 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; +//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 { + BitStream[bitnum++]=7; + errCnt++; } + if(bitnum>MaxBits) break; } - if (lowestTransition == 255) lowestTransition = 0; - if (g_debugMode==2) prnt("DEBUG NRZ: detectstrongNRZclk smallest wave: %d",lowestTransition); - return lowestTransition; + *size=bitnum; + return errCnt; } //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) { - size_t i=0; - uint8_t clk[]={8,16,32,40,50,64,100,128,255}; - size_t loopCnt = 4096; //don't need to loop through entire array... - if (size == 0) return 0; - if (size= peak || dest[i] <= low){ - if (!firstpeak) continue; - smplCnt++; +//take 10 and 01 and manchester decode +//run through 2 times and take least errCnt +int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert, uint8_t *alignPos) { + 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 (bestErr>errCnt){ + bestErr=errCnt; + bestRun=ii; + } + errCnt=0; + } + *alignPos=bestRun; + //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 { - 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; - } + BitStream[bitnum++]=7; } + if(bitnum>MaxBits) break; } - bool errBitHigh = 0; - bool bitHigh = 0; - uint8_t ignoreCnt = 0; - uint8_t ignoreWindow = 4; - bool lastPeakHigh = 0; - int lastBit = 0; - 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){ - //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; + *size=bitnum; + return bestErr; +} + +//by marshmellow +//demodulates strong heavily clipped samples +int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low, int *startIdx) +{ + *startIdx=0; + size_t bitCnt=0, smplCnt=1, errCnt=0; + bool waveHigh = (BinStream[0] >= high); + for (size_t i=1; 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; } + if (*startIdx==0) *startIdx = i-clk; + waveHigh = !waveHigh; + smplCnt = 0; + } else if (smplCnt > (clk/2) - (clk/4)-1) { //half clock + if (waveHigh) { + BinStream[bitCnt++] = invert; + } else if (!waveHigh) { + BinStream[bitCnt++] = invert ^ 1; + } + if (*startIdx==0) *startIdx = i-(clk/2); + waveHigh = !waveHigh; + smplCnt = 0; + } else { + smplCnt++; + //transition bit oops } - if(peakcnt>peaksdet[clkCnt]) { - bestStart[clkCnt]=ii; - 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 { //haven't hit new high or new low yet + smplCnt++; } - } 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); } - *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); + *size = bitCnt; + return errCnt; } //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 < 180) return 0; +//attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester +int askdemod_ext(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType, int *startIdx) { + if (*size==0) return -1; + int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default + if (*clk==0 || start < 0) return -3; + if (*invert != 1) *invert = 0; + if (amp==1) askAmp(BinStream, *size); + if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d, amp %d", *clk, start, amp); - // 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; + //start pos from detect ask clock is 1/2 clock offset + // NOTE: can be negative (demod assumes rest of wave was there) + *startIdx = start - (*clk/2); + 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 - 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; - } + 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, startIdx); + if (askType) { //askman + uint8_t alignPos = 0; + errCnt = manrawdecode(BinStream, size, 0, &alignPos); + *startIdx += *clk/2 * alignPos; + if (g_debugMode) prnt("DEBUG ASK CLEAN: startIdx %i, alignPos %u", *startIdx, alignPos); + return errCnt; + } else { //askraw + return errCnt; + } + } + if (g_debugMode) prnt("DEBUG ASK WEAK: startIdx %i", *startIdx); + 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; } - if (fcCounter>0 && fcLensFnd<15){ - //add new fc length - fcCnts[fcLensFnd]++; - fcLens[fcLensFnd++]=fcCounter; + 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; } - fcCounter=0; - } else { - // count sample - fcCounter++; + midBit = 1; } + if (bitnum >= MaxBits) break; } + *size = bitnum; + return errCnt; +} + +int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType) { + int start = 0; + return askdemod_ext(BinStream, size, clk, invert, maxErr, amp, askType, &start); +} + +// 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) { + if (justNoise(dest, *size)) return -1; + *clk = DetectNRZClock(dest, *size, *clk); + if (*clk==0) return -2; + size_t i, gLen = 4096; + if (gLen>*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 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]; + 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; } - 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 + //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; + if (lastBit == 0) { + *startIdx = i - (numBits * *clk); + if (g_debugMode==2) prnt("DEBUG NRZ: startIdx %i", *startIdx); + } + lastBit = i-1; + } } - // 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]; + *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); } -//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) { - uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock - uint16_t loopCnt = 4096; //don't need to loop through entire array... - if (size == 0) return 0; - if (size= dest[i+2]){ - if (waveStart == 0) { - waveStart = i+1; - //prnt("DEBUG: waveStart: %d",waveStart); - } else { - waveEnd = i+1; - //prnt("DEBUG: waveEnd: %d",waveEnd); - waveLenCnt = waveEnd-waveStart; - if (waveLenCnt > fc){ - firstFullWave = waveStart; - fullWaveLen=waveLenCnt; - break; - } - waveStart=0; + // Check for 0->1 transition + 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 (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 (numBits > 1 && LastSample > (fchigh-2) && (preLastSample < (fchigh-1))){ + dest[numBits-1]=1; + } + dest[numBits++]=1; + if (numBits > 0 && *startIdx==0) *startIdx = idx - fclow; + } else if (currSample > (fchigh+1) && numBits < 3) { //12 + and first two bit = unusable garbage + //do nothing with beginning garbage and reset.. should be rare.. + numBits = 0; + } else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's (or 4 then a 6 should be two 5's) + dest[numBits++]=1; + if (numBits > 0 && *startIdx==0) *startIdx = idx - fclow; + } else { //9+ = 10 sample waves (or 6+ = 7) + dest[numBits++]=0; + if (numBits > 0 && *startIdx==0) *startIdx = idx - fchigh; } + last_transition = idx; } } - *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--){ - 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); + return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0 +} - 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; - } - } +//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, int *startIdx) { + 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; //skip until we hit a transition + + //find out how many bits (n) we collected (use 1/2 clk tolerance) + //if lastval was 1, we have a 1->0 crossing + if (dest[idx-1]==1) { + n = (n * fclow + rfLen/2) / rfLen; + } else {// 0->1 crossing + n = (n * fchigh + rfLen/2) / rfLen; } - if (errCnt == 0){ - return clk[clkCnt]; + if (n == 0) n = 1; + + //first transition - save startidx + if (numBits == 0) { + if (lastval == 1) { //high to low + *startIdx += (fclow * idx) - (n*rfLen); + if (g_debugMode==2) prnt("DEBUG FSK: startIdx %i, fclow*idx %i, n*rflen %u", *startIdx, fclow*(idx), n*rfLen); + } else { + *startIdx += (fchigh * idx) - (n*rfLen); + if (g_debugMode==2) prnt("DEBUG FSK: startIdx %i, fchigh*idx %i, n*rflen %u", *startIdx, fchigh*(idx), n*rfLen); + } } - 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; + + //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; } - if (g_debugMode == 2) prnt("DEBUG PSK: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[i],peaksdet[i],bestErr[i],clk[best]); + memset(dest+numBits, dest[idx-1]^invert , n); + numBits += n; } - return clk[best]; + return numBits; } -int DetectPSKClock(uint8_t dest[], size_t size, int clock) { - int firstPhaseShift = 0; - return DetectPSKClock_ext(dest, size, clock, &firstPhaseShift); +//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) { + // FSK demodulator + size = fsk_wave_demod(dest, size, fchigh, fclow, startIdx); + size = aggregate_bits(dest, size, rfLen, invert, fchigh, fclow, startIdx); + return size; } -//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 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; +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); +} - 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; +// 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 fcLow) - fcCounter = lastFCcnt; - else if (fcCounter < fcLow+fcTol) - fcCounter = fcLow; - else //set it to the large fc - fcCounter = fcHigh; +//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 lastFCcnt)){ - //not the same size as the last wave - start of new bit sequence - if (firstBitFnd > 1){ //skip first wave change - probably not a complete bit - for (int ii=0; ii<15; ii++){ - if (rfLens[ii] >= (rfCounter-4) && rfLens[ii] <= (rfCounter+4)){ - rfCnts[ii]++; - rfCounter = 0; - break; - } - } - if (rfCounter > 0 && rfLensFnd < 15){ - //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter); - rfCnts[rfLensFnd]++; - rfLens[rfLensFnd++] = rfCounter; - } - } else { - *firstClockEdge = i; - firstBitFnd++; + size_t numBits=0; + uint8_t curPhase = *invert; + size_t i=0, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0; + uint16_t fc=0, fullWaveLen=0, tol=1; + uint16_t errCnt=0, waveLenCnt=0, errCnt2=0; + fc = countFC(dest, *size, 1); + uint8_t fc2 = fc >> 8; + if (fc2 == 10) return -1; //fsk found - quit + fc = fc & 0xFF; + if (fc!=2 && fc!=4 && fc!=8) return -1; + //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; } - 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; + waveStart = i+1; + avgWaveVal = 0; } - 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; + 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); + *startIdx = firstFullWave - (*clock * numBits)+2; + //set start of wave as clock align + lastClkBit = firstFullWave; + if (g_debugMode==2) prnt("DEBUG PSK: firstFullWave: %u, waveLen: %u, startIdx %i",firstFullWave,fullWaveLen, *startIdx); + 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++){ + //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; + } else if (waveLenCnt < fc - 1) { //wave is smaller than field clock (shouldn't happen often) + errCnt2++; + if(errCnt2 > 101) return errCnt2; } + avgWaveVal = 0; + waveStart = i+1; } } + avgWaveVal += dest[i+1]; } - - if (ii<2) return 0; // oops we went too far - - return clk[ii]; + *size = numBits; + return errCnt; } -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); +int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) { + int startIdx = 0; + return pskRawDemod_ext(dest, size, clock, invert, &startIdx); } -//-----------------Tag format detection section-------------------------------------------------------------- +//********************************************************************************************** +//-----------------Tag format detection section------------------------------------------------- +//********************************************************************************************** // by marshmellow // FSK Demod then try to locate an AWID ID