+//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 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
+void psk1TOpsk2(uint8_t *BitStream, size_t size) {
+ size_t i=1;
+ uint8_t lastBit=BitStream[0];
+ for (; i<size; i++){
+ if (BitStream[i]==7){
+ //ignore errors
+ } else if (lastBit!=BitStream[i]){
+ lastBit=BitStream[i];
+ BitStream[i]=1;
+ } else {
+ BitStream[i]=0;
+ }
+ }
+ return;
+}
+
+// by marshmellow
+// convert psk2 demod to psk1 demod
+// from only transition waves are 1s to phase shifts change bit
+void psk2TOpsk1(uint8_t *BitStream, size_t size) {
+ uint8_t phase=0;
+ for (size_t i=0; i<size; i++){
+ if (BitStream[i]==1){
+ phase ^=1;
+ }
+ 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<loopCnt) loopCnt = *size;
+
+ 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<loopCnt; i++) {
+ // find peak
+ if (dest[i]+fc < dest[i+1] && dest[i+1] >= 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];
+ }
+ 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];
+ }
+ *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);
+}
+
+//-------------------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 ((dest[i] > low) && (i < size))
+ ++i;
+
+ // loop through all samples
+ while (i < size) {
+ // measure from low to low
+ while ((dest[i] > low) && (i < size))
+ ++i;
+ startwave = i;
+ while ((dest[i] < high) && (i < size))
+ ++i;
+ while ((dest[i] > low) && (i < size))
+ ++i;
+ //get minimum measured distance
+ if (i-startwave < minClk && i < size) {
+ minClk = i - startwave;
+ shortestWaveIdx = startwave;
+ }
+ }
+ // set clock
+ if (g_debugMode==2) prnt("DEBUG ASK: detectstrongASKclk smallest wave: %d",minClk);
+ for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
+ if (minClk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1) {
+ *clock = fndClk[clkCnt];
+ return shortestWaveIdx;
+ }
+ }
+ 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<clkEnd;++i)
+ if (clk[i] == *clock) clockFnd = i;
+ //clock found but continue to find best startpos
+
+ //get high and low peak
+ int peak, low;
+ if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return -1;
+
+ //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
+ }
+ }
+ }
+ uint8_t ii;
+ uint8_t clkCnt, tol = 0;
+ uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
+ uint8_t bestStart[]={0,0,0,0,0,0,0,0,0};
+ size_t errCnt = 0;
+ size_t arrLoc, loopEnd;
+
+ if (clockFnd>0) {
+ clkCnt = clockFnd;
+ clkEnd = clockFnd+1;
+ }
+ else clkCnt=1;
+
+ //test each valid clock from smallest to greatest to see which lines up
+ for(; clkCnt < clkEnd; clkCnt++){
+ if (clk[clkCnt] <= 32){
+ tol=1;
+ }else{
+ tol=0;
+ }
+ //if no errors allowed - keep start within the first clock
+ if (!maxErr && size > clk[clkCnt]*2 + tol && clk[clkCnt]<128) loopCnt=clk[clkCnt]*2;
+ bestErr[clkCnt]=1000;
+ //try lining up the peaks by moving starting point (try first few clocks)
+ for (ii=0; ii < loopCnt; ii++){
+ if (dest[ii] < peak && dest[ii] > low) continue;
+
+ errCnt=0;
+ // now that we have the first one lined up test rest of wave array
+ loopEnd = ((size-ii-tol) / clk[clkCnt]) - 1;
+ for (i=0; i < loopEnd; ++i){
+ arrLoc = ii + (i * clk[clkCnt]);
+ if (dest[arrLoc] >= peak || dest[arrLoc] <= low){
+ }else if (dest[arrLoc-tol] >= peak || dest[arrLoc-tol] <= low){
+ }else if (dest[arrLoc+tol] >= peak || dest[arrLoc+tol] <= low){
+ }else{ //error no peak detected
+ errCnt++;
+ }
+ }
+ //if we found no errors then we can stop here and a low clock (common clocks)
+ // this is correct one - return this clock
+ if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, err %d, startpos %d, endpos %d",clk[clkCnt],errCnt,ii,i);
+ if(errCnt==0 && clkCnt<7) {
+ if (!clockFnd) *clock = clk[clkCnt];
+ return ii;
+ }
+ //if we found errors see if it is lowest so far and save it as best run
+ if(errCnt<bestErr[clkCnt]){
+ bestErr[clkCnt]=errCnt;
+ bestStart[clkCnt]=ii;
+ }
+ }
+ }
+ uint8_t iii;
+ uint8_t best=0;
+ for (iii=1; iii<clkEnd; ++iii){
+ if (bestErr[iii] < bestErr[best]){
+ if (bestErr[iii] == 0) bestErr[iii]=1;
+ // current best bit to error ratio vs new bit to error ratio
+ if ( (size/clk[best])/bestErr[best] < (size/clk[iii])/bestErr[iii] ){
+ best = iii;
+ }
+ }
+ 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]);
+ }
+ if (!clockFnd) *clock = clk[best];
+ return bestStart[best];
+}
+
+int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low){