-// 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)
-{
- int i=0;
- int clk[]={8,16,32,40,50,64,100,128,256};
- int loopCnt = 256; //don't need to loop through entire array...
- if (size == 0) return -1;
- if (size<loopCnt) loopCnt = size;
- //if we already have a valid clock quit
-
- for (;i<8;++i)
- if (clk[i] == *clock) return 0;
-
- //get high and low peak
- int peak, low;
- getHiLo(dest, loopCnt, &peak, &low, 75, 75);
-
- //test for large clean peaks
- if (DetectCleanAskWave(dest, size, peak, low)==1){
- int ans = DetectStrongAskClock(dest, size);
- for (i=7; i>0; i--){
- if (clk[i] == ans) {
- *clock=ans;
- return 0;
- }
- }
- }
- int ii;
- int clkCnt;
- int tol = 0;
- int bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
- int bestStart[]={0,0,0,0,0,0,0,0,0};
- int errCnt=0;
- //test each valid clock from smallest to greatest to see which lines up
- for(clkCnt=0; clkCnt < 8; clkCnt++){
- if (clk[clkCnt] == 32){
- tol=1;
- }else{
- tol=0;
- }
- if (!maxErr) loopCnt=clk[clkCnt]*2;
- bestErr[clkCnt]=1000;
- //try lining up the peaks by moving starting point (try first 256)
- for (ii=0; ii < loopCnt; ii++){
- if ((dest[ii] >= peak) || (dest[ii] <= low)){
- errCnt=0;
- // now that we have the first one lined up test rest of wave array
- for (i=0; i<((int)((size-ii-tol)/clk[clkCnt])-1); ++i){
- if (dest[ii+(i*clk[clkCnt])]>=peak || dest[ii+(i*clk[clkCnt])]<=low){
- }else if(dest[ii+(i*clk[clkCnt])-tol]>=peak || dest[ii+(i*clk[clkCnt])-tol]<=low){
- }else if(dest[ii+(i*clk[clkCnt])+tol]>=peak || dest[ii+(i*clk[clkCnt])+tol]<=low){
- }else{ //error no peak detected
- errCnt++;
- }
- }
- //if we found no errors then we can stop here
- // this is correct one - return this clock
- //PrintAndLog("DEBUG: clk %d, err %d, ii %d, i %d",clk[clkCnt],errCnt,ii,i);
- if(errCnt==0 && clkCnt<6) {
- *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=0;
- uint8_t best=0;
- for (iii=0; iii<8; ++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 (bestErr[best]>maxErr) return -1;
- *clock=clk[best];
- return bestStart[best];
-}
-
-//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(uint8_t dest[], size_t size, int clock)
-{
- 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<loopCnt) loopCnt = size;
-
- //if we already have a valid clock quit
- size_t i=1;
- for (; i < 8; ++i)
- 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;
- uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
- uint16_t peaksdet[]={0,0,0,0,0,0,0,0,0};
- countFC(dest, size, &fc);
- //PrintAndLog("DEBUG: FC: %d",fc);
-
- //find first full wave
- for (i=0; i<loopCnt; i++){
- if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
- if (waveStart == 0) {
- waveStart = i+1;
- //PrintAndLog("DEBUG: waveStart: %d",waveStart);
- } else {
- waveEnd = i+1;
- //PrintAndLog("DEBUG: waveEnd: %d",waveEnd);
- waveLenCnt = waveEnd-waveStart;
- if (waveLenCnt > fc){
- firstFullWave = waveStart;
- fullWaveLen=waveLenCnt;
- break;
- }
- waveStart=0;
- }
- }
- }
- //PrintAndLog("DEBUG: 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;
- //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit);
-
- for (i = firstFullWave+fullWaveLen-1; i < loopCnt-2; i++){
- //top edge of wave = start of new wave
- if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
- if (waveStart == 0) {
- waveStart = i+1;
- waveLenCnt=0;
- } else { //waveEnd
- waveEnd = i+1;
- waveLenCnt = waveEnd-waveStart;
- if (waveLenCnt > fc){
- //if this wave is a phase shift
- //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, ii: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+clk[clkCnt]-tol,ii+1,fc);
- if (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit
- peakcnt++;
- lastClkBit+=clk[clkCnt];
- } else if (i<lastClkBit+8){
- //noise after a phase shift - ignore
- } else { //phase shift before supposed to based on clock
- errCnt++;
- }
- } else if (i+1 > lastClkBit + clk[clkCnt] + tol + fc){
- lastClkBit+=clk[clkCnt]; //no phase shift but clock bit
- }
- waveStart=i+1;
- }
- }
- }
- if (errCnt == 0){
- return clk[clkCnt];
- }
- if (errCnt <= bestErr[clkCnt]) bestErr[clkCnt]=errCnt;
- if (peakcnt > peaksdet[clkCnt]) peaksdet[clkCnt]=peakcnt;
- }
- //all tested with errors
- //return the highest clk with the most peaks found
- uint8_t best=7;
- for (i=7; i>=1; i--){
- if (peaksdet[i] > peaksdet[best]) {
- best = i;
- }
- //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]);
- }
- return clk[best];
-}
-
-//by marshmellow
-//detect nrz clock by reading #peaks vs no peaks(or errors)
-int DetectNRZClock(uint8_t dest[], size_t size, int clock)
-{
- int i=0;
- int clk[]={8,16,32,40,50,64,100,128,256};
- int loopCnt = 4096; //don't need to loop through entire array...
- if (size == 0) return 0;
- if (size<loopCnt) loopCnt = size;
-
- //if we already have a valid clock quit
- for (; i < 8; ++i)
- if (clk[i] == clock) return clock;
-
- //get high and low peak
- int peak, low;
- getHiLo(dest, loopCnt, &peak, &low, 75, 75);
-
- //PrintAndLog("DEBUG: peak: %d, low: %d",peak,low);
- int ii;
- uint8_t clkCnt;
- uint8_t tol = 0;
- int peakcnt=0;
- int peaksdet[]={0,0,0,0,0,0,0,0};
- int maxPeak=0;
- //test for large clipped waves
- for (i=0; i<loopCnt; i++){
- if (dest[i] >= peak || dest[i] <= low){
- peakcnt++;
- } else {
- if (peakcnt>0 && maxPeak < peakcnt){
- maxPeak = peakcnt;
- }
- peakcnt=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 largest peak
- if (clk[clkCnt]<maxPeak) continue;
-
- //try lining up the peaks by moving starting point (try first 256)
- for (ii=0; ii< loopCnt; ++ii){
- if ((dest[ii] >= peak) || (dest[ii] <= low)){
- peakcnt=0;
- // now that we have the first one lined up test rest of wave array
- for (i=0; i < ((int)((size-ii-tol)/clk[clkCnt])-1); ++i){
- if (dest[ii+(i*clk[clkCnt])]>=peak || dest[ii+(i*clk[clkCnt])]<=low){
- peakcnt++;
- }
- }
- if(peakcnt>peaksdet[clkCnt]) {
- peaksdet[clkCnt]=peakcnt;
- }
- }
- }
- }
- int iii=7;
- int best=0;
- for (iii=7; iii > 0; iii--){
- if (peaksdet[iii] > peaksdet[best]){
- best = iii;
- }
- //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]);
- }
- return clk[best];
-}
-
-// 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]==77){
- //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;
-}
-
-// redesigned by marshmellow adjusted from existing decode functions
-// indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
-int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert)
-{
- //26 bit 40134 format (don't know other formats)
- int i;
- int long_wait=29;//29 leading zeros in format
- int start;
- int first = 0;
- int first2 = 0;
- int bitCnt = 0;
- int ii;
- // Finding the start of a UID
- for (start = 0; start <= *size - 250; start++) {
- first = bitStream[start];
- for (i = start; i < start + long_wait; i++) {
- if (bitStream[i] != first) {
- break;
- }
- }
- if (i == (start + long_wait)) {
- break;
- }
- }
- if (start == *size - 250 + 1) {
- // did not find start sequence
- return -1;
- }
- // Inverting signal if needed
- if (first == 1) {
- for (i = start; i < *size; i++) {
- bitStream[i] = !bitStream[i];
- }
- *invert = 1;
- }else *invert=0;
-
- int iii;
- //found start once now test length by finding next one
- for (ii=start+29; ii <= *size - 250; ii++) {
- first2 = bitStream[ii];
- for (iii = ii; iii < ii + long_wait; iii++) {
- if (bitStream[iii] != first2) {
- break;
- }
- }
- if (iii == (ii + long_wait)) {
- break;
- }
- }
- if (ii== *size - 250 + 1){
- // did not find second start sequence
- return -2;
- }
- bitCnt=ii-start;
-
- // Dumping UID
- i = start;
- for (ii = 0; ii < bitCnt; ii++) {
- bitStream[ii] = bitStream[i++];
- }
- *size=bitCnt;
- return 1;
-}
-
-// by marshmellow - demodulate NRZ wave (both similar enough)
-// peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
-// there probably is a much simpler way to do this....
-int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert, int maxErr)
-{
- if (justNoise(dest, *size)) return -1;
- *clk = DetectNRZClock(dest, *size, *clk);
- if (*clk==0) return -2;
- uint32_t i;
- uint32_t gLen = 4096;
- if (gLen>*size) gLen = *size;
- int high, low;
- if (getHiLo(dest, gLen, &high, &low, 75, 75) < 1) return -3; //25% fuzz on high 25% fuzz on low
- int lastBit = 0; //set first clock check
- uint32_t bitnum = 0; //output counter
- uint8_t tol = 1; //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave
- uint32_t iii = 0;
- uint16_t errCnt =0;
- uint16_t MaxBits = 1000;
- uint32_t bestErrCnt = maxErr+1;
- uint32_t bestPeakCnt = 0;
- uint32_t bestPeakStart=0;
- uint8_t bestFirstPeakHigh=0;
- uint8_t firstPeakHigh=0;
- uint8_t curBit=0;
- uint8_t bitHigh=0;
- uint8_t errBitHigh=0;
- uint16_t peakCnt=0;
- uint8_t ignoreWindow=4;
- uint8_t ignoreCnt=ignoreWindow; //in case of noice near peak
- //loop to find first wave that works - align to clock
- for (iii=0; iii < gLen; ++iii){
- if ((dest[iii]>=high) || (dest[iii]<=low)){
- if (dest[iii]>=high) firstPeakHigh=1;
- else firstPeakHigh=0;
- lastBit=iii-*clk;
- peakCnt=0;
- errCnt=0;
- bitnum=0;
- //loop through to see if this start location works
- for (i = iii; i < *size; ++i) {
- //if we found a high bar and we are at a clock bit
- if ((dest[i]>=high ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
- bitHigh=1;
- lastBit+=*clk;
- bitnum++;
- peakCnt++;
- errBitHigh=0;
- ignoreCnt=ignoreWindow;
- //else if low bar found and we are at a clock point
- }else if ((dest[i]<=low ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
- bitHigh=1;
- lastBit+=*clk;
- bitnum++;
- peakCnt++;
- errBitHigh=0;
- ignoreCnt=ignoreWindow;
- //else if no bars found
- }else if(dest[i] < high && dest[i] > low) {
- if (ignoreCnt==0){
- bitHigh=0;
- if (errBitHigh==1){
- errCnt++;
- }
- errBitHigh=0;
- } else {
- ignoreCnt--;
- }
- //if we are past a clock point
- if (i >= lastBit+*clk+tol){ //clock val
- lastBit+=*clk;
- bitnum++;
- }
- //else if bar found but we are not at a clock bit and we did not just have a clock bit
- }else if ((dest[i]>=high || dest[i]<=low) && (i<lastBit+*clk-tol || i>lastBit+*clk+tol) && (bitHigh==0)){
- //error bar found no clock...
- errBitHigh=1;
- }
- if (bitnum>=MaxBits) break;
- }
- //we got more than 64 good bits and not all errors
- if (bitnum > (64) && (errCnt <= (maxErr))) {
- //possible good read
- if (errCnt == 0){
- //bestStart = iii;
- bestFirstPeakHigh=firstPeakHigh;
- bestErrCnt = errCnt;
- bestPeakCnt = peakCnt;
- bestPeakStart = iii;
- break; //great read - finish
- }
- if (errCnt < bestErrCnt){ //set this as new best run
- bestErrCnt = errCnt;
- //bestStart = iii;
- }
- if (peakCnt > bestPeakCnt){
- bestFirstPeakHigh=firstPeakHigh;
- bestPeakCnt=peakCnt;
- bestPeakStart=iii;
- }
- }
- }
- }
- //PrintAndLog("DEBUG: bestErrCnt: %d, maxErr: %d, bestStart: %d, bestPeakCnt: %d, bestPeakStart: %d",bestErrCnt,maxErr,bestStart,bestPeakCnt,bestPeakStart);
- if (bestErrCnt <= maxErr){
- //best run is good enough set to best run and set overwrite BinStream
- iii=bestPeakStart;
- lastBit=bestPeakStart-*clk;
- bitnum=0;
- memset(dest, bestFirstPeakHigh^1, bestPeakStart / *clk);
- bitnum += (bestPeakStart / *clk);
- for (i = iii; i < *size; ++i) {
- //if we found a high bar and we are at a clock bit
- if ((dest[i] >= high ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
- bitHigh=1;
- lastBit+=*clk;
- curBit=1-*invert;
- dest[bitnum]=curBit;
- bitnum++;
- errBitHigh=0;
- ignoreCnt=ignoreWindow;
- //else if low bar found and we are at a clock point
- }else if ((dest[i]<=low ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
- bitHigh=1;
- lastBit+=*clk;
- curBit=*invert;
- dest[bitnum]=curBit;
- bitnum++;
- errBitHigh=0;
- ignoreCnt=ignoreWindow;
- //else if no bars found
- }else if(dest[i]<high && dest[i]>low) {
- if (ignoreCnt==0){
- bitHigh=0;
- //if peak is done was it an error peak?
- if (errBitHigh==1){
- dest[bitnum]=77;
- bitnum++;
- errCnt++;
- }
- errBitHigh=0;
- } else {
- ignoreCnt--;
- }
- //if we are past a clock point
- if (i>=lastBit+*clk+tol){ //clock val
- lastBit+=*clk;
- dest[bitnum]=curBit;
- bitnum++;
- }
- //else if bar found but we are not at a clock bit and we did not just have a clock bit
- }else if ((dest[i]>=high || dest[i]<=low) && ((i<lastBit+*clk-tol) || (i>lastBit+*clk+tol)) && (bitHigh==0)){
- //error bar found no clock...
- errBitHigh=1;
- }
- if (bitnum >= MaxBits) break;
- }
- *size=bitnum;
- } else{
- *size=bitnum;
- return bestErrCnt;
- }
-
- if (bitnum>16){
- *size=bitnum;
- } else return -5;
- return errCnt;
-}
-
-//by marshmellow
-//detects the bit clock for FSK given the high and low Field Clocks
-uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow)
-{
- uint8_t clk[] = {8,16,32,40,50,64,100,128,0};
- uint16_t rfLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
- uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
- uint8_t rfLensFnd = 0;
- uint8_t lastFCcnt=0;
- uint32_t fcCounter = 0;
- uint16_t rfCounter = 0;
- uint8_t firstBitFnd = 0;
- size_t i;
- if (size == 0) return 0;
-
- uint8_t fcTol = (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 up transition
- for (i = 1; i < size-1; i++)
- if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1])
- break;
-
- for (; i < size-1; i++){
- if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1]){
- // new peak
- fcCounter++;
- rfCounter++;
- // if we got less than the small fc + tolerance then set it to the small fc
- if (fcCounter < fcLow+fcTol)
- fcCounter = fcLow;
- else //set it to the large fc
- fcCounter = fcHigh;
-
- //look for bit clock (rf/xx)
- if ((fcCounter<lastFCcnt || fcCounter>lastFCcnt)){
- //not the same size as the last wave - start of new bit sequence
-
- if (firstBitFnd>1){ //skip first wave change - probably not a complete bit
- for (int ii=0; ii<15; ii++){
- if (rfLens[ii]==rfCounter){
- rfCnts[ii]++;
- rfCounter=0;
- break;
- }
- }
- if (rfCounter>0 && rfLensFnd<15){
- //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
- rfCnts[rfLensFnd]++;
- rfLens[rfLensFnd++]=rfCounter;
- }
- } else {
- firstBitFnd++;
- }
- rfCounter=0;
- lastFCcnt=fcCounter;
- }
- fcCounter=0;
- } else {
- // count sample
- fcCounter++;
- rfCounter++;
- }
- }
- uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15;
-
- for (i=0; i<15; i++){
- //PrintAndLog("DEBUG: RF %d, cnts %d",rfLens[i], rfCnts[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;
- }
- }
- // 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;
-
- //PrintAndLog("DEBUG: hightest: 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
- int ii=7;
- for (; ii>=0; 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){
- break;
- }
- }
- }
- }
-
- if (ii<0) return 0; // oops we went too far
-
- return clk[ii];
-}
-
-//by marshmellow
-//countFC is to detect the field clock lengths.
-//counts and returns the 2 most common wave lengths
-//mainly used for FSK field clock detection
-uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t *mostFC)
-{
- uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0};
- uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0};
- uint8_t fcLensFnd = 0;
- uint8_t lastFCcnt=0;
- uint32_t fcCounter = 0;
- size_t i;
- if (size == 0) return 0;
-
- // prime i to first up transition
- for (i = 1; i < size-1; i++)
- if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1])
- break;
-
- for (; i < size-1; i++){
- if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){
- // new up transition
- fcCounter++;
-
- //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 odd and not rc/5 add one (for when we get a fc 9 instead of 10)
- if ((fcCounter==9 && fcCounter & 1) || fcCounter==4) fcCounter++;
-
- // save last field clock count (fc/xx)
- // find which fcLens to save it to:
- for (int ii=0; ii<10; ii++){
- if (fcLens[ii]==fcCounter){
- fcCnts[ii]++;
- fcCounter=0;
- break;
- }
- }
- if (fcCounter>0 && fcLensFnd<10){
- //add new fc length
- fcCnts[fcLensFnd]++;
- fcLens[fcLensFnd++]=fcCounter;
- }
- fcCounter=0;
- } else {
- // count sample
- fcCounter++;
- }
- }
-
- uint8_t best1=9, best2=9, best3=9;
- uint16_t maxCnt1=0;
- // go through fclens and find which ones are bigest 2
- for (i=0; i<10; i++){
- // PrintAndLog("DEBUG: FC %d, Cnt %d, Errs %d",fcLens[i],fcCnts[i],errCnt);
- // 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;
- }
- }
- uint8_t fcH=0, fcL=0;
- if (fcLens[best1]>fcLens[best2]){
- fcH=fcLens[best1];
- fcL=fcLens[best2];
- } else{
- fcH=fcLens[best2];
- fcL=fcLens[best1];
- }
-
- *mostFC=fcLens[best1];
- // TODO: take top 3 answers and compare to known Field clocks to get top 2
-
- uint16_t fcs = (((uint16_t)fcH)<<8) | fcL;
- // PrintAndLog("DEBUG: Best %d best2 %d best3 %d",fcLens[best1],fcLens[best2],fcLens[best3]);
-
- return fcs;
-}