]> git.zerfleddert.de Git - proxmark3-svn/blobdiff - common/lfdemod.c
FIX: increased the limit to 0xE6 for MIFARE_ULEV1_FASTREAD
[proxmark3-svn] / common / lfdemod.c
index fae612060b462392bd4e1e99457b4d40577a2b01..7d40d22e5aa44551835ae4ada1f69947f132e488 100644 (file)
@@ -11,8 +11,6 @@
 #include <stdlib.h>
 #include <string.h>
 #include "lfdemod.h"
-
-
 uint8_t justNoise(uint8_t *BitStream, size_t size)
 {
        static const uint8_t THRESHOLD = 123;
@@ -31,13 +29,13 @@ int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi
        *high=0;
        *low=255;
        // get high and low thresholds 
-       for (int i=0; i < size; i++){
+       for (size_t i=0; i < size; i++){
                if (BitStream[i] > *high) *high = BitStream[i];
                if (BitStream[i] < *low) *low = BitStream[i];
        }
        if (*high < 123) return -1; // just noise
-       *high = (int)(((*high-128)*(((float)fuzzHi)/100))+128);
-       *low = (int)(((*low-128)*(((float)fuzzLo)/100))+128);
+       *high = ((*high-128)*fuzzHi + 12800)/100;
+       *low = ((*low-128)*fuzzLo + 12800)/100;
        return 1;
 }
 
@@ -83,10 +81,8 @@ uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_
        //  otherwise could be a void with no arguments
        //set defaults
        uint32_t i = 0;
-       if (BitStream[1]>1){  //allow only 1s and 0s
-               // PrintAndLog("no data found");
-               return 0;
-       }
+       if (BitStream[1]>1) return 0;  //allow only 1s and 0s
+
        // 111111111 bit pattern represent start of frame
        //  include 0 in front to help get start pos
        uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1};
@@ -102,11 +98,8 @@ uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_
        idx = *startIdx + 9;
        for (i=0; i<FmtLen; i++){ //loop through 10 or 22 sets of 5 bits (50-10p = 40 bits or 88 bits)
                parityBits = bytebits_to_byte(BitStream+(i*5)+idx,5);
-               //check even parity
-               if (parityTest(parityBits, 5, 0) == 0){
-                       //parity failed quit
-                       return 0;
-               }
+               //check even parity - quit if failed
+               if (parityTest(parityBits, 5, 0) == 0) return 0;
                //set uint64 with ID from BitStream
                for (uint8_t ii=0; ii<4; ii++){
                        *hi = (*hi << 1) | (*lo >> 63);
@@ -120,185 +113,189 @@ uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_
 }
 
 //by marshmellow
-//takes 3 arguments - clock, invert, maxErr as integers
-//attempts to demodulate ask while decoding manchester
-//prints binary found and saves in graphbuffer for further commands
-int askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr)
+//demodulates strong heavily clipped samples
+int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low)
 {
-       int i;
-       //int clk2=*clk;
-       int start = DetectASKClock(BinStream, *size, clk, 20); //clock default
-       if (*clk==0) return -3;
-       if (start < 0) return -3;
-       // if autodetected too low then adjust  //MAY NEED ADJUSTMENT
-       //if (clk2==0 && *clk<8) *clk =64;
-       //if (clk2==0 && *clk<32) *clk=32;
-       if (*invert != 0 && *invert != 1) *invert=0;
-       uint32_t initLoopMax = 200;
-       if (initLoopMax > *size) initLoopMax=*size;
-       // Detect high and lows
-       // 25% fuzz in case highs and lows aren't clipped [marshmellow]
-       int high, low, ans;
-       ans = getHiLo(BinStream, initLoopMax, &high, &low, 75, 75);
-       if (ans<1) return -2; //just noise
-
-       // PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
-       int lastBit = 0;  //set first clock check
-       uint32_t bitnum = 0;     //output counter
-       int 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
-       int iii = 0;
-       uint32_t gLen = *size;
-       if (gLen > 3000) gLen=3000;
-       //if 0 errors allowed then only try first 2 clock cycles as we want a low tolerance
-       if (!maxErr) gLen=*clk*2; 
-       uint8_t errCnt =0;
-       uint16_t MaxBits = 500;
-       uint32_t bestStart = *size;
-       int bestErrCnt = maxErr+1;
-       // PrintAndLog("DEBUG - lastbit - %d",lastBit);
-       // loop to find first wave that works
-       for (iii=0; iii < gLen; ++iii){
-               if ((BinStream[iii] >= high) || (BinStream[iii] <= low)){
-                       lastBit=iii-*clk;
-                       errCnt=0;
-                       // loop through to see if this start location works
-                       for (i = iii; i < *size; ++i) {
-                               if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){
-                                       lastBit+=*clk;
-                               } else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){
-                                       //low found and we are expecting a bar
-                                       lastBit+=*clk;
-                               } else {
-                                       //mid value found or no bar supposed to be here
-                                       if ((i-lastBit)>(*clk+tol)){
-                                               //should have hit a high or low based on clock!!
-
-                                               //debug
-                                               //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
-
+       size_t bitCnt=0, smplCnt=0, errCnt=0;
+       uint8_t waveHigh = 0;
+       for (size_t i=0; i < *size; i++){
+               if (BinStream[i] >= high && waveHigh){
+                       smplCnt++;
+               } else if (BinStream[i] <= low && !waveHigh){
+                       smplCnt++;
+               } else { //transition
+                       if ((BinStream[i] >= high && !waveHigh) || (BinStream[i] <= low && waveHigh)){
+                               if (smplCnt > clk-(clk/4)-1) { //full clock
+                                       if (smplCnt > clk + (clk/4)+1) { //too many samples
                                                errCnt++;
-                                               lastBit+=*clk;//skip over until hit too many errors
-                                               if (errCnt>(maxErr)) break;  //allow 1 error for every 1000 samples else start over
+                                               BinStream[bitCnt++]=7;
+                                       } else if (waveHigh) {
+                                               BinStream[bitCnt++] = invert;
+                                               BinStream[bitCnt++] = invert;
+                                       } else if (!waveHigh) {
+                                               BinStream[bitCnt++] = invert ^ 1;
+                                               BinStream[bitCnt++] = invert ^ 1;
                                        }
+                                       waveHigh ^= 1;  
+                                       smplCnt = 0;
+                               } else if (smplCnt > (clk/2) - (clk/4)-1) {
+                                       if (waveHigh) {
+                                               BinStream[bitCnt++] = invert;
+                                       } else if (!waveHigh) {
+                                               BinStream[bitCnt++] = invert ^ 1;
+                                       }
+                                       waveHigh ^= 1;  
+                                       smplCnt = 0;
+                               } else if (!bitCnt) {
+                                       //first bit
+                                       waveHigh = (BinStream[i] >= high);
+                                       smplCnt = 1;
+                               } else {
+                                       smplCnt++;
+                                       //transition bit oops
                                }
-                               if ((i-iii) >(MaxBits * *clk)) break; //got plenty of bits
-                       }
-                       //we got more than 64 good bits and not all errors
-                       if ((((i-iii)/ *clk) > (64)) && (errCnt<=maxErr)) {
-                               //possible good read
-                               if (errCnt==0){
-                                       bestStart=iii;
-                                       bestErrCnt=errCnt;
-                                       break;  //great read - finish
-                               }
-                               if (errCnt<bestErrCnt){  //set this as new best run
-                                       bestErrCnt=errCnt;
-                                       bestStart = iii;
-                               }
+                       } else { //haven't hit new high or new low yet
+                               smplCnt++;
                        }
                }
        }
-       if (bestErrCnt<=maxErr){
-               //best run is good enough set to best run and set overwrite BinStream
-               iii=bestStart;
-               lastBit = bestStart - *clk;
-               bitnum=0;
-               for (i = iii; i < *size; ++i) {
-                       if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){
-                               lastBit += *clk;
-                               BinStream[bitnum] = *invert;
-                               bitnum++;
-                       } else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){
-                               //low found and we are expecting a bar
-                               lastBit+=*clk;
-                               BinStream[bitnum] = 1-*invert;
-                               bitnum++;
-                       } else {
-                               //mid value found or no bar supposed to be here
-                               if ((i-lastBit)>(*clk+tol)){
-                                       //should have hit a high or low based on clock!!
-
-                                       //debug
-                                       //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
-                                       if (bitnum > 0){
-                                               BinStream[bitnum]=77;
-                                               bitnum++;
-                                       }
+       *size = bitCnt;
+       return errCnt;
+}
 
-                                       lastBit+=*clk;//skip over error
-                               }
-                       }
-                       if (bitnum >=MaxBits) break;
-               }
-               *size=bitnum;
-       } else{
-               *invert=bestStart;
-               *clk=iii;
-               return -1;
+//by marshmellow
+void askAmp(uint8_t *BitStream, size_t size)
+{
+       for(size_t i = 1; i<size; i++){
+               if (BitStream[i]-BitStream[i-1]>=30) //large jump up
+                       BitStream[i]=127;
+               else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down
+                       BitStream[i]=-127;
        }
-       return bestErrCnt;
+       return;
 }
 
 //by marshmellow
-//encode binary data into binary manchester 
-int ManchesterEncode(uint8_t *BitStream, size_t size)
+//attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester
+int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType)
 {
-       size_t modIdx=20000, i=0;
-       if (size>modIdx) return -1;
-       for (size_t idx=0; idx < size; idx++){
-               BitStream[idx+modIdx++] = BitStream[idx];
-               BitStream[idx+modIdx++] = BitStream[idx]^1;
+       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);
+
+       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)) {
+               errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
+               if (askType) //askman
+                       return manrawdecode(BinStream, size, 0);        
+               else //askraw
+                       return errCnt;
        }
-       for (; i<(size*2); i++){
-               BitStream[i] = BitStream[i+20000];
+
+       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 = 1024;
+       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) {
+                                       BinStream[bitnum++]=7;
+                                       errCnt++;                                               
+                               } 
+                       } else { //in tolerance - looking for peak
+                               continue;
+                       }
+                       midBit = 0;
+                       lastBit += *clk;
+               } else if (i-lastBit >= (*clk/2-tol) && !midBit && !askType){
+                       if (BinStream[i] >= high) {
+                               BinStream[bitnum++] = *invert;
+                       } else if (BinStream[i] <= low) {
+                               BinStream[bitnum++] = *invert ^ 1;
+                       } else if (i-lastBit >= *clk/2+tol) {
+                               BinStream[bitnum] = BinStream[bitnum-1];
+                               bitnum++;
+                       } else { //in tolerance - looking for peak
+                               continue;
+                       }
+                       midBit = 1;
+               }
+               if (bitnum >= MaxBits) break;
        }
-       return i;
+       *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)
+int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert)
 {
        uint16_t bitnum=0, MaxBits = 512, errCnt = 0;
        size_t i, ii;
        uint16_t bestErr = 1000, bestRun = 0;
-       if (size == 0) return -1;
+       if (*size < 16) return -1;
+       //find correct start position [alignment]
        for (ii=0;ii<2;++ii){
-               i=0;
-               for (i=i+ii;i<*size-2;i+=2){
-                       if(BitStream[i]==1 && (BitStream[i+1]==0)){
-                       } else if((BitStream[i]==0)&& BitStream[i+1]==1){
-                       } else {
+               for (i=ii; i<*size-3; i+=2)
+                       if (BitStream[i]==BitStream[i+1])
                                errCnt++;
-                       }
-                       if(bitnum>MaxBits) break;
-               }
+
                if (bestErr>errCnt){
                        bestErr=errCnt;
                        bestRun=ii;
                }
                errCnt=0;
        }
-       errCnt=bestErr;
-       if (errCnt<20){
-               ii=bestRun;
-               i=0;
-               for (i=i+ii; i < *size-2; i+=2){
-                       if(BitStream[i] == 1 && (BitStream[i+1] == 0)){
-                               BitStream[bitnum++]=0;
-                       } else if((BitStream[i] == 0) && BitStream[i+1] == 1){
-                               BitStream[bitnum++]=1;
-                       } else {
-                               BitStream[bitnum++]=77;
-                               //errCnt++;
-                       }
-                       if(bitnum>MaxBits) break;
+       //decode
+       for (i=bestRun; i < *size-3; i+=2){
+               if(BitStream[i] == 1 && (BitStream[i+1] == 0)){
+                       BitStream[bitnum++]=invert;
+               } else if((BitStream[i] == 0) && BitStream[i+1] == 1){
+                       BitStream[bitnum++]=invert^1;
+               } else {
+                       BitStream[bitnum++]=7;
                }
-               *size=bitnum;
+               if(bitnum>MaxBits) break;
        }
-       return errCnt;
+       *size=bitnum;
+       return bestErr;
+}
+
+//by marshmellow
+//encode binary data into binary manchester 
+int ManchesterEncode(uint8_t *BitStream, size_t size)
+{
+       size_t modIdx=20000, i=0;
+       if (size>modIdx) return -1;
+       for (size_t idx=0; idx < size; idx++){
+               BitStream[idx+modIdx++] = BitStream[idx];
+               BitStream[idx+modIdx++] = BitStream[idx]^1;
+       }
+       for (; i<(size*2); i++){
+               BitStream[i] = BitStream[i+20000];
+       }
+       return i;
 }
 
 //by marshmellow
@@ -307,9 +304,9 @@ int manrawdecode(uint8_t * BitStream, size_t *size)
 //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;
-       uint32_t errCnt =0;
-       size_t i=offset;
+       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;
@@ -323,7 +320,7 @@ int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert)
        for (i=offset; i<*size-3; i+=2){
                //check for phase error
                if (BitStream[i+1]==BitStream[i+2]) {
-                       BitStream[bitnum++]=77;
+                       BitStream[bitnum++]=7;
                        errCnt++;
                }
                if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){
@@ -331,7 +328,7 @@ int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert)
                } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){
                        BitStream[bitnum++]=invert;
                } else {
-                       BitStream[bitnum++]=77;
+                       BitStream[bitnum++]=7;
                        errCnt++;
                }
                if(bitnum>MaxBits) break;
@@ -340,238 +337,7 @@ int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert)
        return errCnt;
 }
 
-//by marshmellow
-void askAmp(uint8_t *BitStream, size_t size)
-{
-       int shift = 127;
-       int shiftedVal=0;
-       for(int i = 1; i<size; i++){
-               if (BitStream[i]-BitStream[i-1]>=30) //large jump up
-                       shift=127;
-               else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down
-                       shift=-127;
-
-               shiftedVal=BitStream[i]+shift;
-
-               if (shiftedVal>255) 
-                       shiftedVal=255;
-               else if (shiftedVal<0) 
-                       shiftedVal=0;
-               BitStream[i-1] = shiftedVal;
-       }
-       return;
-}
-
-int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low)
-{
-       size_t bitCnt=0, smplCnt=0, errCnt=0;
-       uint8_t waveHigh = 0;
-       //PrintAndLog("clk: %d", clk);
-       for (size_t i=0; i < *size; i++){
-               if (BinStream[i] >= high && waveHigh){
-                       smplCnt++;
-               } else if (BinStream[i] <= low && !waveHigh){
-                       smplCnt++;
-               } else { //transition
-                       if ((BinStream[i] >= high && !waveHigh) || (BinStream[i] <= low && waveHigh)){
-                               if (smplCnt > clk-(clk/4)-1) { //full clock
-                                       if (smplCnt > clk + (clk/4)+1) { //too many samples
-                                               errCnt++;
-                                               BinStream[bitCnt++]=77;
-                                       } else if (waveHigh) {
-                                               BinStream[bitCnt++] = invert;
-                                               BinStream[bitCnt++] = invert;
-                                       } else if (!waveHigh) {
-                                               BinStream[bitCnt++] = invert ^ 1;
-                                               BinStream[bitCnt++] = invert ^ 1;
-                                       }
-                                       waveHigh ^= 1;  
-                                       smplCnt = 0;
-                               } else if (smplCnt > (clk/2) - (clk/4)-1) {
-                                       if (waveHigh) {
-                                               BinStream[bitCnt++] = invert;
-                                       } else if (!waveHigh) {
-                                               BinStream[bitCnt++] = invert ^ 1;
-                                       }
-                                       waveHigh ^= 1;  
-                                       smplCnt = 0;
-                               } else if (!bitCnt) {
-                                       //first bit
-                                       waveHigh = (BinStream[i] >= high);
-                                       smplCnt = 1;
-                               } else {
-                                       smplCnt++;
-                                       //transition bit oops
-                               }
-                       } else { //haven't hit new high or new low yet
-                               smplCnt++;
-                       }
-               }
-       }
-       *size = bitCnt;
-       return errCnt;
-}
-
-//by marshmellow
-//takes 3 arguments - clock, invert and maxErr as integers
-//attempts to demodulate ask only
-int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp)
-{
-       uint32_t i;
-       if (*size==0) return -1;
-       int start = DetectASKClock(BinStream, *size, clk, 20); //clock default
-       if (*clk==0) return -1;
-       if (start<0) return -1;
-       if (*invert != 0 && *invert != 1) *invert =0;
-       if (amp==1) askAmp(BinStream, *size);
-
-       uint32_t initLoopMax = 200;
-       if (initLoopMax > *size) initLoopMax=*size;
-       // Detect high and lows
-       //25% clip in case highs and lows aren't clipped [marshmellow]
-       uint8_t clip = 75;
-       int high, low, ans;
-       ans = getHiLo(BinStream, initLoopMax, &high, &low, clip, clip);
-       if (ans<1) return -1; //just noise
-
-       if (DetectCleanAskWave(BinStream, *size, high, low)) {
-               //PrintAndLog("Clean");
-               return cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
-       }
-
-       //PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
-       int lastBit = 0;  //set first clock check
-       uint32_t bitnum = 0;     //output counter
-       uint8_t tol = 0;  //clock tolerance adjust - waves will be accepted as within the clock
-                                                                               //  if they fall + or - this value + clock from last valid wave
-       if (*clk == 32) tol=0;    //clock tolerance may not be needed anymore currently set to
-                                                                                                               //  + or - 1 but could be increased for poor waves or removed entirely
-       uint32_t iii = 0;
-       uint32_t gLen = *size;
-       if (gLen > 500) gLen=500;
-       //if 0 errors allowed then only try first 2 clock cycles as we want a low tolerance
-       if (!maxErr) gLen = *clk * 2; 
-       uint8_t errCnt =0;
-       uint32_t bestStart = *size;
-       uint32_t bestErrCnt = maxErr; //(*size/1000);
-       uint8_t midBit=0;
-       uint16_t MaxBits=1000;
-
-       //PrintAndLog("DEBUG - lastbit - %d",lastBit);
-       //loop to find first wave that works
-       for (iii=start; iii < gLen; ++iii){
-               if ((BinStream[iii]>=high) || (BinStream[iii]<=low)){
-                       lastBit=iii-*clk;
-                       errCnt=0;
-                       //loop through to see if this start location works
-                       for (i = iii; i < *size; ++i) {
-                               if ((BinStream[i] >= high) && ((i-lastBit)>(*clk-tol))){
-                                       lastBit+=*clk;
-                                       midBit=0;
-                               } else if ((BinStream[i] <= low) && ((i-lastBit)>(*clk-tol))){
-                                       //low found and we are expecting a bar
-                                       lastBit+=*clk;
-                                       midBit=0;
-                               } else if ((BinStream[i]<=low) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
-                                       //mid bar?
-                                       midBit=1;
-                               } else if ((BinStream[i]>=high) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
-                                       //mid bar?
-                                       midBit=1;
-                               } else if ((i-lastBit)>((*clk/2)+tol) && (midBit==0)){
-                                       //no mid bar found
-                                       midBit=1;
-                               } else {
-                                       //mid value found or no bar supposed to be here
-
-                                       if ((i-lastBit)>(*clk+tol)){
-                                               //should have hit a high or low based on clock!!
-                                               //debug
-                                               //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
-
-                                               errCnt++;
-                                               lastBit+=*clk;//skip over until hit too many errors
-                                               if (errCnt > maxErr){  
-                                                       //errCnt=0;
-                                                       break;
-                                               }
-                                       }
-                               }
-                               if ((i-iii)>(MaxBits * *clk)) break; //got enough bits
-                       }
-                       //we got more than 64 good bits and not all errors
-                       if ((((i-iii)/ *clk) > (64)) && (errCnt<=maxErr)) {
-                               //possible good read
-                               if (errCnt==0){
-                                       bestStart=iii;
-                                       bestErrCnt=errCnt;
-                                       break;  //great read - finish
-                               } 
-                               if (errCnt<bestErrCnt){  //set this as new best run
-                                       bestErrCnt=errCnt;
-                                       bestStart = iii;
-                               }
-                       }
-               }
-       }
-       if (bestErrCnt<=maxErr){
-               //best run is good enough - set to best run and overwrite BinStream
-               iii = bestStart;
-               lastBit = bestStart - *clk;
-               bitnum=0;
-               for (i = iii; i < *size; ++i) {
-                       if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){
-                               lastBit += *clk;
-                               BinStream[bitnum] = *invert;
-                               bitnum++;
-                               midBit=0;
-                       } else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){
-                               //low found and we are expecting a bar
-                               lastBit+=*clk;
-                               BinStream[bitnum] = 1 - *invert;
-                               bitnum++;
-                               midBit=0;
-                       } else if ((BinStream[i]<=low) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
-                               //mid bar?
-                               midBit=1;
-                               BinStream[bitnum] = 1 - *invert;
-                               bitnum++;
-                       } else if ((BinStream[i]>=high) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
-                               //mid bar?
-                               midBit=1;
-                               BinStream[bitnum] = *invert;
-                               bitnum++;
-                       } else if ((i-lastBit)>((*clk/2)+tol) && (midBit==0)){
-                               //no mid bar found
-                               midBit=1;
-                               if (bitnum!=0) BinStream[bitnum] = BinStream[bitnum-1];
-                               bitnum++;
-                               
-                       } else {
-                               //mid value found or no bar supposed to be here
-                               if ((i-lastBit)>(*clk+tol)){
-                                       //should have hit a high or low based on clock!!
-
-                                       //debug
-                                       //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
-                                       if (bitnum > 0){
-                                               BinStream[bitnum]=77;
-                                               bitnum++;
-                                       }
-                                       lastBit+=*clk;//skip over error
-                               }
-                       }
-                       if (bitnum >= MaxBits) break;
-               }
-               *size=bitnum;
-       } else{
-               *invert=bestStart;
-               *clk=iii;
-               return -1;
-       }
-       return bestErrCnt;
-}
-
+// by marshmellow
 // demod gProxIIDemod 
 // error returns as -x 
 // success returns start position in BitStream
@@ -596,8 +362,8 @@ int gProxII_Demod(uint8_t BitStream[], size_t *size)
 //translate wave to 11111100000 (1 for each short wave 0 for each long wave)
 size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow)
 {
-       uint32_t last_transition = 0;
-       uint32_t idx = 1;
+       size_t last_transition = 0;
+       size_t idx = 1;
        //uint32_t maxVal=0;
        if (fchigh==0) fchigh=10;
        if (fclow==0) fclow=8;
@@ -626,82 +392,62 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow
                        if ((idx-last_transition)<(fclow-2)){            //0-5 = garbage noise
                                //do nothing with extra garbage
                        } else if ((idx-last_transition) < (fchigh-1)) { //6-8 = 8 waves
-                               dest[numBits]=1;
+                               dest[numBits++]=1;
                        } else if ((idx-last_transition) > (fchigh+1) && !numBits) { //12 + and first bit = garbage 
                                //do nothing with beginning garbage
                        } else {                                         //9+ = 10 waves
-                               dest[numBits]=0;
+                               dest[numBits++]=0;
                        }
                        last_transition = idx;
-                       numBits++;
                }
        }
        return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
 }
 
-uint32_t myround2(float f)
-{
-       if (f >= 2000) return 2000;//something bad happened
-       return (uint32_t) (f + (float)0.5);
-}
-
 //translate 11111100000 to 10
-size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t maxConsequtiveBits,
+size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen,
                uint8_t invert, uint8_t fchigh, uint8_t fclow)
 {
        uint8_t lastval=dest[0];
-       uint32_t idx=0;
+       size_t idx=0;
        size_t numBits=0;
        uint32_t n=1;
-       float lowWaves = (((float)(rfLen))/((float)fclow));
-       float highWaves = (((float)(rfLen))/((float)fchigh));
        for( idx=1; idx < size; idx++) {
-
-               if (dest[idx]==lastval) {
-                       n++;
-                       continue;
-               }
                n++;
+               if (dest[idx]==lastval) continue; 
+               
                //if lastval was 1, we have a 1->0 crossing
                if (dest[idx-1]==1) {
-                       if (!numBits && n < (uint8_t)lowWaves) {
+                       if (!numBits && n < rfLen/fclow) {
                                n=0;
                                lastval = dest[idx];
                                continue;
                        }
-                       n=myround2(((float)n)/lowWaves);
+                       n = (n * fclow + rfLen/2) / rfLen;
                } else {// 0->1 crossing 
                        //test first bitsample too small
-                       if (!numBits && n < (uint8_t)highWaves) {
+                       if (!numBits && n < rfLen/fchigh) {
                                n=0;
                                lastval = dest[idx];
                                continue;
                        }
-                       n = myround2(((float)n)/highWaves);  //-1 for fudge factor
+                       n = (n * fchigh + rfLen/2) / rfLen; 
                }
                if (n == 0) n = 1;
 
-               if(n < maxConsequtiveBits) //Consecutive
-               {
-                       if(invert==0){ //invert bits
-                               memset(dest+numBits, dest[idx-1] , n);
-                       }else{
-                               memset(dest+numBits, dest[idx-1]^1 , n);
-                       }
-                       numBits += n;
-               }
+               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 > lowWaves && n > highWaves) {
+       if (n > rfLen/fchigh) {
                if (dest[idx-2]==1) {
-                       n=myround2((float)(n+1)/((float)(rfLen)/(float)fclow));
+                       n = (n * fclow + rfLen/2) / rfLen;
                } else {
-                       n=myround2((float)(n+1)/((float)(rfLen-1)/(float)fchigh));  //-1 for fudge factor                       
+                       n = (n * fchigh + rfLen/2) / rfLen;
                }
-               memset(dest, dest[idx-1]^invert , n);
+               memset(dest+numBits, dest[idx-1]^invert , n);
                numBits += n;
        }
        return numBits;
@@ -712,7 +458,7 @@ int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t
 {
        // FSK demodulator
        size = fsk_wave_demod(dest, size, fchigh, fclow);
-       size = aggregate_bits(dest, size, rfLen, 192, invert, fchigh, fclow);
+       size = aggregate_bits(dest, size, rfLen, invert, fchigh, fclow);
        return size;
 }
 
@@ -724,7 +470,7 @@ int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32
        size_t numStart=0, size2=*size, startIdx=0; 
        // FSK demodulator
        *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
-       if (*size < 96) return -2;
+       if (*size < 96*2) return -2;
        // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
        uint8_t preamble[] = {0,0,0,1,1,1,0,1};
        // find bitstring in array  
@@ -887,12 +633,13 @@ int PyramiddemodFSK(uint8_t *dest, size_t *size)
        return (int)startIdx;
 }
 
-
-uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, int high, int low)
+// 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)
 {
        uint16_t allPeaks=1;
        uint16_t cntPeaks=0;
-       size_t loopEnd = 572;
+       size_t loopEnd = 512+60;
        if (loopEnd > size) loopEnd = size;
        for (size_t i=60; i<loopEnd; i++){
                if (dest[i]>low && dest[i]<high) 
@@ -906,52 +653,41 @@ uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, int high, int low)
        return allPeaks;
 }
 
-int DetectStrongAskClock(uint8_t dest[], size_t size)
+// 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 clk[]={0,8,16,32,40,50,64,100,128,256};
-       size_t idx = 40;
-       uint8_t high=0;
-       size_t cnt = 0;
-       size_t highCnt = 0;
-       size_t highCnt2 = 0;
-       for (;idx < size; idx++){
-               if (dest[idx]>128) {
-                       if (!high){
-                               high=1;
-                               if (cnt > highCnt){
-                                       if (highCnt != 0) highCnt2 = highCnt;
-                                       highCnt = cnt;
-                               } else if (cnt > highCnt2) {
-                                       highCnt2 = cnt;
-                               }
-                               cnt=1;
-                       } else {
-                               cnt++;
-                       }
-               } else if (dest[idx] <= 128){
-                       if (high) {
-                               high=0;
-                               if (cnt > highCnt) {
-                                       if (highCnt != 0) highCnt2 = highCnt;
-                                       highCnt = cnt;
-                               } else if (cnt > highCnt2) {
-                                       highCnt2 = cnt;
-                               }
-                               cnt=1;
-                       } else {
-                               cnt++;
-                       }
-               }
+       uint8_t fndClk[] = {8,16,32,40,50,64,128};
+       size_t startwave;
+       size_t i = 0;
+       size_t minClk = 255;
+               // get to first full low to prime loop and skip incomplete first pulse
+       while ((dest[i] < high) && (i < size))
+               ++i;
+       while ((dest[i] > low) && (i < size))
+               ++i;
+
+       // loop through all samples
+       while (i < size) {
+               // measure from low to low
+               while ((dest[i] > low) && (i < size))
+                       ++i;
+               startwave= i;
+               while ((dest[i] < high) && (i < size))
+                       ++i;
+               while ((dest[i] > low) && (i < size))
+                       ++i;
+               //get minimum measured distance
+               if (i-startwave < minClk && i < size)
+                       minClk = i - startwave;
        }
-       uint8_t tol;
-       for (idx=8; idx>0; idx--){
-               tol = clk[idx]/8;
-               if (clk[idx] >= highCnt - tol && clk[idx] <= highCnt + tol)
-                       return clk[idx];
-               if (clk[idx] >= highCnt2 - tol && clk[idx] <= highCnt2 + tol)
-                       return clk[idx];
+       // set clock
+       for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
+               if (minClk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1)
+                       return fndClk[clkCnt];
        }
-       return -1;
+       return 0;
 }
 
 // by marshmellow
@@ -960,86 +696,103 @@ int DetectStrongAskClock(uint8_t dest[], size_t size)
 // 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;
+       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) return -1; //not enough samples
+
+       //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;
-       getHiLo(dest, loopCnt, &peak, &low, 75, 75);
+       if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return -1;
        
        //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;
+       if (!clockFnd){
+               if (DetectCleanAskWave(dest, size, peak, low)==1){
+                       int ans = DetectStrongAskClock(dest, size, peak, low);
+                       for (i=clkEnd-1; i>0; i--){
+                               if (clk[i] == ans) {
+                                       *clock = ans;
+                                       //clockFnd = i;
+                                       return 0;  // for strong waves i don't use the 'best start position' yet...
+                                       //break; //clock found but continue to find best startpos [not yet]
+                               }
                        }
                }
        }
-       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;
+       
+       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=0; clkCnt < 8; clkCnt++){
-               if (clk[clkCnt] == 32){
+       for(; clkCnt < clkEnd; clkCnt++){
+               if (clk[clkCnt] <= 32){
                        tol=1;
                }else{
                        tol=0;
                }
-               if (!maxErr) loopCnt=clk[clkCnt]*2;
+               //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 256)
+               //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)){
-                               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;
+                       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
+                                       //PrintAndLog("DEBUG: clk %d, err %d, ii %d, i %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=0;
+       uint8_t iii;
        uint8_t best=0;
-       for (iii=0; iii<8; ++iii){
-               if (bestErr[iii]<bestErr[best]){
-                       if (bestErr[iii]==0) bestErr[iii]=1;
+       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]) ){
+                       if ( (size/clk[best])/bestErr[best] < (size/clk[iii])/bestErr[iii] ){
                                best = iii;
                        }
                }
        }
-       if (bestErr[best]>maxErr) return -1;
-       *clock=clk[best];
+       //if (bestErr[best] > maxErr) return -1;
+       if (!clockFnd) *clock = clk[best];
        return bestStart[best];
 }
 
@@ -1063,7 +816,8 @@ int DetectPSKClock(uint8_t dest[], size_t size, int clock)
        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);
+       fc = countFC(dest, size, 0);
+       if (fc!=2 && fc!=4 && fc!=8) return -1;
        //PrintAndLog("DEBUG: FC: %d",fc);
 
        //find first full wave
@@ -1144,9 +898,9 @@ int DetectPSKClock(uint8_t dest[], size_t size, int clock)
 //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...
+       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<loopCnt) loopCnt = size;
 
@@ -1156,15 +910,15 @@ int DetectNRZClock(uint8_t dest[], size_t size, int clock)
 
        //get high and low peak
        int peak, low;
-       getHiLo(dest, loopCnt, &peak, &low, 75, 75);
+       if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return 0;
 
        //PrintAndLog("DEBUG: peak: %d, low: %d",peak,low);
-       int ii;
+       size_t ii;
        uint8_t clkCnt;
        uint8_t tol = 0;
-       int peakcnt=0;
-       int peaksdet[]={0,0,0,0,0,0,0,0};
-       int maxPeak=0;
+       uint16_t peakcnt=0;
+       uint16_t peaksdet[]={0,0,0,0,0,0,0,0};
+       uint16_t maxPeak=0;
        //test for large clipped waves
        for (i=0; i<loopCnt; i++){
                if (dest[i] >= peak || dest[i] <= low){
@@ -1199,7 +953,7 @@ int DetectNRZClock(uint8_t dest[], size_t size, int clock)
                }
        }
        int iii=7;
-       int best=0;
+       uint8_t best=0;
        for (iii=7; iii > 0; iii--){
                if (peaksdet[iii] > peaksdet[best]){
                        best = iii;
@@ -1217,7 +971,7 @@ 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){
+               if (BitStream[i]==7){
                        //ignore errors
                } else if (lastBit!=BitStream[i]){
                        lastBit=BitStream[i];
@@ -1316,28 +1070,20 @@ 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;
+       size_t i, 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
+       size_t iii = 0, bitnum = 0; //bitnum counter
+       uint16_t errCnt = 0, MaxBits = 1000;
+       size_t bestErrCnt = maxErr+1;
+       size_t bestPeakCnt = 0, bestPeakStart = 0;
+       uint8_t bestFirstPeakHigh=0, firstPeakHigh=0, curBit=0, bitHigh=0, errBitHigh=0;
        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
+       uint8_t ignoreCnt=ignoreWindow; //in case of noise 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)){
@@ -1346,135 +1092,93 @@ int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert, int maxErr)
                        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;
+                               // if we are at a clock bit
+                               if ((i >= lastBit + *clk - tol) && (i <= lastBit + *clk + tol)) {
+                                       //test high/low
+                                       if (dest[i] >= high || dest[i] <= low) {
+                                               bitHigh = 1;
+                                               peakCnt++;
+                                               errBitHigh = 0;
+                                               ignoreCnt = ignoreWindow;
+                                               lastBit += *clk;
+                                       } else if (i == lastBit + *clk + tol) {
+                                               lastBit += *clk;
+                                       }
                                //else if no bars found
-                               }else if(dest[i] < high && dest[i] > low) {
+                               } else if (dest[i] < high && dest[i] > low){
                                        if (ignoreCnt==0){
                                                bitHigh=0;
-                                               if (errBitHigh==1){
-                                                       errCnt++;
-                                               }
+                                               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)){
+                               } else if ((dest[i]>=high || dest[i]<=low) && (bitHigh==0)) {
                                        //error bar found no clock...
                                        errBitHigh=1;
                                }
-                               if (bitnum>=MaxBits) break;
+                               if (((i-iii) / *clk)>=MaxBits) break;
                        }
                        //we got more than 64 good bits and not all errors
-                       if (bitnum > (64) && (errCnt <= (maxErr))) {
+                       if (((i-iii) / *clk) > 64 && (errCnt <= (maxErr))) {
                                //possible good read
-                               if (errCnt == 0){
-                                       //bestStart = iii;
+                               if (!errCnt || peakCnt > bestPeakCnt){
                                        bestFirstPeakHigh=firstPeakHigh;
                                        bestErrCnt = errCnt;
                                        bestPeakCnt = peakCnt;
                                        bestPeakStart = iii;
-                                       break;  //great read - finish
+                                       if (!errCnt) 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++;
+       if (bestErrCnt > maxErr) return bestErrCnt;             
+
+       //best run is good enough set to best run and set overwrite BinStream
+       lastBit = bestPeakStart - *clk;
+       memset(dest, bestFirstPeakHigh^1, bestPeakStart / *clk);
+       bitnum += (bestPeakStart / *clk);
+       for (i = bestPeakStart; i < *size; ++i) {
+               // if expecting a clock bit
+               if ((i >= lastBit + *clk - tol) && (i <= lastBit + *clk + tol)) {
+                       // test high/low
+                       if (dest[i] >= high || dest[i] <= low) {
+                               peakCnt++;
+                               bitHigh = 1;
+                               errBitHigh = 0;
+                               ignoreCnt = ignoreWindow;
+                               curBit = *invert;
+                               if (dest[i] >= high) curBit ^= 1;
+                               dest[bitnum++] = curBit;
+                               lastBit += *clk;
+                       //else no bars found in clock area
+                       } else if (i == lastBit + *clk + tol) {
+                               dest[bitnum++] = curBit;
+                               lastBit += *clk;
+                       }
+               //else if no bars found
+               } else if (dest[i] < high && dest[i] > low){
+                       if (ignoreCnt == 0){
+                               bitHigh = 0;
+                               if (errBitHigh == 1){
+                                       dest[bitnum++] = 7;
+                                       errCnt++;
                                }
-                       //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;
+                               errBitHigh=0;
+                       } else {
+                               ignoreCnt--;
                        }
-                       if (bitnum >= MaxBits) break;
+               } else if ((dest[i] >= high || dest[i] <= low) && (bitHigh == 0)) {
+                       //error bar found no clock...
+                       errBitHigh=1;
                }
-               *size=bitnum;
-       } else{
-               *size=bitnum;
-               return bestErrCnt;
+               if (bitnum >= MaxBits) break;
        }
-
-       if (bitnum>16){
-               *size=bitnum;
-       } else return -5;
-       return errCnt;
+       *size = bitnum;
+       return bestErrCnt;
 }
 
 //by marshmellow
@@ -1485,8 +1189,8 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc
        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;
+       uint8_t lastFCcnt = 0;
+       uint16_t fcCounter = 0;
        uint16_t rfCounter = 0;
        uint8_t firstBitFnd = 0;
        size_t i;
@@ -1504,45 +1208,41 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc
                        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;
-                                               }
+               fcCounter++;
+               rfCounter++;
+
+               if (BitStream[i] <= BitStream[i-1] || BitStream[i] < BitStream[i+1]) 
+                       continue;               
+               // else new peak 
+               // if we got less than the small fc + tolerance then set it to the small fc
+               if (fcCounter < fcLow+fcTol) 
+                       fcCounter = fcLow;
+               else //set it to the large fc
+                       fcCounter = fcHigh;
+
+               //look for bit clock  (rf/xx)
+               if ((fcCounter < lastFCcnt || fcCounter > lastFCcnt)){
+                       //not the same size as the last wave - start of new bit sequence
+                       if (firstBitFnd > 1){ //skip first wave change - probably not a complete bit
+                               for (int ii=0; ii<15; ii++){
+                                       if (rfLens[ii] == rfCounter){
+                                               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;
+                               if (rfCounter > 0 && rfLensFnd < 15){
+                                       //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
+                                       rfCnts[rfLensFnd]++;
+                                       rfLens[rfLensFnd++] = rfCounter;
+                               }
+                       } else {
+                               firstBitFnd++;
                        }
-                       fcCounter=0;
-               } else {
-                       // count sample
-                       fcCounter++;
-                       rfCounter++;
+                       rfCounter=0;
+                       lastFCcnt=fcCounter;
                }
+               fcCounter=0;
        }
        uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15;
 
@@ -1588,13 +1288,13 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc
 //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)
+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};
        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;
+       uint8_t fcCounter = 0;
        size_t i;
        if (size == 0) return 0;
 
@@ -1607,13 +1307,14 @@ uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t *mostFC)
                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++;
-
+                       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<10; ii++){
                                if (fcLens[ii]==fcCounter){
@@ -1661,89 +1362,31 @@ uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t *mostFC)
                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;
-}
-
-//by marshmellow
-//countPSK_FC is to detect the psk carrier clock length.
-//counts and returns the 1 most common wave length
-uint8_t countPSK_FC(uint8_t *BitStream, size_t size)
-{
-       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;
-       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++;
-                       
-                       // 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;
-       uint16_t maxCnt1=0;
-       // go through fclens and find which ones are bigest  
-       for (i=0; i<10; i++){
-               //PrintAndLog("DEBUG: FC %d, Cnt %d",fcLens[i],fcCnts[i]);    
-               // get the best FC value
-               if (fcCnts[i]>maxCnt1) {
-                       maxCnt1=fcCnts[i];
-                       best1=i;
-               }
-       }
-       return fcLens[best1]; 
+       if (fskAdj) return fcs; 
+       return fcLens[best1];
 }
 
 //by marshmellow - demodulate PSK1 wave 
 //uses wave lengths (# Samples) 
 int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
 {
-       uint16_t loopCnt = 4096;  //don't need to loop through entire array...
        if (size == 0) return -1;
+       uint16_t loopCnt = 4096;  //don't need to loop through entire array...
        if (*size<loopCnt) loopCnt = *size;
 
        uint8_t curPhase = *invert;
        size_t i, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0;
        uint8_t fc=0, fullWaveLen=0, tol=1;
        uint16_t errCnt=0, waveLenCnt=0;
-       fc = countPSK_FC(dest, *size);
+       fc = countFC(dest, *size, 0);
        if (fc!=2 && fc!=4 && fc!=8) return -1;
        //PrintAndLog("DEBUG: FC: %d",fc);
        *clock = DetectPSKClock(dest, *size, *clock);
-       if (*clock==0) return -1;
+       if (*clock == 0) return -1;
        int avgWaveVal=0, lastAvgWaveVal=0;
        //find first phase shift
        for (i=0; i<loopCnt; i++){
@@ -1756,30 +1399,29 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
                                firstFullWave = waveStart;
                                fullWaveLen=waveLenCnt;
                                //if average wave value is > graph 0 then it is an up wave or a 1
-                               if (lastAvgWaveVal > 123) curPhase^=1;  //fudge graph 0 a little 123 vs 128
+                               if (lastAvgWaveVal > 123) curPhase ^= 1;  //fudge graph 0 a little 123 vs 128
                                break;
                        } 
                        waveStart = i+1;
                        avgWaveVal = 0;
                }
-               avgWaveVal+=dest[i+2];
+               avgWaveVal += dest[i+2];
        }
        //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);  
        lastClkBit = firstFullWave; //set start of wave as clock align
        //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d", *clock, lastClkBit);
        waveStart = 0;
-       errCnt=0;
        size_t numBits=0;
        //set skipped bits
-       memset(dest,curPhase^1,firstFullWave / *clock);
+       memset(dest, curPhase^1, firstFullWave / *clock);
        numBits += (firstFullWave / *clock);
        dest[numBits++] = curPhase; //set first read bit
-       for (i = firstFullWave+fullWaveLen-1; i < *size-3; i++){
+       for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){
                //top edge of wave = start of new wave 
                if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
                        if (waveStart == 0) {
                                waveStart = i+1;
-                               waveLenCnt=0;
+                               waveLenCnt = 0;
                                avgWaveVal = dest[i+1];
                        } else { //waveEnd
                                waveEnd = i+1;
@@ -1787,27 +1429,27 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
                                lastAvgWaveVal = avgWaveVal/waveLenCnt;
                                if (waveLenCnt > fc){  
                                        //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);
-                                       //if this wave is a phase shift
+                                       //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;
+                                               curPhase ^= 1;
                                                dest[numBits++] = curPhase;
                                                lastClkBit += *clock;
-                                       } else if (i<lastClkBit+10+fc){
+                                       } else if (i < lastClkBit+10+fc){
                                                //noise after a phase shift - ignore
                                        } else { //phase shift before supposed to based on clock
                                                errCnt++;
-                                               dest[numBits++] = 77;
+                                               dest[numBits++] = 7;
                                        }
                                } else if (i+1 > lastClkBit + *clock + tol + fc){
                                        lastClkBit += *clock; //no phase shift but clock bit
                                        dest[numBits++] = curPhase;
                                }
-                               avgWaveVal=0;
-                               waveStart=i+1;
+                               avgWaveVal = 0;
+                               waveStart = i+1;
                        }
                }
-               avgWaveVal+=dest[i+1];
+               avgWaveVal += dest[i+1];
        }
        *size = numBits;
        return errCnt;
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