]> git.zerfleddert.de Git - proxmark3-svn/blobdiff - common/lfdemod.c
lf cleaning
[proxmark3-svn] / common / lfdemod.c
index 88a250d87efd105fa85f70ef919c2fd89585a75d..58221546b24da9ce67c6aa60495f325d6a911ec1 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;
@@ -25,19 +23,19 @@ uint8_t justNoise(uint8_t *BitStream, size_t size)
 }
 
 //by marshmellow
-//get high and low with passed in fuzz factor. also return noise test = 1 for passed or 0 for only noise
+//get high and low values of a wave with passed in fuzz factor. also return noise test = 1 for passed or 0 for only noise
 int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi, uint8_t fuzzLo)
 {
        *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;
 }
 
@@ -50,191 +48,173 @@ uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType)
        for (uint8_t i = 0; i < bitLen; i++){
                ans ^= ((bits >> i) & 1);
        }
-  //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType);
+       //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType);
        return (ans == pType);
 }
 
 //by marshmellow
-//search for given preamble in given BitStream and return startIndex and length
+//search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length
 uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx)
 {
-  uint8_t foundCnt=0;
-  for (int idx=0; idx < *size - pLen; idx++){
-    if (memcmp(BitStream+idx, preamble, pLen) == 0){
-      //first index found
-      foundCnt++;
-      if (foundCnt == 1){
-        *startIdx = idx;
-      }
-      if (foundCnt == 2){
-        *size = idx - *startIdx;
-        return 1;
-      }
-    }
-  }
-  return 0;
+       uint8_t foundCnt=0;
+       for (int idx=0; idx < *size - pLen; idx++){
+               if (memcmp(BitStream+idx, preamble, pLen) == 0){
+                       //first index found
+                       foundCnt++;
+                       if (foundCnt == 1){
+                               *startIdx = idx;
+                       }
+                       if (foundCnt == 2){
+                               *size = idx - *startIdx;
+                               return 1;
+                       }
+               }
+       }
+       return 0;
 }
 
-
 //by marshmellow
 //takes 1s and 0s and searches for EM410x format - output EM ID
-uint64_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx)
+uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo)
 {
-  //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
-  //  otherwise could be a void with no arguments
-  //set defaults
-  uint64_t lo=0;
-  uint32_t i = 0;
-  if (BitStream[1]>1){  //allow only 1s and 0s
-    // PrintAndLog("no data found");
-    return 0;
-  }
-  // 111111111 bit pattern represent start of frame
-  uint8_t preamble[] = {1,1,1,1,1,1,1,1,1};
-  uint32_t idx = 0;
-  uint32_t parityBits = 0;
-  uint8_t errChk = 0;
-  *startIdx = 0;
-  for (uint8_t extraBitChk=0; extraBitChk<5; extraBitChk++){
-    errChk = preambleSearch(BitStream+extraBitChk+*startIdx, preamble, sizeof(preamble), size, startIdx);
-    if (errChk == 0) return 0;
-    idx = *startIdx + 9;
-    for (i=0; i<10;i++){ //loop through 10 sets of 5 bits (50-10p = 40 bits)
-      parityBits = bytebits_to_byte(BitStream+(i*5)+idx,5);
-      //check even parity
-      if (parityTest(parityBits, 5, 0) == 0){
-        //parity failed try next bit (in the case of 1111111111) but last 9 = preamble
-        startIdx++;
-        errChk = 0;
-        break;
-      }
-      for (uint8_t ii=0; ii<4; ii++){
-        lo = (lo << 1LL) | (BitStream[(i*5)+ii+idx]);
-      }
-    }
-    if (errChk != 0) return lo;
-    //skip last 5 bit parity test for simplicity.
-    // *size = 64;
-  }
-  return 0;
+       //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
+       //  otherwise could be a void with no arguments
+       //set defaults
+       uint32_t i = 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};
+       uint32_t idx = 0;
+       uint32_t parityBits = 0;
+       uint8_t errChk = 0;
+       uint8_t FmtLen = 10;
+       *startIdx = 0;
+       errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx);
+       if (errChk == 0 || *size < 64) return 0;
+       if (*size > 64) FmtLen = 22;
+       *startIdx += 1; //get rid of 0 from preamble
+       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 - 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);
+                       *lo = (*lo << 1) | (BitStream[(i*5)+ii+idx]);
+               }
+       }
+       if (errChk != 0) return 1;
+       //skip last 5 bit parity test for simplicity.
+       // *size = 64 | 128;
+       return 0;
+}
+
+// demodulates strong heavily clipped samples
+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++]=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
+                               }
+                       } else { //haven't hit new high or new low yet
+                               smplCnt++;
+                       }
+               }
+       }
+       *size = bitCnt;
+       return errCnt;
 }
 
 //by marshmellow
-//takes 2 arguments - clock and invert both as integers
+//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 askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr)
 {
-       int i;
-       int clk2=*clk;
-       *clk=DetectASKClock(BinStream, *size, *clk); //clock default
-
-       // 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;
+       size_t i;
+       int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default
+       if (*clk==0 || start < 0) return -3;
+       if (*invert != 1) *invert=0;
+       uint8_t initLoopMax = 255;
+       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;
-       uint8_t errCnt =0;
-       uint32_t bestStart = *size;
-       uint32_t bestErrCnt = (*size/1000);
-       uint32_t maxErr = (*size/1000);
-       // 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);
+       int high, low;
+       if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1) return -2; //just noise
 
-                                               errCnt++;
-                                               lastBit+=*clk;//skip over until hit too many errors
-                                               if (errCnt>(maxErr)) break;  //allow 1 error for every 1000 samples else start over
-                                       }
-                               }
-                               if ((i-iii) >(400 * *clk)) break; //got plenty of bits
-                       }
-                       //we got more than 64 good bits and not all errors
-                       if ((((i-iii)/ *clk) > (64+errCnt)) && (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 clean clipped waves detected run alternate demod
+       if (DetectCleanAskWave(BinStream, *size, high, low)) {
+               cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
+               return manrawdecode(BinStream, size);   
        }
-       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++;
-                                       }
 
-                                       lastBit+=*clk;//skip over error
-                               }
-                       }
-                       if (bitnum >=400) break;
+       // PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
+       int lastBit;  //set first clock check
+       uint16_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=1;    //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely
+       uint16_t errCnt = 0, MaxBits = 512;
+       lastBit = start - *clk;
+       for (i = start; i < *size; ++i) {
+               if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){
+                       //high found and we are expecting a bar
+                       lastBit += *clk;
+                       BinStream[bitnum++] = *invert;
+               } else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){
+                       //low found and we are expecting a bar
+                       lastBit += *clk;
+                       BinStream[bitnum++] = *invert ^ 1;
+               } else if ((i-lastBit)>(*clk+tol)){
+                       //should have hit a high or low based on clock!!
+                       //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++] = 7;
+                               errCnt++;
+                       }               
+                       lastBit += *clk;//skip over error
                }
-               *size=bitnum;
-       } else{
-               *invert=bestStart;
-               *clk=iii;
-               return -1;
+               if (bitnum >= MaxBits) break;
        }
-       return bestErrCnt;
+       *size = bitnum;
+       return errCnt;
 }
 
 //by marshmellow
@@ -243,14 +223,14 @@ 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;
+       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
@@ -258,229 +238,185 @@ int ManchesterEncode(uint8_t *BitStream, size_t size)
 //run through 2 times and take least errCnt
 int manrawdecode(uint8_t * BitStream, size_t *size)
 {
-       int bitnum=0;
-       int errCnt =0;
-       int i=1;
-       int bestErr = 1000;
-       int bestRun = 0;
-       int ii=1;
-       for (ii=1;ii<3;++ii){
-               i=1;
-               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 {
+       uint16_t bitnum=0, MaxBits = 512, errCnt = 0;
+       size_t i, ii;
+       uint16_t bestErr = 1000, bestRun = 0;
+       if (size == 0) return -1;
+       //find correct start position [alignment]
+       for (ii=0;ii<2;++ii){
+               for (i=ii; i<*size-2; i+=2)
+                       if (BitStream[i]==BitStream[i+1])
                                errCnt++;
-                       }
-                       if(bitnum>300) break;
-               }
+
                if (bestErr>errCnt){
                        bestErr=errCnt;
                        bestRun=ii;
                }
                errCnt=0;
        }
-       errCnt=bestErr;
-       if (errCnt<20){
-               ii=bestRun;
-               i=1;
-               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>300) break;
+       //decode
+       for (i=bestRun; 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++]=7;
                }
-               *size=bitnum;
+               if(bitnum>MaxBits) break;
        }
-       return errCnt;
+       *size=bitnum;
+       return bestErr;
 }
 
 //by marshmellow
-//take 01 or 10 = 0 and 11 or 00 = 1
+//take 01 or 10 = 1 and 11 or 00 = 0
+//check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010
+//decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding
 int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert)
 {
-       uint8_t bitnum=0;
-       uint32_t errCnt =0;
-       uint32_t i;
-       i=offset;
-       for (;i<*size-2; i+=2){
+       uint16_t bitnum = 0;
+       uint16_t errCnt = 0;
+       size_t i = offset;
+       uint16_t MaxBits=512;
+       //if not enough samples - error
+       if (*size < 51) return -1;
+       //check for phase change faults - skip one sample if faulty
+       uint8_t offsetA = 1, offsetB = 1;
+       for (; i<48; i+=2){
+               if (BitStream[i+1]==BitStream[i+2]) offsetA=0; 
+               if (BitStream[i+2]==BitStream[i+3]) offsetB=0;                                  
+       }
+       if (!offsetA && offsetB) offset++;
+       for (i=offset; i<*size-3; i+=2){
+               //check for phase error
+               if (BitStream[i+1]==BitStream[i+2]) {
+                       BitStream[bitnum++]=7;
+                       errCnt++;
+               }
                if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){
                        BitStream[bitnum++]=1^invert;
                } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){
                        BitStream[bitnum++]=invert;
                } else {
-                       BitStream[bitnum++]=77;
+                       BitStream[bitnum++]=7;
                        errCnt++;
                }
-               if(bitnum>250) break;
+               if(bitnum>MaxBits) break;
        }
        *size=bitnum;
        return errCnt;
 }
 
 //by marshmellow
-//takes 2 arguments - clock and invert both as integers
+void askAmp(uint8_t *BitStream, size_t size)
+{
+       int shift = 127;
+       int shiftedVal=0;
+       for(size_t 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;
+}
+
+//by marshmellow
+//takes 3 arguments - clock, invert and maxErr as integers
 //attempts to demodulate ask only
-//prints binary found and saves in graphbuffer for further commands
-int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert)
+int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp)
 {
-       uint32_t i;
-       // int invert=0;  //invert default
-       int clk2 = *clk;
-       *clk=DetectASKClock(BinStream, *size, *clk); //clock default
-       //uint8_t BitStream[502] = {0};
-
-       //HACK: if clock not detected correctly - default
-       if (clk2==0 && *clk<8) *clk =64;
-       if (clk2==0 && *clk<32 && clk2==0) *clk=32;
-       if (*invert != 0 && *invert != 1) *invert =0;
-       uint32_t initLoopMax = 200;
-       if (initLoopMax > *size) initLoopMax=*size;
+       if (*size==0) return -1;
+       int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default
+       if (*clk==0 || start < 0) return -1;
+       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% 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
-       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
-       uint32_t iii = 0;
-       uint32_t gLen = *size;
-       if (gLen > 500) gLen=500;
-       uint8_t errCnt =0;
-       uint32_t bestStart = *size;
-       uint32_t bestErrCnt = (*size/1000);
-       uint32_t maxErr = bestErrCnt;
-       uint8_t midBit=0;
-       //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;
-                       //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 > ((*size/1000))){  //allow 1 error for every 1000 samples else start over
-                                                       errCnt=0;
-                                                       break;
-                                               }
-                                       }
-                               }
-                               if ((i-iii)>(500 * *clk)) break; //got enough bits
-                       }
-                       //we got more than 64 good bits and not all errors
-                       if ((((i-iii)/ *clk) > (64+errCnt)) && (errCnt<(*size/1000))) {
-                               //possible good read
-                               if (errCnt==0){
-                                       bestStart=iii;
-                                       bestErrCnt=errCnt;
-                                       break;  //great read - finish
+       //25% clip in case highs and lows aren't clipped [marshmellow]
+       int high, low;
+       if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1) 
+               return -1; //just noise
+
+       // if clean clipped waves detected run alternate demod
+       if (DetectCleanAskWave(BinStream, *size, high, low))
+               return cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
+
+       int lastBit;  //set first clock check - can go negative
+       size_t i, errCnt = 0, bitnum = 0;     //output counter
+       uint8_t midBit = 0;
+       size_t MaxBits = 1024;
+       lastBit = start - *clk;
+
+       for (i = start; i < *size; ++i) {
+               if (i - lastBit > *clk){
+                       if (BinStream[i] >= high) {
+                               BinStream[bitnum++] = *invert;
+                       } else if (BinStream[i] <= low) {
+                               BinStream[bitnum++] = *invert ^ 1;
+                       } else {
+                               if (bitnum > 0) {
+                                       BinStream[bitnum++]=7;
+                                       errCnt++;                                               
                                } 
-                               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++;
-                               
+                       midBit = 0;
+                       lastBit += *clk;
+               } else if (i-lastBit > (*clk/2) && midBit == 0){
+                       if (BinStream[i] >= high) {
+                               BinStream[bitnum++] = *invert;
+                       } else if (BinStream[i] <= low) {
+                               BinStream[bitnum++] = *invert ^ 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);
-                                       if (bitnum > 0){
-                                               BinStream[bitnum]=77;
-                                               bitnum++;
-                                       }
 
-                                       lastBit+=*clk;//skip over error
-                               }
+                               BinStream[bitnum] = BinStream[bitnum-1];
+                               bitnum++;
                        }
-                       if (bitnum >=400) break;
+                       midBit = 1;
                }
-               *size=bitnum;
-       } else{
-               *invert=bestStart;
-               *clk=iii;
-               return -1;
+               if (bitnum >= MaxBits) break;
        }
-       return bestErrCnt;
+       *size = bitnum;
+       return errCnt;
 }
+
+// demod gProxIIDemod 
+// error returns as -x 
+// success returns start position in BitStream
+// BitStream must contain previously askrawdemod and biphasedemoded data
+int gProxII_Demod(uint8_t BitStream[], size_t *size)
+{
+       size_t startIdx=0;
+       uint8_t preamble[] = {1,1,1,1,1,0};
+
+       uint8_t errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, &startIdx);
+       if (errChk == 0) return -3; //preamble not found
+       if (*size != 96) return -2; //should have found 96 bits
+       //check first 6 spacer bits to verify format
+       if (!BitStream[startIdx+5] && !BitStream[startIdx+10] && !BitStream[startIdx+15] && !BitStream[startIdx+20] && !BitStream[startIdx+25] && !BitStream[startIdx+30]){
+               //confirmed proper separator bits found
+               //return start position
+               return (int) startIdx;
+       }
+       return -5;
+}
+
 //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;
@@ -509,58 +445,64 @@ 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;
-                       } else {                                                        //9+ = 10 waves
-                               dest[numBits]=0;
+                               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;
                        }
                        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,
-    uint8_t invert, uint8_t fchigh, uint8_t fclow)
+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;
-
        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 ) {
-                       n=myround2((float)(n+1)/((float)(rfLen)/(float)fclow));
-               } else {// 0->1 crossing
-                       n=myround2((float)(n+1)/((float)(rfLen-1)/(float)fchigh));  //-1 for fudge factor
+               if (dest[idx-1]==1) {
+                       if (!numBits && n < rfLen/fclow) {
+                               n=0;
+                               lastval = dest[idx];
+                               continue;
+                       }
+                       n = (n * fclow + rfLen/2) / rfLen;
+               } else {// 0->1 crossing 
+                       //test first bitsample too small
+                       if (!numBits && n < rfLen/fchigh) {
+                               n=0;
+                               lastval = dest[idx];
+                               continue;
+                       }
+                       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 > rfLen/fchigh) {
+               if (dest[idx-2]==1) {
+                       n = (n * fclow + rfLen/2) / rfLen;
+               } else {
+                       n = (n * fchigh + rfLen/2) / rfLen;
+               }
+               memset(dest+numBits, dest[idx-1]^invert , n);
+               numBits += n;
+       }
        return numBits;
 }
 //by marshmellow  (from holiman's base)
@@ -569,40 +511,40 @@ 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;
 }
 
 // loop to get raw HID waveform then FSK demodulate the TAG ID from it
 int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo)
 {
-  if (justNoise(dest, *size)) return -1;
-
-  size_t numStart=0, size2=*size, startIdx=0; 
-  // FSK demodulator
-  *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
-  if (*size < 96) 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  
-  uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
-  if (errChk == 0) return -3; //preamble not found
-
-  numStart = startIdx + sizeof(preamble);
-  // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
-  for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
-    if (dest[idx] == dest[idx+1]){
-      return -4; //not manchester data
-    }
-    *hi2 = (*hi2<<1)|(*hi>>31);
-    *hi = (*hi<<1)|(*lo>>31);
-    //Then, shift in a 0 or one into low
-    if (dest[idx] && !dest[idx+1])  // 1 0
-      *lo=(*lo<<1)|1;
-    else // 0 1
-      *lo=(*lo<<1)|0;
-  }
-  return (int)startIdx;
+       if (justNoise(dest, *size)) return -1;
+
+       size_t numStart=0, size2=*size, startIdx=0; 
+       // FSK demodulator
+       *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
+       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  
+       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+       if (errChk == 0) return -3; //preamble not found
+
+       numStart = startIdx + sizeof(preamble);
+       // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
+       for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
+               if (dest[idx] == dest[idx+1]){
+                       return -4; //not manchester data
+               }
+               *hi2 = (*hi2<<1)|(*hi>>31);
+               *hi = (*hi<<1)|(*lo>>31);
+               //Then, shift in a 0 or one into low
+               if (dest[idx] && !dest[idx+1])  // 1 0
+                       *lo=(*lo<<1)|1;
+               else // 0 1
+                       *lo=(*lo<<1)|0;
+       }
+       return (int)startIdx;
 }
 
 // loop to get raw paradox waveform then FSK demodulate the TAG ID from it
@@ -688,7 +630,7 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p
        for (int word = 0; word < (bLen); word+=pLen){
                for (int bit=0; bit < pLen; bit++){
                        parityWd = (parityWd << 1) | BitStream[startIdx+word+bit];
-      BitStream[j++] = (BitStream[startIdx+word+bit]);
+                       BitStream[j++] = (BitStream[startIdx+word+bit]);
                }
                j--;
                // if parity fails then return 0
@@ -726,17 +668,17 @@ int AWIDdemodFSK(uint8_t *dest, size_t *size)
 // FSK Demod then try to locate an Farpointe Data (pyramid) ID
 int PyramiddemodFSK(uint8_t *dest, size_t *size)
 {
-  //make sure buffer has data
-  if (*size < 128*50) return -5;
+       //make sure buffer has data
+       if (*size < 128*50) return -5;
 
-  //test samples are not just noise
-  if (justNoise(dest, *size)) return -1;
+       //test samples are not just noise
+       if (justNoise(dest, *size)) return -1;
 
-  // FSK demodulator
-  *size = fskdemod(dest, *size, 50, 1, 10, 8);  // fsk2a RF/50 
-  if (*size < 128) return -2;  //did we get a good demod?
+       // FSK demodulator
+       *size = fskdemod(dest, *size, 50, 1, 10, 8);  // fsk2a RF/50 
+       if (*size < 128) return -2;  //did we get a good demod?
 
-  uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
+       uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
        size_t startIdx = 0;
        uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
        if (errChk == 0) return -4; //preamble not found
@@ -744,187 +686,343 @@ int PyramiddemodFSK(uint8_t *dest, size_t *size)
        return (int)startIdx;
 }
 
+
+uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, int high, int low)
+{
+       uint16_t allPeaks=1;
+       uint16_t cntPeaks=0;
+       size_t loopEnd = 572;
+       if (loopEnd > size) loopEnd = size;
+       for (size_t i=60; i<loopEnd; i++){
+               if (dest[i]>low && dest[i]<high) 
+                       allPeaks=0;
+               else
+                       cntPeaks++;
+       }
+       if (allPeaks == 0){
+               if (cntPeaks > 300) return 1;
+       }
+       return allPeaks;
+}
+
+// by marshmellow
+// to help detect clocks on heavily clipped samples
+// based on counts between zero crossings
+int DetectStrongAskClock(uint8_t dest[], size_t size)
+{
+       int clk[]={0,8,16,32,40,50,64,100,128};
+       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 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];
+       }
+       return -1;
+}
+
 // by marshmellow
 // not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)
 // maybe somehow adjust peak trimming value based on samples to fix?
-int DetectASKClock(uint8_t dest[], size_t size, int clock)
+// 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<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);
-  
-  int ii;
-  int clkCnt;
-  int tol = 0;
-  int bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
-  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;
-    }
-    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) return clk[clkCnt];
-        //if we found errors see if it is lowest so far and save it as best run
-        if(errCnt<bestErr[clkCnt]) bestErr[clkCnt]=errCnt;
-      }
-    }
-  }
-  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;
-      }
-    }
-  }
-  return clk[best];
+       size_t i=1;
+       uint8_t clk[]={255,8,16,32,40,50,64,100,128,255};
+       uint8_t loopCnt = 255;  //don't need to loop through entire array...
+       if (size==0) return -1;
+       if (size <= loopCnt) loopCnt = size-1; //not enough samples
+
+       //if we already have a valid clock
+       uint8_t clockFnd=0;
+       for (;i<9;++i)
+               if (clk[i] == *clock) clockFnd=i;
+               //clock found but continue to find best startpos
+
+       //get high and low peak
+       int peak, low;
+       if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return -1;
+       
+       //test for large clean peaks
+       if (DetectCleanAskWave(dest, size, peak, low)==1){
+               int ans = DetectStrongAskClock(dest, size);
+               for (i=8; i>1; 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]
+                       }
+               }
+       }
+       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;
+       //test each valid clock from smallest to greatest to see which lines up
+       uint8_t clkEnd=9;
+       if (clockFnd>0) clkEnd=clockFnd+1;
+       else clockFnd=1;
+
+       for(clkCnt=clockFnd; clkCnt < clkEnd; clkCnt++){
+               if (clk[clkCnt] == 32){
+                       tol=1;
+               }else{
+                       tol=0;
+               }
+               //if no errors allowed - keep start within the first clock
+               if (!maxErr && size > clk[clkCnt]*3 + tol) loopCnt=clk[clkCnt]*2;
+               bestErr[clkCnt]=1000;
+               //try lining up the peaks by moving starting point (try first few clocks)
+               for (ii=0; ii < loopCnt-clk[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
+                       //  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 #peaks vs no peaks(or errors)
-int DetectpskNRZClock(uint8_t dest[], size_t size, int clock)
+//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)
 {
-       int i=0;
-       int clk[]={16,32,40,50,64,100,128,256};
-       int loopCnt = 2048;  //don't need to loop through entire array...
+       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
-       for (; i < 7; ++i)
+       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};
+       fc = countFC(dest, size, 0);
+       if (fc!=2 && fc!=4 && fc!=8) return -1;
+       //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)
+{
+       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;
+
+       //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);
+       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 errCnt=0;
-       int bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000};
-       int peaksdet[]={0,0,0,0,0,0,0,0};
-       //test each valid clock from smallest to greatest to see which lines up
-       for(clkCnt=0; clkCnt < 7; ++clkCnt){
-               if (clk[clkCnt] <= 32){
-                       tol=1;
-               }else{
-                       tol=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){
+                       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)){
-                               errCnt=0;
                                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++;
-                                       }else if(dest[ii+(i*clk[clkCnt])-tol]>=peak || dest[ii+(i*clk[clkCnt])-tol]<=low){
-                                               peakcnt++;
-                                       }else if(dest[ii+(i*clk[clkCnt])+tol]>=peak || dest[ii+(i*clk[clkCnt])+tol]<=low){
-                                               peakcnt++;
-                                       }else{  //error no peak detected
-                                               errCnt++;
                                        }
                                }
                                if(peakcnt>peaksdet[clkCnt]) {
                                        peaksdet[clkCnt]=peakcnt;
-                                       bestErr[clkCnt]=errCnt;
                                }
                        }
                }
        }
-       int iii=0;
-       int best=0;
-       //int ratio2;  //debug
-       int ratio;
-       //int bits;
-       for (iii=0; iii < 7; ++iii){
-               ratio=1000;
-               //ratio2=1000;  //debug
-               //bits=size/clk[iii];  //debug
-               if (peaksdet[iii] > 0){
-                       ratio=bestErr[iii]/peaksdet[iii];
-                       if (((bestErr[best]/peaksdet[best]) > (ratio)+1)){
-                               best = iii;
-                       }
-                       //ratio2=bits/peaksdet[iii]; //debug
+       int iii=7;
+       uint8_t 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, ratio: %d, bits: %d, peakbitr: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best],ratio, bits,ratio2);
+               //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]);
        }
        return clk[best];
 }
 
-// by marshmellow (attempt to get rid of high immediately after a low)
-void pskCleanWave(uint8_t *BitStream, size_t size)
-{
-       int i;
-       int gap = 4;
-       int newLow=0;
-       int newHigh=0;
-       int high, low;
-       getHiLo(BitStream, size, &high, &low, 80, 90);
-       for (i=0; i < size; ++i){
-               if (newLow == 1){
-                       if (BitStream[i]>low){
-                               BitStream[i]=low+8;
-                               gap--;
-                       }
-                       if (gap == 0){
-                               newLow=0;
-                               gap=4;
-                       }
-               }else if (newHigh == 1){
-                       if (BitStream[i]<high){
-                               BitStream[i]=high-8;
-                               gap--;
-                       }
-                       if (gap == 0){
-                               newHigh=0;
-                               gap=4;
-                       }
-               }
-               if (BitStream[i] <= low) newLow=1;
-               if (BitStream[i] >= high) newHigh=1;
-       }
-       return;
-}
-
 // by marshmellow
 // convert psk1 demod to psk2 demod
 // only transition waves are 1s
@@ -933,7 +1031,9 @@ void psk1TOpsk2(uint8_t *BitStream, size_t size)
        size_t i=1;
        uint8_t lastBit=BitStream[0];
        for (; i<size; i++){
-               if (lastBit!=BitStream[i]){
+               if (BitStream[i]==7){
+                       //ignore errors
+               } else if (lastBit!=BitStream[i]){
                        lastBit=BitStream[i];
                        BitStream[i]=1;
                } else {
@@ -943,6 +1043,21 @@ void psk1TOpsk2(uint8_t *BitStream, size_t size)
        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)
@@ -1007,324 +1122,395 @@ int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert)
        return 1;
 }
 
-// by marshmellow - demodulate PSK1 wave or NRZ wave (both similar enough)
+// by marshmellow - demodulate NRZ wave (both similar enough)
 // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
-int pskNRZrawDemod(uint8_t *dest, size_t *size, int *clk, int *invert)
+// 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;
-       pskCleanWave(dest,*size);
-       int clk2 = DetectpskNRZClock(dest, *size, *clk);
-       *clk=clk2;
-       uint32_t i;
-       int high, low, ans;
-       ans = getHiLo(dest, 1260, &high, &low, 75, 80); //25% fuzz on high 20% fuzz on low
-       if (ans<1) return -2; //just noise
-       uint32_t gLen = *size;
-       //PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
+       *clk = DetectNRZClock(dest, *size, *clk);
+       if (*clk==0) return -2;
+       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
-       if (*clk==32) tol = 2;    //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;
-       uint8_t errCnt =0;
-       uint32_t bestStart = *size;
-       uint32_t maxErr = (*size/1000);
-       uint32_t bestErrCnt = maxErr;
-       uint8_t curBit=0;
-       uint8_t bitHigh=0;
-       uint8_t ignorewin=*clk/8;
-       //PrintAndLog("DEBUG - lastbit - %d",lastBit);
+       uint16_t peakCnt=0;
+       uint8_t ignoreWindow=4;
+       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)){
+                       if (dest[iii]>=high) firstPeakHigh=1;
+                       else firstPeakHigh=0;
                        lastBit=iii-*clk;
+                       peakCnt=0;
+                       errCnt=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;
-                                       ignorewin=*clk/8;
-                                       bitnum++;
-                               //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;
-                                       ignorewin=*clk/8;
-                                       bitnum++;
+                               // 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) {
-                                       if (ignorewin==0){
+                               } else if (dest[i] < high && dest[i] > low){
+                                       if (ignoreCnt==0){
                                                bitHigh=0;
-                                       }else ignorewin--;
-                                                                               //if we are past a clock point
-                                       if (i >= lastBit+*clk+tol){ //clock val
-                                               lastBit+=*clk;
-                                               bitnum++;
+                                               if (errBitHigh==1) errCnt++;
+                                               errBitHigh=0;
+                                       } else {
+                                               ignoreCnt--;
                                        }
-                               //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...
-                                       errCnt++;
+                                       errBitHigh=1;
                                }
-                               if (bitnum>=1000) break;
+                               if (((i-iii) / *clk)>=MaxBits) break;
                        }
                        //we got more than 64 good bits and not all errors
-                       if ((bitnum > (64+errCnt)) && (errCnt < (maxErr))) {
+                       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
+                               if (!errCnt || peakCnt > bestPeakCnt){
+                                       bestFirstPeakHigh=firstPeakHigh;
                                        bestErrCnt = errCnt;
-                                       bestStart = iii;
+                                       bestPeakCnt = peakCnt;
+                                       bestPeakStart = iii;
+                                       if (!errCnt) break;  //great read - finish
                                }
                        }
                }
        }
-       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 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;
-                               ignorewin=*clk/8;
-                               bitnum++;
-                       //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;
-                               ignorewin=*clk/8;
-                               bitnum++;
-                       //else if no bars found
-                       }else if(dest[i]<high && dest[i]>low) {
-                               if (ignorewin==0){
-                                       bitHigh=0;
-                               }else ignorewin--;
-                               //if we are past a clock point
-                               if (i>=lastBit+*clk+tol){ //clock val
-                                       lastBit+=*clk;
-                                       dest[bitnum]=curBit;
-                                       bitnum++;
+       //PrintAndLog("DEBUG: bestErrCnt: %d, maxErr: %d, bestStart: %d, bestPeakCnt: %d, bestPeakStart: %d",bestErrCnt,maxErr,bestStart,bestPeakCnt,bestPeakStart);
+       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...
-                               bitHigh=1;
-                               dest[bitnum]=77;
-                               bitnum++;
-                               errCnt++;
+                               errBitHigh=0;
+                       } else {
+                               ignoreCnt--;
                        }
-                       if (bitnum >=1000) break;
+               } else if ((dest[i] >= high || dest[i] <= low) && (bitHigh == 0)) {
+                       //error bar found no clock...
+                       errBitHigh=1;
                }
-               *size=bitnum;
-       } else{
-               *size=bitnum;
-               *clk=bestStart;
-               return -1;
+               if (bitnum >= MaxBits) break;
        }
-
-       if (bitnum>16){
-               *size=bitnum;
-       } else return -1;
-       return errCnt;
+       *size = bitnum;
+       return bestErrCnt;
 }
 
 //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;
-
-  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];
+       uint8_t clk[] = {8,16,32,40,50,64,100,128,0};
+       uint16_t rfLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+       uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+       uint8_t rfLensFnd = 0;
+       uint8_t lastFCcnt = 0;
+       uint16_t fcCounter = 0;
+       uint16_t rfCounter = 0;
+       uint8_t firstBitFnd = 0;
+       size_t i;
+       if (size == 0) return 0;
+
+       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++){
+               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;
+               }
+               fcCounter=0;
+       }
+       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
-uint16_t countFC(uint8_t *BitStream, size_t size)
+//mainly used for FSK field clock detection
+uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj)
 {
-  uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0};
-  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;
-  
-  // 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];
-  }
-  // 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;
+       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;
+       uint8_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 (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){
+                                       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];
+       }
+
+       // 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]);
+       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)
+{
+       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 = 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;
+       int avgWaveVal=0, lastAvgWaveVal=0;
+       //find first phase shift
+       for (i=0; i<loopCnt; i++){
+               if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
+                       waveEnd = i+1;
+                       //PrintAndLog("DEBUG: waveEnd: %d",waveEnd);
+                       waveLenCnt = waveEnd-waveStart;
+                       if (waveLenCnt > fc && waveStart > fc){ //not first peak and is a large wave 
+                               lastAvgWaveVal = avgWaveVal/(waveLenCnt);
+                               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
+                               break;
+                       } 
+                       waveStart = i+1;
+                       avgWaveVal = 0;
+               }
+               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;
+       size_t numBits=0;
+       //set skipped bits
+       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++){
+               //top edge of wave = start of new wave 
+               if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
+                       if (waveStart == 0) {
+                               waveStart = i+1;
+                               waveLenCnt = 0;
+                               avgWaveVal = dest[i+1];
+                       } else { //waveEnd
+                               waveEnd = i+1;
+                               waveLenCnt = waveEnd-waveStart;
+                               lastAvgWaveVal = avgWaveVal/waveLenCnt;
+                               if (waveLenCnt > fc){  
+                                       //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);
+                                       //this wave is a phase shift
+                                       //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc);
+                                       if (i+1 >= lastClkBit + *clock - tol){ //should be a clock bit
+                                               curPhase ^= 1;
+                                               dest[numBits++] = curPhase;
+                                               lastClkBit += *clock;
+                                       } else if (i < lastClkBit+10+fc){
+                                               //noise after a phase shift - ignore
+                                       } else { //phase shift before supposed to based on clock
+                                               errCnt++;
+                                               dest[numBits++] = 7;
+                                       }
+                               } else if (i+1 > lastClkBit + *clock + tol + fc){
+                                       lastClkBit += *clock; //no phase shift but clock bit
+                                       dest[numBits++] = curPhase;
+                               }
+                               avgWaveVal = 0;
+                               waveStart = i+1;
+                       }
+               }
+               avgWaveVal += dest[i+1];
+       }
+       *size = numBits;
+       return errCnt;
 }
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