Merge remote-tracking branch 'upstream/master'

[proxmark3-svn] / common / lfdemod.c

diff --git a/common/lfdemod.c b/common/lfdemod.c
index 062818ef45a62f1dfda102035b8e4fea39f9a545..47e63ef6ec64515b7ff190bbc9cce0a79c99f074 100644 (file)
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -5,116 +5,162 @@
 // at your option, any later version. See the LICENSE.txt file for the text of
 // the license.
 //-----------------------------------------------------------------------------
 // at your option, any later version. See the LICENSE.txt file for the text of
 // the license.
 //-----------------------------------------------------------------------------

-// Low frequency commands
+// Low frequency demod/decode commands

 //-----------------------------------------------------------------------------
 
 #include <stdlib.h>
 #include <string.h>
 #include "lfdemod.h"
 
 //-----------------------------------------------------------------------------
 
 #include <stdlib.h>
 #include <string.h>
 #include "lfdemod.h"
 

+
+uint8_t justNoise(uint8_t *BitStream, size_t size)
+{
+       static const uint8_t THRESHOLD = 123;
+       //test samples are not just noise
+       uint8_t justNoise1 = 1;
+       for(size_t idx=0; idx < size && justNoise1 ;idx++){
+               justNoise1 = BitStream[idx] < THRESHOLD;
+       }
+       return justNoise1;
+}
+

 //by marshmellow
 //by marshmellow

-//takes 1s and 0s and searches for EM410x format - output EM ID
-uint64_t Em410xDecode(uint8_t *BitStream, size_t size)
-{
-       //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[10]>1){  //allow only 1s and 0s
-               // PrintAndLog("no data found");
-               return 0;
+//get high and low 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++){
+               if (BitStream[i] > *high) *high = BitStream[i];
+               if (BitStream[i] < *low) *low = BitStream[i];

        }
        }

-       uint8_t parityTest=0;
-       // 111111111 bit pattern represent start of frame
-       uint8_t frame_marker_mask[] = {1,1,1,1,1,1,1,1,1};
-       uint32_t idx = 0;
-       uint32_t ii=0;
-       uint8_t resetCnt = 0;
-       while( (idx + 64) < size) {
- restart:
-               // search for a start of frame marker
-               if ( memcmp(BitStream+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
-               { // frame marker found
-                       idx+=9;
-                       for (i=0; i<10;i++){
-                               for(ii=0; ii<5; ++ii){
-                                       parityTest ^= BitStream[(i*5)+ii+idx];
-                               }
-                               if (!parityTest){
-                                       parityTest=0;
-                                       for (ii=0; ii<4;++ii){
-                                               lo=(lo<<1LL)|(BitStream[(i*5)+ii+idx]);
-                                       }
-                                       //PrintAndLog("DEBUG: EM parity passed parity val: %d, i:%d, ii:%d,idx:%d, Buffer: %d%d%d%d%d,lo: %d",parityTest,i,ii,idx,BitStream[idx+ii+(i*5)-5],BitStream[idx+ii+(i*5)-4],BitStream[idx+ii+(i*5)-3],BitStream[idx+ii+(i*5)-2],BitStream[idx+ii+(i*5)-1],lo);
-                               }else {//parity failed
-                                       //PrintAndLog("DEBUG: EM parity failed parity val: %d, i:%d, ii:%d,idx:%d, Buffer: %d%d%d%d%d",parityTest,i,ii,idx,BitStream[idx+ii+(i*5)-5],BitStream[idx+ii+(i*5)-4],BitStream[idx+ii+(i*5)-3],BitStream[idx+ii+(i*5)-2],BitStream[idx+ii+(i*5)-1]);
-                                       parityTest=0;
-                                       idx-=8;
-                                       if (resetCnt>5)return 0; //try 5 times
-                                       resetCnt++;
-                                       goto restart;//continue;
-                               }
-                       }
-                       //skip last 5 bit parity test for simplicity.
-                       return lo;
-               }else{
-                       idx++;
-               }
+       if (*high < 123) return -1; // just noise
+       *high = (int)(((*high-128)*(((float)fuzzHi)/100))+128);
+       *low = (int)(((*low-128)*(((float)fuzzLo)/100))+128);
+       return 1;
+}
+
+// by marshmellow
+// pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType
+// returns 1 if passed
+uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType)
+{
+       uint8_t ans = 0;
+       for (uint8_t i = 0; i < bitLen; i++){
+               ans ^= ((bits >> i) & 1);

        }
        }

-       return 0;
+       //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType);
+       return (ans == pType);

 }
 
 //by marshmellow
 }
 
 //by marshmellow

-//takes 2 arguments - clock and invert both as integers
+//search for given preamble in given BitStream and return 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;
+}
+
+
+//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)
+{
+  //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;
+}
+
+//by marshmellow
+//takes 3 arguments - clock, invert, maxErr as integers

 //attempts to demodulate ask while decoding manchester
 //prints binary found and saves in graphbuffer for further commands
 //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 i;

-       int high = 0, low = 255;
-       *clk=DetectASKClock(BinStream, *size, *clk); //clock default
-
-       if (*clk<8) *clk =64;
-       if (*clk<32) *clk=32;
+       //int clk2=*clk;
+       int start = DetectASKClock(BinStream, *size, clk, 20); //clock default
+       if (*clk==0) return -3;
+       if (start < 0) return -3;
+       // if autodetected too low then adjust  //MAY NEED ADJUSTMENT
+       //if (clk2==0 && *clk<8) *clk =64;
+       //if (clk2==0 && *clk<32) *clk=32;

        if (*invert != 0 && *invert != 1) *invert=0;
        uint32_t initLoopMax = 200;
        if (initLoopMax > *size) initLoopMax=*size;
        // Detect high and lows
        if (*invert != 0 && *invert != 1) *invert=0;
        uint32_t initLoopMax = 200;
        if (initLoopMax > *size) initLoopMax=*size;
        // Detect high and lows

-       for (i = 0; i < initLoopMax; ++i) //200 samples should be enough to find high and low values
-       {
-               if (BinStream[i] > high)
-                       high = BinStream[i];
-               else if (BinStream[i] < low)
-                       low = BinStream[i];
-       }
-       if ((high < 129) ){  //throw away static (anything < 1 graph)
-               //PrintAndLog("no data found");
-               return -2;
-       }
-       //25% fuzz in case highs and lows aren't clipped [marshmellow]
-       high=(int)(((high-128)*.75)+128);
-       low= (int)(((low-128)*.75)+128);
+       // 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);
+       // 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
        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
+       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;
        int iii = 0;
        uint32_t gLen = *size;
        if (gLen > 3000) gLen=3000;
        uint8_t errCnt =0;

+       uint16_t MaxBits = 500;

        uint32_t bestStart = *size;
        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
+       int bestErrCnt = maxErr+1;
+       // PrintAndLog("DEBUG - lastbit - %d",lastBit);
+       // loop to find first wave that works

        for (iii=0; iii < gLen; ++iii){
                if ((BinStream[iii] >= high) || (BinStream[iii] <= low)){
                        lastBit=iii-*clk;
                        errCnt=0;
        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
+                       // 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;
                        for (i = iii; i < *size; ++i) {
                                if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){
                                        lastBit+=*clk;


@@ -134,10 +180,10 @@ int askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert)
                                                if (errCnt>(maxErr)) break;  //allow 1 error for every 1000 samples else start over
                                        }
                                }
                                                if (errCnt>(maxErr)) break;  //allow 1 error for every 1000 samples else start over
                                        }
                                }

-                               if ((i-iii) >(400 * *clk)) break; //got plenty of bits
+                               if ((i-iii) >(MaxBits * *clk)) break; //got plenty of bits

                        }
                        //we got more than 64 good bits and not all errors
                        }
                        //we got more than 64 good bits and not all errors

-                       if ((((i-iii)/ *clk) > (64+errCnt)) && (errCnt<maxErr)) {
+                       if ((((i-iii)/ *clk) > (64)) && (errCnt<=maxErr)) {

                                //possible good read
                                if (errCnt==0){
                                        bestStart=iii;
                                //possible good read
                                if (errCnt==0){
                                        bestStart=iii;


@@ -151,7 +197,7 @@ int askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert)
                        }
                }
        }
                        }
                }
        }

-       if (bestErrCnt<maxErr){
+       if (bestErrCnt<=maxErr){

                //best run is good enough set to best run and set overwrite BinStream
                iii=bestStart;
                lastBit = bestStart - *clk;
                //best run is good enough set to best run and set overwrite BinStream
                iii=bestStart;
                lastBit = bestStart - *clk;


@@ -181,7 +227,7 @@ int askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert)
                                        lastBit+=*clk;//skip over error
                                }
                        }
                                        lastBit+=*clk;//skip over error
                                }
                        }

-                       if (bitnum >=400) break;
+                       if (bitnum >=MaxBits) break;

                }
                *size=bitnum;
        } else{
                }
                *size=bitnum;
        } else{


@@ -192,17 +238,35 @@ int askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert)
        return bestErrCnt;
 }
 
        return bestErrCnt;
 }
 

+//by marshmellow
+//encode binary data into binary manchester 
+int ManchesterEncode(uint8_t *BitStream, size_t size)
+{
+       size_t modIdx=20000, i=0;
+       if (size>modIdx) return -1;
+       for (size_t idx=0; idx < size; idx++){
+               BitStream[idx+modIdx++] = BitStream[idx];
+               BitStream[idx+modIdx++] = BitStream[idx]^1;
+       }
+       for (; i<(size*2); i++){
+               BitStream[i] = BitStream[i+20000];
+       }
+       return i;
+}
+

 //by marshmellow
 //take 10 and 01 and manchester decode
 //run through 2 times and take least errCnt
 int manrawdecode(uint8_t * BitStream, size_t *size)
 {
 //by marshmellow
 //take 10 and 01 and manchester decode
 //run through 2 times and take least errCnt
 int manrawdecode(uint8_t * BitStream, size_t *size)
 {

-       int bitnum=0;
-       int errCnt =0;
-       int i=1;
-       int bestErr = 1000;
-       int bestRun = 0;
-       int ii=1;
+       uint16_t bitnum=0;
+       uint16_t MaxBits = 500;
+       uint16_t errCnt = 0;
+       size_t i=1;
+       uint16_t bestErr = 1000;
+       uint16_t bestRun = 0;
+       size_t ii=1;
+       if (size == 0) return -1;

        for (ii=1;ii<3;++ii){
                i=1;
                for (i=i+ii;i<*size-2;i+=2){
        for (ii=1;ii<3;++ii){
                i=1;
                for (i=i+ii;i<*size-2;i+=2){


@@ -211,7 +275,7 @@ int manrawdecode(uint8_t * BitStream, size_t *size)
                        } else {
                                errCnt++;
                        }
                        } else {
                                errCnt++;
                        }

-                       if(bitnum>300) break;
+                       if(bitnum>MaxBits) break;

                }
                if (bestErr>errCnt){
                        bestErr=errCnt;
                }
                if (bestErr>errCnt){
                        bestErr=errCnt;


@@ -223,7 +287,7 @@ int manrawdecode(uint8_t * BitStream, size_t *size)
        if (errCnt<20){
                ii=bestRun;
                i=1;
        if (errCnt<20){
                ii=bestRun;
                i=1;

-               for (i=i+ii;i < *size-2;i+=2){
+               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){
                        if(BitStream[i] == 1 && (BitStream[i+1] == 0)){
                                BitStream[bitnum++]=0;
                        } else if((BitStream[i] == 0) && BitStream[i+1] == 1){


@@ -232,118 +296,120 @@ int manrawdecode(uint8_t * BitStream, size_t *size)
                                BitStream[bitnum++]=77;
                                //errCnt++;
                        }
                                BitStream[bitnum++]=77;
                                //errCnt++;
                        }

-                       if(bitnum>300) break;
+                       if(bitnum>MaxBits) break;

                }
                *size=bitnum;
        }
        return errCnt;
 }
 
                }
                *size=bitnum;
        }
        return errCnt;
 }
 

-

 //by marshmellow
 //take 01 or 10 = 0 and 11 or 00 = 1
 //by marshmellow
 //take 01 or 10 = 0 and 11 or 00 = 1

-int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset)
+int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert)

 {
 {

-       uint8_t bitnum=0;
+       uint16_t bitnum=0;

        uint32_t errCnt =0;
        uint32_t errCnt =0;

-       uint32_t i=1;
+       uint32_t i;
+       uint16_t MaxBits=500;

        i=offset;
        i=offset;

-       for (;i<*size-2;i+=2){
+       if (size == 0) return -1;
+       for (;i<*size-2; i+=2){

                if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){
                if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){

-                       BitStream[bitnum++]=1;
+                       BitStream[bitnum++]=1^invert;

                } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){
                } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){

-                       BitStream[bitnum++]=0;
+                       BitStream[bitnum++]=invert;

                } else {
                        BitStream[bitnum++]=77;
                        errCnt++;
                }
                } else {
                        BitStream[bitnum++]=77;
                        errCnt++;
                }

-               if(bitnum>250) break;
+               if(bitnum>MaxBits) break;

        }
        *size=bitnum;
        return errCnt;
 }
 
 //by marshmellow
        }
        *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(int i = 1; i<size; i++){
+               if (BitStream[i]-BitStream[i-1]>=30) //large jump up
+                       shift=127;
+               else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down
+                       shift=-127;
+
+               shiftedVal=BitStream[i]+shift;
+
+               if (shiftedVal>255) 
+                       shiftedVal=255;
+               else if (shiftedVal<0) 
+                       shiftedVal=0;
+               BitStream[i-1] = shiftedVal;
+       }
+       return;
+}
+
+//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
 //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;
 {
        uint32_t i;

-       // int invert=0;  //invert default
-       int high = 0, low = 255;
-       *clk=DetectASKClock(BinStream, *size, *clk); //clock default
-       uint8_t BitStream[502] = {0};
-
-       if (*clk<8) *clk =64;
-       if (*clk<32) *clk=32;
+       if (*size==0) return -1;
+       int start = DetectASKClock(BinStream, *size, clk, 20); //clock default
+       if (*clk==0) return -1;
+       if (start<0) return -1;

        if (*invert != 0 && *invert != 1) *invert =0;
        uint32_t initLoopMax = 200;
        if (initLoopMax > *size) initLoopMax=*size;
        // Detect high and lows
        if (*invert != 0 && *invert != 1) *invert =0;
        uint32_t initLoopMax = 200;
        if (initLoopMax > *size) initLoopMax=*size;
        // Detect high and lows

-       for (i = 0; i < initLoopMax; ++i) //200 samples should be plenty to find high and low values
-       {
-               if (BinStream[i] > high)
-                       high = BinStream[i];
-               else if (BinStream[i] < low)
-                       low = BinStream[i];
-       }
-       if ((high < 129)){  //throw away static  high has to be more than 0 on graph. 
-                                                                                                       //noise <= -10 here
-               //   PrintAndLog("no data found");
-               return -2;
-       }

        //25% fuzz in case highs and lows aren't clipped [marshmellow]
        //25% fuzz in case highs and lows aren't clipped [marshmellow]

-       high=(int)(((high-128)*.75)+128);
-       low= (int)(((low-128)*.75)+128);
+       int high, low, ans;
+       if (amp==1) askAmp(BinStream, *size);
+       ans = getHiLo(BinStream, initLoopMax, &high, &low, 75, 75);
+       if (ans<1) return -1; //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
 
        //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
+       if (*clk == 32) tol=0;    //clock tolerance may not be needed anymore currently set to

                                  //  + or - 1 but could be increased for poor waves or removed entirely
        uint32_t iii = 0;
        uint32_t gLen = *size;
        if (gLen > 500) gLen=500;
        uint8_t errCnt =0;
        uint32_t bestStart = *size;
                                  //  + 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 bestErrCnt = maxErr; //(*size/1000);

        uint8_t midBit=0;
        uint8_t midBit=0;

+       uint16_t MaxBits=1000;

        //PrintAndLog("DEBUG - lastbit - %d",lastBit);
        //loop to find first wave that works
        //PrintAndLog("DEBUG - lastbit - %d",lastBit);
        //loop to find first wave that works

-       for (iii=0; iii < gLen; ++iii){
+       for (iii=start; iii < gLen; ++iii){

                if ((BinStream[iii]>=high) || (BinStream[iii]<=low)){
                        lastBit=iii-*clk;
                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;
                        //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;

-                                       BitStream[bitnum] = *invert;
-                                       bitnum++;

                                        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) && ((i-lastBit)>(*clk-tol))){
                                        //low found and we are expecting a bar
                                        lastBit+=*clk;

-                                       BitStream[bitnum] = 1- *invert;
-                                       bitnum++;

                                        midBit=0;
                                } else if ((BinStream[i]<=low) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
                                        //mid bar?
                                        midBit=1;
                                        midBit=0;
                                } else if ((BinStream[i]<=low) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
                                        //mid bar?
                                        midBit=1;

-                                       BitStream[bitnum]= 1- *invert;
-                                       bitnum++;

                                } else if ((BinStream[i]>=high) && (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;

-                                       BitStream[bitnum]= *invert;
-                                       bitnum++;

                                } else if ((i-lastBit)>((*clk/2)+tol) && (midBit==0)){
                                        //no mid bar found
                                        midBit=1;
                                } else if ((i-lastBit)>((*clk/2)+tol) && (midBit==0)){
                                        //no mid bar found
                                        midBit=1;

-                                       BitStream[bitnum]= BitStream[bitnum-1];
-                                       bitnum++;

                                } else {
                                        //mid value found or no bar supposed to be here
 
                                } else {
                                        //mid value found or no bar supposed to be here
 


@@ -351,45 +417,88 @@ int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert)
                                                //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);
                                                //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){
-                                                       BitStream[bitnum]=77;
-                                                       bitnum++;
-                                               }

 
                                                errCnt++;
                                                lastBit+=*clk;//skip over until hit too many errors
 
                                                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;
-                                                       bitnum=0;//start over
+                                               if (errCnt > maxErr){  
+                                                       //errCnt=0;

                                                        break;
                                                }
                                        }
                                }
                                                        break;
                                                }
                                        }
                                }

-                               if (bitnum>500) break;
+                               if ((i-iii)>(MaxBits * *clk)) break; //got enough bits

                        }
                        //we got more than 64 good bits and not all errors
                        }
                        //we got more than 64 good bits and not all errors

-                       if ((bitnum > (64+errCnt)) && (errCnt<(*size/1000))) {
+                       if ((((i-iii)/ *clk) > (64)) && (errCnt<=maxErr)) {

                                //possible good read
                                //possible good read

-                               if (errCnt==0) break;  //great read - finish
-                               if (bestStart == iii) break;  //if current run == bestErrCnt run (after exhausted testing) then finish
+                               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 (errCnt<bestErrCnt){  //set this as new best run
                                        bestErrCnt=errCnt;
                                        bestStart = iii;
                                }
                        }
                }

-               if (iii>=gLen){ //exhausted test
-                       //if there was a ok test go back to that one and re-run the best run (then dump after that run)
-                       if (bestErrCnt < (*size/1000)) iii=bestStart;
-               }

        }
        }

-       if (bitnum>16){
-               for (i=0; i < bitnum; ++i){
-                       BinStream[i]=BitStream[i];
+       if (bestErrCnt<=maxErr){
+               //best run is good enough - set to best run and overwrite BinStream
+               iii = bestStart;
+               lastBit = bestStart - *clk;
+               bitnum=0;
+               for (i = iii; i < *size; ++i) {
+                       if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){
+                               lastBit += *clk;
+                               BinStream[bitnum] = *invert;
+                               bitnum++;
+                               midBit=0;
+                       } else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){
+                               //low found and we are expecting a bar
+                               lastBit+=*clk;
+                               BinStream[bitnum] = 1 - *invert;
+                               bitnum++;
+                               midBit=0;
+                       } else if ((BinStream[i]<=low) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
+                               //mid bar?
+                               midBit=1;
+                               BinStream[bitnum] = 1 - *invert;
+                               bitnum++;
+                       } else if ((BinStream[i]>=high) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
+                               //mid bar?
+                               midBit=1;
+                               BinStream[bitnum] = *invert;
+                               bitnum++;
+                       } else if ((i-lastBit)>((*clk/2)+tol) && (midBit==0)){
+                               //no mid bar found
+                               midBit=1;
+                               if (bitnum!=0) BinStream[bitnum] = BinStream[bitnum-1];
+                               bitnum++;
+                               
+                       } else {
+                               //mid value found or no bar supposed to be here
+                               if ((i-lastBit)>(*clk+tol)){
+                                       //should have hit a high or low based on clock!!
+
+                                       //debug
+                                       //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
+                                       if (bitnum > 0){
+                                               BinStream[bitnum]=77;
+                                               bitnum++;
+                                       }
+                                       lastBit+=*clk;//skip over error
+                               }
+                       }
+                       if (bitnum >= MaxBits) break;

                }
                *size=bitnum;
                }
                *size=bitnum;

-       } else return -1;
-       return errCnt;
+       } else{
+               *invert=bestStart;
+               *clk=iii;
+               return -1;
+       }
+       return bestErrCnt;

 }
 //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)
 }
 //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)


@@ -487,56 +596,69 @@ int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t
        size = aggregate_bits(dest, size, rfLen, 192, invert, fchigh, fclow);
        return size;
 }
        size = aggregate_bits(dest, size, rfLen, 192, invert, fchigh, fclow);
        return size;
 }

+

 // loop to get raw HID waveform then FSK demodulate the TAG ID from it
 // 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)
+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

 
 

-       size_t idx=0; //, found=0; //size=0,
+  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
+int ParadoxdemodFSK(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
        // FSK demodulator

-       size = fskdemod(dest, size,50,0,10,8);
-
-       // final loop, go over previously decoded manchester data and decode into usable tag ID
-       // 111000 bit pattern represent start of frame, 01 pattern represents a 1 and 10 represents a 0
-       uint8_t frame_marker_mask[] = {1,1,1,0,0,0};
-       int numshifts = 0;
-       idx = 0;
-       //one scan
-       while( idx + sizeof(frame_marker_mask) < size) {
-               // search for a start of frame marker
-               if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
-               { // frame marker found
-                       idx+=sizeof(frame_marker_mask);
-                       while(dest[idx] != dest[idx+1] && idx < size-2)
-                       {
-                               // Keep going until next frame marker (or error)
-                               // Shift in a bit. Start by shifting high registers
-                               *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)|0;
-                               else // 0 1
-                                       *lo=(*lo<<1)|1;
-                               numshifts++;
-                               idx += 2;
-                       }
-                       // Hopefully, we read a tag and  hit upon the next frame marker
-                       if(idx + sizeof(frame_marker_mask) < size)
-                       {
-                               if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
-                               {
-                                       //good return
-                                       return idx;
-                               }
-                       }
-                       // reset
-                       *hi2 = *hi = *lo = 0;
-                       numshifts = 0;
-               }else   {
-                       idx++;
-               }
+       *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
+       if (*size < 96) return -2;
+
+       // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
+       uint8_t preamble[] = {0,0,0,0,1,1,1,1};
+
+       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 -1;
+       return (int)startIdx;

 }
 
 uint32_t bytebits_to_byte(uint8_t* src, size_t numbits)
 }
 
 uint32_t bytebits_to_byte(uint8_t* src, size_t numbits)


@@ -552,20 +674,12 @@ uint32_t bytebits_to_byte(uint8_t* src, size_t numbits)
 
 int IOdemodFSK(uint8_t *dest, size_t size)
 {
 
 int IOdemodFSK(uint8_t *dest, size_t size)
 {

-       static const uint8_t THRESHOLD = 129;
-       uint32_t idx=0;
+       if (justNoise(dest, size)) return -1;

        //make sure buffer has data
        //make sure buffer has data

-       if (size < 66) return -1;
-       //test samples are not just noise
-       uint8_t justNoise = 1;
-       for(idx=0;idx< size && justNoise ;idx++){
-               justNoise = dest[idx] < THRESHOLD;
-       }
-       if(justNoise) return 0;
-
+       if (size < 66*64) return -2;

        // FSK demodulator
        // FSK demodulator

-       size = fskdemod(dest, size, 64, 1, 10, 8);  //  RF/64 and invert
-       if (size < 65) return -1;  //did we get a good demod?
+       size = fskdemod(dest, size, 64, 1, 10, 8);  // FSK2a RF/64 
+       if (size < 65) return -3;  //did we get a good demod?

        //Index map
        //0           10          20          30          40          50          60
        //|           |           |           |           |           |           |
        //Index map
        //0           10          20          30          40          50          60
        //|           |           |           |           |           |           |


@@ -575,221 +689,386 @@ int IOdemodFSK(uint8_t *dest, size_t size)
        //
        //XSF(version)facility:codeone+codetwo
        //Handle the data
        //
        //XSF(version)facility:codeone+codetwo
        //Handle the data

-       uint8_t mask[] = {0,0,0,0,0,0,0,0,0,1};
-       for( idx=0; idx < (size - 65); idx++) {
-               if ( memcmp(dest + idx, mask, sizeof(mask))==0) {
-                       //frame marker found
-                       if (!dest[idx+8] && dest[idx+17]==1 && dest[idx+26]==1 && dest[idx+35]==1 && dest[idx+44]==1 && dest[idx+53]==1){
-                               //confirmed proper separator bits found
-                               //return start position
-                               return (int) idx;
-                       }
-               }
+       size_t startIdx = 0;
+       uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,1};
+       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), &size, &startIdx);
+       if (errChk == 0) return -4; //preamble not found
+
+       if (!dest[startIdx+8] && dest[startIdx+17]==1 && dest[startIdx+26]==1 && dest[startIdx+35]==1 && dest[startIdx+44]==1 && dest[startIdx+53]==1){
+               //confirmed proper separator bits found
+               //return start position
+               return (int) startIdx;

        }
        }

-       return 0;
+       return -5;

 }
 
 // by marshmellow
 }
 
 // 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)
-{
-       int i=0;
-       int peak=0;
-       int low=255;
-       int clk[]={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
-       for (i=0; i < loopCnt; ++i){
-               if(dest[i] > peak){
-                       peak = dest[i];
-               }
-               if(dest[i] < low){
-                       low = dest[i];
+// takes a array of binary values, start position, length of bits per parity (includes parity bit),
+//   Parity Type (1 for odd 0 for even), and binary Length (length to run) 
+size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen)
+{
+       uint32_t parityWd = 0;
+       size_t j = 0, bitCnt = 0;
+       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]);

                }
                }

+               j--;
+               // if parity fails then return 0
+               if (parityTest(parityWd, pLen, pType) == 0) return -1;
+               bitCnt+=(pLen-1);
+               parityWd = 0;

        }
        }

-       peak=(int)(((peak-128)*.75)+128);
-       low= (int)(((low-128)*.75)+128);
-       int ii;
-       int clkCnt;
-       int tol = 0;
-       int bestErr[]={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 < 6; ++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/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 this is correct one - return this clock
-                               if(errCnt==0) 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;
-                       }
-               }
+       // if we got here then all the parities passed
+       //return ID start index and size
+       return bitCnt;
+}
+
+// by marshmellow
+// FSK Demod then try to locate an AWID ID
+int AWIDdemodFSK(uint8_t *dest, size_t *size)
+{
+       //make sure buffer has enough data
+       if (*size < 96*50) return -1;
+
+       if (justNoise(dest, *size)) return -2;
+
+       // FSK demodulator
+       *size = fskdemod(dest, *size, 50, 1, 10, 8);  // fsk2a RF/50 
+       if (*size < 96) return -3;  //did we get a good demod?
+
+       uint8_t preamble[] = {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
+       if (*size != 96) return -5;
+       return (int)startIdx;
+}
+
+// by marshmellow
+// 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;
+
+       //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?
+
+       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
+       if (*size != 128) return -3;
+       return (int)startIdx;
+}
+
+
+uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, int high, int low)
+{
+       uint8_t allPeaks=1;
+       uint16_t cntPeaks=0;
+       for (size_t i=20; i<255; i++){
+               if (dest[i]>low && dest[i]<high) 
+                       allPeaks=0;
+               else
+                       cntPeaks++;

        }
        }

-       int iii=0;
-       int best=0;
-       for (iii=0; iii<7;++iii){
-               if (bestErr[iii]<bestErr[best]){
-                       //                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 (allPeaks==0){
+               if (cntPeaks>190) return 1;

        }
        }

-       return clk[best];
+       return allPeaks;
+}
+
+// by marshmellow
+// not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)
+// maybe somehow adjust peak trimming value based on samples to fix?
+// return start index of best starting position for that clock and return clock (by reference)
+int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
+{
+  int i=0;
+  int clk[]={8,16,32,40,50,64,100,128,256};
+  int loopCnt = 256;  //don't need to loop through entire array...
+  if (size == 0) return -1;
+  if (size<loopCnt) loopCnt = size;
+  //if we already have a valid clock quit
+  
+  for (;i<8;++i)
+    if (clk[i] == *clock) return 0;
+
+  //get high and low peak
+  int peak, low;
+  getHiLo(dest, loopCnt, &peak, &low, 75, 75);
+  
+  //test for large clean peaks
+  if (DetectCleanAskWave(dest, size, peak, low)==1){
+         uint16_t fcTest=0;
+         uint8_t mostFC=0;
+         fcTest=countFC(dest, size, &mostFC);
+         uint8_t fc1 = fcTest >> 8;
+         uint8_t fc2 = fcTest & 0xFF;
+
+         for (i=0; i<8; i++){
+               if (clk[i] == fc1) {
+                       *clock=fc1;
+                       return 0;
+               }
+               if (clk[i] == fc2) {
+                       *clock=fc2;
+                       return 0;
+               }
+         }
+  }
+  
+  int ii;
+  int clkCnt;
+  int tol = 0;
+  int bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
+  int bestStart[]={0,0,0,0,0,0,0,0,0};
+  int errCnt=0;
+  //test each valid clock from smallest to greatest to see which lines up
+  for(clkCnt=0; clkCnt < 8; clkCnt++){
+    if (clk[clkCnt] == 32){
+      tol=1;
+    }else{
+      tol=0;
+    }
+    bestErr[clkCnt]=1000;
+    //try lining up the peaks by moving starting point (try first 256)
+    for (ii=0; ii < loopCnt; ii++){
+      if ((dest[ii] >= peak) || (dest[ii] <= low)){
+        errCnt=0;
+        // now that we have the first one lined up test rest of wave array
+        for (i=0; i<((int)((size-ii-tol)/clk[clkCnt])-1); ++i){
+          if (dest[ii+(i*clk[clkCnt])]>=peak || dest[ii+(i*clk[clkCnt])]<=low){
+          }else if(dest[ii+(i*clk[clkCnt])-tol]>=peak || dest[ii+(i*clk[clkCnt])-tol]<=low){
+          }else if(dest[ii+(i*clk[clkCnt])+tol]>=peak || dest[ii+(i*clk[clkCnt])+tol]<=low){
+          }else{  //error no peak detected
+            errCnt++;
+          }
+        }
+        //if we found no errors then we can stop here
+        //  this is correct one - return this clock
+            //PrintAndLog("DEBUG: clk %d, err %d, ii %d, i %d",clk[clkCnt],errCnt,ii,i);
+        if(errCnt==0 && clkCnt<6) {
+          *clock = clk[clkCnt];
+          return ii;
+        }
+        //if we found errors see if it is lowest so far and save it as best run
+        if(errCnt<bestErr[clkCnt]){
+          bestErr[clkCnt]=errCnt;
+          bestStart[clkCnt]=ii;
+        }
+      }
+    }
+  }
+  uint8_t iii=0;
+  uint8_t best=0;
+  for (iii=0; iii<8; ++iii){
+    if (bestErr[iii]<bestErr[best]){
+      if (bestErr[iii]==0) bestErr[iii]=1;
+      // current best bit to error ratio     vs  new bit to error ratio
+      if (((size/clk[best])/bestErr[best] < (size/clk[iii])/bestErr[iii]) ){
+        best = iii;
+      }
+    }
+  }
+  if (bestErr[best]>maxErr) return -1;
+  *clock=clk[best];
+  return bestStart[best];

 }
 
 //by marshmellow
 }
 
 //by marshmellow

-//detect psk clock by reading #peaks vs no peaks(or errors)
-int DetectpskNRZClock(uint8_t dest[], size_t size, int clock)
-{
-       int i=0;
-       int peak=0;
-       int low=255;
-       int clk[]={16,32,40,50,64,100,128,256};
-       int loopCnt = 2048;  //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
-       for (i=0; i < loopCnt; ++i){
-               if(dest[i] > peak){
-                       peak = dest[i];
-               }
-               if(dest[i] < low){
-                       low = dest[i];
-               }
-       }
-       peak=(int)(((peak-128)*.75)+128);
-       low= (int)(((low-128)*.75)+128);
-       //PrintAndLog("DEBUG: peak: %d, low: %d",peak,low);
-       int ii;
-       uint8_t clkCnt;
-       uint8_t tol = 0;
-       int peakcnt=0;
-       int errCnt=0;
-       int bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
-       int peaksdet[]={0,0,0,0,0,0,0,0,0};
-       //test each valid clock from smallest to greatest to see which lines up
-       for(clkCnt=0; clkCnt < 6; ++clkCnt){
-               if (clk[clkCnt] == 32){
-                       tol=1;
-               }else{
-                       tol=0;
-               }
-               //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/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
-               }
-               //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);
-       }
-       return clk[best];
+//detect psk clock by reading each phase shift
+// a phase shift is determined by measuring the sample length of each wave
+int DetectPSKClock(uint8_t dest[], size_t size, int clock)
+{
+  uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock
+  uint16_t loopCnt = 4096;  //don't need to loop through entire array...
+  if (size == 0) return 0;
+  if (size<loopCnt) loopCnt = size;
+
+  //if we already have a valid clock quit
+  size_t i=1;
+  for (; i < 8; ++i)
+    if (clk[i] == clock) return clock;
+
+  size_t waveStart=0, waveEnd=0, firstFullWave=0, lastClkBit=0;
+  uint8_t clkCnt, fc=0, fullWaveLen=0, tol=1;
+  uint16_t peakcnt=0, errCnt=0, waveLenCnt=0;
+  uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
+  uint16_t peaksdet[]={0,0,0,0,0,0,0,0,0};
+  countFC(dest, size, &fc);
+  //PrintAndLog("DEBUG: FC: %d",fc);
+
+  //find first full wave
+  for (i=0; i<loopCnt; i++){
+    if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
+      if (waveStart == 0) {
+        waveStart = i+1;
+        //PrintAndLog("DEBUG: waveStart: %d",waveStart);
+      } else {
+        waveEnd = i+1;
+        //PrintAndLog("DEBUG: waveEnd: %d",waveEnd);
+        waveLenCnt = waveEnd-waveStart;
+        if (waveLenCnt > fc){
+          firstFullWave = waveStart;
+          fullWaveLen=waveLenCnt;
+          break;
+        } 
+        waveStart=0;
+      }
+    }
+  }
+  //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);
+  
+  //test each valid clock from greatest to smallest to see which lines up
+  for(clkCnt=7; clkCnt >= 1 ; clkCnt--){
+    lastClkBit = firstFullWave; //set end of wave as clock align
+    waveStart = 0;
+    errCnt=0;
+    peakcnt=0;
+    //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit);
+
+    for (i = firstFullWave+fullWaveLen-1; i < loopCnt-2; i++){
+      //top edge of wave = start of new wave 
+      if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
+        if (waveStart == 0) {
+          waveStart = i+1;
+          waveLenCnt=0;
+        } else { //waveEnd
+          waveEnd = i+1;
+          waveLenCnt = waveEnd-waveStart;
+          if (waveLenCnt > fc){ 
+            //if this wave is a phase shift
+            //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, ii: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+clk[clkCnt]-tol,ii+1,fc);
+            if (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit
+              peakcnt++;
+              lastClkBit+=clk[clkCnt];
+            } else if (i<lastClkBit+8){
+              //noise after a phase shift - ignore
+            } else { //phase shift before supposed to based on clock
+              errCnt++;
+            }
+          } else if (i+1 > lastClkBit + clk[clkCnt] + tol + fc){
+            lastClkBit+=clk[clkCnt]; //no phase shift but clock bit
+          }
+          waveStart=i+1;
+        }
+      }
+    }
+    if (errCnt == 0){
+      return clk[clkCnt];
+    }
+    if (errCnt <= bestErr[clkCnt]) bestErr[clkCnt]=errCnt;
+    if (peakcnt > peaksdet[clkCnt]) peaksdet[clkCnt]=peakcnt;
+  } 
+  //all tested with errors 
+  //return the highest clk with the most peaks found
+  uint8_t best=7;
+  for (i=7; i>=1; i--){
+    if (peaksdet[i] > peaksdet[best]) {
+      best = i;
+    }
+    //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]);
+  }
+  return clk[best];

 }
 
 }
 

-//by marshmellow (attempt to get rid of high immediately after a low)
-void pskCleanWave(uint8_t *bitStream, size_t size)
+//by marshmellow
+//detect nrz clock by reading #peaks vs no peaks(or errors)
+int DetectNRZClock(uint8_t dest[], size_t size, int clock)

 {
 {

-       int i;
-       int low=255;
-       int high=0;
-       int gap = 4;
- // int loopMax = 2048;
-       int newLow=0;
-       int newHigh=0;
-       for (i=0; i < size; ++i){
-               if (bitStream[i] < low) low=bitStream[i];
-               if (bitStream[i] > high) high=bitStream[i];
-       }
-       high = (int)(((high-128)*.80)+128);
-       low = (int)(((low-128)*.90)+128);
-       //low = (uint8_t)(((int)(low)-128)*.80)+128;
-       for (i=0; i < size; ++i){
-               if (newLow == 1){
-                       bitStream[i]=low+8;
-                       gap--;
-                       if (gap == 0){
-                               newLow=0;
-                               gap=4;
-                       }
-               }else if (newHigh == 1){
-                       bitStream[i]=high-8;
-                       gap--;
-                       if (gap == 0){
-                               newHigh=0;
-                               gap=4;
-                       }
+  int i=0;
+  int clk[]={8,16,32,40,50,64,100,128,256};
+  int loopCnt = 4096;  //don't need to loop through entire array...
+  if (size == 0) return 0;
+  if (size<loopCnt) loopCnt = size;
+
+  //if we already have a valid clock quit
+  for (; i < 8; ++i)
+    if (clk[i] == clock) return clock;
+
+  //get high and low peak
+  int peak, low;
+  getHiLo(dest, loopCnt, &peak, &low, 75, 75);
+
+  //PrintAndLog("DEBUG: peak: %d, low: %d",peak,low);
+  int ii;
+  uint8_t clkCnt;
+  uint8_t tol = 0;
+  int peakcnt=0;
+  int peaksdet[]={0,0,0,0,0,0,0,0};
+  int maxPeak=0;
+  //test for large clipped waves
+  for (i=0; i<loopCnt; i++){
+       if (dest[i] >= peak || dest[i] <= low){
+               peakcnt++;
+       } else {
+               if (peakcnt>0 && maxPeak < peakcnt){
+                       maxPeak = peakcnt;
+               }
+               peakcnt=0;
+       }
+  }
+  peakcnt=0;
+  //test each valid clock from smallest to greatest to see which lines up
+  for(clkCnt=0; clkCnt < 8; ++clkCnt){
+       //ignore clocks smaller than largest peak
+       if (clk[clkCnt]<maxPeak) continue;
+
+    //try lining up the peaks by moving starting point (try first 256)
+    for (ii=0; ii< loopCnt; ++ii){
+      if ((dest[ii] >= peak) || (dest[ii] <= low)){
+        peakcnt=0;
+        // now that we have the first one lined up test rest of wave array
+        for (i=0; i < ((int)((size-ii-tol)/clk[clkCnt])-1); ++i){
+          if (dest[ii+(i*clk[clkCnt])]>=peak || dest[ii+(i*clk[clkCnt])]<=low){
+            peakcnt++;
+          }
+        }
+        if(peakcnt>peaksdet[clkCnt]) {
+          peaksdet[clkCnt]=peakcnt;
+        }
+      }
+    }
+  }
+  int iii=7;
+  int best=0;
+  for (iii=7; iii > 0; iii--){
+    if (peaksdet[iii] > peaksdet[best]){
+       best = iii;
+    }
+    //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]);
+  }
+  return clk[best];
+}
+
+// by marshmellow
+// convert psk1 demod to psk2 demod
+// only transition waves are 1s
+void psk1TOpsk2(uint8_t *BitStream, size_t size)
+{
+       size_t i=1;
+       uint8_t lastBit=BitStream[0];
+       for (; i<size; i++){
+               if (lastBit!=BitStream[i]){
+                       lastBit=BitStream[i];
+                       BitStream[i]=1;
+               } else {
+                       BitStream[i]=0;

                }
                }

-               if (bitStream[i] <= low) newLow=1;
-               if (bitStream[i] >= high) newHigh=1;

        }
        return;
 }
 
        }
        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
+// redesigned by marshmellow adjusted from existing decode functions
+// indala id decoding - only tested on 26 bit tags, but attempted to make it work for more

 int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert)
 {
        //26 bit 40134 format  (don't know other formats)
 int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert)
 {
        //26 bit 40134 format  (don't know other formats)


@@ -852,146 +1131,506 @@ int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert)
        return 1;
 }
 
        return 1;
 }
 

+// by marshmellow - demodulate NRZ wave (both similar enough)
+// peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
+// there probably is a much simpler way to do this.... 
+int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert, int maxErr)
+{
+  if (justNoise(dest, *size)) return -1;
+  *clk = DetectNRZClock(dest, *size, *clk);
+  if (*clk==0) return -2;
+  uint32_t i;
+  int high, low, ans;
+  ans = getHiLo(dest, 1260, &high, &low, 75, 75); //25% fuzz on high 25% fuzz on low
+  if (ans<1) return -2; //just noise
+  uint32_t gLen = 256;
+  if (gLen>*size) gLen = *size;
+  int lastBit = 0;  //set first clock check
+  uint32_t bitnum = 0;     //output counter
+  uint8_t tol = 1;  //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave
+  uint32_t iii = 0;
+  uint16_t errCnt =0;
+  uint16_t MaxBits = 1000;
+  uint32_t bestErrCnt = maxErr+1;
+  uint32_t bestPeakCnt = 0;
+  uint32_t bestPeakStart=0;
+  uint8_t curBit=0;
+  uint8_t bitHigh=0;
+  uint8_t errBitHigh=0;
+  uint16_t peakCnt=0;
+  uint8_t ignoreWindow=4;
+  uint8_t ignoreCnt=ignoreWindow; //in case of noice near peak
+  //loop to find first wave that works - align to clock
+  for (iii=0; iii < gLen; ++iii){
+    if ((dest[iii]>=high) || (dest[iii]<=low)){
+      lastBit=iii-*clk;
+      peakCnt=0;
+      errCnt=0;
+      bitnum=0;
+      //loop through to see if this start location works
+      for (i = iii; i < *size; ++i) {
+        //if we found a high bar and we are at a clock bit
+        if ((dest[i]>=high ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
+          bitHigh=1;
+          lastBit+=*clk;
+          bitnum++;
+          peakCnt++;
+          errBitHigh=0;
+          ignoreCnt=ignoreWindow;
+        //else if low bar found and we are at a clock point
+        }else if ((dest[i]<=low ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
+          bitHigh=1;
+          lastBit+=*clk;
+          bitnum++;
+          peakCnt++;
+          errBitHigh=0;
+          ignoreCnt=ignoreWindow;
+        //else if no bars found
+        }else if(dest[i] < high && dest[i] > low) {
+          if (ignoreCnt==0){
+            bitHigh=0;
+            if (errBitHigh==1){
+              errCnt++;
+            }
+            errBitHigh=0;
+          } else {
+            ignoreCnt--;
+          }
+          //if we are past a clock point
+          if (i >= lastBit+*clk+tol){ //clock val
+            lastBit+=*clk;
+            bitnum++;
+          }
+        //else if bar found but we are not at a clock bit and we did not just have a clock bit
+        }else if ((dest[i]>=high || dest[i]<=low) && (i<lastBit+*clk-tol || i>lastBit+*clk+tol) && (bitHigh==0)){
+          //error bar found no clock...
+          errBitHigh=1;
+        }
+        if (bitnum>=MaxBits) break;
+      }
+      //we got more than 64 good bits and not all errors
+      if (bitnum > (64) && (errCnt <= (maxErr))) {
+        //possible good read
+        if (errCnt == 0){
+          //bestStart = iii;
+          bestErrCnt = errCnt;
+          bestPeakCnt = peakCnt;
+          bestPeakStart = iii;
+          break;  //great read - finish
+        }
+        if (errCnt < bestErrCnt){  //set this as new best run
+          bestErrCnt = errCnt;
+          //bestStart = iii;
+        }
+        if (peakCnt > bestPeakCnt){
+          bestPeakCnt=peakCnt;
+          bestPeakStart=iii;
+        } 
+      }
+    }
+  }
+  //PrintAndLog("DEBUG: bestErrCnt: %d, maxErr: %d, bestStart: %d, bestPeakCnt: %d, bestPeakStart: %d",bestErrCnt,maxErr,bestStart,bestPeakCnt,bestPeakStart);
+  if (bestErrCnt <= maxErr){
+    //best run is good enough set to best run and set overwrite BinStream
+    iii=bestPeakStart;
+    lastBit=bestPeakStart-*clk;
+    bitnum=0;
+    for (i = iii; i < *size; ++i) {
+      //if we found a high bar and we are at a clock bit
+      if ((dest[i] >= high ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
+        bitHigh=1;
+        lastBit+=*clk;
+        curBit=1-*invert;
+        dest[bitnum]=curBit;
+        bitnum++;
+        errBitHigh=0;
+        ignoreCnt=ignoreWindow;
+      //else if low bar found and we are at a clock point
+      }else if ((dest[i]<=low ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
+        bitHigh=1;
+        lastBit+=*clk;
+        curBit=*invert;
+        dest[bitnum]=curBit;
+        bitnum++;
+        errBitHigh=0;
+        ignoreCnt=ignoreWindow;
+      //else if no bars found
+      }else if(dest[i]<high && dest[i]>low) {
+        if (ignoreCnt==0){
+          bitHigh=0;
+          //if peak is done was it an error peak?
+          if (errBitHigh==1){
+            dest[bitnum]=77;
+            bitnum++;
+            errCnt++;
+          }
+          errBitHigh=0;
+        } else {
+          ignoreCnt--;
+        }
+        //if we are past a clock point
+        if (i>=lastBit+*clk+tol){ //clock val
+          lastBit+=*clk;
+          dest[bitnum]=curBit;
+          bitnum++;
+        }
+      //else if bar found but we are not at a clock bit and we did not just have a clock bit
+      }else if ((dest[i]>=high || dest[i]<=low) && ((i<lastBit+*clk-tol) || (i>lastBit+*clk+tol)) && (bitHigh==0)){
+        //error bar found no clock...
+        errBitHigh=1;
+      }
+      if (bitnum >= MaxBits) break;
+    }
+    *size=bitnum;
+  } else{
+    *size=bitnum;
+    return -1;
+  }

 
 

-//by marshmellow - demodulate PSK wave or NRZ wave (both similar enough)
-//peaks switch 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)
+  if (bitnum>16){
+    *size=bitnum;
+  } else return -1;
+  return errCnt;
+}
+
+//by marshmellow
+//detects the bit clock for FSK given the high and low Field Clocks
+uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow)

 {
 {

-       pskCleanWave(dest,*size);
-       int clk2 = DetectpskNRZClock(dest, *size, *clk);
-       *clk=clk2;
-       uint32_t i;
-       uint8_t high=0, low=255;
-       uint32_t gLen = *size;
-       if (gLen > 1280) gLen=1280;
-       // get high
-       for (i=0; i < gLen; ++i){
-               if (dest[i] > high) high = dest[i];
-               if (dest[i] < low) low = dest[i];
-       }
-       //fudge high/low bars by 25%
-       high = (uint8_t)((((int)(high)-128)*.75)+128);
-       low = (uint8_t)((((int)(low)-128)*.80)+128);
+  uint8_t clk[] = {8,16,32,40,50,64,100,128,0};
+  uint16_t rfLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+  uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+  uint8_t rfLensFnd = 0;
+  uint8_t lastFCcnt=0;
+  uint32_t fcCounter = 0;
+  uint16_t rfCounter = 0;
+  uint8_t firstBitFnd = 0;
+  size_t i;
+  if (size == 0) return 0;

 
 

-       //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 = 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 midBit=0;
-       uint8_t curBit=0;
-       uint8_t bitHigh=0;
-       uint8_t ignorewin=*clk/8;
-       //PrintAndLog("DEBUG - lastbit - %d",lastBit);
-       //loop to find first wave that works - align to clock
-       for (iii=0; iii < gLen; ++iii){
-               if ((dest[iii]>=high) || (dest[iii]<=low)){
-                       lastBit=iii-*clk;
-                       //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++;
-                               //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;
-                                               bitnum++;
-                                       }
-                               //else if bar found but we are not at a clock bit and we did not just have a clock bit
-                               }else if ((dest[i]>=high || dest[i]<=low) && (i<lastBit+*clk-tol || i>lastBit+*clk+tol) && (bitHigh==0)){
-                                       //error bar found no clock...
-                                       errCnt++;
-                               }
-                               if (bitnum>=1000) break;
-                       }
-                       //we got more than 64 good bits and not all errors
-                       if ((bitnum > (64+errCnt)) && (errCnt < (maxErr))) {
-                               //possible good read
-                               if (errCnt == 0){
-                                       bestStart = iii;
-                                       bestErrCnt = errCnt;
-                                       break;  //great read - finish
-                               }
-                               if (bestStart == iii) break;  //if current run == bestErrCnt run (after exhausted testing) then finish
-                               if (errCnt < bestErrCnt){  //set this as new best run
-                                       bestErrCnt = errCnt;
-                                       bestStart = iii;
-                               }
-                       }
-               }
-       }
-       if (bestErrCnt < maxErr){
-               //best run is good enough set to best run and 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++;
-                               }
-                       //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++;
-                       }
-                       if (bitnum >=1000) break;
-               }
-               *size=bitnum;
-       } else{
-               *size=bitnum;
-               *clk=bestStart;
-               return -1;
-       }
+  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;

 
 

-       if (bitnum>16){
-               *size=bitnum;
-       } else return -1;
-       return errCnt;
+  for (; i < size-1; i++){
+    if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1]){
+      // new peak 
+      fcCounter++;
+      rfCounter++;
+      // if we got less than the small fc + tolerance then set it to the small fc
+      if (fcCounter < fcLow+fcTol) 
+        fcCounter = fcLow;
+      else //set it to the large fc
+        fcCounter = fcHigh;
+
+      //look for bit clock  (rf/xx)
+      if ((fcCounter<lastFCcnt || fcCounter>lastFCcnt)){
+        //not the same size as the last wave - start of new bit sequence
+
+        if (firstBitFnd>1){ //skip first wave change - probably not a complete bit
+          for (int ii=0; ii<15; ii++){
+            if (rfLens[ii]==rfCounter){
+              rfCnts[ii]++;
+              rfCounter=0;
+              break;
+            }
+          }
+          if (rfCounter>0 && rfLensFnd<15){
+            //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
+            rfCnts[rfLensFnd]++;
+            rfLens[rfLensFnd++]=rfCounter;
+          }
+        } else {
+          firstBitFnd++;
+        }
+        rfCounter=0;
+        lastFCcnt=fcCounter;
+      }
+      fcCounter=0;
+    } else {
+      // count sample
+      fcCounter++;
+      rfCounter++;
+    }
+  }
+  uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15;
+
+  for (i=0; i<15; i++){
+    //PrintAndLog("DEBUG: RF %d, cnts %d",rfLens[i], rfCnts[i]);
+    //get highest 2 RF values  (might need to get more values to compare or compare all?)
+    if (rfCnts[i]>rfCnts[rfHighest]){
+      rfHighest3=rfHighest2;
+      rfHighest2=rfHighest;
+      rfHighest=i;
+    } else if(rfCnts[i]>rfCnts[rfHighest2]){
+      rfHighest3=rfHighest2;
+      rfHighest2=i;
+    } else if(rfCnts[i]>rfCnts[rfHighest3]){
+      rfHighest3=i;
+    }
+  }  
+  // set allowed clock remainder tolerance to be 1 large field clock length+1 
+  //   we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off  
+  uint8_t tol1 = fcHigh+1; 
+  
+  //PrintAndLog("DEBUG: hightest: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]);
+
+  // loop to find the highest clock that has a remainder less than the tolerance
+  //   compare samples counted divided by
+  int ii=7;
+  for (; ii>=0; ii--){
+    if (rfLens[rfHighest] % clk[ii] < tol1 || rfLens[rfHighest] % clk[ii] > clk[ii]-tol1){
+      if (rfLens[rfHighest2] % clk[ii] < tol1 || rfLens[rfHighest2] % clk[ii] > clk[ii]-tol1){
+        if (rfLens[rfHighest3] % clk[ii] < tol1 || rfLens[rfHighest3] % clk[ii] > clk[ii]-tol1){
+          break;
+        }
+      }
+    }
+  }
+
+  if (ii<0) return 0; // oops we went too far
+
+  return clk[ii];
+}
+
+//by marshmellow
+//countFC is to detect the field clock lengths.
+//counts and returns the 2 most common wave lengths
+//mainly used for FSK field clock detection
+uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t *mostFC)
+{
+  uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0};
+  uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0};
+  uint8_t fcLensFnd = 0;
+  uint8_t lastFCcnt=0;
+  uint32_t fcCounter = 0;
+  size_t i;
+  if (size == 0) return 0;
+
+  // prime i to first up transition
+  for (i = 1; i < size-1; i++)
+    if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1])
+      break;
+
+  for (; i < size-1; i++){
+    if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){
+       // new up transition
+       fcCounter++;
+       
+      //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8)
+      if (lastFCcnt==5 && fcCounter==9) fcCounter--;
+      //if odd and not rc/5 add one (for when we get a fc 9 instead of 10)
+      if ((fcCounter==9 && fcCounter & 1) || fcCounter==4) fcCounter++;
+
+      // save last field clock count  (fc/xx)
+      // find which fcLens to save it to:
+      for (int ii=0; ii<10; ii++){
+        if (fcLens[ii]==fcCounter){
+          fcCnts[ii]++;
+          fcCounter=0;
+          break;
+        }
+      }
+      if (fcCounter>0 && fcLensFnd<10){
+        //add new fc length 
+        fcCnts[fcLensFnd]++;
+        fcLens[fcLensFnd++]=fcCounter;
+      }
+      fcCounter=0;
+    } else {
+      // count sample
+      fcCounter++;
+    }
+  }
+  
+  uint8_t best1=9, best2=9, best3=9;
+  uint16_t maxCnt1=0;
+  // go through fclens and find which ones are bigest 2  
+  for (i=0; i<10; i++){
+    // PrintAndLog("DEBUG: FC %d, Cnt %d, Errs %d",fcLens[i],fcCnts[i],errCnt);    
+    // get the 3 best FC values
+    if (fcCnts[i]>maxCnt1) {
+      best3=best2;
+      best2=best1;
+      maxCnt1=fcCnts[i];
+      best1=i;
+    } else if(fcCnts[i]>fcCnts[best2]){
+      best3=best2;
+      best2=i;
+    } else if(fcCnts[i]>fcCnts[best3]){
+      best3=i;
+    }
+  }
+  uint8_t fcH=0, fcL=0;
+  if (fcLens[best1]>fcLens[best2]){
+    fcH=fcLens[best1];
+    fcL=fcLens[best2];
+  } else{
+    fcH=fcLens[best2];
+    fcL=fcLens[best1];
+  }
+
+  *mostFC=fcLens[best1]; 
+  // TODO: take top 3 answers and compare to known Field clocks to get top 2
+
+  uint16_t fcs = (((uint16_t)fcH)<<8) | fcL;
+  // PrintAndLog("DEBUG: Best %d  best2 %d best3 %d",fcLens[best1],fcLens[best2],fcLens[best3]);
+  
+  return fcs;

 }
 
 }
 

+//by marshmellow
+//countPSK_FC is to detect the psk carrier clock length.
+//counts and returns the 1 most common wave length
+uint8_t countPSK_FC(uint8_t *BitStream, size_t size)
+{
+  uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0};
+  uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0};
+  uint8_t fcLensFnd = 0;
+  uint32_t fcCounter = 0;
+  size_t i;
+  if (size == 0) return 0;
+  
+  // prime i to first up transition
+  for (i = 1; i < size-1; i++)
+    if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1])
+      break;
+
+  for (; i < size-1; i++){
+    if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){
+      // new up transition
+      fcCounter++;
+      
+      // save last field clock count  (fc/xx)
+      // find which fcLens to save it to:
+      for (int ii=0; ii<10; ii++){
+        if (fcLens[ii]==fcCounter){
+          fcCnts[ii]++;
+          fcCounter=0;
+          break;
+        }
+      }
+      if (fcCounter>0 && fcLensFnd<10){
+        //add new fc length 
+        fcCnts[fcLensFnd]++;
+        fcLens[fcLensFnd++]=fcCounter;
+      }
+      fcCounter=0;
+    } else {
+      // count sample
+      fcCounter++;
+    }
+  }
+  
+  uint8_t best1=9;
+  uint16_t maxCnt1=0;
+  // go through fclens and find which ones are bigest  
+  for (i=0; i<10; i++){
+    //PrintAndLog("DEBUG: FC %d, Cnt %d",fcLens[i],fcCnts[i]);    
+    // get the best FC value
+    if (fcCnts[i]>maxCnt1) {
+      maxCnt1=fcCnts[i];
+      best1=i;
+    }
+  }
+  return fcLens[best1]; 
+}
+
+//by marshmellow - demodulate PSK1 wave 
+//uses wave lengths (# Samples) 
+int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
+{
+  uint16_t loopCnt = 4096;  //don't need to loop through entire array...
+  if (size == 0) return -1;
+  if (*size<loopCnt) loopCnt = *size;
+
+  uint8_t curPhase = *invert;
+  size_t i, waveStart=0, waveEnd=0, firstFullWave=0, lastClkBit=0;
+  uint8_t fc=0, fullWaveLen=0, tol=1;
+  uint16_t errCnt=0, waveLenCnt=0;
+  fc = countPSK_FC(dest, *size);
+  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 full wave
+  for (i=0; i<loopCnt; i++){
+    if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
+      if (waveStart == 0) {
+        waveStart = i+1;
+        avgWaveVal=dest[i+1];
+        //PrintAndLog("DEBUG: waveStart: %d",waveStart);
+      } else {
+        waveEnd = i+1;
+        //PrintAndLog("DEBUG: waveEnd: %d",waveEnd);
+        waveLenCnt = waveEnd-waveStart;
+        lastAvgWaveVal = avgWaveVal/waveLenCnt;
+        if (waveLenCnt > fc){
+          firstFullWave = waveStart;
+          fullWaveLen=waveLenCnt;
+          //if average wave value is > graph 0 then it is an up wave or a 1
+          if (lastAvgWaveVal > 128) curPhase^=1;
+          break;
+        } 
+        waveStart=0;
+        avgWaveVal=0;
+      }
+    }
+    avgWaveVal+=dest[i+1];
+  }
+  //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);  
+  lastClkBit = firstFullWave; //set start of wave as clock align
+  waveStart = 0;
+  errCnt=0;
+  size_t numBits=0;
+  //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d", *clock, lastClkBit);
+
+  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);
+          //if 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;
+            numBits++;
+            lastClkBit += *clock;
+          } else if (i<lastClkBit+10){
+            //noise after a phase shift - ignore
+          } else { //phase shift before supposed to based on clock
+            errCnt++;
+            dest[numBits] = 77;
+            numBits++;
+          }
+        } else if (i+1 > lastClkBit + *clock + tol + fc){
+          lastClkBit += *clock; //no phase shift but clock bit
+          dest[numBits] = curPhase;
+          numBits++;
+        }
+        avgWaveVal=0;
+        waveStart=i+1;
+      }
+    }
+    avgWaveVal+=dest[i+1];
+  }
+  *size = numBits;
+  return errCnt;
+}