]> cvs.zerfleddert.de Git - proxmark3-svn/commitdiff
re-organize lfdemod.c
authormarshmellow42 <marshmellowrf@gmail.com>
Mon, 13 Mar 2017 02:47:50 +0000 (22:47 -0400)
committermarshmellow42 <marshmellowrf@gmail.com>
Mon, 13 Mar 2017 02:47:50 +0000 (22:47 -0400)
sorry but it was ugly  (still is... but i can get to things easier)

common/lfdemod.c

index 660b54279a8d83000f542b719b9ef1cf2d09a273..a6e215c90a2321316dbc71675a24f1f319cf9c16 100644 (file)
@@ -6,6 +6,26 @@
 // the license.
 //-----------------------------------------------------------------------------
 // Low frequency demod/decode commands
+//
+// NOTES: 
+// LF Demod functions are placed here to allow the flexability to use client or
+// device side. Most BUT NOT ALL of these functions are currenlty safe for 
+// device side use currently. (DetectST for example...)
+//
+// There are likely many improvements to the code that could be made, please
+// make suggestions...
+//
+// There are 4 main sections of code below:
+// Utilities Section: 
+//    for general utilities used by multiple other functions
+// Modulation Demods &/or Decoding Section:
+//    for main general modulation demodulating and encoding decoding code.
+// Clock / Bitrate Detection Section:
+//    for clock detection functions for each modulation
+// Tag format detection section:
+//    for detection of specific tag formats within demodulated data
+//
+// marshmellow
 //-----------------------------------------------------------------------------
 
 #include <stdlib.h>
@@ -25,6 +45,8 @@ void dummy(char *fmt, ...){}
 #define prnt dummy
 #endif
 
+//---------------------------------Utilities Section--------------------------------------------------
+
 uint8_t justNoise(uint8_t *BitStream, size_t size)
 {
        static const uint8_t THRESHOLD = 123;
@@ -204,92 +226,8 @@ size_t findModStart(uint8_t dest[], size_t size, uint8_t threshold_value, uint8_
 }
 
 //by marshmellow
-//takes 1s and 0s and searches for EM410x format - output EM ID
-uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo)
-{
-       //sanity checks
-       if (*size < 64) return 0;
-       if (BitStream[1]>1) return 0;  //allow only 1s and 0s
-
-       // 111111111 bit pattern represent start of frame
-       //  include 0 in front to help get start pos
-       uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1};
-       uint8_t errChk = 0;
-       uint8_t FmtLen = 10; // sets of 4 bits = end data 
-       *startIdx = 0;
-       errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx);
-       if ( errChk == 0 || (*size != 64 && *size != 128) ) return 0;
-       if (*size == 128) FmtLen = 22; // 22 sets of 4 bits
-
-       //skip last 4bit parity row for simplicity
-       *size = removeParity(BitStream, *startIdx + sizeof(preamble), 5, 0, FmtLen * 5);
-       if (*size == 40) { // std em410x format
-               *hi = 0;
-               *lo = ((uint64_t)(bytebits_to_byte(BitStream, 8)) << 32) | (bytebits_to_byte(BitStream + 8, 32));
-       } else if (*size == 88) { // long em format
-               *hi = (bytebits_to_byte(BitStream, 24)); 
-               *lo = ((uint64_t)(bytebits_to_byte(BitStream + 24, 32)) << 32) | (bytebits_to_byte(BitStream + 24 + 32, 32));
-       } else {
-               return 0;
-       }
-       return 1;
-}
-
-//by marshmellow
-//demodulates strong heavily clipped samples
-int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low, int *startIdx)
-{
-       *startIdx=0;
-       size_t bitCnt=0, smplCnt=1, errCnt=0;
-       bool waveHigh = (BinStream[0] >= high);
-       for (size_t i=1; 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++;
-                                               if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
-                                               BinStream[bitCnt++] = 7;
-                                       } else if (waveHigh) {
-                                               BinStream[bitCnt++] = invert;
-                                               BinStream[bitCnt++] = invert;
-                                       } else if (!waveHigh) {
-                                               BinStream[bitCnt++] = invert ^ 1;
-                                               BinStream[bitCnt++] = invert ^ 1;
-                                       }
-                                       if (*startIdx==0) *startIdx = i-clk;
-                                       waveHigh = !waveHigh;  
-                                       smplCnt = 0;
-                               } else if (smplCnt > (clk/2) - (clk/4)-1) { //half clock
-                                       if (waveHigh) {
-                                               BinStream[bitCnt++] = invert;
-                                       } else if (!waveHigh) {
-                                               BinStream[bitCnt++] = invert ^ 1;
-                                       }
-                                       if (*startIdx==0) *startIdx = i-(clk/2);
-                                       waveHigh = !waveHigh;  
-                                       smplCnt = 0;
-                               } else {
-                                       smplCnt++;
-                                       //transition bit oops
-                               }
-                       } else { //haven't hit new high or new low yet
-                               smplCnt++;
-                       }
-               }
-       }
-       *size = bitCnt;
-       return errCnt;
-}
-
-//by marshmellow
-//amplify based on ask edge detection
-void askAmp(uint8_t *BitStream, size_t size)
-{
+//amplify based on ask edge detection  -  not accurate enough to use all the time
+void askAmp(uint8_t *BitStream, size_t size) {
        uint8_t Last = 128;
        for(size_t i = 1; i<size; i++){
                if (BitStream[i]-BitStream[i-1]>=30) //large jump up
@@ -301,130 +239,6 @@ void askAmp(uint8_t *BitStream, size_t size)
        }
        return;
 }
-//by marshmellow
-//attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester
-int askdemod_ext(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType, int *startIdx) {
-       if (*size==0) return -1;
-       int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default
-       if (*clk==0 || start < 0) return -3;
-       if (*invert != 1) *invert = 0;
-       if (amp==1) askAmp(BinStream, *size);
-       if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d, amp %d", *clk, start, amp);
-
-       //start pos from detect ask clock is 1/2 clock offset
-       // NOTE: can be negative (demod assumes rest of wave was there)
-       *startIdx = start - (*clk/2); 
-       uint8_t initLoopMax = 255;
-       if (initLoopMax > *size) initLoopMax = *size;
-       // Detect high and lows
-       //25% clip in case highs and lows aren't clipped [marshmellow]
-       int high, low;
-       if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1) 
-               return -2; //just noise
-
-       size_t errCnt = 0;
-       // if clean clipped waves detected run alternate demod
-       if (DetectCleanAskWave(BinStream, *size, high, low)) {
-               if (g_debugMode==2) prnt("DEBUG ASK: Clean Wave Detected - using clean wave demod");
-               errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low, startIdx);
-               if (askType) { //askman
-                       uint8_t alignPos = 0;
-                       errCnt = manrawdecode(BinStream, size, 0, &alignPos);
-                       *startIdx += *clk/2 * alignPos;
-                       if (g_debugMode) prnt("DEBUG ASK CLEAN: startIdx %i, alignPos %u", *startIdx, alignPos);
-                       return errCnt;
-               } else { //askraw
-                       return errCnt;
-               }
-       }
-       if (g_debugMode) prnt("DEBUG ASK WEAK: startIdx %i", *startIdx);
-       if (g_debugMode==2) prnt("DEBUG ASK: Weak Wave Detected - using weak wave demod");
-
-       int lastBit;              //set first clock check - can go negative
-       size_t i, bitnum = 0;     //output counter
-       uint8_t midBit = 0;
-       uint8_t tol = 0;          //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave
-       if (*clk <= 32) tol = 1;  //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely
-       size_t MaxBits = 3072;    //max bits to collect
-       lastBit = start - *clk;
-
-       for (i = start; i < *size; ++i) {
-               if (i-lastBit >= *clk-tol){
-                       if (BinStream[i] >= high) {
-                               BinStream[bitnum++] = *invert;
-                       } else if (BinStream[i] <= low) {
-                               BinStream[bitnum++] = *invert ^ 1;
-                       } else if (i-lastBit >= *clk+tol) {
-                               if (bitnum > 0) {
-                                       if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
-                                       BinStream[bitnum++]=7;
-                                       errCnt++;                                               
-                               } 
-                       } else { //in tolerance - looking for peak
-                               continue;
-                       }
-                       midBit = 0;
-                       lastBit += *clk;
-               } else if (i-lastBit >= (*clk/2-tol) && !midBit && !askType){
-                       if (BinStream[i] >= high) {
-                               BinStream[bitnum++] = *invert;
-                       } else if (BinStream[i] <= low) {
-                               BinStream[bitnum++] = *invert ^ 1;
-                       } else if (i-lastBit >= *clk/2+tol) {
-                               BinStream[bitnum] = BinStream[bitnum-1];
-                               bitnum++;
-                       } else { //in tolerance - looking for peak
-                               continue;
-                       }
-                       midBit = 1;
-               }
-               if (bitnum >= MaxBits) break;
-       }
-       *size = bitnum;
-       return errCnt;
-}
-
-int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType) {
-       int start = 0;
-       return askdemod_ext(BinStream, size, clk, invert, maxErr, amp, askType, &start);
-}
-//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, uint8_t invert, uint8_t *alignPos)
-{
-       uint16_t bitnum=0, MaxBits = 512, errCnt = 0;
-       size_t i, ii;
-       uint16_t bestErr = 1000, bestRun = 0;
-       if (*size < 16) return -1;
-       //find correct start position [alignment]
-       for (ii=0;ii<2;++ii){
-               for (i=ii; i<*size-3; i+=2)
-                       if (BitStream[i]==BitStream[i+1])
-                               errCnt++;
-
-               if (bestErr>errCnt){
-                       bestErr=errCnt;
-                       bestRun=ii;
-               }
-               errCnt=0;
-       }
-       *alignPos=bestRun;
-       //decode
-       for (i=bestRun; i < *size-3; i+=2){
-               if(BitStream[i] == 1 && (BitStream[i+1] == 0)){
-                       BitStream[bitnum++]=invert;
-               } else if((BitStream[i] == 0) && BitStream[i+1] == 1){
-                       BitStream[bitnum++]=invert^1;
-               } else {
-                       BitStream[bitnum++]=7;
-               }
-               if(bitnum>MaxBits) break;
-       }
-       *size=bitnum;
-       return bestErr;
-}
 
 uint32_t manchesterEncode2Bytes(uint16_t datain) {
        uint32_t output = 0;
@@ -438,47 +252,242 @@ uint32_t manchesterEncode2Bytes(uint16_t datain) {
 
 //by marshmellow
 //encode binary data into binary manchester 
-int ManchesterEncode(uint8_t *BitStream, size_t size)
-{
-       size_t modIdx=20000, i=0;
+//NOTE: BitStream must have double the size available in memory to do the swap
+int ManchesterEncode(uint8_t *BitStream, size_t size) {
+       size_t modIdx=size, 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];
+               BitStream[i] = BitStream[i+size];
        }
        return i;
 }
 
+//------------------------------Modulation Demods &/or Decoding Section------------------------------------------------------
+
 //by marshmellow
-//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)
-{
-       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;                                  
+//attempt to identify a Sequence Terminator in ASK modulated raw wave
+bool DetectST_ext(uint8_t buffer[], size_t *size, int *foundclock, size_t *ststart, size_t *stend) {
+       size_t bufsize = *size;
+       //need to loop through all samples and identify our clock, look for the ST pattern
+       uint8_t fndClk[] = {8,16,32,40,50,64,128};
+       int clk = 0; 
+       int tol = 0;
+       int i, j, skip, start, end, low, high, minClk, waveStart;
+       bool complete = false;
+       int tmpbuff[bufsize / 32]; //guess rf/32 clock, if click is smaller we will only have room for a fraction of the samples captured
+       int waveLen[bufsize / 32]; //  if clock is larger then we waste memory in array size that is not needed...
+       size_t testsize = (bufsize < 512) ? bufsize : 512;
+       int phaseoff = 0;
+       high = low = 128;
+       memset(tmpbuff, 0, sizeof(tmpbuff));
+
+       if ( getHiLo(buffer, testsize, &high, &low, 80, 80) == -1 ) {
+               if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting");
+               return false; //just noise
        }
-       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;
+       i = 0;
+       j = 0;
+       minClk = 255;
+       // get to first full low to prime loop and skip incomplete first pulse
+       while ((buffer[i] < high) && (i < bufsize))
+               ++i;
+       while ((buffer[i] > low) && (i < bufsize))
+               ++i;
+       skip = i;
+
+       // populate tmpbuff buffer with pulse lengths
+       while (i < bufsize) {
+               // measure from low to low
+               while ((buffer[i] > low) && (i < bufsize))
+                       ++i;
+               start= i;
+               while ((buffer[i] < high) && (i < bufsize))
+                       ++i;
+               //first high point for this wave
+               waveStart = i;
+               while ((buffer[i] > low) && (i < bufsize))
+                       ++i;
+               if (j >= (bufsize/32)) {
+                       break;
+               }
+               waveLen[j] = i - waveStart; //first high to first low
+               tmpbuff[j++] = i - start;
+               if (i-start < minClk && i < bufsize) {
+                       minClk = i - start;
+               }
+       }
+       // set clock  - might be able to get this externally and remove this work...
+       if (!clk) {
+               for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
+                       tol = fndClk[clkCnt]/8;
+                       if (minClk >= fndClk[clkCnt]-tol && minClk <= fndClk[clkCnt]+1) { 
+                               clk=fndClk[clkCnt];
+                               break;
+                       }
+               }
+               // clock not found - ERROR
+               if (!clk) {
+                       if (g_debugMode==2) prnt("DEBUG STT: clock not found - quitting");
+                       return false;
+               }
+       } else tol = clk/8;
+
+       *foundclock = clk;
+
+       // look for Sequence Terminator - should be pulses of clk*(1 or 1.5), clk*2, clk*(1.5 or 2)
+       start = -1;
+       for (i = 0; i < j - 4; ++i) {
+               skip += tmpbuff[i];
+               if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol && waveLen[i] < clk+tol) {           //1 to 2 clocks depending on 2 bits prior
+                       if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) {       //2 clocks and wave size is 1 1/2
+                               if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave
+                                       if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit
+                                               start = i + 3;
+                                               break;
+                                       }
+                               }
+                       }
+               }
+       }
+       // first ST not found - ERROR
+       if (start < 0) {
+               if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting");
+               return false;
+       } else {
+               if (g_debugMode==2) prnt("DEBUG STT: first STT found at: %d, j=%d",start, j);
+       }
+       if (waveLen[i+2] > clk*1+tol)
+               phaseoff = 0;
+       else
+               phaseoff = clk/2;
+       
+       // skip over the remainder of ST
+       skip += clk*7/2; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point
+
+       // now do it again to find the end
+       end = skip;
+       for (i += 3; i < j - 4; ++i) {
+               end += tmpbuff[i];
+               if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol && waveLen[i] < clk+tol) {           //1 to 2 clocks depending on 2 bits prior
+                       if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) {       //2 clocks and wave size is 1 1/2
+                               if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave
+                                       if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit
+                                               complete = true;
+                                               break;
+                                       }
+                               }
+                       }
+               }
+       }
+       end -= phaseoff;
+       //didn't find second ST - ERROR
+       if (!complete) {
+               if (g_debugMode==2) prnt("DEBUG STT: second STT not found - quitting");
+               return false;
+       }
+       if (g_debugMode==2) prnt("DEBUG STT: start of data: %d end of data: %d, datalen: %d, clk: %d, bits: %d, phaseoff: %d", skip, end, end-skip, clk, (end-skip)/clk, phaseoff);
+       //now begin to trim out ST so we can use normal demod cmds
+       start = skip;
+       size_t datalen = end - start;
+       // check validity of datalen (should be even clock increments)  - use a tolerance of up to 1/8th a clock
+       if ( clk - (datalen % clk) <= clk/8) {
+               // padd the amount off - could be problematic...  but shouldn't happen often
+               datalen += clk - (datalen % clk);
+       } else if ( (datalen % clk) <= clk/8 ) {
+               // padd the amount off - could be problematic...  but shouldn't happen often
+               datalen -= datalen % clk;
+       } else {
+               if (g_debugMode==2) prnt("DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting", datalen, clk, datalen % clk);
+               return false;
+       }
+       // if datalen is less than one t55xx block - ERROR
+       if (datalen/clk < 8*4) {
+               if (g_debugMode==2) prnt("DEBUG STT: datalen is less than 1 full t55xx block - quitting");              
+               return false;
+       }
+       size_t dataloc = start;
+       if (buffer[dataloc-(clk*4)-(clk/8)] <= low && buffer[dataloc] <= low && buffer[dataloc-(clk*4)] >= high) {
+               //we have low drift (and a low just before the ST and a low just after the ST) - compensate by backing up the start 
+               for ( i=0; i <= (clk/8); ++i ) {
+                       if ( buffer[dataloc - (clk*4) - i] <= low ) {
+                               dataloc -= i;
+                               break;
+                       }
+               }
+       }
+       
+       size_t newloc = 0;
+       i=0;
+       if (g_debugMode==2) prnt("DEBUG STT: Starting STT trim - start: %d, datalen: %d ",dataloc, datalen);            
+       bool firstrun = true;
+       // warning - overwriting buffer given with raw wave data with ST removed...
+       while ( dataloc < bufsize-(clk/2) ) {
+               //compensate for long high at end of ST not being high due to signal loss... (and we cut out the start of wave high part)
+               if (buffer[dataloc]<high && buffer[dataloc]>low && buffer[dataloc+3]<high && buffer[dataloc+3]>low) {
+                       for(i=0; i < clk/2-tol; ++i) {
+                               buffer[dataloc+i] = high+5;
+                       }
+               } //test for single sample outlier (high between two lows) in the case of very strong waves
+               if (buffer[dataloc] >= high && buffer[dataloc+2] <= low) {
+                       buffer[dataloc] = buffer[dataloc+2];
+                       buffer[dataloc+1] = buffer[dataloc+2];
+               }
+               if (firstrun) {
+                       *stend = dataloc;
+                       *ststart = dataloc-(clk*4);
+                       firstrun=false;
+               }
+               for (i=0; i<datalen; ++i) {
+                       if (i+newloc < bufsize) {
+                               if (i+newloc < dataloc)
+                                       buffer[i+newloc] = buffer[dataloc];
+
+                               dataloc++;
+                       }
+               }
+               newloc += i;
+               //skip next ST  -  we just assume it will be there from now on...
+               if (g_debugMode==2) prnt("DEBUG STT: skipping STT at %d to %d", dataloc, dataloc+(clk*4));
+               dataloc += clk*4;
+       }
+       *size = newloc;
+       return true;
+}
+bool DetectST(uint8_t  buffer[], size_t *size, int *foundclock) {
+       size_t ststart = 0, stend = 0;
+       return DetectST_ext(buffer, size, foundclock, &ststart, &stend);
+}
+
+//by marshmellow
+//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) {
+       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 {
@@ -491,39 +500,251 @@ int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert)
        return errCnt;
 }
 
-// by marshmellow
-// 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};
+//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, uint8_t invert, uint8_t *alignPos) {
+       uint16_t bitnum=0, MaxBits = 512, errCnt = 0;
+       size_t i, ii;
+       uint16_t bestErr = 1000, bestRun = 0;
+       if (*size < 16) return -1;
+       //find correct start position [alignment]
+       for (ii=0;ii<2;++ii){
+               for (i=ii; i<*size-3; i+=2)
+                       if (BitStream[i]==BitStream[i+1])
+                               errCnt++;
 
-       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;
+               if (bestErr>errCnt){
+                       bestErr=errCnt;
+                       bestRun=ii;
+               }
+               errCnt=0;
        }
-       return -5; //spacer bits not found - not a valid gproxII
+       *alignPos=bestRun;
+       //decode
+       for (i=bestRun; i < *size-3; i+=2){
+               if(BitStream[i] == 1 && (BitStream[i+1] == 0)){
+                       BitStream[bitnum++]=invert;
+               } else if((BitStream[i] == 0) && BitStream[i+1] == 1){
+                       BitStream[bitnum++]=invert^1;
+               } else {
+                       BitStream[bitnum++]=7;
+               }
+               if(bitnum>MaxBits) break;
+       }
+       *size=bitnum;
+       return bestErr;
 }
 
-//translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq])
-size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow, int *startIdx)
-{
-       size_t last_transition = 0;
-       size_t idx = 1;
-       if (fchigh==0) fchigh=10;
-       if (fclow==0) fclow=8;
-       //set the threshold close to 0 (graph) or 128 std to avoid static
-       uint8_t threshold_value = 123; 
-       size_t preLastSample = 0;
-       size_t LastSample = 0;
+// by marshmellow
+// to detect a wave that has heavily clipped (clean) samples
+uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low) {
+       bool allArePeaks = true;
+       uint16_t cntPeaks=0;
+       size_t loopEnd = 512+160;
+       if (loopEnd > size) loopEnd = size;
+       for (size_t i=160; i<loopEnd; i++){
+               if (dest[i]>low && dest[i]<high) 
+                       allArePeaks = false;
+               else
+                       cntPeaks++;
+       }
+       if (!allArePeaks){
+               if (cntPeaks > 300) return true;
+       }
+       return allArePeaks;
+}
+
+//by marshmellow
+//demodulates strong heavily clipped samples
+int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low, int *startIdx)
+{
+       *startIdx=0;
+       size_t bitCnt=0, smplCnt=1, errCnt=0;
+       bool waveHigh = (BinStream[0] >= high);
+       for (size_t i=1; 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++;
+                                               if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
+                                               BinStream[bitCnt++] = 7;
+                                       } else if (waveHigh) {
+                                               BinStream[bitCnt++] = invert;
+                                               BinStream[bitCnt++] = invert;
+                                       } else if (!waveHigh) {
+                                               BinStream[bitCnt++] = invert ^ 1;
+                                               BinStream[bitCnt++] = invert ^ 1;
+                                       }
+                                       if (*startIdx==0) *startIdx = i-clk;
+                                       waveHigh = !waveHigh;  
+                                       smplCnt = 0;
+                               } else if (smplCnt > (clk/2) - (clk/4)-1) { //half clock
+                                       if (waveHigh) {
+                                               BinStream[bitCnt++] = invert;
+                                       } else if (!waveHigh) {
+                                               BinStream[bitCnt++] = invert ^ 1;
+                                       }
+                                       if (*startIdx==0) *startIdx = i-(clk/2);
+                                       waveHigh = !waveHigh;  
+                                       smplCnt = 0;
+                               } else {
+                                       smplCnt++;
+                                       //transition bit oops
+                               }
+                       } else { //haven't hit new high or new low yet
+                               smplCnt++;
+                       }
+               }
+       }
+       *size = bitCnt;
+       return errCnt;
+}
+
+//by marshmellow
+//attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester
+int askdemod_ext(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType, int *startIdx) {
+       if (*size==0) return -1;
+       int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default
+       if (*clk==0 || start < 0) return -3;
+       if (*invert != 1) *invert = 0;
+       if (amp==1) askAmp(BinStream, *size);
+       if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d, amp %d", *clk, start, amp);
+
+       //start pos from detect ask clock is 1/2 clock offset
+       // NOTE: can be negative (demod assumes rest of wave was there)
+       *startIdx = start - (*clk/2); 
+       uint8_t initLoopMax = 255;
+       if (initLoopMax > *size) initLoopMax = *size;
+       // Detect high and lows
+       //25% clip in case highs and lows aren't clipped [marshmellow]
+       int high, low;
+       if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1) 
+               return -2; //just noise
+
+       size_t errCnt = 0;
+       // if clean clipped waves detected run alternate demod
+       if (DetectCleanAskWave(BinStream, *size, high, low)) {
+               if (g_debugMode==2) prnt("DEBUG ASK: Clean Wave Detected - using clean wave demod");
+               errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low, startIdx);
+               if (askType) { //askman
+                       uint8_t alignPos = 0;
+                       errCnt = manrawdecode(BinStream, size, 0, &alignPos);
+                       *startIdx += *clk/2 * alignPos;
+                       if (g_debugMode) prnt("DEBUG ASK CLEAN: startIdx %i, alignPos %u", *startIdx, alignPos);
+                       return errCnt;
+               } else { //askraw
+                       return errCnt;
+               }
+       }
+       if (g_debugMode) prnt("DEBUG ASK WEAK: startIdx %i", *startIdx);
+       if (g_debugMode==2) prnt("DEBUG ASK: Weak Wave Detected - using weak wave demod");
+
+       int lastBit;              //set first clock check - can go negative
+       size_t i, bitnum = 0;     //output counter
+       uint8_t midBit = 0;
+       uint8_t tol = 0;          //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave
+       if (*clk <= 32) tol = 1;  //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely
+       size_t MaxBits = 3072;    //max bits to collect
+       lastBit = start - *clk;
+
+       for (i = start; i < *size; ++i) {
+               if (i-lastBit >= *clk-tol){
+                       if (BinStream[i] >= high) {
+                               BinStream[bitnum++] = *invert;
+                       } else if (BinStream[i] <= low) {
+                               BinStream[bitnum++] = *invert ^ 1;
+                       } else if (i-lastBit >= *clk+tol) {
+                               if (bitnum > 0) {
+                                       if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
+                                       BinStream[bitnum++]=7;
+                                       errCnt++;                                               
+                               } 
+                       } else { //in tolerance - looking for peak
+                               continue;
+                       }
+                       midBit = 0;
+                       lastBit += *clk;
+               } else if (i-lastBit >= (*clk/2-tol) && !midBit && !askType){
+                       if (BinStream[i] >= high) {
+                               BinStream[bitnum++] = *invert;
+                       } else if (BinStream[i] <= low) {
+                               BinStream[bitnum++] = *invert ^ 1;
+                       } else if (i-lastBit >= *clk/2+tol) {
+                               BinStream[bitnum] = BinStream[bitnum-1];
+                               bitnum++;
+                       } else { //in tolerance - looking for peak
+                               continue;
+                       }
+                       midBit = 1;
+               }
+               if (bitnum >= MaxBits) break;
+       }
+       *size = bitnum;
+       return errCnt;
+}
+
+int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType) {
+       int start = 0;
+       return askdemod_ext(BinStream, size, clk, invert, maxErr, amp, askType, &start);
+}
+
+// by marshmellow - demodulate NRZ wave - requires a read with strong signal
+// peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
+int nrzRawDemod_ext(uint8_t *dest, size_t *size, int *clk, int *invert, int *startIdx) {
+       if (justNoise(dest, *size)) return -1;
+       *clk = DetectNRZClock(dest, *size, *clk);
+       if (*clk==0) return -2;
+       size_t i, gLen = 4096;
+       if (gLen>*size) gLen = *size-20;
+       int high, low;
+       if (getHiLo(dest, gLen, &high, &low, 75, 75) < 1) return -3; //25% fuzz on high 25% fuzz on low
+       
+       uint8_t bit=0;
+       //convert wave samples to 1's and 0's
+       for(i=20; i < *size-20; i++){
+               if (dest[i] >= high) bit = 1;
+               if (dest[i] <= low)  bit = 0;
+               dest[i] = bit;
+       }
+       //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit) 
+       size_t lastBit = 0;
+       size_t numBits = 0;
+       for(i=21; i < *size-20; i++) {
+               //if transition detected or large number of same bits - store the passed bits
+               if (dest[i] != dest[i-1] || (i-lastBit) == (10 * *clk)) {
+                       memset(dest+numBits, dest[i-1] ^ *invert, (i - lastBit + (*clk/4)) / *clk);
+                       numBits += (i - lastBit + (*clk/4)) / *clk;
+                       if (lastBit == 0) {
+                               *startIdx = i - (numBits * *clk);
+                               if (g_debugMode==2) prnt("DEBUG NRZ: startIdx %i", *startIdx);
+                       }
+                       lastBit = i-1;
+               }
+       }
+       *size = numBits;
+       return 0;
+}
+int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert) {
+       int startIdx = 0;
+       return nrzRawDemod_ext(dest, size, clk, invert, &startIdx);
+}
+
+//translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq])
+size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow, int *startIdx) {
+       size_t last_transition = 0;
+       size_t idx = 1;
+       if (fchigh==0) fchigh=10;
+       if (fclow==0) fclow=8;
+       //set the threshold close to 0 (graph) or 128 std to avoid static
+       uint8_t threshold_value = 123; 
+       size_t preLastSample = 0;
+       size_t LastSample = 0;
        size_t currSample = 0;
        if ( size < 1024 ) return 0; // not enough samples
 
@@ -577,9 +798,7 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow
 
 //translate 11111100000 to 10
 //rfLen = clock, fchigh = larger field clock, fclow = smaller field clock
-size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen,
-               uint8_t invert, uint8_t fchigh, uint8_t fclow, int *startIdx)
-{
+size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow, int *startIdx) {
        uint8_t lastval=dest[0];
        size_t idx=0;
        size_t numBits=0;
@@ -641,257 +860,200 @@ int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t
        return fskdemod_ext(dest, size, rfLen, invert, fchigh, fclow, &startIdx);
 }
 
-// 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*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
+// by marshmellow
+// convert psk1 demod to psk2 demod
+// only transition waves are 1s
+void psk1TOpsk2(uint8_t *BitStream, size_t size) {
+       size_t i=1;
+       uint8_t lastBit=BitStream[0];
+       for (; i<size; i++){
+               if (BitStream[i]==7){
+                       //ignore errors
+               } else if (lastBit!=BitStream[i]){
+                       lastBit=BitStream[i];
+                       BitStream[i]=1;
+               } else {
+                       BitStream[i]=0;
                }
-               *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;
+       return;
 }
 
-// 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
-       *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;
+// 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 (int)startIdx;
+       return;
 }
 
-int IOdemodFSK(uint8_t *dest, size_t size)
-{
-       if (justNoise(dest, size)) return -1;
-       //make sure buffer has data
-       if (size < 66*64) return -2;
-       // FSK demodulator
-       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
-       //|           |           |           |           |           |           |
-       //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
-       //-----------------------------------------------------------------------------
-       //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
-       //
-       //XSF(version)facility:codeone+codetwo
-       //Handle the data
-       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
+//by marshmellow - demodulate PSK1 wave 
+//uses wave lengths (# Samples) 
+int pskRawDemod_ext(uint8_t dest[], size_t *size, int *clock, int *invert, int *startIdx) {
+       if (size == 0) return -1;
+       uint16_t loopCnt = 4096;  //don't need to loop through entire array...
+       if (*size<loopCnt) loopCnt = *size;
 
-       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 -5;
-} 
+       size_t numBits=0;
+       uint8_t curPhase = *invert;
+       size_t i=0, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0;
+       uint16_t fc=0, fullWaveLen=0, tol=1;
+       uint16_t errCnt=0, waveLenCnt=0, errCnt2=0;
+       fc = countFC(dest, *size, 1);
+       uint8_t fc2 = fc >> 8;
+       if (fc2 == 10) return -1; //fsk found - quit
+       fc = fc & 0xFF;
+       if (fc!=2 && fc!=4 && fc!=8) return -1;
+       //PrintAndLog("DEBUG: FC: %d",fc);
+       *clock = DetectPSKClock(dest, *size, *clock);
+       if (*clock == 0) return -1;
 
-// by marshmellow
-// find viking preamble 0xF200 in already demoded data
-int VikingDemod_AM(uint8_t *dest, size_t *size) {
-       //make sure buffer has data
-       if (*size < 64*2) return -2;
+       //find start of modulating data in trace 
+       uint8_t threshold_value = 123; //-5
+       i = findModStart(dest, *size, threshold_value, fc);
 
-       size_t startIdx = 0;
-       uint8_t preamble[] = {1,1,1,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
-       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
-       if (errChk == 0) return -4; //preamble not found
-       uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^ bytebits_to_byte(dest+startIdx+8,8) ^ bytebits_to_byte(dest+startIdx+16,8)
-           ^ bytebits_to_byte(dest+startIdx+24,8) ^ bytebits_to_byte(dest+startIdx+32,8) ^ bytebits_to_byte(dest+startIdx+40,8) 
-           ^ bytebits_to_byte(dest+startIdx+48,8) ^ bytebits_to_byte(dest+startIdx+56,8);
-       if ( checkCalc != 0xA8 ) return -5;
-       if (*size != 64) return -6;
-       //return start position
-       return (int) startIdx;
-}
+       //find first phase shift
+       int avgWaveVal=0, lastAvgWaveVal=0;
+       waveStart = i;
+       for (; i<loopCnt; i++) {
+               // find peak 
+               if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
+                       waveEnd = i+1;
+                       if (g_debugMode == 2) prnt("DEBUG PSK: waveEnd: %u, waveStart: %u",waveEnd, waveStart);
+                       waveLenCnt = waveEnd-waveStart;
+                       if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+3)){ //not first peak and is a large wave but not out of whack
+                               lastAvgWaveVal = avgWaveVal/(waveLenCnt);
+                               firstFullWave = waveStart;
+                               fullWaveLen=waveLenCnt;
+                               //if average wave value is > graph 0 then it is an up wave or a 1 (could cause inverting)
+                               if (lastAvgWaveVal > threshold_value) curPhase ^= 1;
+                               break;
+                       }
 
-// find presco preamble 0x10D in already demoded data
-int PrescoDemod(uint8_t *dest, size_t *size) {
-       //make sure buffer has data
-       if (*size < 64*2) return -2;
+                       waveStart = i+1;
+                       avgWaveVal = 0;
+               }
+               avgWaveVal += dest[i+2];
+       }
+       if (firstFullWave == 0) {
+               // no phase shift detected - could be all 1's or 0's - doesn't matter where we start
+               // so skip a little to ensure we are past any Start Signal
+               firstFullWave = 160;
+               memset(dest, curPhase, firstFullWave / *clock);
+       } else {
+               memset(dest, curPhase^1, firstFullWave / *clock);
+       }
+       //advance bits
+       numBits += (firstFullWave / *clock);
+       *startIdx = firstFullWave - (*clock * numBits)+2;
+       //set start of wave as clock align
+       lastClkBit = firstFullWave;
+       if (g_debugMode==2) prnt("DEBUG PSK: firstFullWave: %u, waveLen: %u, startIdx %i",firstFullWave,fullWaveLen, *startIdx);
+       if (g_debugMode==2) prnt("DEBUG PSK: clk: %d, lastClkBit: %u, fc: %u", *clock, lastClkBit,(unsigned int) fc);
+       waveStart = 0;
+       dest[numBits++] = curPhase; //set first read bit
+       for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){
+               //top edge of wave = start of new wave 
+               if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
+                       if (waveStart == 0) {
+                               waveStart = i+1;
+                               waveLenCnt = 0;
+                               avgWaveVal = dest[i+1];
+                       } else { //waveEnd
+                               waveEnd = i+1;
+                               waveLenCnt = waveEnd-waveStart;
+                               lastAvgWaveVal = avgWaveVal/waveLenCnt;
+                               if (waveLenCnt > fc){
+                                       //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);
+                                       //this wave is a phase shift
+                                       //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc);
+                                       if (i+1 >= lastClkBit + *clock - tol){ //should be a clock bit
+                                               curPhase ^= 1;
+                                               dest[numBits++] = curPhase;
+                                               lastClkBit += *clock;
+                                       } else if (i < lastClkBit+10+fc){
+                                               //noise after a phase shift - ignore
+                                       } else { //phase shift before supposed to based on clock
+                                               errCnt++;
+                                               dest[numBits++] = 7;
+                                       }
+                               } else if (i+1 > lastClkBit + *clock + tol + fc){
+                                       lastClkBit += *clock; //no phase shift but clock bit
+                                       dest[numBits++] = curPhase;
+                               } else if (waveLenCnt < fc - 1) { //wave is smaller than field clock (shouldn't happen often)
+                                       errCnt2++;
+                                       if(errCnt2 > 101) return errCnt2;
+                               }
+                               avgWaveVal = 0;
+                               waveStart = i+1;
+                       }
+               }
+               avgWaveVal += dest[i+1];
+       }
+       *size = numBits;
+       return errCnt;
+}
 
-       size_t startIdx = 0;
-       uint8_t preamble[] = {1,0,0,0,0,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0};
-       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
-       if (errChk == 0) return -4; //preamble not found
-       //return start position
-       return (int) startIdx;
+int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) {
+       int startIdx = 0;
+       return pskRawDemod_ext(dest, size, clock, invert, &startIdx);
 }
 
-// Ask/Biphase Demod then try to locate an ISO 11784/85 ID
-// BitStream must contain previously askrawdemod and biphasedemoded data
-int FDXBdemodBI(uint8_t *dest, size_t *size)
-{
-       //make sure buffer has enough data
-       if (*size < 128) return -1;
+//-------------------Clock / Bitrate Detection Section------------------------------------------------------------------------------------
 
-       size_t startIdx = 0;
-       uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,1};
+// by marshmellow
+// to help detect clocks on heavily clipped samples
+// based on count of low to low
+int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low, int *clock) {
+       uint8_t fndClk[] = {8,16,32,40,50,64,128};
+       size_t startwave;
+       size_t i = 100;
+       size_t minClk = 255;
+       int shortestWaveIdx = 0;
+               // get to first full low to prime loop and skip incomplete first pulse
+       while ((dest[i] < high) && (i < size))
+               ++i;
+       while ((dest[i] > low) && (i < size))
+               ++i;
 
-       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
-       if (errChk == 0) return -2; //preamble not found
-       return (int)startIdx;
-}
-
-// 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 a 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;
-}
-
-// by marshmellow
-// to detect a wave that has heavily clipped (clean) samples
-uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low)
-{
-       bool allArePeaks = true;
-       uint16_t cntPeaks=0;
-       size_t loopEnd = 512+160;
-       if (loopEnd > size) loopEnd = size;
-       for (size_t i=160; i<loopEnd; i++){
-               if (dest[i]>low && dest[i]<high) 
-                       allArePeaks = false;
-               else
-                       cntPeaks++;
-       }
-       if (!allArePeaks){
-               if (cntPeaks > 300) return true;
-       }
-       return allArePeaks;
-}
-// by marshmellow
-// to help detect clocks on heavily clipped samples
-// based on count of low to low
-int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low, int *clock) {
-       uint8_t fndClk[] = {8,16,32,40,50,64,128};
-       size_t startwave;
-       size_t i = 100;
-       size_t minClk = 255;
-       int shortestWaveIdx = 0;
-               // get to first full low to prime loop and skip incomplete first pulse
-       while ((dest[i] < high) && (i < size))
-               ++i;
-       while ((dest[i] > low) && (i < size))
-               ++i;
-
-       // loop through all samples
-       while (i < size) {
-               // measure from low to low
-               while ((dest[i] > low) && (i < size))
-                       ++i;
-               startwave = i;
-               while ((dest[i] < high) && (i < size))
-                       ++i;
-               while ((dest[i] > low) && (i < size))
-                       ++i;
-               //get minimum measured distance
-               if (i-startwave < minClk && i < size) {
-                       minClk = i - startwave;
-                       shortestWaveIdx = startwave;
-               }
-       }
-       // set clock
-       if (g_debugMode==2) prnt("DEBUG ASK: detectstrongASKclk smallest wave: %d",minClk);
-       for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
-               if (minClk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1) {
-                       *clock = fndClk[clkCnt];
-                       return shortestWaveIdx;
-               }
-       }
-       return 0;
+       // loop through all samples
+       while (i < size) {
+               // measure from low to low
+               while ((dest[i] > low) && (i < size))
+                       ++i;
+               startwave = i;
+               while ((dest[i] < high) && (i < size))
+                       ++i;
+               while ((dest[i] > low) && (i < size))
+                       ++i;
+               //get minimum measured distance
+               if (i-startwave < minClk && i < size) {
+                       minClk = i - startwave;
+                       shortestWaveIdx = startwave;
+               }
+       }
+       // set clock
+       if (g_debugMode==2) prnt("DEBUG ASK: detectstrongASKclk smallest wave: %d",minClk);
+       for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
+               if (minClk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1) {
+                       *clock = fndClk[clkCnt];
+                       return shortestWaveIdx;
+               }
+       }
+       return 0;
 }
 
 // by marshmellow
 // not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)
 // maybe somehow adjust peak trimming value based on samples to fix?
 // return start index of best starting position for that clock and return clock (by reference)
-int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
-{
+int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr) {
        size_t i=1;
        uint8_t clk[] = {255,8,16,32,40,50,64,100,128,255};
        uint8_t clkEnd = 9;
@@ -987,108 +1149,6 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
        return bestStart[best];
 }
 
-//by marshmellow
-//detect psk clock by reading each phase shift
-// a phase shift is determined by measuring the sample length of each wave
-int DetectPSKClock_ext(uint8_t dest[], size_t size, int clock, int *firstPhaseShift) {
-       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-20;
-
-       //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};
-       fc = countFC(dest, size, 0);
-       if (fc!=2 && fc!=4 && fc!=8) return -1;
-       if (g_debugMode==2) prnt("DEBUG PSK: FC: %d",fc);
-
-       //find first full wave
-       for (i=160; i<loopCnt; i++){
-               if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
-                       if (waveStart == 0) {
-                               waveStart = i+1;
-                               //prnt("DEBUG: waveStart: %d",waveStart);
-                       } else {
-                               waveEnd = i+1;
-                               //prnt("DEBUG: waveEnd: %d",waveEnd);
-                               waveLenCnt = waveEnd-waveStart;
-                               if (waveLenCnt > fc){
-                                       firstFullWave = waveStart;
-                                       fullWaveLen=waveLenCnt;
-                                       break;
-                               } 
-                               waveStart=0;
-                       }
-               }
-       }
-       *firstPhaseShift = firstFullWave;
-       if (g_debugMode ==2) prnt("DEBUG PSK: 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;
-               if (g_debugMode == 2) prnt("DEBUG PSK: 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
-                                               if (g_debugMode == 2) prnt("DEBUG PSK: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+clk[clkCnt]-tol,i+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;
-               }
-               if (g_debugMode == 2) prnt("DEBUG PSK: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[i],peaksdet[i],bestErr[i],clk[best]);
-       }
-       return clk[best];
-}
-
-int DetectPSKClock(uint8_t dest[], size_t size, int clock) {
-       int firstPhaseShift = 0;
-       return DetectPSKClock_ext(dest, size, clock, &firstPhaseShift);
-}
-
 int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low){
        //find shortest transition from high to low
        size_t i = 0;
@@ -1241,101 +1301,194 @@ int DetectNRZClock(uint8_t dest[], size_t size, int clock) {
        return DetectNRZClock_ext(dest, size, clock, &bestStart);
 }
 
-// by marshmellow
-// convert psk1 demod to psk2 demod
-// only transition waves are 1s
-void psk1TOpsk2(uint8_t *BitStream, size_t size)
-{
-       size_t i=1;
-       uint8_t lastBit=BitStream[0];
-       for (; i<size; i++){
-               if (BitStream[i]==7){
-                       //ignore errors
-               } else if (lastBit!=BitStream[i]){
-                       lastBit=BitStream[i];
-                       BitStream[i]=1;
+//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 fskAdj) {
+       uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+       uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+       uint8_t fcLensFnd = 0;
+       uint8_t lastFCcnt = 0;
+       uint8_t fcCounter = 0;
+       size_t i;
+       if (size < 180) return 0;
+
+       // prime i to first up transition
+       for (i = 160; i < size-20; i++)
+               if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1])
+                       break;
+
+       for (; i < size-20; 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<15; ii++){
+                               if (fcLens[ii]==fcCounter){
+                                       fcCnts[ii]++;
+                                       fcCounter=0;
+                                       break;
+                               }
+                       }
+                       if (fcCounter>0 && fcLensFnd<15){
+                               //add new fc length 
+                               fcCnts[fcLensFnd]++;
+                               fcLens[fcLensFnd++]=fcCounter;
+                       }
+                       fcCounter=0;
                } else {
-                       BitStream[i]=0;
+                       // count sample
+                       fcCounter++;
                }
        }
-       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;
+       
+       uint8_t best1=14, best2=14, best3=14;
+       uint16_t maxCnt1=0;
+       // go through fclens and find which ones are bigest 2  
+       for (i=0; i<15; i++){
+               // 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;
                }
-               BitStream[i]=phase;
+               if (g_debugMode==2) prnt("DEBUG countfc: FC %u, Cnt %u, best fc: %u, best2 fc: %u",fcLens[i],fcCnts[i],fcLens[best1],fcLens[best2]);
        }
-       return;
+       if (fcLens[best1]==0) return 0;
+       uint8_t fcH=0, fcL=0;
+       if (fcLens[best1]>fcLens[best2]){
+               fcH=fcLens[best1];
+               fcL=fcLens[best2];
+       } else{
+               fcH=fcLens[best2];
+               fcL=fcLens[best1];
+       }
+       if ((size-180)/fcH/3 > fcCnts[best1]+fcCnts[best2]) {
+               if (g_debugMode==2) prnt("DEBUG countfc: fc is too large: %u > %u. Not psk or fsk",(size-180)/fcH/3,fcCnts[best1]+fcCnts[best2]);
+               return 0; //lots of waves not psk or fsk
+       }
+       // TODO: take top 3 answers and compare to known Field clocks to get top 2
+
+       uint16_t fcs = (((uint16_t)fcH)<<8) | fcL;
+       if (fskAdj) return fcs; 
+       return fcLens[best1];
 }
 
-// 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)
-       uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
-       uint8_t preamble_i[] = {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0};
-       size_t startidx = 0; 
-       if (!preambleSearch(bitStream, preamble, sizeof(preamble), size, &startidx)){
-               // if didn't find preamble try again inverting
-               if (!preambleSearch(bitStream, preamble_i, sizeof(preamble_i), size, &startidx)) return -1;
-               *invert ^= 1;
-       } 
-       if (*size != 64 && *size != 224) return -2;
-       if (*invert==1)
-               for (size_t i = startidx; i < *size; i++)
-                       bitStream[i] ^= 1;
+//by marshmellow
+//detect psk clock by reading each phase shift
+// a phase shift is determined by measuring the sample length of each wave
+int DetectPSKClock_ext(uint8_t dest[], size_t size, int clock, int *firstPhaseShift) {
+       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-20;
 
-       return (int) startidx;
-}
+       //if we already have a valid clock quit
+       size_t i=1;
+       for (; i < 8; ++i)
+               if (clk[i] == clock) return clock;
 
-// by marshmellow - demodulate NRZ wave - requires a read with strong signal
-// peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
-int nrzRawDemod_ext(uint8_t *dest, size_t *size, int *clk, int *invert, int *startIdx) {
-       if (justNoise(dest, *size)) return -1;
-       *clk = DetectNRZClock(dest, *size, *clk);
-       if (*clk==0) return -2;
-       size_t i, gLen = 4096;
-       if (gLen>*size) gLen = *size-20;
-       int high, low;
-       if (getHiLo(dest, gLen, &high, &low, 75, 75) < 1) return -3; //25% fuzz on high 25% fuzz on low
-       
-       uint8_t bit=0;
-       //convert wave samples to 1's and 0's
-       for(i=20; i < *size-20; i++){
-               if (dest[i] >= high) bit = 1;
-               if (dest[i] <= low)  bit = 0;
-               dest[i] = bit;
+       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;
+       if (g_debugMode==2) prnt("DEBUG PSK: FC: %d",fc);
+
+       //find first full wave
+       for (i=160; i<loopCnt; i++){
+               if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
+                       if (waveStart == 0) {
+                               waveStart = i+1;
+                               //prnt("DEBUG: waveStart: %d",waveStart);
+                       } else {
+                               waveEnd = i+1;
+                               //prnt("DEBUG: waveEnd: %d",waveEnd);
+                               waveLenCnt = waveEnd-waveStart;
+                               if (waveLenCnt > fc){
+                                       firstFullWave = waveStart;
+                                       fullWaveLen=waveLenCnt;
+                                       break;
+                               } 
+                               waveStart=0;
+                       }
+               }
        }
-       //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit) 
-       size_t lastBit = 0;
-       size_t numBits = 0;
-       for(i=21; i < *size-20; i++) {
-               //if transition detected or large number of same bits - store the passed bits
-               if (dest[i] != dest[i-1] || (i-lastBit) == (10 * *clk)) {
-                       memset(dest+numBits, dest[i-1] ^ *invert, (i - lastBit + (*clk/4)) / *clk);
-                       numBits += (i - lastBit + (*clk/4)) / *clk;
-                       if (lastBit == 0) {
-                               *startIdx = i - (numBits * *clk);
-                               if (g_debugMode==2) prnt("DEBUG NRZ: startIdx %i", *startIdx);
+       *firstPhaseShift = firstFullWave;
+       if (g_debugMode ==2) prnt("DEBUG PSK: 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;
+               if (g_debugMode == 2) prnt("DEBUG PSK: 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
+                                               if (g_debugMode == 2) prnt("DEBUG PSK: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+clk[clkCnt]-tol,i+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;
+                               }
                        }
-                       lastBit = 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;
+               }
+               if (g_debugMode == 2) prnt("DEBUG PSK: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[i],peaksdet[i],bestErr[i],clk[best]);
        }
-       *size = numBits;
-       return 0;
+       return clk[best];
 }
-int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert) {
-       int startIdx = 0;
-       return nrzRawDemod_ext(dest, size, clk, invert, &startIdx);
+
+int DetectPSKClock(uint8_t dest[], size_t size, int clock) {
+       int firstPhaseShift = 0;
+       return DetectPSKClock_ext(dest, size, clock, &firstPhaseShift);
 }
 
 //by marshmellow
@@ -1451,402 +1604,260 @@ uint8_t       detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc
        return detectFSKClk_ext(BitStream, size, fcHigh, fcLow, &firstClockEdge);
 }
 
+//-----------------Tag format detection section--------------------------------------------------------------
+
+// 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
-//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 fskAdj)
+//takes 1s and 0s and searches for EM410x format - output EM ID
+uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo)
 {
-       uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
-       uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
-       uint8_t fcLensFnd = 0;
-       uint8_t lastFCcnt = 0;
-       uint8_t fcCounter = 0;
-       size_t i;
-       if (size < 180) return 0;
+       //sanity checks
+       if (*size < 64) return 0;
+       if (BitStream[1]>1) return 0;  //allow only 1s and 0s
 
-       // prime i to first up transition
-       for (i = 160; i < size-20; i++)
-               if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1])
-                       break;
+       // 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};
+       uint8_t errChk = 0;
+       uint8_t FmtLen = 10; // sets of 4 bits = end data 
+       *startIdx = 0;
+       errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx);
+       if ( errChk == 0 || (*size != 64 && *size != 128) ) return 0;
+       if (*size == 128) FmtLen = 22; // 22 sets of 4 bits
 
-       for (; i < size-20; 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<15; ii++){
-                               if (fcLens[ii]==fcCounter){
-                                       fcCnts[ii]++;
-                                       fcCounter=0;
-                                       break;
-                               }
-                       }
-                       if (fcCounter>0 && fcLensFnd<15){
-                               //add new fc length 
-                               fcCnts[fcLensFnd]++;
-                               fcLens[fcLensFnd++]=fcCounter;
-                       }
-                       fcCounter=0;
-               } else {
-                       // count sample
-                       fcCounter++;
-               }
-       }
-       
-       uint8_t best1=14, best2=14, best3=14;
-       uint16_t maxCnt1=0;
-       // go through fclens and find which ones are bigest 2  
-       for (i=0; i<15; i++){
-               // 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;
-               }
-               if (g_debugMode==2) prnt("DEBUG countfc: FC %u, Cnt %u, best fc: %u, best2 fc: %u",fcLens[i],fcCnts[i],fcLens[best1],fcLens[best2]);
-       }
-       if (fcLens[best1]==0) return 0;
-       uint8_t fcH=0, fcL=0;
-       if (fcLens[best1]>fcLens[best2]){
-               fcH=fcLens[best1];
-               fcL=fcLens[best2];
-       } else{
-               fcH=fcLens[best2];
-               fcL=fcLens[best1];
-       }
-       if ((size-180)/fcH/3 > fcCnts[best1]+fcCnts[best2]) {
-               if (g_debugMode==2) prnt("DEBUG countfc: fc is too large: %u > %u. Not psk or fsk",(size-180)/fcH/3,fcCnts[best1]+fcCnts[best2]);
-               return 0; //lots of waves not psk or fsk
+       //skip last 4bit parity row for simplicity
+       *size = removeParity(BitStream, *startIdx + sizeof(preamble), 5, 0, FmtLen * 5);
+       if (*size == 40) { // std em410x format
+               *hi = 0;
+               *lo = ((uint64_t)(bytebits_to_byte(BitStream, 8)) << 32) | (bytebits_to_byte(BitStream + 8, 32));
+       } else if (*size == 88) { // long em format
+               *hi = (bytebits_to_byte(BitStream, 24)); 
+               *lo = ((uint64_t)(bytebits_to_byte(BitStream + 24, 32)) << 32) | (bytebits_to_byte(BitStream + 24 + 32, 32));
+       } else {
+               return 0;
        }
-       // TODO: take top 3 answers and compare to known Field clocks to get top 2
-
-       uint16_t fcs = (((uint16_t)fcH)<<8) | fcL;
-       if (fskAdj) return fcs; 
-       return fcLens[best1];
+       return 1;
 }
 
-//by marshmellow - demodulate PSK1 wave 
-//uses wave lengths (# Samples) 
-int pskRawDemod_ext(uint8_t dest[], size_t *size, int *clock, int *invert, int *startIdx) {
-       if (size == 0) return -1;
-       uint16_t loopCnt = 4096;  //don't need to loop through entire array...
-       if (*size<loopCnt) loopCnt = *size;
+// Ask/Biphase Demod then try to locate an ISO 11784/85 ID
+// BitStream must contain previously askrawdemod and biphasedemoded data
+int FDXBdemodBI(uint8_t *dest, size_t *size) {
+       //make sure buffer has enough data
+       if (*size < 128) return -1;
 
-       size_t numBits=0;
-       uint8_t curPhase = *invert;
-       size_t i=0, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0;
-       uint16_t fc=0, fullWaveLen=0, tol=1;
-       uint16_t errCnt=0, waveLenCnt=0, errCnt2=0;
-       fc = countFC(dest, *size, 1);
-       uint8_t fc2 = fc >> 8;
-       if (fc2 == 10) return -1; //fsk found - quit
-       fc = fc & 0xFF;
-       if (fc!=2 && fc!=4 && fc!=8) return -1;
-       //PrintAndLog("DEBUG: FC: %d",fc);
-       *clock = DetectPSKClock(dest, *size, *clock);
-       if (*clock == 0) return -1;
+       size_t startIdx = 0;
+       uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,1};
 
-       //find start of modulating data in trace 
-       uint8_t threshold_value = 123; //-5
-       i = findModStart(dest, *size, threshold_value, fc);
+       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+       if (errChk == 0) return -2; //preamble not found
+       return (int)startIdx;
+}
 
-       //find first phase shift
-       int avgWaveVal=0, lastAvgWaveVal=0;
-       waveStart = i;
-       for (; i<loopCnt; i++) {
-               // find peak 
-               if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
-                       waveEnd = i+1;
-                       if (g_debugMode == 2) prnt("DEBUG PSK: waveEnd: %u, waveStart: %u",waveEnd, waveStart);
-                       waveLenCnt = waveEnd-waveStart;
-                       if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+3)){ //not first peak and is a large wave but not out of whack
-                               lastAvgWaveVal = avgWaveVal/(waveLenCnt);
-                               firstFullWave = waveStart;
-                               fullWaveLen=waveLenCnt;
-                               //if average wave value is > graph 0 then it is an up wave or a 1 (could cause inverting)
-                               if (lastAvgWaveVal > threshold_value) curPhase ^= 1;
-                               break;
-                       }
+// by marshmellow
+// 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};
 
-                       waveStart = i+1;
-                       avgWaveVal = 0;
-               }
-               avgWaveVal += dest[i+2];
-       }
-       if (firstFullWave == 0) {
-               // no phase shift detected - could be all 1's or 0's - doesn't matter where we start
-               // so skip a little to ensure we are past any Start Signal
-               firstFullWave = 160;
-               memset(dest, curPhase, firstFullWave / *clock);
-       } else {
-               memset(dest, curPhase^1, firstFullWave / *clock);
-       }
-       //advance bits
-       numBits += (firstFullWave / *clock);
-       *startIdx = firstFullWave - (*clock * numBits)+2;
-       //set start of wave as clock align
-       lastClkBit = firstFullWave;
-       if (g_debugMode==2) prnt("DEBUG PSK: firstFullWave: %u, waveLen: %u, startIdx %i",firstFullWave,fullWaveLen, *startIdx);
-       if (g_debugMode==2) prnt("DEBUG PSK: clk: %d, lastClkBit: %u, fc: %u", *clock, lastClkBit,(unsigned int) fc);
-       waveStart = 0;
-       dest[numBits++] = curPhase; //set first read bit
-       for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){
-               //top edge of wave = start of new wave 
-               if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
-                       if (waveStart == 0) {
-                               waveStart = i+1;
-                               waveLenCnt = 0;
-                               avgWaveVal = dest[i+1];
-                       } else { //waveEnd
-                               waveEnd = i+1;
-                               waveLenCnt = waveEnd-waveStart;
-                               lastAvgWaveVal = avgWaveVal/waveLenCnt;
-                               if (waveLenCnt > fc){
-                                       //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);
-                                       //this wave is a phase shift
-                                       //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc);
-                                       if (i+1 >= lastClkBit + *clock - tol){ //should be a clock bit
-                                               curPhase ^= 1;
-                                               dest[numBits++] = curPhase;
-                                               lastClkBit += *clock;
-                                       } else if (i < lastClkBit+10+fc){
-                                               //noise after a phase shift - ignore
-                                       } else { //phase shift before supposed to based on clock
-                                               errCnt++;
-                                               dest[numBits++] = 7;
-                                       }
-                               } else if (i+1 > lastClkBit + *clock + tol + fc){
-                                       lastClkBit += *clock; //no phase shift but clock bit
-                                       dest[numBits++] = curPhase;
-                               } else if (waveLenCnt < fc - 1) { //wave is smaller than field clock (shouldn't happen often)
-                                       errCnt2++;
-                                       if(errCnt2 > 101) return errCnt2;
-                               }
-                               avgWaveVal = 0;
-                               waveStart = i+1;
-                       }
-               }
-               avgWaveVal += dest[i+1];
+       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;
        }
-       *size = numBits;
-       return errCnt;
-}
-
-int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) {
-       int startIdx = 0;
-       return pskRawDemod_ext(dest, size, clock, invert, &startIdx);
+       return -5; //spacer bits not found - not a valid gproxII
 }
 
-//by marshmellow
-//attempt to identify a Sequence Terminator in ASK modulated raw wave
-bool DetectST_ext(uint8_t buffer[], size_t *size, int *foundclock, size_t *ststart, size_t *stend) {
-       size_t bufsize = *size;
-       //need to loop through all samples and identify our clock, look for the ST pattern
-       uint8_t fndClk[] = {8,16,32,40,50,64,128};
-       int clk = 0; 
-       int tol = 0;
-       int i, j, skip, start, end, low, high, minClk, waveStart;
-       bool complete = false;
-       int tmpbuff[bufsize / 32]; //guess rf/32 clock, if click is smaller we will only have room for a fraction of the samples captured
-       int waveLen[bufsize / 32]; //  if clock is larger then we waste memory in array size that is not needed...
-       size_t testsize = (bufsize < 512) ? bufsize : 512;
-       int phaseoff = 0;
-       high = low = 128;
-       memset(tmpbuff, 0, sizeof(tmpbuff));
+// 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;
 
-       if ( getHiLo(buffer, testsize, &high, &low, 80, 80) == -1 ) {
-               if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting");
-               return false; //just noise
-       }
-       i = 0;
-       j = 0;
-       minClk = 255;
-       // get to first full low to prime loop and skip incomplete first pulse
-       while ((buffer[i] < high) && (i < bufsize))
-               ++i;
-       while ((buffer[i] > low) && (i < bufsize))
-               ++i;
-       skip = i;
+       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
 
-       // populate tmpbuff buffer with pulse lengths
-       while (i < bufsize) {
-               // measure from low to low
-               while ((buffer[i] > low) && (i < bufsize))
-                       ++i;
-               start= i;
-               while ((buffer[i] < high) && (i < bufsize))
-                       ++i;
-               //first high point for this wave
-               waveStart = i;
-               while ((buffer[i] > low) && (i < bufsize))
-                       ++i;
-               if (j >= (bufsize/32)) {
-                       break;
-               }
-               waveLen[j] = i - waveStart; //first high to first low
-               tmpbuff[j++] = i - start;
-               if (i-start < minClk && i < bufsize) {
-                       minClk = i - start;
+       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;
        }
-       // set clock  - might be able to get this externally and remove this work...
-       if (!clk) {
-               for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
-                       tol = fndClk[clkCnt]/8;
-                       if (minClk >= fndClk[clkCnt]-tol && minClk <= fndClk[clkCnt]+1) { 
-                               clk=fndClk[clkCnt];
-                               break;
-                       }
-               }
-               // clock not found - ERROR
-               if (!clk) {
-                       if (g_debugMode==2) prnt("DEBUG STT: clock not found - quitting");
-                       return false;
-               }
-       } else tol = clk/8;
+       return (int)startIdx;
+}
 
-       *foundclock = clk;
+int IOdemodFSK(uint8_t *dest, size_t size) {
+       if (justNoise(dest, size)) return -1;
+       //make sure buffer has data
+       if (size < 66*64) return -2;
+       // FSK demodulator
+       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
+       //|           |           |           |           |           |           |
+       //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
+       //-----------------------------------------------------------------------------
+       //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
+       //
+       //XSF(version)facility:codeone+codetwo
+       //Handle the data
+       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
 
-       // look for Sequence Terminator - should be pulses of clk*(1 or 1.5), clk*2, clk*(1.5 or 2)
-       start = -1;
-       for (i = 0; i < j - 4; ++i) {
-               skip += tmpbuff[i];
-               if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol && waveLen[i] < clk+tol) {           //1 to 2 clocks depending on 2 bits prior
-                       if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) {       //2 clocks and wave size is 1 1/2
-                               if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave
-                                       if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit
-                                               start = i + 3;
-                                               break;
-                                       }
-                               }
-                       }
-               }
-       }
-       // first ST not found - ERROR
-       if (start < 0) {
-               if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting");
-               return false;
-       } else {
-               if (g_debugMode==2) prnt("DEBUG STT: first STT found at: %d, j=%d",start, j);
+       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;
        }
-       if (waveLen[i+2] > clk*1+tol)
-               phaseoff = 0;
-       else
-               phaseoff = clk/2;
-       
-       // skip over the remainder of ST
-       skip += clk*7/2; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point
+       return -5;
+} 
 
-       // now do it again to find the end
-       end = skip;
-       for (i += 3; i < j - 4; ++i) {
-               end += tmpbuff[i];
-               if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol && waveLen[i] < clk+tol) {           //1 to 2 clocks depending on 2 bits prior
-                       if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) {       //2 clocks and wave size is 1 1/2
-                               if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave
-                                       if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit
-                                               complete = true;
-                                               break;
-                                       }
-                               }
-                       }
-               }
-       }
-       end -= phaseoff;
-       //didn't find second ST - ERROR
-       if (!complete) {
-               if (g_debugMode==2) prnt("DEBUG STT: second STT not found - quitting");
-               return false;
-       }
-       if (g_debugMode==2) prnt("DEBUG STT: start of data: %d end of data: %d, datalen: %d, clk: %d, bits: %d, phaseoff: %d", skip, end, end-skip, clk, (end-skip)/clk, phaseoff);
-       //now begin to trim out ST so we can use normal demod cmds
-       start = skip;
-       size_t datalen = end - start;
-       // check validity of datalen (should be even clock increments)  - use a tolerance of up to 1/8th a clock
-       if ( clk - (datalen % clk) <= clk/8) {
-               // padd the amount off - could be problematic...  but shouldn't happen often
-               datalen += clk - (datalen % clk);
-       } else if ( (datalen % clk) <= clk/8 ) {
-               // padd the amount off - could be problematic...  but shouldn't happen often
-               datalen -= datalen % clk;
-       } else {
-               if (g_debugMode==2) prnt("DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting", datalen, clk, datalen % clk);
-               return false;
-       }
-       // if datalen is less than one t55xx block - ERROR
-       if (datalen/clk < 8*4) {
-               if (g_debugMode==2) prnt("DEBUG STT: datalen is less than 1 full t55xx block - quitting");              
-               return false;
-       }
-       size_t dataloc = start;
-       if (buffer[dataloc-(clk*4)-(clk/8)] <= low && buffer[dataloc] <= low && buffer[dataloc-(clk*4)] >= high) {
-               //we have low drift (and a low just before the ST and a low just after the ST) - compensate by backing up the start 
-               for ( i=0; i <= (clk/8); ++i ) {
-                       if ( buffer[dataloc - (clk*4) - i] <= low ) {
-                               dataloc -= i;
-                               break;
-                       }
-               }
-       }
+// 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)
+       uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
+       uint8_t preamble_i[] = {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0};
+       size_t startidx = 0; 
+       if (!preambleSearch(bitStream, preamble, sizeof(preamble), size, &startidx)){
+               // if didn't find preamble try again inverting
+               if (!preambleSearch(bitStream, preamble_i, sizeof(preamble_i), size, &startidx)) return -1;
+               *invert ^= 1;
+       } 
+       if (*size != 64 && *size != 224) return -2;
+       if (*invert==1)
+               for (size_t i = startidx; i < *size; i++)
+                       bitStream[i] ^= 1;
+
+       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 newloc = 0;
-       i=0;
-       if (g_debugMode==2) prnt("DEBUG STT: Starting STT trim - start: %d, datalen: %d ",dataloc, datalen);            
-       bool firstrun = true;
-       // warning - overwriting buffer given with raw wave data with ST removed...
-       while ( dataloc < bufsize-(clk/2) ) {
-               //compensate for long high at end of ST not being high due to signal loss... (and we cut out the start of wave high part)
-               if (buffer[dataloc]<high && buffer[dataloc]>low && buffer[dataloc+3]<high && buffer[dataloc+3]>low) {
-                       for(i=0; i < clk/2-tol; ++i) {
-                               buffer[dataloc+i] = high+5;
-                       }
-               } //test for single sample outlier (high between two lows) in the case of very strong waves
-               if (buffer[dataloc] >= high && buffer[dataloc+2] <= low) {
-                       buffer[dataloc] = buffer[dataloc+2];
-                       buffer[dataloc+1] = buffer[dataloc+2];
-               }
-               if (firstrun) {
-                       *stend = dataloc;
-                       *ststart = dataloc-(clk*4);
-                       firstrun=false;
-               }
-               for (i=0; i<datalen; ++i) {
-                       if (i+newloc < bufsize) {
-                               if (i+newloc < dataloc)
-                                       buffer[i+newloc] = buffer[dataloc];
+       size_t numStart=0, size2=*size, startIdx=0;
+       // FSK demodulator
+       *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
+       if (*size < 96) return -2;
 
-                               dataloc++;
-                       }
-               }
-               newloc += i;
-               //skip next ST  -  we just assume it will be there from now on...
-               if (g_debugMode==2) prnt("DEBUG STT: skipping STT at %d to %d", dataloc, dataloc+(clk*4));
-               dataloc += clk*4;
+       // 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;
        }
-       *size = newloc;
-       return true;
+       return (int)startIdx;
 }
 
-bool DetectST(uint8_t  buffer[], size_t *size, int *foundclock) {
-       size_t ststart = 0, stend = 0;
-       return DetectST_ext(buffer, size, foundclock, &ststart, &stend);
+// find presco preamble 0x10D in already demoded data
+int PrescoDemod(uint8_t *dest, size_t *size) {
+       //make sure buffer has data
+       if (*size < 64*2) return -2;
+
+       size_t startIdx = 0;
+       uint8_t preamble[] = {1,0,0,0,0,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0};
+       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+       if (errChk == 0) return -4; //preamble not found
+       //return start position
+       return (int) startIdx;
 }
 
+// by marshmellow
+// FSK Demod then try to locate a 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;
+}
+
+// by marshmellow
+// find viking preamble 0xF200 in already demoded data
+int VikingDemod_AM(uint8_t *dest, size_t *size) {
+       //make sure buffer has data
+       if (*size < 64*2) return -2;
+
+       size_t startIdx = 0;
+       uint8_t preamble[] = {1,1,1,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+       if (errChk == 0) return -4; //preamble not found
+       uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^ bytebits_to_byte(dest+startIdx+8,8) ^ bytebits_to_byte(dest+startIdx+16,8)
+           ^ bytebits_to_byte(dest+startIdx+24,8) ^ bytebits_to_byte(dest+startIdx+32,8) ^ bytebits_to_byte(dest+startIdx+40,8) 
+           ^ bytebits_to_byte(dest+startIdx+48,8) ^ bytebits_to_byte(dest+startIdx+56,8);
+       if ( checkCalc != 0xA8 ) return -5;
+       if (*size != 64) return -6;
+       //return start position
+       return (int) startIdx;
+}
+
+
 // by iceman
 // find Visa2000 preamble in already demoded data
 int Visa2kDemod_AM(uint8_t *dest, size_t *size) {
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