Moved LogTraceHitag to BigBuf (no changes to the function ... yet)

[proxmark3-svn] / common / lfdemod.c

diff --git a/common/lfdemod.c b/common/lfdemod.c
index 34194394deea0ded2029bbe3e173a7261c36fc7e..88a250d87efd105fa85f70ef919c2fd89585a75d 100644 (file)
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -12,6 +12,18 @@
 #include <string.h>
 #include "lfdemod.h"
 
 #include <string.h>
 #include "lfdemod.h"
 

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

 //by marshmellow
 //get high and low with passed in fuzz factor. also return noise test = 1 for passed or 0 for only noise
 int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi, uint8_t fuzzLo)
 //by marshmellow
 //get high and low with passed in fuzz factor. also return noise test = 1 for passed or 0 for only noise
 int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi, uint8_t fuzzLo)


@@ -29,59 +41,82 @@ int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi
        return 1;
 }
 
        return 1;
 }
 

+// by marshmellow
+// pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType
+// returns 1 if passed
+uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType)
+{
+       uint8_t ans = 0;
+       for (uint8_t i = 0; i < bitLen; i++){
+               ans ^= ((bits >> i) & 1);
+       }
+  //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType);
+       return (ans == pType);
+}
+
+//by marshmellow
+//search for given preamble in given BitStream and return startIndex and length
+uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx)
+{
+  uint8_t foundCnt=0;
+  for (int idx=0; idx < *size - pLen; idx++){
+    if (memcmp(BitStream+idx, preamble, pLen) == 0){
+      //first index found
+      foundCnt++;
+      if (foundCnt == 1){
+        *startIdx = idx;
+      }
+      if (foundCnt == 2){
+        *size = idx - *startIdx;
+        return 1;
+      }
+    }
+  }
+  return 0;
+}
+
+

 //by marshmellow
 //takes 1s and 0s and searches for EM410x format - output EM ID
 uint64_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx)
 {
 //by marshmellow
 //takes 1s and 0s and searches for EM410x format - output EM ID
 uint64_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx)
 {

-       //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
-       //  otherwise could be a void with no arguments
-       //set defaults
-       uint64_t lo=0;
-       uint32_t i = 0;
-       if (BitStream[10]>1){  //allow only 1s and 0s
-               // PrintAndLog("no data found");
-               return 0;
-       }
-       uint8_t parityTest=0;
-       // 111111111 bit pattern represent start of frame
-       uint8_t frame_marker_mask[] = {1,1,1,1,1,1,1,1,1};
-       uint32_t idx = 0;
-       uint32_t ii=0;
-       uint8_t resetCnt = 0;
-       while( (idx + 64) < *size) {
- restart:
-               // search for a start of frame marker
-               if ( memcmp(BitStream+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
-               { // frame marker found
-                       *startIdx=idx;
-                       idx+=9;
-                       for (i=0; i<10;i++){
-                               for(ii=0; ii<5; ++ii){
-                                       parityTest ^= BitStream[(i*5)+ii+idx];
-                               }
-                               if (!parityTest){ //even parity
-                                       parityTest=0;
-                                       for (ii=0; ii<4;++ii){
-                                               lo=(lo<<1LL)|(BitStream[(i*5)+ii+idx]);
-                                       }
-                                       //PrintAndLog("DEBUG: EM parity passed parity val: %d, i:%d, ii:%d,idx:%d, Buffer: %d%d%d%d%d,lo: %d",parityTest,i,ii,idx,BitStream[idx+ii+(i*5)-5],BitStream[idx+ii+(i*5)-4],BitStream[idx+ii+(i*5)-3],BitStream[idx+ii+(i*5)-2],BitStream[idx+ii+(i*5)-1],lo);
-                               }else {//parity failed
-                                       //PrintAndLog("DEBUG: EM parity failed parity val: %d, i:%d, ii:%d,idx:%d, Buffer: %d%d%d%d%d",parityTest,i,ii,idx,BitStream[idx+ii+(i*5)-5],BitStream[idx+ii+(i*5)-4],BitStream[idx+ii+(i*5)-3],BitStream[idx+ii+(i*5)-2],BitStream[idx+ii+(i*5)-1]);
-                                       parityTest=0;
-                                       idx-=8;
-                                       if (resetCnt>5)return 0; //try 5 times
-                                       resetCnt++;
-                                       goto restart;//continue;
-                               }
-                       }
-                       //skip last 5 bit parity test for simplicity.
-                       *size = 64;
-                       return lo;
-               }else{
-                       idx++;
-               }
-       }
-       return 0;
+  //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
+  //  otherwise could be a void with no arguments
+  //set defaults
+  uint64_t lo=0;
+  uint32_t i = 0;
+  if (BitStream[1]>1){  //allow only 1s and 0s
+    // PrintAndLog("no data found");
+    return 0;
+  }
+  // 111111111 bit pattern represent start of frame
+  uint8_t preamble[] = {1,1,1,1,1,1,1,1,1};
+  uint32_t idx = 0;
+  uint32_t parityBits = 0;
+  uint8_t errChk = 0;
+  *startIdx = 0;
+  for (uint8_t extraBitChk=0; extraBitChk<5; extraBitChk++){
+    errChk = preambleSearch(BitStream+extraBitChk+*startIdx, preamble, sizeof(preamble), size, startIdx);
+    if (errChk == 0) return 0;
+    idx = *startIdx + 9;
+    for (i=0; i<10;i++){ //loop through 10 sets of 5 bits (50-10p = 40 bits)
+      parityBits = bytebits_to_byte(BitStream+(i*5)+idx,5);
+      //check even parity
+      if (parityTest(parityBits, 5, 0) == 0){
+        //parity failed try next bit (in the case of 1111111111) but last 9 = preamble
+        startIdx++;
+        errChk = 0;
+        break;
+      }
+      for (uint8_t ii=0; ii<4; ii++){
+        lo = (lo << 1LL) | (BitStream[(i*5)+ii+idx]);
+      }
+    }
+    if (errChk != 0) return lo;
+    //skip last 5 bit parity test for simplicity.
+    // *size = 64;
+  }
+  return 0;

 }
 
 //by marshmellow
 }
 
 //by marshmellow


@@ -336,30 +371,20 @@ int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert)
                        for (i = iii; i < *size; ++i) {
                                if ((BinStream[i] >= high) && ((i-lastBit)>(*clk-tol))){
                                        lastBit+=*clk;
                        for (i = iii; i < *size; ++i) {
                                if ((BinStream[i] >= high) && ((i-lastBit)>(*clk-tol))){
                                        lastBit+=*clk;

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

                                        midBit=0;
                                } else if ((BinStream[i] <= low) && ((i-lastBit)>(*clk-tol))){
                                        //low found and we are expecting a bar
                                        lastBit+=*clk;
                                        midBit=0;
                                } else if ((BinStream[i] <= low) && ((i-lastBit)>(*clk-tol))){
                                        //low found and we are expecting a bar
                                        lastBit+=*clk;

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

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

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

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

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

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

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

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


@@ -367,16 +392,11 @@ int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert)
                                                //should have hit a high or low based on clock!!
                                                //debug
                                                //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
                                                //should have hit a high or low based on clock!!
                                                //debug
                                                //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);

-                                               //if (bitnum > 0){
-                                               //      BitStream[bitnum]=77;
-                                               //      bitnum++;
-                                               //}

 
                                                errCnt++;
                                                lastBit+=*clk;//skip over until hit too many errors
                                                if (errCnt > ((*size/1000))){  //allow 1 error for every 1000 samples else start over
                                                        errCnt=0;
 
                                                errCnt++;
                                                lastBit+=*clk;//skip over until hit too many errors
                                                if (errCnt > ((*size/1000))){  //allow 1 error for every 1000 samples else start over
                                                        errCnt=0;

-                                                       //      bitnum=0;//start over

                                                        break;
                                                }
                                        }
                                                        break;
                                                }
                                        }


@@ -552,114 +572,69 @@ int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t
        size = aggregate_bits(dest, size, rfLen, 192, invert, fchigh, fclow);
        return size;
 }
        size = aggregate_bits(dest, size, rfLen, 192, invert, fchigh, fclow);
        return size;
 }

+

 // loop to get raw HID waveform then FSK demodulate the TAG ID from it
 int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo)
 {
 // 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 idx=0, size2=*size, startIdx=0; 
-       // FSK demodulator
-
-       *size = fskdemod(dest, size2,50,0,10,8);
-
-       // final loop, go over previously decoded manchester data and decode into usable tag ID
-       // 111000 bit pattern represent start of frame, 01 pattern represents a 1 and 10 represents a 0
-       uint8_t frame_marker_mask[] = {1,1,1,0,0,0};
-       int numshifts = 0;
-       idx = 0;
-       //one scan
-       while( idx + sizeof(frame_marker_mask) < *size) {
-               // search for a start of frame marker
-               if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
-               { // frame marker found
-                       startIdx=idx;
-                       idx+=sizeof(frame_marker_mask);
-                       while(dest[idx] != dest[idx+1] && idx < *size-2)
-                       {
-                               // Keep going until next frame marker (or error)
-                               // Shift in a bit. Start by shifting high registers
-                               *hi2 = (*hi2<<1)|(*hi>>31);
-                               *hi = (*hi<<1)|(*lo>>31);
-                               //Then, shift in a 0 or one into low
-                               if (dest[idx] && !dest[idx+1])  // 1 0
-                                       *lo=(*lo<<1)|0;
-                               else // 0 1
-                                       *lo=(*lo<<1)|1;
-                               numshifts++;
-                               idx += 2;
-                       }
-                       // Hopefully, we read a tag and  hit upon the next frame marker
-                       if(idx + sizeof(frame_marker_mask) < *size)
-                       {
-                               if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
-                               {
-                                       //good return
-                                       *size=idx-startIdx;
-                                       return startIdx;
-                               }
-                       }
-                       // reset
-                       *hi2 = *hi = *lo = 0;
-                       numshifts = 0;
-               }else   {
-                       idx++;
-               }
-       }
-       return -1;
+  size_t numStart=0, size2=*size, startIdx=0; 
+  // FSK demodulator
+  *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
+  if (*size < 96) return -2;
+  // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
+  uint8_t preamble[] = {0,0,0,1,1,1,0,1};
+  // find bitstring in array  
+  uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+  if (errChk == 0) return -3; //preamble not found
+
+  numStart = startIdx + sizeof(preamble);
+  // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
+  for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
+    if (dest[idx] == dest[idx+1]){
+      return -4; //not manchester data
+    }
+    *hi2 = (*hi2<<1)|(*hi>>31);
+    *hi = (*hi<<1)|(*lo>>31);
+    //Then, shift in a 0 or one into low
+    if (dest[idx] && !dest[idx+1])  // 1 0
+      *lo=(*lo<<1)|1;
+    else // 0 1
+      *lo=(*lo<<1)|0;
+  }
+  return (int)startIdx;

 }
 
 // loop to get raw paradox waveform then FSK demodulate the TAG ID from it
 }
 
 // loop to get raw paradox waveform then FSK demodulate the TAG ID from it

-size_t ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo)
+int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo)

 {
 {

-
-       size_t idx=0, size2=*size;
+       if (justNoise(dest, *size)) return -1;
+       
+       size_t numStart=0, size2=*size, startIdx=0;

        // FSK demodulator
        // FSK demodulator

-
-       *size = fskdemod(dest, size2,50,1,10,8);
-
-       // final loop, go over previously decoded manchester data and decode into usable tag ID
-       // 00001111 bit pattern represent start of frame, 01 pattern represents a 1 and 10 represents a 0
-       uint8_t frame_marker_mask[] = {0,0,0,0,1,1,1,1};
-       uint16_t numshifts = 0;
-       idx = 0;
-       //one scan
-       while( idx + sizeof(frame_marker_mask) < *size) {
-               // search for a start of frame marker
-               if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
-               { // frame marker found
-                       size2=idx;
-                       idx+=sizeof(frame_marker_mask);
-                       while(dest[idx] != dest[idx+1] && idx < *size-2)
-                       {
-                               // Keep going until next frame marker (or error)
-                               // Shift in a bit. Start by shifting high registers
-                               *hi2 = (*hi2<<1)|(*hi>>31);
-                               *hi = (*hi<<1)|(*lo>>31);
-                               //Then, shift in a 0 or one into low
-                               if (dest[idx] && !dest[idx+1])  // 1 0
-                                       *lo=(*lo<<1)|1;
-                               else // 0 1
-                                       *lo=(*lo<<1)|0;
-                               numshifts++;
-                               idx += 2;
-                       }
-                       // Hopefully, we read a tag and  hit upon the next frame marker and got enough bits
-                       if(idx + sizeof(frame_marker_mask) < *size && numshifts > 40)
-                       {
-                               if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
-                               {
-                                       //good return - return start grid position and bits found
-                                       *size = ((numshifts*2)+8);
-                                       return size2;
-                               }
-                       }
-                       // reset
-                       *hi2 = *hi = *lo = 0;
-                       numshifts = 0;
-               }else   {
-                       idx++;
-               }
+       *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
+       if (*size < 96) return -2;
+
+       // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
+       uint8_t preamble[] = {0,0,0,0,1,1,1,1};
+
+       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+       if (errChk == 0) return -3; //preamble not found
+
+       numStart = startIdx + sizeof(preamble);
+       // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
+       for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
+               if (dest[idx] == dest[idx+1]) 
+                       return -4; //not manchester data
+               *hi2 = (*hi2<<1)|(*hi>>31);
+               *hi = (*hi<<1)|(*lo>>31);
+               //Then, shift in a 0 or one into low
+               if (dest[idx] && !dest[idx+1])  // 1 0
+                       *lo=(*lo<<1)|1;
+               else // 0 1
+                       *lo=(*lo<<1)|0;

        }
        }

-       return 0;
+       return (int)startIdx;

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


@@ -675,20 +650,12 @@ uint32_t bytebits_to_byte(uint8_t* src, size_t numbits)
 
 int IOdemodFSK(uint8_t *dest, size_t size)
 {
 
 int IOdemodFSK(uint8_t *dest, size_t size)
 {

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

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

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

        // FSK demodulator
        // FSK demodulator

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

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


@@ -698,31 +665,17 @@ int IOdemodFSK(uint8_t *dest, size_t size)
        //
        //XSF(version)facility:codeone+codetwo
        //Handle the data
        //
        //XSF(version)facility:codeone+codetwo
        //Handle the data

-       uint8_t mask[] = {0,0,0,0,0,0,0,0,0,1};
-       for( idx=0; idx < (size - 65); idx++) {
-               if ( memcmp(dest + idx, mask, sizeof(mask))==0) {
-                       //frame marker found
-                       if (!dest[idx+8] && dest[idx+17]==1 && dest[idx+26]==1 && dest[idx+35]==1 && dest[idx+44]==1 && dest[idx+53]==1){
-                               //confirmed proper separator bits found
-                               //return start position
-                               return (int) idx;
-                       }
-               }
-       }
-       return 0;
-}
-
-// by marshmellow
-// pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType
-// returns 1 if passed
-uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType)
-{
-       uint8_t ans = 0;
-       for (uint8_t i = 0; i < bitLen; i++){
-               ans ^= ((bits >> i) & 1);
+       size_t startIdx = 0;
+       uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,1};
+       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), &size, &startIdx);
+       if (errChk == 0) return -4; //preamble not found
+
+       if (!dest[startIdx+8] && dest[startIdx+17]==1 && dest[startIdx+26]==1 && dest[startIdx+35]==1 && dest[startIdx+44]==1 && dest[startIdx+53]==1){
+               //confirmed proper separator bits found
+               //return start position
+               return (int) startIdx;

        }
        }

-  //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType);
-       return (ans == pType);
+       return -5;

 }
 
 // by marshmellow
 }
 
 // by marshmellow


@@ -750,73 +703,47 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p
 
 // by marshmellow
 // FSK Demod then try to locate an AWID ID
 
 // by marshmellow
 // FSK Demod then try to locate an AWID ID

-int AWIDdemodFSK(uint8_t *dest, size_t size)
+int AWIDdemodFSK(uint8_t *dest, size_t *size)

 {
 {

-       static const uint8_t THRESHOLD = 123;
-       uint32_t idx=0, idx2=0;
-       //make sure buffer has data
-       if (size < 96*50) return -1;
-       //test samples are not just noise
-       uint8_t justNoise = 1;
-       for(idx=0; idx < size && justNoise ;idx++){
-               justNoise = dest[idx] < THRESHOLD;
-       }
-       if(justNoise) return -2;
+       //make sure buffer has enough data
+       if (*size < 96*50) return -1;
+
+       if (justNoise(dest, *size)) return -2;

 
        // FSK demodulator
 
        // FSK demodulator

-       size = fskdemod(dest, size, 50, 1, 10, 8);  //  RF/64 and invert
-       if (size < 96) return -3;  //did we get a good demod?
-
-       uint8_t mask[] = {0,0,0,0,0,0,0,1};
-       for( idx=0; idx < (size - 96); idx++) {
-               if ( memcmp(dest + idx, mask, sizeof(mask))==0) {
-                       // frame marker found
-                       //return ID start index
-                       if (idx2 == 0) idx2=idx;
-                       else if(idx-idx2==96) return idx2;
-                       else return -5;
-
-                       // should always get 96 bits if it is awid
-               }
-       }
-       //never found mask
-       return -4;
+       *size = fskdemod(dest, *size, 50, 1, 10, 8);  // fsk2a RF/50 
+       if (*size < 96) return -3;  //did we get a good demod?
+
+       uint8_t preamble[] = {0,0,0,0,0,0,0,1};
+       size_t startIdx = 0;
+       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+       if (errChk == 0) return -4; //preamble not found
+       if (*size != 96) return -5;
+       return (int)startIdx;

 }
 
 // by marshmellow
 // FSK Demod then try to locate an Farpointe Data (pyramid) ID
 }
 
 // by marshmellow
 // FSK Demod then try to locate an Farpointe Data (pyramid) ID

-int PyramiddemodFSK(uint8_t *dest, size_t size)
+int PyramiddemodFSK(uint8_t *dest, size_t *size)

 {
 {

-  static const uint8_t THRESHOLD = 123;
-  uint32_t idx=0, idx2=0;
-  // size_t size2 = size;

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

-  if (size < 128*50) return -5;
+  if (*size < 128*50) return -5;
+

   //test samples are not just noise
   //test samples are not just noise

-  uint8_t justNoise = 1;
-  for(idx=0; idx < size && justNoise ;idx++){
-    justNoise = dest[idx] < THRESHOLD;
-  }
-  if(justNoise) return -1;
+  if (justNoise(dest, *size)) return -1;

 
   // FSK demodulator
 
   // FSK demodulator

-  size = fskdemod(dest, size, 50, 1, 10, 8);  //  RF/64 and invert
-  if (size < 128) return -2;  //did we get a good demod?
-
-  uint8_t mask[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
-  for( idx=0; idx < (size - 128); idx++) {
-    if ( memcmp(dest + idx, mask, sizeof(mask))==0) {
-      // frame marker found
-      if (idx2==0) idx2=idx;
-      else if (idx-idx2==128) return idx2;
-      else return -3;
-    }
-  }
-  //never found mask
-  return -4;
+  *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
 // not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)
 // maybe somehow adjust peak trimming value based on samples to fix?
 // 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?


@@ -885,7 +812,6 @@ int DetectASKClock(uint8_t dest[], size_t size, int clock)
   return clk[best];
 }
 
   return clk[best];
 }
 

-

 //by marshmellow
 //detect psk clock by reading #peaks vs no peaks(or errors)
 int DetectpskNRZClock(uint8_t dest[], size_t size, int clock)
 //by marshmellow
 //detect psk clock by reading #peaks vs no peaks(or errors)
 int DetectpskNRZClock(uint8_t dest[], size_t size, int clock)


@@ -963,7 +889,7 @@ int DetectpskNRZClock(uint8_t dest[], size_t size, int clock)
        return clk[best];
 }
 
        return clk[best];
 }
 

-//by marshmellow (attempt to get rid of high immediately after a low)
+// by marshmellow (attempt to get rid of high immediately after a low)

 void pskCleanWave(uint8_t *BitStream, size_t size)
 {
        int i;
 void pskCleanWave(uint8_t *BitStream, size_t size)
 {
        int i;


@@ -999,9 +925,26 @@ void pskCleanWave(uint8_t *BitStream, size_t size)
        return;
 }
 
        return;
 }
 

+// by marshmellow
+// convert psk1 demod to psk2 demod
+// only transition waves are 1s
+void psk1TOpsk2(uint8_t *BitStream, size_t size)
+{
+       size_t i=1;
+       uint8_t lastBit=BitStream[0];
+       for (; i<size; i++){
+               if (lastBit!=BitStream[i]){
+                       lastBit=BitStream[i];
+                       BitStream[i]=1;
+               } else {
+                       BitStream[i]=0;
+               }
+       }
+       return;
+}

 
 

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

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


@@ -1064,11 +1007,11 @@ int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert)
        return 1;
 }
 
        return 1;
 }
 

-
-//by marshmellow - demodulate PSK1 wave or NRZ wave (both similar enough)
-//peaks switch bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
+// by marshmellow - demodulate PSK1 wave or NRZ wave (both similar enough)
+// peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak

 int pskNRZrawDemod(uint8_t *dest, size_t *size, int *clk, int *invert)
 {
 int pskNRZrawDemod(uint8_t *dest, size_t *size, int *clk, int *invert)
 {

+       if (justNoise(dest, *size)) return -1;

        pskCleanWave(dest,*size);
        int clk2 = DetectpskNRZClock(dest, *size, *clk);
        *clk=clk2;
        pskCleanWave(dest,*size);
        int clk2 = DetectpskNRZClock(dest, *size, *clk);
        *clk=clk2;


@@ -1087,7 +1030,6 @@ int pskNRZrawDemod(uint8_t *dest, size_t *size, int *clk, int *invert)
        uint32_t bestStart = *size;
        uint32_t maxErr = (*size/1000);
        uint32_t bestErrCnt = maxErr;
        uint32_t bestStart = *size;
        uint32_t maxErr = (*size/1000);
        uint32_t bestErrCnt = maxErr;

-       //uint8_t midBit=0;

        uint8_t curBit=0;
        uint8_t bitHigh=0;
        uint8_t ignorewin=*clk/8;
        uint8_t curBit=0;
        uint8_t bitHigh=0;
        uint8_t ignorewin=*clk/8;


@@ -1198,7 +1140,6 @@ int pskNRZrawDemod(uint8_t *dest, size_t *size, int *clk, int *invert)
        return errCnt;
 }
 
        return errCnt;
 }
 

-

 //by marshmellow
 //detects the bit clock for FSK given the high and low Field Clocks
 uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow)
 //by marshmellow
 //detects the bit clock for FSK given the high and low Field Clocks
 uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow)