lf demod bug fix & refactor

fixed bug in lfops.c in hid fskdemod
refactored data fskXXXDemods for specific tags to use more common code.

diff --git a/armsrc/lfops.c b/armsrc/lfops.c
index 8ea9b317fc00d6374016f6871e2ece5e9a5cf310..3cc98446e6afd107297d46e45a304403c96b447c 100644 (file)
--- a/armsrc/lfops.c
+++ b/armsrc/lfops.c
@@ -633,9 +633,9 @@ void CmdHIDdemodFSK(int findone, int *high, int *low, int ledcontrol)
 {
     uint8_t *dest = (uint8_t *)BigBuf;
 
 {
     uint8_t *dest = (uint8_t *)BigBuf;
 

-    size_t size=sizeof(BigBuf), idx=0; //, found=0;
+    size_t size=sizeof(BigBuf); 

     uint32_t hi2=0, hi=0, lo=0;
     uint32_t hi2=0, hi=0, lo=0;

-
+    int idx=0;

     // Configure to go in 125Khz listen mode
     LFSetupFPGAForADC(95, true);
 
     // Configure to go in 125Khz listen mode
     LFSetupFPGAForADC(95, true);
 


@@ -646,10 +646,11 @@ void CmdHIDdemodFSK(int findone, int *high, int *low, int ledcontrol)
 
         DoAcquisition125k_internal(-1,true);
         // FSK demodulator
 
         DoAcquisition125k_internal(-1,true);
         // FSK demodulator

-               idx = HIDdemodFSK(dest, &size, &hi2, &hi, &lo);
-

         WDT_HIT();
         WDT_HIT();

+        size = sizeof(BigBuf);

 
 

+               idx = HIDdemodFSK(dest, &size, &hi2, &hi, &lo);
+        

                if (idx>0 && lo>0){
             // 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
                if (idx>0 && lo>0){
             // 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

diff --git a/client/cmddata.c b/client/cmddata.c
index 9ed228a440948a1984e66712d9b36edfff937e6a..79ff93bed314a40cc0a0f1a8258c5bc57f6f6c7b 100644 (file)
--- a/client/cmddata.c
+++ b/client/cmddata.c
@@ -659,9 +659,21 @@ int CmdFSKdemodHID(const char *Cmd)
   uint8_t BitStream[MAX_GRAPH_TRACE_LEN]={0};
        size_t BitLen = getFromGraphBuf(BitStream);
   //get binary from fsk wave
   uint8_t BitStream[MAX_GRAPH_TRACE_LEN]={0};
        size_t BitLen = getFromGraphBuf(BitStream);
   //get binary from fsk wave

-       size_t idx  = HIDdemodFSK(BitStream,&BitLen,&hi2,&hi,&lo);
+       int idx  = HIDdemodFSK(BitStream,&BitLen,&hi2,&hi,&lo);

   if (idx<0){
   if (idx<0){

-    if (g_debugMode) PrintAndLog("DEBUG: Error demoding fsk");
+    if (g_debugMode){
+      if (idx==-1){
+        PrintAndLog("DEBUG: Just Noise Detected");     
+      } else if (idx == -2) {
+        PrintAndLog("DEBUG: Error demoding fsk");
+      } else if (idx == -3) {
+        PrintAndLog("DEBUG: Preamble not found");
+      } else if (idx == -4) {
+        PrintAndLog("DEBUG: Error in Manchester data, SIZE: %d", BitLen);
+      } else {
+        PrintAndLog("DEBUG: Error demoding fsk %d", idx);
+      }   
+    }

     return 0;
   }
   if (hi2==0 && hi==0 && lo==0) {
     return 0;
   }
   if (hi2==0 && hi==0 && lo==0) {


@@ -732,9 +744,21 @@ int CmdFSKdemodParadox(const char *Cmd)
   uint8_t BitStream[MAX_GRAPH_TRACE_LEN]={0};
   size_t BitLen = getFromGraphBuf(BitStream);
   //get binary from fsk wave
   uint8_t BitStream[MAX_GRAPH_TRACE_LEN]={0};
   size_t BitLen = getFromGraphBuf(BitStream);
   //get binary from fsk wave

-  size_t idx = ParadoxdemodFSK(BitStream,&BitLen,&hi2,&hi,&lo);
+  int idx = ParadoxdemodFSK(BitStream,&BitLen,&hi2,&hi,&lo);

   if (idx<0){
   if (idx<0){

-    if (g_debugMode) PrintAndLog("DEBUG: Error demoding fsk");
+    if (g_debugMode){
+      if (idx==-1){
+        PrintAndLog("DEBUG: Just Noise Detected");     
+      } else if (idx == -2) {
+        PrintAndLog("DEBUG: Error demoding fsk");
+      } else if (idx == -3) {
+        PrintAndLog("DEBUG: Preamble not found");
+      } else if (idx == -4) {
+        PrintAndLog("DEBUG: Error in Manchester data");
+      } else {
+        PrintAndLog("DEBUG: Error demoding fsk %d", idx);
+      }
+    }

     return 0;
   }
   if (hi2==0 && hi==0 && lo==0){
     return 0;
   }
   if (hi2==0 && hi==0 && lo==0){


@@ -774,7 +798,21 @@ int CmdFSKdemodIO(const char *Cmd)
   //get binary from fsk wave
        idx = IOdemodFSK(BitStream,BitLen);
   if (idx<0){
   //get binary from fsk wave
        idx = IOdemodFSK(BitStream,BitLen);
   if (idx<0){

-    if (g_debugMode==1) PrintAndLog("DEBUG: demoding fsk error: %d", idx);
+    if (g_debugMode){
+      if (idx==-1){
+        PrintAndLog("DEBUG: Just Noise Detected");     
+      } else if (idx == -2) {
+        PrintAndLog("DEBUG: not enough samples");
+      } else if (idx == -3) {
+        PrintAndLog("DEBUG: error during fskdemod");        
+      } else if (idx == -4) {
+        PrintAndLog("DEBUG: Preamble not found");
+      } else if (idx == -5) {
+        PrintAndLog("DEBUG: Separator bits not found");
+      } else {
+        PrintAndLog("DEBUG: Error demoding fsk %d", idx);
+      }
+    }

     return 0;
   }
   if (idx==0){
     return 0;
   }
   if (idx==0){


@@ -834,13 +872,13 @@ int CmdFSKdemodAWID(const char *Cmd)
   size_t size = getFromGraphBuf(BitStream);
 
   //get binary from fsk wave
   size_t size = getFromGraphBuf(BitStream);
 
   //get binary from fsk wave

-  int idx = AWIDdemodFSK(BitStream, size);
+  int idx = AWIDdemodFSK(BitStream, &size);

   if (idx<=0){
     if (g_debugMode==1){
       if (idx == -1)
         PrintAndLog("DEBUG: Error - not enough samples");
       else if (idx == -2)
   if (idx<=0){
     if (g_debugMode==1){
       if (idx == -1)
         PrintAndLog("DEBUG: Error - not enough samples");
       else if (idx == -2)

-        PrintAndLog("DEBUG: Error - only noise found - no waves");
+        PrintAndLog("DEBUG: Error - only noise found");

       else if (idx == -3)
         PrintAndLog("DEBUG: Error - problem during FSK demod");
     //  else if (idx == -3)
       else if (idx == -3)
         PrintAndLog("DEBUG: Error - problem during FSK demod");
     //  else if (idx == -3)


@@ -848,7 +886,7 @@ int CmdFSKdemodAWID(const char *Cmd)
       else if (idx == -4)
         PrintAndLog("DEBUG: Error - AWID preamble not found");
       else if (idx == -5)
       else if (idx == -4)
         PrintAndLog("DEBUG: Error - AWID preamble not found");
       else if (idx == -5)

-        PrintAndLog("DEBUG: Error - Second AWID preamble not found");
+        PrintAndLog("DEBUG: Error - Size not correct: %d", size);

       else
         PrintAndLog("DEBUG: Error %d",idx);
     }
       else
         PrintAndLog("DEBUG: Error %d",idx);
     }


@@ -933,17 +971,17 @@ int CmdFSKdemodPyramid(const char *Cmd)
   size_t size = getFromGraphBuf(BitStream);
 
   //get binary from fsk wave
   size_t size = getFromGraphBuf(BitStream);
 
   //get binary from fsk wave

-  int idx = PyramiddemodFSK(BitStream, size);
+  int idx = PyramiddemodFSK(BitStream, &size);

   if (idx < 0){
     if (g_debugMode==1){
       if (idx == -5)
         PrintAndLog("DEBUG: Error - not enough samples");
       else if (idx == -1)
   if (idx < 0){
     if (g_debugMode==1){
       if (idx == -5)
         PrintAndLog("DEBUG: Error - not enough samples");
       else if (idx == -1)

-        PrintAndLog("DEBUG: Error - only noise found - no waves");
+        PrintAndLog("DEBUG: Error - only noise found");

       else if (idx == -2)
         PrintAndLog("DEBUG: Error - problem during FSK demod");
       else if (idx == -3)
       else if (idx == -2)
         PrintAndLog("DEBUG: Error - problem during FSK demod");
       else if (idx == -3)

-        PrintAndLog("DEBUG: Error - Second Pyramid preamble not found");
+        PrintAndLog("DEBUG: Error - Size not correct: %d", size);

       else if (idx == -4)
         PrintAndLog("DEBUG: Error - Pyramid preamble not found");
       else
       else if (idx == -4)
         PrintAndLog("DEBUG: Error - Pyramid preamble not found");
       else


@@ -1039,7 +1077,6 @@ int CmdFSKdemodPyramid(const char *Cmd)
       PrintAndLog("Pyramid ID Found - BitLength: %d -unknown BitLength- (%d), Raw: %x%08x%08x%08x", fmtLen, cardnum, rawHi3, rawHi2, rawHi, rawLo);
     }
   }
       PrintAndLog("Pyramid ID Found - BitLength: %d -unknown BitLength- (%d), Raw: %x%08x%08x%08x", fmtLen, cardnum, rawHi3, rawHi2, rawHi, rawLo);
     }
   }

-  //todo - convert hi2, hi, lo to demodbuffer for future sim/clone commands

   if (g_debugMode){
     PrintAndLog("DEBUG: idx: %d, Len: %d, Printing Demod Buffer:", idx, 128);
     printDemodBuff();
   if (g_debugMode){
     PrintAndLog("DEBUG: idx: %d, Len: %d, Printing Demod Buffer:", idx, 128);
     printDemodBuff();


@@ -1248,7 +1285,7 @@ int CmdIndalaDecode(const char *Cmd)
       PrintAndLog("Error2: %d",ans);
                return -1;
        }
       PrintAndLog("Error2: %d",ans);
                return -1;
        }

-       char showbits[251];
+       char showbits[251]={0x00};

        if (invert)
     if (g_debugMode==1)
       PrintAndLog("Had to invert bits");
        if (invert)
     if (g_debugMode==1)
       PrintAndLog("Had to invert bits");


@@ -1298,6 +1335,10 @@ int CmdIndalaDecode(const char *Cmd)
                showbits[idx]='\0';
                PrintAndLog("Indala UID=%s (%x%08x%08x%08x%08x%08x%08x)", showbits, uid1, uid2, uid3, uid4, uid5, uid6, uid7);
        }
                showbits[idx]='\0';
                PrintAndLog("Indala UID=%s (%x%08x%08x%08x%08x%08x%08x)", showbits, uid1, uid2, uid3, uid4, uid5, uid6, uid7);
        }

+  if (g_debugMode){
+    PrintAndLog("DEBUG: printing demodbuffer:");
+    printDemodBuff();
+  }

        return 1;
 }
 
        return 1;
 }
 

diff --git a/common/lfdemod.c b/common/lfdemod.c
index 1b499158b09c025b7784b07d1c694e98a27d2de7..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


@@ -537,114 +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)


@@ -660,20 +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
        //|           |           |           |           |           |           |


@@ -683,31 +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


@@ -735,70 +703,45 @@ 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
 }
 
 // by marshmellow


@@ -1068,6 +1011,7 @@ int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert)
 // 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)
 {
 // 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)
 {

+       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;

diff --git a/common/lfdemod.h b/common/lfdemod.h
index a2eb2c7828d6c4a01c9b33701d1f6291b162b86e..dbeab0f7b58621290100544e209436a42fad5d99 100644 (file)
--- a/common/lfdemod.h
+++ b/common/lfdemod.h
@@ -31,12 +31,15 @@ void psk1TOpsk2(uint8_t *BitStream, size_t size);
 int DetectpskNRZClock(uint8_t dest[], size_t size, int clock);
 int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert);
 void pskCleanWave(uint8_t *bitStream, size_t size);
 int DetectpskNRZClock(uint8_t dest[], size_t size, int clock);
 int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert);
 void pskCleanWave(uint8_t *bitStream, size_t size);

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

 size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen);
 uint16_t countFC(uint8_t *BitStream, size_t size);
 uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow);
 int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi, uint8_t fuzzLo);
 size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen);
 uint16_t countFC(uint8_t *BitStream, size_t size);
 uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow);
 int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi, uint8_t fuzzLo);

-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);
+uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx);
+uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType);
+uint8_t justNoise(uint8_t *BitStream, size_t size);

 
 #endif
 
 #endif