Refactoring low frequency operations, now 'lf hid fskdemod' is more stable. Also...

[proxmark3-svn] / armsrc / lfops.c

diff --git a/armsrc/lfops.c b/armsrc/lfops.c
index 76c4b44e7f1090c5193ceefdb2ae5ea269db407c..397ea8475e8af050eab2670bece8f59b1555c0ac 100644 (file)
--- a/armsrc/lfops.c
+++ b/armsrc/lfops.c
@@ -15,7 +15,40 @@
 #include "crc16.h"
 #include "string.h"
 
 #include "crc16.h"
 #include "string.h"
 

-void AcquireRawAdcSamples125k(int divisor)
+// split into two routines so we can avoid timing issues after sending commands //
+void DoAcquisition125k_internal(bool silent)
+{
+       uint8_t *dest = (uint8_t *)BigBuf;
+       int n = sizeof(BigBuf);
+       int i;
+
+       memset(dest, 0, n);
+       i = 0;
+       for(;;) {
+               if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
+                       AT91C_BASE_SSC->SSC_THR = 0x43;
+                       LED_D_ON();
+               }
+               if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
+                       dest[i] = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+                       i++;
+                       LED_D_OFF();
+                       if (i >= n) break;
+               }
+       }
+       if( ! silent)
+       {
+               Dbprintf("buffer samples: %02x %02x %02x %02x %02x %02x %02x %02x ...",
+                               dest[0], dest[1], dest[2], dest[3], dest[4], dest[5], dest[6], dest[7]);
+       }
+}
+
+void DoAcquisition125k(void)
+{
+       DoAcquisition125k_internal(false);
+}
+
+void SetupToAcquireRawAdcSamples(int divisor)

 {
        if ( (divisor == 1) || (divisor < 0) || (divisor > 255) )
                FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
 {
        if ( (divisor == 1) || (divisor < 0) || (divisor > 255) )
                FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz


@@ -34,34 +67,13 @@ void AcquireRawAdcSamples125k(int divisor)
 
        // Now set up the SSC to get the ADC samples that are now streaming at us.
        FpgaSetupSsc();
 
        // Now set up the SSC to get the ADC samples that are now streaming at us.
        FpgaSetupSsc();

-
-       // Now call the acquisition routine
-       DoAcquisition125k();

 }
 
 }
 

-// split into two routines so we can avoid timing issues after sending commands //
-void DoAcquisition125k(void)
+void AcquireRawAdcSamples125k(int divisor)

 {
 {

-       uint8_t *dest = (uint8_t *)BigBuf;
-       int n = sizeof(BigBuf);
-       int i;
-
-       memset(dest, 0, n);
-       i = 0;
-       for(;;) {
-               if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
-                       AT91C_BASE_SSC->SSC_THR = 0x43;
-                       LED_D_ON();
-               }
-               if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
-                       dest[i] = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-                       i++;
-                       LED_D_OFF();
-                       if (i >= n) break;
-               }
-       }
-       Dbprintf("buffer samples: %02x %02x %02x %02x %02x %02x %02x %02x ...",
-                       dest[0], dest[1], dest[2], dest[3], dest[4], dest[5], dest[6], dest[7]);
+       SetupToAcquireRawAdcSamples(divisor);
+       // Now call the acquisition routine
+       DoAcquisition125k_internal(false);

 }
 
 void ModThenAcquireRawAdcSamples125k(int delay_off, int period_0, int period_1, uint8_t *command)
 }
 
 void ModThenAcquireRawAdcSamples125k(int delay_off, int period_0, int period_1, uint8_t *command)


@@ -594,414 +606,213 @@ void CmdHIDsimTAG(int hi, int lo, int ledcontrol)
                LED_A_OFF();
 }
 
                LED_A_OFF();
 }
 

-
-// loop to capture raw HID waveform then FSK demodulate the TAG ID from it
-void CmdHIDdemodFSK(int findone, int *high, int *low, int ledcontrol)
+size_t fsk_demod(uint8_t * dest, size_t size)

 {
 {

-       uint8_t *dest = (uint8_t *)BigBuf;
-       int m=0, n=0, i=0, idx=0, found=0, lastval=0;
-  uint32_t hi2=0, hi=0, lo=0;
+       uint32_t last_transition = 0;
+       uint32_t idx = 1;

 
 

-       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
+       // we don't care about actual value, only if it's more or less than a
+       // threshold essentially we capture zero crossings for later analysis
+       uint8_t threshold_value = 127;

 
 

-       // Connect the A/D to the peak-detected low-frequency path.
-       SetAdcMuxFor(GPIO_MUXSEL_LOPKD);

 
 

-       // Give it a bit of time for the resonant antenna to settle.
-       SpinDelay(50);
+       // sync to first lo-hi transition, and threshold

 
 

-       // Now set up the SSC to get the ADC samples that are now streaming at us.
-       FpgaSetupSsc();
+       //Need to threshold first sample
+       if(dest[0] < threshold_value) dest[0] = 0;
+       else dest[0] = 1;

 
 

-       for(;;) {
-               WDT_HIT();
-               if (ledcontrol)
-                       LED_A_ON();
-               if(BUTTON_PRESS()) {
-                       DbpString("Stopped");
-                       if (ledcontrol)
-                               LED_A_OFF();
-                       return;
-               }
+       size_t numBits = 0;
+       // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
+       // or 10 (fc/10) cycles but in practice due to noise etc we may end up with with anywhere
+       // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
+       for(idx = 1; idx < size; idx++) {
+               // threshold current value
+               if (dest[idx] < threshold_value) dest[idx] = 0;
+               else dest[idx] = 1;

 
 

-               i = 0;
-               m = sizeof(BigBuf);
-               memset(dest,128,m);
-               for(;;) {
-                       if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-                               AT91C_BASE_SSC->SSC_THR = 0x43;
-                               if (ledcontrol)
-                                       LED_D_ON();
-                       }
-                       if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-                               dest[i] = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-                               // we don't care about actual value, only if it's more or less than a
-                               // threshold essentially we capture zero crossings for later analysis
-                               if(dest[i] < 127) dest[i] = 0; else dest[i] = 1;
-                               i++;
-                               if (ledcontrol)
-                                       LED_D_OFF();
-                               if(i >= m) {
-                                       break;
-                               }
+               // Check for 0->1 transition
+               if (dest[idx-1] < dest[idx]) { // 0 -> 1 transition
+
+                       if (idx-last_transition <  9) {
+                                       dest[numBits]=1;
+                       } else {
+                                       dest[numBits]=0;

                        }
                        }

+                       last_transition = idx;
+                       numBits++;

                }
                }

+       }
+       return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
+}

 
 

-               // FSK demodulator

 
 

-               // sync to first lo-hi transition
-               for( idx=1; idx<m; idx++) {
-                       if (dest[idx-1]<dest[idx])
-                               lastval=idx;
-                               break;
+size_t aggregate_bits(uint8_t *dest,size_t size, uint8_t h2l_crossing_value,uint8_t l2h_crossing_value, uint8_t maxConsequtiveBits )
+{
+       uint8_t lastval=dest[0];
+       uint32_t idx=0;
+       size_t numBits=0;
+       uint32_t n=1;
+
+       for( idx=1; idx < size; idx++) {
+
+               if (dest[idx]==lastval) {
+                       n++;
+                       continue;
+               }
+               //if lastval was 1, we have a 1->0 crossing
+               if ( dest[idx-1] ) {
+                       n=(n+1) / h2l_crossing_value;
+               } else {// 0->1 crossing
+                       n=(n+1) / l2h_crossing_value;

                }
                }

+               if (n == 0) n = 1;
+
+               if(n < maxConsequtiveBits)
+               {
+                       memset(dest+numBits, dest[idx-1] , n);
+                       numBits += n;
+               }
+               n=0;
+               lastval=dest[idx];
+       }//end for
+
+       return numBits;
+
+}
+// loop to capture raw HID waveform then FSK demodulate the TAG ID from it
+void CmdHIDdemodFSK(int findone, int *high, int *low, int ledcontrol)
+{
+       uint8_t *dest = (uint8_t *)BigBuf;
+
+       size_t size=0,idx=0; //, found=0;
+       uint32_t hi2=0, hi=0, lo=0;
+
+
+       while(!BUTTON_PRESS()) {
+
+               // Configure to go in 125Khz listen mode
+               SetupToAcquireRawAdcSamples(0);
+

                WDT_HIT();
                WDT_HIT();

+               if (ledcontrol) LED_A_ON();

 
 

-               // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
-               // or 10 (fc/10) cycles but in practice due to noise etc we may end up with with anywhere
-               // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
-               for( i=0; idx<m; idx++) {
-                       if (dest[idx-1]<dest[idx]) {
-                               dest[i]=idx-lastval;
-                               if (dest[i] <= 8) {
-                                               dest[i]=1;
-                               } else {
-                                               dest[i]=0;
-                               }
+               DoAcquisition125k_internal(true);
+               size  = sizeof(BigBuf);

 
 

-                               lastval=idx;
-                               i++;
-                       }
-               }
-               m=i;
+               // FSK demodulator
+               size = fsk_demod(dest, size);

                WDT_HIT();
 
                // we now have a set of cycle counts, loop over previous results and aggregate data into bit patterns
                WDT_HIT();
 
                // we now have a set of cycle counts, loop over previous results and aggregate data into bit patterns

-               lastval=dest[0];
-               idx=0;
-               i=0;
-               n=0;
-               for( idx=0; idx<m; idx++) {
-                       if (dest[idx]==lastval) {
-                               n++;
-                       } else {
-                               // a bit time is five fc/10 or six fc/8 cycles so figure out how many bits a pattern width represents,
-                               // an extra fc/8 pattern preceeds every 4 bits (about 200 cycles) just to complicate things but it gets
-                               // swallowed up by rounding
-                               // expected results are 1 or 2 bits, any more and it's an invalid manchester encoding
-                               // special start of frame markers use invalid manchester states (no transitions) by using sequences
-                               // like 111000
-                               if (dest[idx-1]) {
-                                       n=(n+1)/6;                      // fc/8 in sets of 6
-                               } else {
-                                       n=(n+1)/5;                      // fc/10 in sets of 5
-                               }
-                               switch (n) {                    // stuff appropriate bits in buffer
-                                       case 0:
-                                       case 1: // one bit
-                                               dest[i++]=dest[idx-1];
-                                               break;
-                                       case 2: // two bits
-                                               dest[i++]=dest[idx-1];
-                                               dest[i++]=dest[idx-1];
-                                               break;
-                                       case 3: // 3 bit start of frame markers
-                                               dest[i++]=dest[idx-1];
-                                               dest[i++]=dest[idx-1];
-                                               dest[i++]=dest[idx-1];
-                                               break;
-                                       // When a logic 0 is immediately followed by the start of the next transmisson
-                                       // (special pattern) a pattern of 4 bit duration lengths is created.
-                                       case 4:
-                                               dest[i++]=dest[idx-1];
-                                               dest[i++]=dest[idx-1];
-                                               dest[i++]=dest[idx-1];
-                                               dest[i++]=dest[idx-1];
-                                               break;
-                                       default:        // this shouldn't happen, don't stuff any bits
-                                               break;
-                               }
-                               n=0;
-                               lastval=dest[idx];
-                       }
-               }
-               m=i;
+               // 1->0 : fc/8 in sets of 6
+               // 0->1 : fc/10 in sets of 5
+               size = aggregate_bits(dest,size, 6,5,5);
+

                WDT_HIT();
 
                // 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
                WDT_HIT();
 
                // 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

-               for( idx=0; idx<m-6; idx++) {
+               uint8_t frame_marker_mask[] = {1,1,1,0,0,0};
+               int numshifts = 0;
+               idx = 0;
+               while( idx + sizeof(frame_marker_mask) < size) {

                        // search for a start of frame marker
                        // search for a start of frame marker

-                       if ( dest[idx] && dest[idx+1] && dest[idx+2] && (!dest[idx+3]) && (!dest[idx+4]) && (!dest[idx+5]) )
-                       {
-                               found=1;
-                               idx+=6;
-        if (found && (hi2|hi|lo)) {
-          if (hi2 != 0){
-            Dbprintf("TAG ID: %x%08x%08x (%d)",
-                     (unsigned int) hi2, (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
-          }
-          else {
-            Dbprintf("TAG ID: %x%08x (%d)",
-                     (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
-          }
-                                       /* if we're only looking for one tag */
-                                       if (findone)
-                                       {
-                                               *high = hi;
-                                               *low = lo;
-                                               return;
-                                       }
-          hi2=0;
-                                       hi=0;
-                                       lo=0;
-                                       found=0;
+                       if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
+                       { // frame marker found
+                               idx+=sizeof(frame_marker_mask);
+
+                               while(dest[idx] != dest[idx+1] && idx < size-2)
+                               {       // Keep going until next frame marker (or error)
+                                       // Shift in a bit. Start by shifting high registers
+                                       hi2 = (hi2<<1)|(hi>>31);
+                                       hi = (hi<<1)|(lo>>31);
+                                       //Then, shift in a 0 or one into low
+                                       if (dest[idx] && !dest[idx+1])  // 1 0
+                                               lo=(lo<<1)|0;
+                                       else // 0 1
+                                               lo=(lo<<1)|
+                                                               1;
+                                       numshifts ++;
+                                       idx += 2;

                                }
                                }

-                       }
-                       if (found) {
-                               if (dest[idx] && (!dest[idx+1]) ) {
-          hi2=(hi2<<1)|(hi>>31);
-                                       hi=(hi<<1)|(lo>>31);
-                                       lo=(lo<<1)|0;
-                               } else if ( (!dest[idx]) && dest[idx+1]) {
-          hi2=(hi2<<1)|(hi>>31);
-                                       hi=(hi<<1)|(lo>>31);
-                                       lo=(lo<<1)|1;
-                               } else {
-                                       found=0;
-          hi2=0;
-                                       hi=0;
-                                       lo=0;
-                               }
-                               idx++;
-                       }
-                       if ( dest[idx] && dest[idx+1] && dest[idx+2] && (!dest[idx+3]) && (!dest[idx+4]) && (!dest[idx+5]) )
-                       {
-                               found=1;
-                               idx+=6;
-                               if (found && (hi|lo)) {
-          if (hi2 != 0){
-            Dbprintf("TAG ID: %x%08x%08x (%d)",
-                     (unsigned int) hi2, (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
-          }
-          else {
-            Dbprintf("TAG ID: %x%08x (%d)",
-                     (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
-          }
-                                       /* if we're only looking for one tag */
-                                       if (findone)
-                                       {
-                                               *high = hi;
-                                               *low = lo;
-                                               return;
+                               //Dbprintf("Num shifts: %d ", numshifts);
+                               // Hopefully, we read a tag and  hit upon the next frame marker
+                               if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
+                               {
+                                       if (hi2 != 0){
+                                               Dbprintf("TAG ID: %x%08x%08x (%d)",
+                                                        (unsigned int) hi2, (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
+                                       }
+                                       else {
+                                               Dbprintf("TAG ID: %x%08x (%d)",
+                                                (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);

                                        }
                                        }

-          hi2=0;
-                                       hi=0;
-                                       lo=0;
-                                       found=0;

                                }
                                }

+
+                               // reset
+                               hi2 = hi = lo = 0;
+                               numshifts = 0;
+                       }else
+                       {
+                               idx++;

                        }
                }
                WDT_HIT();
                        }
                }
                WDT_HIT();

+

        }
        }

+       DbpString("Stopped");
+       if (ledcontrol) LED_A_OFF();

 }
 
 }
 

+uint32_t bytebits_to_byte(uint8_t* src, int numbits)
+{
+       uint32_t num = 0;
+       for(int i = 0 ; i < numbits ; i++)
+       {
+               num = (num << 1) | (*src);
+               src++;
+       }
+       return num;
+}
+
+

 void CmdIOdemodFSK(int findone, int *high, int *low, int ledcontrol)
 {
        uint8_t *dest = (uint8_t *)BigBuf;
 void CmdIOdemodFSK(int findone, int *high, int *low, int ledcontrol)
 {
        uint8_t *dest = (uint8_t *)BigBuf;

-       int m=0, n=0, i=0, idx=0, lastval=0;
-       int found=0;
-       uint32_t code=0, code2=0;
-       //uint32_t hi2=0, hi=0, lo=0;

 
 

-       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
+       size_t size=0, idx=0;
+       uint32_t code=0, code2=0;

 
 

-       // Connect the A/D to the peak-detected low-frequency path.
-       SetAdcMuxFor(GPIO_MUXSEL_LOPKD);

 
 

-       // Give it a bit of time for the resonant antenna to settle.
-       SpinDelay(50);
+       while(!BUTTON_PRESS()) {

 
 

-       // Now set up the SSC to get the ADC samples that are now streaming at us.
-       FpgaSetupSsc();
+               // Configure to go in 125Khz listen mode
+               SetupToAcquireRawAdcSamples(0);

 
 

-       for(;;) {

                WDT_HIT();
                WDT_HIT();

-               if (ledcontrol)
-                       LED_A_ON();
-               if(BUTTON_PRESS()) {
-                       DbpString("Stopped");
-                       if (ledcontrol)
-                               LED_A_OFF();
-                       return;
-               }
+               if (ledcontrol) LED_A_ON();

 
 

-               i = 0;
-               m = sizeof(BigBuf);
-               memset(dest,128,m);
-               for(;;) {
-                       if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-                               AT91C_BASE_SSC->SSC_THR = 0x43;
-                               if (ledcontrol)
-                                       LED_D_ON();
-                       }
-                       if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-                               dest[i] = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-                               // we don't care about actual value, only if it's more or less than a
-                               // threshold essentially we capture zero crossings for later analysis
-                               if(dest[i] < 127) dest[i] = 0; else dest[i] = 1;
-                               i++;
-                               if (ledcontrol)
-                                       LED_D_OFF();
-                               if(i >= m) {
-                                       break;
-                               }
-                       }
-               }
+               DoAcquisition125k_internal(true);
+               size  = sizeof(BigBuf);

 
                // FSK demodulator
 
                // FSK demodulator

-
-               // sync to first lo-hi transition
-               for( idx=1; idx<m; idx++) {
-                       if (dest[idx-1]<dest[idx])
-                               lastval=idx;
-                               break;
-               }
-               WDT_HIT();
-
-               // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
-               // or 10 (fc/10) cycles but in practice due to noise etc we may end up with with anywhere
-               // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
-               for( i=0; idx<m; idx++) {
-                       if (dest[idx-1]<dest[idx]) {
-                               dest[i]=idx-lastval;
-                               if (dest[i] <= 8) {
-                                               dest[i]=1;
-                               } else {
-                                               dest[i]=0;
-                               }
-
-                               lastval=idx;
-                               i++;
-                       }
-               }
-               m=i;
+               size = fsk_demod(dest, size);

                WDT_HIT();
 
                // we now have a set of cycle counts, loop over previous results and aggregate data into bit patterns
                WDT_HIT();
 
                // we now have a set of cycle counts, loop over previous results and aggregate data into bit patterns

-               lastval=dest[0];
-               idx=0;
-               i=0;
-               n=0;
-               for( idx=0; idx<m; idx++) {
-                       if (dest[idx]==lastval) {
-                               n++;
-                       } else {
-                               // a bit time is five fc/10 or six fc/8 cycles so figure out how many bits a pattern width represents,
-                               // an extra fc/8 pattern preceeds every 4 bits (about 200 cycles) just to complicate things but it gets
-                               // swallowed up by rounding
-                               // expected results are 1 or 2 bits, any more and it's an invalid manchester encoding
-                               // special start of frame markers use invalid manchester states (no transitions) by using sequences
-                               // like 111000
-                               if (dest[idx-1]) {
-                                       n=(n+1)/7;                      // fc/8 in sets of 7
-                               } else {
-                                       n=(n+1)/6;                      // fc/10 in sets of 6
-                               }
-                               switch (n) {                    // stuff appropriate bits in buffer
-                                       case 0:
-                                       case 1: // one bit
-                                               dest[i++]=dest[idx-1]^1;
-                                               //Dbprintf("%d",dest[idx-1]);
-                                               break;
-                                       case 2: // two bits
-                                               dest[i++]=dest[idx-1]^1;
-                                               dest[i++]=dest[idx-1]^1;
-                                               //Dbprintf("%d",dest[idx-1]);
-                                               //Dbprintf("%d",dest[idx-1]);
-                                               break;
-                                       case 3: // 3 bit start of frame markers
-                                               for(int j=0; j<3; j++){
-                                                 dest[i++]=dest[idx-1]^1;
-                                               //  Dbprintf("%d",dest[idx-1]);
-                                               }
-                                               break;
-                                       case 4:
-                                               for(int j=0; j<4; j++){
-                                                 dest[i++]=dest[idx-1]^1;
-                                               //  Dbprintf("%d",dest[idx-1]);
-                                               }
-                                               break;
-                                       case 5:
-                                               for(int j=0; j<5; j++){
-                                                 dest[i++]=dest[idx-1]^1;
-                                               //  Dbprintf("%d",dest[idx-1]);
-                                               }
-                                               break;
-                                       case 6:
-                                               for(int j=0; j<6; j++){
-                                                 dest[i++]=dest[idx-1]^1;
-                                               //  Dbprintf("%d",dest[idx-1]);
-                                               }
-                                               break;
-                                       case 7:
-                                               for(int j=0; j<7; j++){
-                                                 dest[i++]=dest[idx-1]^1;
-                                               //  Dbprintf("%d",dest[idx-1]);
-                                               }
-                                               break;
-                                       case 8:
-                                               for(int j=0; j<8; j++){
-                                                 dest[i++]=dest[idx-1]^1;
-                                               //  Dbprintf("%d",dest[idx-1]);
-                                               }
-                                               break;
-                                       case 9:
-                                               for(int j=0; j<9; j++){
-                                                 dest[i++]=dest[idx-1]^1;
-                                               //  Dbprintf("%d",dest[idx-1]);
-                                               }
-                                               break;
-                                       case 10:
-                                               for(int j=0; j<10; j++){
-                                                 dest[i++]=dest[idx-1]^1;
-                                               //  Dbprintf("%d",dest[idx-1]);
-                                               }
-                                               break;
-                                       case 11:
-                                               for(int j=0; j<11; j++){
-                                                 dest[i++]=dest[idx-1]^1;
-                                               //  Dbprintf("%d",dest[idx-1]);
-                                               }
-                                               break;
-                                       case 12:
-                                               for(int j=0; j<12; j++){
-                                                 dest[i++]=dest[idx-1]^1;
-                                                // Dbprintf("%d",dest[idx-1]);
-                                               }
-                                               break;
-                                       default:        // this shouldn't happen, don't stuff any bits
-                                               //Dbprintf("%d",dest[idx-1]);
-                                               break;
-                               }
-                               n=0;
-                               lastval=dest[idx];
-                       }
-               }//end for
-               /*for(int j=0; j<64;j+=8){
-                 Dbprintf("%d%d%d%d%d%d%d%d",dest[j],dest[j+1],dest[j+2],dest[j+3],dest[j+4],dest[j+5],dest[j+6],dest[j+7]);
-               }
-               Dbprintf("\n");*/
-               m=i;
+               // 1->0 : fc/8 in sets of 7
+               // 0->1 : fc/10 in sets of 6
+               size = aggregate_bits(dest, size, 7,6,13);
+

                WDT_HIT();
                
                WDT_HIT();
                

-        for( idx=0; idx<m-9; idx++) {
-         if ( !(dest[idx]) && !(dest[idx+1]) && !(dest[idx+2]) && !(dest[idx+3]) && !(dest[idx+4]) && !(dest[idx+5]) && !(dest[idx+6]) && !(dest[idx+7]) && !(dest[idx+8])&& (dest[idx+9])){
-               found=1;
-               //idx+=9;
-               if (found) {
+               //Handle the data
+           uint8_t mask[] = {0,0,0,0,0,0,0,0,0,1};
+               for( idx=0; idx < size - 64; idx++) {
+
+               if ( memcmp(dest + idx, mask, sizeof(mask)) ) continue;
+

                    Dbprintf("%d%d%d%d%d%d%d%d",dest[idx],   dest[idx+1],   dest[idx+2],dest[idx+3],dest[idx+4],dest[idx+5],dest[idx+6],dest[idx+7]);
                    Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+8], dest[idx+9], dest[idx+10],dest[idx+11],dest[idx+12],dest[idx+13],dest[idx+14],dest[idx+15]);                         
                    Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+16],dest[idx+17],dest[idx+18],dest[idx+19],dest[idx+20],dest[idx+21],dest[idx+22],dest[idx+23]);
                    Dbprintf("%d%d%d%d%d%d%d%d",dest[idx],   dest[idx+1],   dest[idx+2],dest[idx+3],dest[idx+4],dest[idx+5],dest[idx+6],dest[idx+7]);
                    Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+8], dest[idx+9], dest[idx+10],dest[idx+11],dest[idx+12],dest[idx+13],dest[idx+14],dest[idx+15]);                         
                    Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+16],dest[idx+17],dest[idx+18],dest[idx+19],dest[idx+20],dest[idx+21],dest[idx+22],dest[idx+23]);


@@ -1010,59 +821,27 @@ void CmdIOdemodFSK(int findone, int *high, int *low, int ledcontrol)
                    Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+40],dest[idx+41],dest[idx+42],dest[idx+43],dest[idx+44],dest[idx+45],dest[idx+46],dest[idx+47]);
                    Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+48],dest[idx+49],dest[idx+50],dest[idx+51],dest[idx+52],dest[idx+53],dest[idx+54],dest[idx+55]);
                    Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+56],dest[idx+57],dest[idx+58],dest[idx+59],dest[idx+60],dest[idx+61],dest[idx+62],dest[idx+63]);
                    Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+40],dest[idx+41],dest[idx+42],dest[idx+43],dest[idx+44],dest[idx+45],dest[idx+46],dest[idx+47]);
                    Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+48],dest[idx+49],dest[idx+50],dest[idx+51],dest[idx+52],dest[idx+53],dest[idx+54],dest[idx+55]);
                    Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+56],dest[idx+57],dest[idx+58],dest[idx+59],dest[idx+60],dest[idx+61],dest[idx+62],dest[idx+63]);

-               
-                   short version='\x00';
-                   char unknown='\x00';
-                   uint16_t number=0;
-                   for(int j=14;j<18;j++){
-                      //Dbprintf("%d",dest[idx+j]);
-                      version <<=1;
-                      if (dest[idx+j]) version |= 1;
-                   }
-                   for(int j=19;j<27;j++){
-                      //Dbprintf("%d",dest[idx+j]);
-                      unknown <<=1;
-                      if (dest[idx+j]) unknown |= 1;
-                   }
-                   for(int j=36;j<45;j++){
-                      //Dbprintf("%d",dest[idx+j]);
-                      number <<=1;
-                      if (dest[idx+j]) number |= 1;
-                   }
-                   for(int j=46;j<53;j++){
-                      //Dbprintf("%d",dest[idx+j]);
-                      number <<=1;
-                      if (dest[idx+j]) number |= 1;
-                   }
-                   for(int j=0; j<32; j++){
-                       code <<=1;
-                       if(dest[idx+j]) code |= 1;
-                   }
-                   for(int j=32; j<64; j++){
-                       code2 <<=1;
-                       if(dest[idx+j]) code2 |= 1;
-                   }
+                       
+                   code = bytebits_to_byte(dest+idx,32);
+                   code2 = bytebits_to_byte(dest+idx+32,32); 
+
+                   short version = bytebits_to_byte(dest+idx+14,4); 
+                   char unknown = bytebits_to_byte(dest+idx+19,8) ;
+                   uint16_t number = bytebits_to_byte(dest+idx+36,9); 

                    
                    Dbprintf("XSF(%02d)%02x:%d (%08x%08x)",version,unknown,number,code,code2);
                    
                    Dbprintf("XSF(%02d)%02x:%d (%08x%08x)",version,unknown,number,code,code2);

-                   if (ledcontrol)
-                       LED_D_OFF();
-               }
-               // if we're only looking for one tag 
-               if (findone){
-                       //*high = hi;
-                       //*low = lo;
-                       LED_A_OFF();
-                       return;
-               }
-      
-               //hi=0;
-               //lo=0;
-               found=0;
-         }
+                   if (ledcontrol)     LED_D_OFF();

                
                

+                       // if we're only looking for one tag 
+                       if (findone){
+                               LED_A_OFF();
+                               return;
+                       }               
+               }
+               WDT_HIT();

        }
        }

-       }
-       WDT_HIT();
+       DbpString("Stopped");
+       if (ledcontrol) LED_A_OFF();

 }
 
 /*------------------------------
 }
 
 /*------------------------------