code to check RndA' from PICC was unreachable

[proxmark3-svn] / armsrc / lfops.c

diff --git a/armsrc/lfops.c b/armsrc/lfops.c
index e086a7174d3e252bf21909ab46fc764e9bc6b121..c80caf776b323d600453b62c557c5f4e4d90778f 100644 (file)
--- a/armsrc/lfops.c
+++ b/armsrc/lfops.c
@@ -17,6 +17,9 @@
 #include "crapto1.h"
 #include "mifareutil.h"
 
 #include "crapto1.h"
 #include "mifareutil.h"
 

+#define SHORT_COIL()   LOW(GPIO_SSC_DOUT)
+#define OPEN_COIL()            HIGH(GPIO_SSC_DOUT)
+

 void LFSetupFPGAForADC(int divisor, bool lf_field)
 {
        FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
 void LFSetupFPGAForADC(int divisor, bool lf_field)
 {
        FpgaDownloadAndGo(FPGA_BITSTREAM_LF);


@@ -42,24 +45,23 @@ void LFSetupFPGAForADC(int divisor, bool lf_field)
 void AcquireRawAdcSamples125k(int divisor)
 {
        LFSetupFPGAForADC(divisor, true);
 void AcquireRawAdcSamples125k(int divisor)
 {
        LFSetupFPGAForADC(divisor, true);

-       DoAcquisition125k(-1);
+       DoAcquisition125k();

 }
 
 void SnoopLFRawAdcSamples(int divisor, int trigger_threshold)
 {
        LFSetupFPGAForADC(divisor, false);
 }
 
 void SnoopLFRawAdcSamples(int divisor, int trigger_threshold)
 {
        LFSetupFPGAForADC(divisor, false);

-       DoAcquisition125k(trigger_threshold);
+       DoAcquisition125k_threshold(trigger_threshold);

 }
 
 // split into two routines so we can avoid timing issues after sending commands //
 }
 
 // split into two routines so we can avoid timing issues after sending commands //

-void DoAcquisition125k(int trigger_threshold)
+void DoAcquisition125k_internal(int trigger_threshold, bool silent)

 {
        uint8_t *dest =  mifare_get_bigbufptr();
 {
        uint8_t *dest =  mifare_get_bigbufptr();

-       int n = 8000;
-       int i;
-
+       int n = 24000;
+       int i = 0;

        memset(dest, 0x00, n);
        memset(dest, 0x00, n);

-       i = 0;
+

        for(;;) {
                if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
                        AT91C_BASE_SSC->SSC_THR = 0x43;
        for(;;) {
                if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
                        AT91C_BASE_SSC->SSC_THR = 0x43;


@@ -75,35 +77,38 @@ void DoAcquisition125k(int trigger_threshold)
                        if (++i >= n) break;
                }
        }
                        if (++i >= n) break;
                }
        }

-       Dbprintf("buffer samples: %02x %02x %02x %02x %02x %02x %02x %02x ...",
+       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]);
                        dest[0], dest[1], dest[2], dest[3], dest[4], dest[5], dest[6], dest[7]);

-                       
+       }

 }
 }

-
+void DoAcquisition125k_threshold(int trigger_threshold) {
+        DoAcquisition125k_internal(trigger_threshold, true);
+}
+void DoAcquisition125k() {
+        DoAcquisition125k_internal(-1, true);
+}      
+       

 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)
 {

-       int at134khz;

 
        /* Make sure the tag is reset */
        FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
        FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
        SpinDelay(2500);
 
 
        /* Make sure the tag is reset */
        FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
        FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
        SpinDelay(2500);
 

+       int divisor_used = 95; // 125 KHz

        // see if 'h' was specified
        // see if 'h' was specified

-       if (command[strlen((char *) command) - 1] == 'h')
-               at134khz = TRUE;
-       else
-               at134khz = FALSE;

 
 

-       if (at134khz)
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
-       else
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+       if (command[strlen((char *) command) - 1] == 'h')
+               divisor_used = 88; // 134.8 KHz

 
 

+       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor_used); 

        FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
        FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);

-

        // Give it a bit of time for the resonant antenna to settle.
        SpinDelay(50);
        // Give it a bit of time for the resonant antenna to settle.
        SpinDelay(50);

+       
+       

        // And a little more time for the tag to fully power up
        SpinDelay(2000);
 
        // And a little more time for the tag to fully power up
        SpinDelay(2000);
 


@@ -115,10 +120,7 @@ void ModThenAcquireRawAdcSamples125k(int delay_off, int period_0, int period_1,
                FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
                LED_D_OFF();
                SpinDelayUs(delay_off);
                FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
                LED_D_OFF();
                SpinDelayUs(delay_off);

-               if (at134khz)
-                       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
-               else
-                       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor_used); 

 
                FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
                LED_D_ON();
 
                FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
                LED_D_ON();


@@ -130,10 +132,7 @@ void ModThenAcquireRawAdcSamples125k(int delay_off, int period_0, int period_1,
        FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
        LED_D_OFF();
        SpinDelayUs(delay_off);
        FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
        LED_D_OFF();
        SpinDelayUs(delay_off);

-       if (at134khz)
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
-       else
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor_used); 

 
        FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
 
 
        FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
 


@@ -292,17 +291,17 @@ void WriteTIbyte(uint8_t b)
        {
                if (b&(1<<i)) {
                        // stop modulating antenna
        {
                if (b&(1<<i)) {
                        // stop modulating antenna

-                       LOW(GPIO_SSC_DOUT);
+                       SHORT_COIL();

                        SpinDelayUs(1000);
                        // modulate antenna
                        SpinDelayUs(1000);
                        // modulate antenna

-                       HIGH(GPIO_SSC_DOUT);
+                       OPEN_COIL();

                        SpinDelayUs(1000);
                } else {
                        // stop modulating antenna
                        SpinDelayUs(1000);
                } else {
                        // stop modulating antenna

-                       LOW(GPIO_SSC_DOUT);
+                       SHORT_COIL();

                        SpinDelayUs(300);
                        // modulate antenna
                        SpinDelayUs(300);
                        // modulate antenna

-                       HIGH(GPIO_SSC_DOUT);
+                       OPEN_COIL();

                        SpinDelayUs(1700);
                }
        }
                        SpinDelayUs(1700);
                }
        }


@@ -452,56 +451,57 @@ void WriteTItag(uint32_t idhi, uint32_t idlo, uint16_t crc)
 
 void SimulateTagLowFrequency(int period, int gap, int ledcontrol)
 {
 
 void SimulateTagLowFrequency(int period, int gap, int ledcontrol)
 {

-       int i;
-       uint8_t *tab = (uint8_t *)BigBuf;
-    
+       int i = 0;
+       uint8_t *buff = (uint8_t *)BigBuf;
+

        FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
        FpgaDownloadAndGo(FPGA_BITSTREAM_LF);

+       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz

        FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_EDGE_DETECT);
        FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_EDGE_DETECT);

-    
-       AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT | GPIO_SSC_CLK;
-    
+       SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
+
+       // Configure output and enable pin that is connected to the FPGA (for modulating)
+       AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT | GPIO_SSC_CLK;    

        AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
        AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;

+       

        AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_CLK;
        AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_CLK;

-    
-#define SHORT_COIL()   LOW(GPIO_SSC_DOUT)
-#define OPEN_COIL()            HIGH(GPIO_SSC_DOUT)
-    
-       i = 0;
-       for(;;) {
+
+       // Give it a bit of time for the resonant antenna to settle.
+       SpinDelay(30);
+
+       for(;;) { 
+               

                while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK)) {
                while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK)) {

-                       if(BUTTON_PRESS()) {
-                               DbpString("Stopped");
-                               return;
-                       }
-                       WDT_HIT();
+                        if(BUTTON_PRESS()) {
+                                DbpString("Stopped at 0");
+                                FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+                                return;
+                        }
+                        WDT_HIT();

                }
         
                }
         

-               if (ledcontrol)
-                       LED_D_ON();
-        
-               if(tab[i])
+               if ( buff[i] )

                        OPEN_COIL();
                else
                        SHORT_COIL();
                        OPEN_COIL();
                else
                        SHORT_COIL();

-        
-               if (ledcontrol)
-                       LED_D_OFF();
-        
-               while(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK) {
-                       if(BUTTON_PRESS()) {
-                               DbpString("Stopped");
+       
+                while(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK) {
+                        if(BUTTON_PRESS()) {
+                               DbpString("Stopped at 1");
+                               FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off

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

-               }
+                }

         
         

-               i++;
+               ++i;

                if(i == period) {
                        i = 0;
                        if (gap) {
                if(i == period) {
                        i = 0;
                        if (gap) {

+                               // turn of modulation

                                SHORT_COIL();
                                SHORT_COIL();

-                               SpinDelayUs(gap);
-                       }
+                               // wait
+                               SpinDelay(gap);
+                       } 

                }
        }
 }
                }
        }
 }


@@ -608,337 +608,213 @@ void CmdHIDsimTAG(int hi, int lo, int ledcontrol)
 
        if (ledcontrol)
                LED_A_ON();
 
        if (ledcontrol)
                LED_A_ON();

+       

        SimulateTagLowFrequency(n, 0, ledcontrol);
 
        if (ledcontrol)
                LED_A_OFF();
 }
 
        SimulateTagLowFrequency(n, 0, ledcontrol);
 
        if (ledcontrol)
                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;

 
 

-       FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
-       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+       // 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);
+       // sync to first lo-hi transition, and threshold

 
 

-       // Give it a bit of time for the resonant antenna to settle.
-       SpinDelay(50);
+       //Need to threshold first sample
+       dest[0] = (dest[0] < threshold_value) ? 0 : 1;

 
 

-       // Now set up the SSC to get the ADC samples that are now streaming at us.
-       FpgaSetupSsc();
+       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
+               dest[idx] = (dest[idx] < threshold_value) ? 0 : 1;

 
 

-       for(;;) {
-               WDT_HIT();
-               if (ledcontrol)
-                       LED_A_ON();
-               if(BUTTON_PRESS()) {
-                       DbpString("Stopped");
-                       if (ledcontrol)
-                               LED_A_OFF();
-                       return;
-               }
+               // Check for 0->1 transition
+               if (dest[idx-1] < dest[idx]) { // 0 -> 1 transition

 
 

-               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;
-                               }
-                       }
+                       dest[numBits] =  (idx-last_transition <  9) ? 1 : 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;
-               }
-               WDT_HIT();
+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;

 
 

-               // 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;
-                               }
+       for( idx=1; idx < size; idx++) {

 
 

-                               lastval=idx;
-                               i++;
-                       }
+               if (dest[idx]==lastval) {
+                       n++;
+                       continue;

                }
                }

-               m=i;
+               //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;
+
+       // Configure to go in 125Khz listen mode
+       LFSetupFPGAForADC(0, true);
+
+       while(!BUTTON_PRESS()) {
+

                WDT_HIT();
                WDT_HIT();

+               if (ledcontrol) LED_A_ON();
+
+               DoAcquisition125k_internal(-1,true);
+               size  = sizeof(BigBuf);
+
+               // FSK demodulator
+               size = fsk_demod(dest, size);

 
                // we now have a set of cycle counts, loop over previous results and aggregate data into bit patterns
 
                // 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 (found) {
-                               if (dest[idx] && (!dest[idx+1]) ) {
+                       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);
           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;
                                        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;
+                                       else // 0 1
+                                               lo=(lo<<1)|
+                                                               1;
+                                       numshifts ++;
+                                       idx += 2;

                                }
                                }

-                               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(idx + sizeof(frame_marker_mask) < size)
+                               {
+                               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)
 {
 void CmdIOdemodFSK(int findone, int *high, int *low, int ledcontrol)
 {

-       uint8_t *dest =  mifare_get_bigbufptr();
-       int m=0, n=0, i=0, idx=0, lastval=0;
-       int found=0;
+       uint8_t *dest = (uint8_t *)BigBuf;
+
+       size_t size=0, idx=0;

        uint32_t code=0, code2=0;
 
        uint32_t code=0, code2=0;
 

+       // Configure to go in 125Khz listen mode

        LFSetupFPGAForADC(0, true);
 
        LFSetupFPGAForADC(0, true);
 

-       for(;;) {
+       while(!BUTTON_PRESS()) {

                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 = 30000;
-               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
-                               dest[i] = (dest[i] < 127) ? 0 : 1;
-                               ++i;
-                               if (ledcontrol)
-                                       LED_D_OFF();
-                               if(i >= m)      
-                                       break;
-                       }
-               }
+               DoAcquisition125k_internal(-1,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;
-                               dest[i] = (dest[i] <= 8) ? 1:0;
-                               lastval=idx;
-                               i++;
-                       }
-               }
-               m=i;
-               WDT_HIT();
+               size = fsk_demod(dest, size);

 
                // we now have a set of cycle counts, loop over previous results and aggregate data into bit patterns
 
                // 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
-                               }
+               // 1->0 : fc/8 in sets of 7
+               // 0->1 : fc/10 in sets of 6
+               size = aggregate_bits(dest, size, 7,6,13);

 
 

-                               // stuff appropriate bits in buffer
-                               if ( n==0 )
-                                       dest[i++]=dest[idx-1]^1;
-                               else {
-                                       if ( n < 13){
-                                               for(int j=0; j<n; j++){
-                                                       dest[i++]=dest[idx-1]^1;
-                                               }
-                                       }
-                               }
-                               
-                               n=0;
-                               lastval=dest[idx];
-                       }
-               }//end for
-
-               m=i;

                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]);


@@ -948,54 +824,26 @@ void CmdIOdemodFSK(int findone, int *high, int *low, int ledcontrol)
                    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+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=37;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;
-                   }
+                   code = bytebits_to_byte(dest+idx,32);
+                   code2 = bytebits_to_byte(dest+idx+32,32); 

                        
                        

-                   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;
-                   }
+                   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 (ledcontrol)     LED_D_OFF();
+               

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

-
-               found=0;
-         }
-       }

        }
        WDT_HIT();
        }
        WDT_HIT();

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

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