X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/7bd30f12ac6def96c82df20ed7d927160db289af..06b58a94f0be3256853a97387fc7e5782ce335c7:/armsrc/lfops.c

diff --git a/armsrc/lfops.c b/armsrc/lfops.c
index e086a717..0755e1e5 100644
--- a/armsrc/lfops.c
+++ b/armsrc/lfops.c
@@ -17,6 +17,9 @@
 #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);
@@ -42,24 +45,23 @@ void LFSetupFPGAForADC(int divisor, bool lf_field)
 void AcquireRawAdcSamples125k(int divisor)
 {
 	LFSetupFPGAForADC(divisor, true);
-	DoAcquisition125k(-1);
+	DoAcquisition125k();
 }
 
 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 //
-void DoAcquisition125k(int trigger_threshold)
+void DoAcquisition125k_internal(int trigger_threshold, bool silent)
 {
 	uint8_t *dest =  mifare_get_bigbufptr();
-	int n = 8000;
-	int i;
-
+	int n = 24000;
+	int i = 0;
 	memset(dest, 0x00, n);
-	i = 0;
+
 	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;
 		}
 	}
-	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]);
-			
+	}
 }
-
+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)
 {
-	int at134khz;
 
 	/* 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
-	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);
-
 	// 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);
 
@@ -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);
-		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();
@@ -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);
-	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);
 
@@ -292,17 +291,17 @@ void WriteTIbyte(uint8_t b)
 	{
 		if (b&(1<<i)) {
 			// stop modulating antenna
-			LOW(GPIO_SSC_DOUT);
+			SHORT_COIL();
 			SpinDelayUs(1000);
 			// modulate antenna
-			HIGH(GPIO_SSC_DOUT);
+			OPEN_COIL();
 			SpinDelayUs(1000);
 		} else {
 			// stop modulating antenna
-			LOW(GPIO_SSC_DOUT);
+			SHORT_COIL();
 			SpinDelayUs(300);
 			// modulate antenna
-			HIGH(GPIO_SSC_DOUT);
+			OPEN_COIL();
 			SpinDelayUs(1700);
 		}
 	}
@@ -450,60 +449,78 @@ void WriteTItag(uint32_t idhi, uint32_t idlo, uint16_t crc)
 	DbpString("Now use tiread to check");
 }
 
+
+        
+// PIO_CODR = Clear Output Data Register
+// PIO_SODR = Set Output Data Register
+//#define LOW(x)	 AT91C_BASE_PIOA->PIO_CODR = (x)
+//#define HIGH(x)	 AT91C_BASE_PIOA->PIO_SODR = (x)
 void SimulateTagLowFrequency(int period, int gap, int ledcontrol)
 {
-	int i;
-	uint8_t *tab = (uint8_t *)BigBuf;
-    
+	int i = 0;
+	uint8_t *buf = (uint8_t *)BigBuf;
+
 	FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+	FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
 	FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_EDGE_DETECT);
-    
-	AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT | GPIO_SSC_CLK;
-    
-	AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
-	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(;;) {
-		while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK)) {
-			if(BUTTON_PRESS()) {
-				DbpString("Stopped");
-				return;
-			}
-			WDT_HIT();
+	
+	// Connect the A/D to the peak-detected low-frequency path.
+	SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
+
+	// Now set up the SSC to get the ADC samples that are now streaming at us.
+	FpgaSetupSsc();
+	
+	// Configure output and enable pin that is connected to the FPGA (for modulating)
+	// AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT | GPIO_SSC_CLK; // (PIO_PER) PIO Enable Register
+	// AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;    // (PIO_OER) Output Enable Register
+	// AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_CLK;     // (PIO_ODR) Output Disable Register
+
+	AT91C_BASE_PIOA->PIO_OER = GPIO_PCK0;
+	
+ 	while(!BUTTON_PRESS()) { 
+		WDT_HIT();
+
+		// PIO_PDSR = Pin Data Status Register  
+		// GPIO_SSC_CLK  = SSC Transmit Clock
+		// wait ssp_clk == high
+		while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK)) {  
+			 if(BUTTON_PRESS()) {
+				 DbpString("Stopped at 0");
+				 return;
+			 }
+			 WDT_HIT();
 		}
-        
-		if (ledcontrol)
-			LED_D_ON();
-        
-		if(tab[i])
+		
+		if ( buf[i] > 0 ){
 			OPEN_COIL();
-		else
+		} else {
 			SHORT_COIL();
-        
-		if (ledcontrol)
-			LED_D_OFF();
-        
-		while(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK) {
-			if(BUTTON_PRESS()) {
-				DbpString("Stopped");
+		}
+	   
+	   DbpString("Enter Sim3");
+	    // wait ssp_clk == low
+		 while( (AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK) ) {  
+			 if(BUTTON_PRESS()) {
+				DbpString("stopped at 1");
 				return;
 			}
 			WDT_HIT();
 		}
-        
-		i++;
+		
+		DbpString("Enter Sim4 ");
+		//SpinDelayUs(512);
+		
+		++i;
 		if(i == period) {
 			i = 0;
 			if (gap) {
 				SHORT_COIL();
-				SpinDelayUs(gap);
-			}
+				SpinDelay(gap);				
+			} 
 		}
 	}
+	DbpString("Stopped");
+	return;
 }
 
 #define DEBUG_FRAME_CONTENTS 1
@@ -608,337 +625,213 @@ void CmdHIDsimTAG(int hi, int lo, int ledcontrol)
 
 	if (ledcontrol)
 		LED_A_ON();
+	
 	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;
+		}
+		//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;
 		}
-		m=i;
+		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();
+		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
-		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
-		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
-			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);
+					//Then, shift in a 0 or one into low
+					if (dest[idx] && !dest[idx+1])	// 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();
+
 	}
+	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 =  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;
 
+	// Configure to go in 125Khz listen mode
 	LFSetupFPGAForADC(0, true);
 
-	for(;;) {
+	while(!BUTTON_PRESS()) {
 		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
-
-		// 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
-		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();
 		
-        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]);
@@ -948,54 +841,26 @@ 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]);
 		
-		    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);
-		    if (ledcontrol)
-			LED_D_OFF();
-		}
+		    if (ledcontrol)	LED_D_OFF();
+		
 		// if we're only looking for one tag 
 		if (findone){
 			LED_A_OFF();
 			return;
 		}
-
-		found=0;
-	  }
-	}
 	}
 	WDT_HIT();
+	}
+	DbpString("Stopped");
+	if (ledcontrol) LED_A_OFF();
 }
 
 /*------------------------------