X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/5b59bf20c73825e3732185d74142c8b955e68758..41863885d0b03223205c2dfc8d87743a100abf28:/armsrc/iso14443b.c

diff --git a/armsrc/iso14443b.c b/armsrc/iso14443b.c
index 05280399..9616cb30 100644
--- a/armsrc/iso14443b.c
+++ b/armsrc/iso14443b.c
@@ -8,18 +8,12 @@
 // Routines to support ISO 14443B. This includes both the reader software and
 // the `fake tag' modes.
 //-----------------------------------------------------------------------------
+#include "iso14443b.h"
 
-#include "proxmark3.h"
-#include "apps.h"
-#include "util.h"
-#include "string.h"
-#include "iso14443crc.h"
-#include "common.h"
-#define RECEIVE_SAMPLES_TIMEOUT 600000
+#define RECEIVE_SAMPLES_TIMEOUT 20000
 #define ISO14443B_DMA_BUFFER_SIZE 256
 
-
-// PCB Block number for APDUs
+// the block number for the ISO14443-4 PCB  (used with APDUs)
 static uint8_t pcb_blocknum = 0;
 
 //=============================================================================
@@ -30,6 +24,93 @@ static uint8_t pcb_blocknum = 0;
 // a response.
 //=============================================================================
 
+
+//-----------------------------------------------------------------------------
+// The software UART that receives commands from the reader, and its state
+// variables.
+//-----------------------------------------------------------------------------
+static struct {
+	enum {
+		STATE_UNSYNCD,
+		STATE_GOT_FALLING_EDGE_OF_SOF,
+		STATE_AWAITING_START_BIT,
+		STATE_RECEIVING_DATA
+	}       state;
+	uint16_t    shiftReg;
+	int     bitCnt;
+	int     byteCnt;
+	int     byteCntMax;
+	int     posCnt;
+	uint8_t   *output;
+} Uart;
+
+static void UartReset()
+{
+	Uart.byteCntMax = MAX_FRAME_SIZE;
+	Uart.state = STATE_UNSYNCD;
+	Uart.byteCnt = 0;
+	Uart.bitCnt = 0;
+	Uart.posCnt = 0;
+	memset(Uart.output, 0x00, MAX_FRAME_SIZE);
+}
+
+static void UartInit(uint8_t *data)
+{
+	Uart.output = data;
+	UartReset();
+}
+
+
+static struct {
+	enum {
+		DEMOD_UNSYNCD,
+		DEMOD_PHASE_REF_TRAINING,
+		DEMOD_AWAITING_FALLING_EDGE_OF_SOF,
+		DEMOD_GOT_FALLING_EDGE_OF_SOF,
+		DEMOD_AWAITING_START_BIT,
+		DEMOD_RECEIVING_DATA
+	}       state;
+	int     bitCount;
+	int     posCount;
+	int     thisBit;
+/* this had been used to add RSSI (Received Signal Strength Indication) to traces. Currently not implemented.
+	int     metric;
+	int     metricN;
+*/
+	uint16_t    shiftReg;
+	uint8_t   *output;
+	int     len;
+	int     sumI;
+	int     sumQ;
+} Demod;
+
+static void DemodReset()
+{
+	// Clear out the state of the "UART" that receives from the tag.
+	Demod.len = 0;
+	Demod.state = DEMOD_UNSYNCD;
+	Demod.posCount = 0;
+	Demod.sumI = 0;
+	Demod.sumQ = 0;
+	Demod.bitCount = 0;
+	Demod.thisBit = 0;
+	Demod.shiftReg = 0;
+	//memset(Demod.output, 0x00, MAX_FRAME_SIZE);
+}
+
+
+static void DemodInit(uint8_t *data)
+{
+	Demod.output = data;
+	DemodReset();
+}
+
+
+void AppendCrc14443b(uint8_t* data, int len)
+{
+	ComputeCrc14443(CRC_14443_B,data,len,data+len,data+len+1);
+}
+
 //-----------------------------------------------------------------------------
 // Code up a string of octets at layer 2 (including CRC, we don't generate
 // that here) so that they can be transmitted to the reader. Doesn't transmit
@@ -114,27 +195,10 @@ static void CodeIso14443bAsTag(const uint8_t *cmd, int len)
 	}
 
 	// Convert from last byte pos to length
-	ToSendMax++;
+	++ToSendMax;
 }
 
-//-----------------------------------------------------------------------------
-// The software UART that receives commands from the reader, and its state
-// variables.
-//-----------------------------------------------------------------------------
-static struct {
-	enum {
-		STATE_UNSYNCD,
-		STATE_GOT_FALLING_EDGE_OF_SOF,
-		STATE_AWAITING_START_BIT,
-		STATE_RECEIVING_DATA
-	}       state;
-	uint16_t    shiftReg;
-	int     bitCnt;
-	int     byteCnt;
-	int     byteCntMax;
-	int     posCnt;
-	uint8_t   *output;
-} Uart;
+
 
 /* Receive & handle a bit coming from the reader.
  *
@@ -262,25 +326,6 @@ static RAMFUNC int Handle14443bUartBit(uint8_t bit)
 	return FALSE;
 }
 
-
-static void UartReset()
-{
-	Uart.byteCntMax = MAX_FRAME_SIZE;
-	Uart.state = STATE_UNSYNCD;
-	Uart.byteCnt = 0;
-	Uart.bitCnt = 0;
-	Uart.posCnt = 0;
-	memset(Uart.output, 0x00, MAX_FRAME_SIZE);
-}
-
-
-static void UartInit(uint8_t *data)
-{
-	Uart.output = data;
-	UartReset();
-}
-
-
 //-----------------------------------------------------------------------------
 // Receive a command (from the reader to us, where we are the simulated tag),
 // and store it in the given buffer, up to the given maximum length. Keeps
@@ -327,13 +372,13 @@ static int GetIso14443bCommandFromReader(uint8_t *received, uint16_t *len)
 void SimulateIso14443bTag(void)
 {
 	// the only commands we understand is WUPB, AFI=0, Select All, N=1:
-	static const uint8_t cmd1[] = { 0x05, 0x00, 0x08, 0x39, 0x73 }; // WUPB
+	static const uint8_t cmd1[] = { ISO14443B_REQB, 0x00, 0x08, 0x39, 0x73 }; // WUPB
 	// ... and REQB, AFI=0, Normal Request, N=1:
-	static const uint8_t cmd2[] = { 0x05, 0x00, 0x00, 0x71, 0xFF }; // REQB
+	static const uint8_t cmd2[] = { ISO14443B_REQB, 0x00, 0x00, 0x71, 0xFF }; // REQB
 	// ... and HLTB
-	static const uint8_t cmd3[] = { 0x50, 0xff, 0xff, 0xff, 0xff }; // HLTB
+	static const uint8_t cmd3[] = { ISO14443B_HALT, 0xff, 0xff, 0xff, 0xff }; // HLTB
 	// ... and ATTRIB
-	static const uint8_t cmd4[] = { 0x1D, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; // ATTRIB
+	static const uint8_t cmd4[] = { ISO14443B_ATTRIB, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; // ATTRIB
 
 	// ... and we always respond with ATQB, PUPI = 820de174, Application Data = 0x20381922,
 	// supports only 106kBit/s in both directions, max frame size = 32Bytes,
@@ -344,8 +389,6 @@ void SimulateIso14443bTag(void)
 	};
 	// response to HLTB and ATTRIB
 	static const uint8_t response2[] = {0x00, 0x78, 0xF0};
-
-	uint8_t parity[MAX_PARITY_SIZE];
 				
 	FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
 
@@ -357,7 +400,8 @@ void SimulateIso14443bTag(void)
 	uint16_t respLen, respCodeLen;
 
 	// allocate command receive buffer
-	BigBuf_free();
+	BigBuf_free(); BigBuf_Clear_ext(false);
+	
 	uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
 
 	uint16_t len;
@@ -383,14 +427,14 @@ void SimulateIso14443bTag(void)
 
 	for(;;) {
 
-		if(!GetIso14443bCommandFromReader(receivedCmd, &len)) {
-		Dbprintf("button pressed, received %d commands", cmdsRecvd);
-		break;
+		if (!GetIso14443bCommandFromReader(receivedCmd, &len)) {
+			Dbprintf("button pressed, received %d commands", cmdsRecvd);
+			break;
 		}
 
-		if (tracing) {
-			LogTrace(receivedCmd, len, 0, 0, parity, TRUE);
-		}
+		if (tracing)
+			LogTrace(receivedCmd, len, 0, 0, NULL, TRUE);	
+			
 
 		// Good, look at the command now.
 		if ( (len == sizeof(cmd1) && memcmp(receivedCmd, cmd1, len) == 0)
@@ -407,17 +451,18 @@ void SimulateIso14443bTag(void)
 			respCodeLen = resp2CodeLen;
 		} else {
 			Dbprintf("new cmd from reader: len=%d, cmdsRecvd=%d", len, cmdsRecvd);
+
 			// And print whether the CRC fails, just for good measure
 			uint8_t b1, b2;
 			if (len >= 3){ // if crc exists
-			ComputeCrc14443(CRC_14443_B, receivedCmd, len-2, &b1, &b2);
-			if(b1 != receivedCmd[len-2] || b2 != receivedCmd[len-1]) {
-				// Not so good, try again.
-				DbpString("+++CRC fail");
-		
-			} else {
-				DbpString("CRC passes");
-			}
+				ComputeCrc14443(CRC_14443_B, receivedCmd, len-2, &b1, &b2);
+				if(b1 != receivedCmd[len-2] || b2 != receivedCmd[len-1]) {
+					// Not so good, try again.
+					DbpString("+++CRC fail");
+			
+				} else {
+					DbpString("CRC passes");
+				}
 			}
 			//get rid of compiler warning
 			respCodeLen = 0;
@@ -428,9 +473,9 @@ void SimulateIso14443bTag(void)
 			//break;
 		}
 
-		cmdsRecvd++;
+		++cmdsRecvd;
 
-		if(cmdsRecvd > 0x30) {
+		if(cmdsRecvd > 0xFF) {
 			DbpString("many commands later...");
 			break;
 		}
@@ -444,41 +489,29 @@ void SimulateIso14443bTag(void)
 		AT91C_BASE_SSC->SSC_THR = 0xff;
 		FpgaSetupSsc();
 
-		uint8_t c;
-	 	// clear receiving shift register and holding register
-		while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
-		c = AT91C_BASE_SSC->SSC_RHR; (void) c;
-		while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
-		c = AT91C_BASE_SSC->SSC_RHR; (void) c;
-		
-		// Clear TXRDY:
-		AT91C_BASE_SSC->SSC_THR = 0x00;
-		
 		// Transmit the response.
-		uint16_t FpgaSendQueueDelay = 0;
 		uint16_t i = 0;
-		for(;i < respCodeLen; ) {
+		volatile uint8_t b;
+		for(;;) {
 			if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-				AT91C_BASE_SSC->SSC_THR = respCode[i++];
-				FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+				uint8_t b = respCode[i];
+
+				AT91C_BASE_SSC->SSC_THR = b;
+
+				++i;
+				if(i > respCodeLen)
+					break;
+
 			}
-				if(BUTTON_PRESS()) break;
-		}
-		
-		// Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
-		uint8_t fpga_queued_bits = FpgaSendQueueDelay >> 3;
-		for (i = 0; i <= fpga_queued_bits/8 + 1; ) {
-			if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-				AT91C_BASE_SSC->SSC_THR = 0x00;
-				FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-				i++;
+			if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
+				b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+				(void)b;
 			}
 		}
 		
-		// trace the response:
-		if (tracing) LogTrace(resp, respLen, 0, 0, parity, FALSE);			
+		if (tracing)
+			LogTrace(resp, respLen, 0, 0, NULL, FALSE);
 	}
-	FpgaDisableSscDma();
 }
 
 //=============================================================================
@@ -488,29 +521,6 @@ void SimulateIso14443bTag(void)
 // PC side.
 //=============================================================================
 
-static struct {
-	enum {
-		DEMOD_UNSYNCD,
-		DEMOD_PHASE_REF_TRAINING,
-		DEMOD_AWAITING_FALLING_EDGE_OF_SOF,
-		DEMOD_GOT_FALLING_EDGE_OF_SOF,
-		DEMOD_AWAITING_START_BIT,
-		DEMOD_RECEIVING_DATA
-	}       state;
-	int     bitCount;
-	int     posCount;
-	int     thisBit;
-/* this had been used to add RSSI (Received Signal Strength Indication) to traces. Currently not implemented.
-	int     metric;
-	int     metricN;
-*/
-	uint16_t    shiftReg;
-	uint8_t   *output;
-	int     len;
-	int     sumI;
-	int     sumQ;
-} Demod;
-
 /*
  * Handles reception of a bit from the tag
  *
@@ -525,14 +535,13 @@ static struct {
  *          false if we are still waiting for some more
  *
  */
+#ifndef SUBCARRIER_DETECT_THRESHOLD
+# define SUBCARRIER_DETECT_THRESHOLD	6
+#endif
+
 static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq)
 {
 	int v = 0;
-	int ai = abs(ci);
-	int aq = abs(cq);
-	int halfci = (ai >> 1);
-	int halfcq = (aq >> 1);
-
 // The soft decision on the bit uses an estimate of just the
 // quadrant of the reference angle, not the exact angle.
 #define MAKE_SOFT_DECISION() { \
@@ -548,18 +557,62 @@ static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq)
 		} \
 	}
 
-#define SUBCARRIER_DETECT_THRESHOLD	8
-
+// Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by abs(ci) + abs(cq)
+/* #define CHECK_FOR_SUBCARRIER() { \
+		v = ci; \
+		if(v < 0) v = -v; \
+		if(cq > 0) { \
+			v += cq; \
+		} else { \
+			v -= cq; \
+		} \
+	}
+ */
 // Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by max(abs(ci),abs(cq)) + 1/2*min(abs(ci),abs(cq)))
 #define CHECK_FOR_SUBCARRIER() { \
-		v = MAX(ai, aq) + MIN(halfci, halfcq); \
-}
+		if(ci < 0) { \
+			if(cq < 0) { /* ci < 0, cq < 0 */ \
+				if (cq < ci) { \
+					v = -cq - (ci >> 1); \
+				} else { \
+					v = -ci - (cq >> 1); \
+				} \
+			} else {	/* ci < 0, cq >= 0 */ \
+				if (cq < -ci) { \
+					v = -ci + (cq >> 1); \
+				} else { \
+					v = cq - (ci >> 1); \
+				} \
+			} \
+		} else { \
+			if(cq < 0) { /* ci >= 0, cq < 0 */ \
+				if (-cq < ci) { \
+					v = ci - (cq >> 1); \
+				} else { \
+					v = -cq + (ci >> 1); \
+				} \
+			} else {	/* ci >= 0, cq >= 0 */ \
+				if (cq < ci) { \
+					v = ci + (cq >> 1); \
+				} else { \
+					v = cq + (ci >> 1); \
+				} \
+			} \
+		} \
+	}
 
+//note: couldn't we just use MAX(ABS(ci),ABS(cq)) + (MIN(ABS(ci),ABS(cq))/2) from common.h - marshmellow
+#define CHECK_FOR_SUBCARRIER_duo() { \
+		v = MAX(ABS(ci),ABS(cq)) + (MIN(ABS(ci),ABS(cq))/2); \
+ 	}
 
 	switch(Demod.state) {
 		case DEMOD_UNSYNCD:
+
 			CHECK_FOR_SUBCARRIER();
-			if(v > SUBCARRIER_DETECT_THRESHOLD) {	// subcarrier detected
+
+			// subcarrier detected
+			if(v > SUBCARRIER_DETECT_THRESHOLD) {
 				Demod.state = DEMOD_PHASE_REF_TRAINING;
 				Demod.sumI = ci;
 				Demod.sumQ = cq;
@@ -569,15 +622,17 @@ static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq)
 
 		case DEMOD_PHASE_REF_TRAINING:
 			if(Demod.posCount < 8) {
-			//if(Demod.posCount < 10*2) {
+
 				CHECK_FOR_SUBCARRIER();
+				
 				if (v > SUBCARRIER_DETECT_THRESHOLD) {
 					// set the reference phase (will code a logic '1') by averaging over 32 1/fs.
 					// note: synchronization time > 80 1/fs
 					Demod.sumI += ci;
 					Demod.sumQ += cq;
-					Demod.posCount++;
-				} else {		// subcarrier lost
+					++Demod.posCount;
+				} else {	
+					// subcarrier lost
 					Demod.state = DEMOD_UNSYNCD;
 				}
 			} else {
@@ -586,37 +641,38 @@ static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq)
 			break;
 
 		case DEMOD_AWAITING_FALLING_EDGE_OF_SOF:
+			
 			MAKE_SOFT_DECISION();
+			
 			//Dbprintf("ICE: %d %d %d %d %d", v, Demod.sumI, Demod.sumQ, ci, cq );
-			if(v <= 0) {	// logic '0' detected
+			if(v < 0) {	// logic '0' detected
 				Demod.state = DEMOD_GOT_FALLING_EDGE_OF_SOF;
 				Demod.posCount = 0;	// start of SOF sequence
 			} else {
-				if(Demod.posCount > 25*2) {	// maximum length of TR1 = 200 1/fs
-					Demod.state = DEMOD_UNSYNCD;
-				}
+				// maximum length of TR1 = 200 1/fs
+				if(Demod.posCount > 25*2) Demod.state = DEMOD_UNSYNCD;
 			}
-			Demod.posCount++;
+			++Demod.posCount;
 			break;
 
 		case DEMOD_GOT_FALLING_EDGE_OF_SOF:
-			Demod.posCount++;
+			++Demod.posCount;
+			
 			MAKE_SOFT_DECISION();
+			
 			if(v > 0) {
-				if(Demod.posCount < 10*2) { // low phase of SOF too short (< 9 etu). Note: spec is >= 10, but FPGA tends to "smear" edges
+				// low phase of SOF too short (< 9 etu). Note: spec is >= 10, but FPGA tends to "smear" edges
+				if(Demod.posCount < 9*2) { 
 					Demod.state = DEMOD_UNSYNCD;
 				} else {
 					LED_C_ON(); // Got SOF
 					Demod.state = DEMOD_AWAITING_START_BIT;
 					Demod.posCount = 0;
 					Demod.len = 0;
-/* this had been used to add RSSI (Received Signal Strength Indication) to traces. Currently not implemented.
-					Demod.metricN = 0;
-					Demod.metric = 0;
-*/
 				}
 			} else {
-				if(Demod.posCount > 13*2) { // low phase of SOF too long (> 12 etu)
+				// low phase of SOF too long (> 12 etu)
+				if (Demod.posCount > 12*2) { 
 					Demod.state = DEMOD_UNSYNCD;
 					LED_C_OFF();
 				}
@@ -624,9 +680,11 @@ static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq)
 			break;
 
 		case DEMOD_AWAITING_START_BIT:
-			Demod.posCount++;
+			++Demod.posCount;
+			
 			MAKE_SOFT_DECISION();
-			if(v > 0) {
+			
+			if (v > 0) {
 				if(Demod.posCount > 3*2) { 		// max 19us between characters = 16 1/fs, max 3 etu after low phase of SOF = 24 1/fs
 					Demod.state = DEMOD_UNSYNCD;
 					LED_C_OFF();
@@ -641,42 +699,39 @@ static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq)
 			break;
 
 		case DEMOD_RECEIVING_DATA:
+			
 			MAKE_SOFT_DECISION();
-			if(Demod.posCount == 0) { 			// first half of bit
+
+			if (Demod.posCount == 0) { 
+				// first half of bit
 				Demod.thisBit = v;
 				Demod.posCount = 1;
-			} else {							// second half of bit
+			} else {
+				// second half of bit
 				Demod.thisBit += v;
-
-/* this had been used to add RSSI (Received Signal Strength Indication) to traces. Currently not implemented.
-				if(Demod.thisBit > 0) {
-					Demod.metric += Demod.thisBit;
-				} else {
-					Demod.metric -= Demod.thisBit;
-				}
-				(Demod.metricN)++;
-*/				
-
 				Demod.shiftReg >>= 1;
-				if(Demod.thisBit > 0) {	// logic '1'
-					Demod.shiftReg |= 0x200;
-				}
 
-				Demod.bitCount++;
+				// logic '1'
+				if(Demod.thisBit > 0)  Demod.shiftReg |= 0x200;
+
+				++Demod.bitCount;
+				
 				if(Demod.bitCount == 10) {
+					
 					uint16_t s = Demod.shiftReg;
-					if((s & 0x200) && !(s & 0x001)) { // stop bit == '1', start bit == '0'
+					
+					// stop bit == '1', start bit == '0'
+					if((s & 0x200) && !(s & 0x001)) { 
 						uint8_t b = (s >> 1);
 						Demod.output[Demod.len] = b;
-						Demod.len++;
+						++Demod.len;
 						Demod.state = DEMOD_AWAITING_START_BIT;
 					} else {
 						Demod.state = DEMOD_UNSYNCD;
 						LED_C_OFF();
-						if(s == 0x000) {
-							// This is EOF (start, stop and all data bits == '0'
-							return TRUE;
-						}
+						
+						// This is EOF (start, stop and all data bits == '0'
+						if(s == 0) return TRUE;
 					}
 				}
 				Demod.posCount = 0;
@@ -692,28 +747,6 @@ static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq)
 }
 
 
-static void DemodReset()
-{
-	// Clear out the state of the "UART" that receives from the tag.
-	Demod.len = 0;
-	Demod.state = DEMOD_UNSYNCD;
-	Demod.posCount = 0;
-	Demod.sumI = 0;
-	Demod.sumQ = 0;
-	Demod.bitCount = 0;
-	Demod.thisBit = 0;
-	Demod.shiftReg = 0;
-	memset(Demod.output, 0x00, MAX_FRAME_SIZE);
-}
-
-
-static void DemodInit(uint8_t *data)
-{
-	Demod.output = data;
-	DemodReset();
-}
-
-
 /*
  *  Demodulate the samples we received from the tag, also log to tracebuffer
  *  quiet: set to 'TRUE' to disable debug output
@@ -726,18 +759,19 @@ static void GetSamplesFor14443bDemod(int n, bool quiet)
 
 	// Allocate memory from BigBuf for some buffers
 	// free all previous allocations first
-	BigBuf_free();
-
-	// And put the FPGA in the appropriate mode
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ);
+	///BigBuf_free();
 
 	// The response (tag -> reader) that we're receiving.
 	// Set up the demodulator for tag -> reader responses.
+	// this init, can take some time to execute,  memset
 	DemodInit(BigBuf_malloc(MAX_FRAME_SIZE));
 	
 	// The DMA buffer, used to stream samples from the FPGA
 	int8_t *dmaBuf = (int8_t*) BigBuf_malloc(ISO14443B_DMA_BUFFER_SIZE);
 
+	// And put the FPGA in the appropriate mode
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ);
+	
 	// Setup and start DMA.
 	FpgaSetupSscDma((uint8_t*) dmaBuf, ISO14443B_DMA_BUFFER_SIZE);
 	
@@ -760,41 +794,40 @@ static void GetSamplesFor14443bDemod(int n, bool quiet)
 				AT91C_BASE_PDC_SSC->PDC_RNCR = ISO14443B_DMA_BUFFER_SIZE;
 			}
 			lastRxCounter -= 2;
-			if(lastRxCounter <= 0) {
-				lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
-			}
+
+			if(lastRxCounter <= 0)
+				lastRxCounter += ISO14443B_DMA_BUFFER_SIZE;
 
 			samples += 2;
 
-			//
-			gotFrame = Handle14443bSamplesDemod(ci , cq );
+			// is this | 0x01 the error?   & 0xfe  in https://github.com/Proxmark/proxmark3/issues/103
+			// can we double this?
+			gotFrame = Handle14443bSamplesDemod(ci<<2 , cq<<2);
 			if ( gotFrame )
 				break;
 		}
 
-		if(samples > n || gotFrame) {
+		if(samples > n || gotFrame)
 			break;
-		}
 	}
 
+	//disable
 	AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS;
 
-	if (!quiet && Demod.len == 0) {
-		Dbprintf("max behindby = %d, samples = %d, gotFrame = %d, Demod.len = %d, Demod.sumI = %d, Demod.sumQ = %d",
+	if (!quiet) {
+		Dbprintf("max behindby = %d, samples = %d, gotFrame = %s, Demod.state = %d, Demod.len = %d, Demod.sumI = %d, Demod.sumQ = %d",
 			max,
 			samples, 
-			gotFrame, 
+			(gotFrame) ? "true" : "false", 
+			Demod.state,
 			Demod.len, 
 			Demod.sumI, 
 			Demod.sumQ
 		);
 	}
 
-	//Tracing
-	if (tracing && Demod.len > 0) {
-		uint8_t parity[MAX_PARITY_SIZE];
-		LogTrace(Demod.output, Demod.len, 0, 0, parity, FALSE);
-	}
+	 if (tracing > 0)
+		LogTrace(Demod.output, Demod.len, samples, samples, NULL, FALSE);
 }
 
 
@@ -804,12 +837,11 @@ static void GetSamplesFor14443bDemod(int n, bool quiet)
 static void TransmitFor14443b(void)
 {
 	int c;
-
+	volatile uint32_t r;
 	FpgaSetupSsc();
 	
-	while(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+	while(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY))
 		AT91C_BASE_SSC->SSC_THR = 0xff;
-	}
 
 	// Signal field is ON with the appropriate Red LED
 	LED_D_ON();
@@ -820,10 +852,10 @@ static void TransmitFor14443b(void)
 	for(c = 0; c < 10;) {
 		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
 			AT91C_BASE_SSC->SSC_THR = 0xff;
-			c++;
+			++c;
 		}
 		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-			volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
+			r = AT91C_BASE_SSC->SSC_RHR;
 			(void)r;
 		}
 		WDT_HIT();
@@ -833,13 +865,12 @@ static void TransmitFor14443b(void)
 	for(;;) {
 		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
 			AT91C_BASE_SSC->SSC_THR = ToSend[c];
-			c++;
-			if(c >= ToSendMax) {
+			++c;
+			if(c >= ToSendMax)
 				break;
-			}
 		}
 		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-			volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
+			r = AT91C_BASE_SSC->SSC_RHR;
 			(void)r;
 		}
 		WDT_HIT();
@@ -860,15 +891,14 @@ static void CodeIso14443bAsReader(const uint8_t *cmd, int len)
 	ToSendReset();
 
 	// Establish initial reference level
-	for(i = 0; i < 40; i++) {
+	for(i = 0; i < 40; ++i)
 		ToSendStuffBit(1);
-	}
+
 	// Send SOF
-	for(i = 0; i < 11; i++) {
+	for(i = 0; i < 10; ++i)
 		ToSendStuffBit(0);
-	}
 
-	for(i = 0; i < len; i++) {
+	for(i = 0; i < len; ++i) {
 		// Stop bits/EGT
 		ToSendStuffBit(1);
 		ToSendStuffBit(1);
@@ -876,32 +906,31 @@ static void CodeIso14443bAsReader(const uint8_t *cmd, int len)
 		ToSendStuffBit(0);
 		// Data bits
 		b = cmd[i];
-		for(j = 0; j < 8; j++) {
-			if(b & 1) {
+		for(j = 0; j < 8; ++j) {
+			if(b & 1)
 				ToSendStuffBit(1);
-			} else {
+			else
 				ToSendStuffBit(0);
-			}
+			
 			b >>= 1;
 		}
 	}
 	// Send EOF
 	ToSendStuffBit(1);
-	for(i = 0; i < 11; i++) {
+	for(i = 0; i < 10; ++i)
 		ToSendStuffBit(0);
-	}
-	for(i = 0; i < 8; i++) {
+	
+	for(i = 0; i < 8; ++i)
 		ToSendStuffBit(1);
-	}
+
 
 	// And then a little more, to make sure that the last character makes
 	// it out before we switch to rx mode.
-	for(i = 0; i < 10; i++) {
+	for(i = 0; i < 24; ++i)
 		ToSendStuffBit(1);
-	}
 
 	// Convert from last character reference to length
-	ToSendMax++;
+	++ToSendMax;
 }
 
 
@@ -912,17 +941,18 @@ static void CodeAndTransmit14443bAsReader(const uint8_t *cmd, int len)
 {
 	CodeIso14443bAsReader(cmd, len);
 	TransmitFor14443b();
-	if (tracing) {
-		uint8_t parity[MAX_PARITY_SIZE];
-		LogTrace(cmd,len, 0, 0, parity, TRUE);
-	}
+
+	if(trigger) LED_A_ON();
+	
+	if (tracing) LogTrace(cmd, len, 0, 0, NULL, TRUE);
 }
 
 /* Sends an APDU to the tag
  * TODO: check CRC and preamble
  */
-int iso14443b_apdu(uint8_t const *message, size_t message_length, uint8_t *response)
+uint8_t iso14443b_apdu(uint8_t const *message, size_t message_length, uint8_t *response)
 {
+	uint8_t crc[2] = {0x00, 0x00};
 	uint8_t message_frame[message_length + 4];
 	// PCB
 	message_frame[0] = 0x0A | pcb_blocknum;
@@ -936,60 +966,136 @@ int iso14443b_apdu(uint8_t const *message, size_t message_length, uint8_t *respo
 	// send
 	CodeAndTransmit14443bAsReader(message_frame, message_length + 4);
 	// get response
-	GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT*100, TRUE);
+	GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
 	if(Demod.len < 3)
-	{
 		return 0;
-	}
-	// TODO: Check CRC
+	
+	// VALIDATE CRC
+    ComputeCrc14443(CRC_14443_B, Demod.output, Demod.len-2, &crc[0], &crc[1]);
+	if ( crc[0] != Demod.output[Demod.len-2] || crc[1] != Demod.output[Demod.len-1] )
+		return 0;
+	
 	// copy response contents
 	if(response != NULL)
-	{
 		memcpy(response, Demod.output, Demod.len);
-	}
+
 	return Demod.len;
 }
 
+/**
+* SRx Initialise.
+*/
+uint8_t iso14443b_select_srx_card(iso14b_card_select_t *card )
+{
+	// INITIATE command: wake up the tag using the INITIATE
+	static const uint8_t init_srx[] = { ISO14443B_INITIATE, 0x00, 0x97, 0x5b };
+	// SELECT command (with space for CRC)
+	uint8_t select_srx[] = { ISO14443B_SELECT, 0x00, 0x00, 0x00};
+	// temp to calc crc.
+	uint8_t crc[2] = {0x00, 0x00};
+	
+	CodeAndTransmit14443bAsReader(init_srx, sizeof(init_srx));
+	GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
+
+	if (Demod.len == 0) return 2;
+
+	// Randomly generated Chip ID	
+	if (card) card->chipid = Demod.output[0];
+	
+	select_srx[1] = Demod.output[0];
+	
+	ComputeCrc14443(CRC_14443_B, select_srx, 2, &select_srx[2], &select_srx[3]);
+	CodeAndTransmit14443bAsReader(select_srx, sizeof(select_srx));
+	GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
+	
+	if (Demod.len != 3)	return 2;
+	
+	// Check the CRC of the answer:
+	ComputeCrc14443(CRC_14443_B, Demod.output, Demod.len-2 , &crc[0], &crc[1]);
+	if(crc[0] != Demod.output[1] || crc[1] != Demod.output[2]) return 3;
+	
+	// Check response from the tag: should be the same UID as the command we just sent:
+	if (select_srx[1] != Demod.output[0]) return 1;
+
+	// First get the tag's UID:
+	select_srx[0] = ISO14443B_GET_UID;
+
+	ComputeCrc14443(CRC_14443_B, select_srx, 1 , &select_srx[1], &select_srx[2]);
+	CodeAndTransmit14443bAsReader(select_srx, 3); // Only first three bytes for this one
+	GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
+
+	if (Demod.len != 10) return 2;
+	
+	// The check the CRC of the answer
+	ComputeCrc14443(CRC_14443_B, Demod.output, Demod.len-2, &crc[0], &crc[1]);
+	if(crc[0] != Demod.output[8] || crc[1] != Demod.output[9]) return 3;
+
+	if (card) {
+		card->uidlen = 8;
+		memcpy(card->uid, Demod.output, 8);
+	}
+
+	return 0;
+}
 /* Perform the ISO 14443 B Card Selection procedure
  * Currently does NOT do any collision handling.
  * It expects 0-1 cards in the device's range.
  * TODO: Support multiple cards (perform anticollision)
  * TODO: Verify CRC checksums
  */
-int iso14443b_select_card()
+uint8_t iso14443b_select_card(iso14b_card_select_t *card )
 {
 	// WUPB command (including CRC)
 	// Note: WUPB wakes up all tags, REQB doesn't wake up tags in HALT state
-	static const uint8_t wupb[] = { 0x05, 0x00, 0x08, 0x39, 0x73 };
+	static const uint8_t wupb[] = { ISO14443B_REQB, 0x00, 0x08, 0x39, 0x73 };
 	// ATTRIB command (with space for CRC)
-	uint8_t attrib[] = { 0x1D, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00};
+	uint8_t attrib[] = { ISO14443B_ATTRIB, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00};
 
+	// temp to calc crc.
+	uint8_t crc[2] = {0x00, 0x00};
+	
 	// first, wake up the tag
 	CodeAndTransmit14443bAsReader(wupb, sizeof(wupb));
 	GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
+	
 	// ATQB too short?
-	if (Demod.len < 14)
-	{
-		return 2;
+	if (Demod.len < 14) return 2;
+	
+	// VALIDATE CRC
+    ComputeCrc14443(CRC_14443_B, Demod.output, Demod.len-2, &crc[0], &crc[1]);
+	if ( crc[0] != Demod.output[12] || crc[1] != Demod.output[13] )
+		return 3;
+	
+	if (card) {
+		card->uidlen = 4;
+		memcpy(card->uid, Demod.output+1, 4);
+		memcpy(card->atqb, Demod.output+5, 7);
 	}
 
-    // select the tag
     // copy the PUPI to ATTRIB
     memcpy(attrib + 1, Demod.output + 1, 4);
-    /* copy the protocol info from ATQB (Protocol Info -> Protocol_Type) into
-    ATTRIB (Param 3) */
+	
+    // copy the protocol info from ATQB (Protocol Info -> Protocol_Type) into ATTRIB (Param 3)
     attrib[7] = Demod.output[10] & 0x0F;
     ComputeCrc14443(CRC_14443_B, attrib, 9, attrib + 9, attrib + 10);
+
     CodeAndTransmit14443bAsReader(attrib, sizeof(attrib));
     GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
+
     // Answer to ATTRIB too short?
-    if(Demod.len < 3)
-	{
-		return 2;
-	}
+    if(Demod.len < 3) return 2;
+
+	// VALIDATE CRC
+    ComputeCrc14443(CRC_14443_B, Demod.output, Demod.len-2, &crc[0], &crc[1]);
+	if ( crc[0] != Demod.output[1] || crc[1] != Demod.output[2] ) 
+		return 3;
+	
+	// CID
+	if (card) card->cid = Demod.output[0];
+	
 	// reset PCB block number
 	pcb_blocknum = 0;
-	return 1;
+	return 0;
 }
 
 // Set up ISO 14443 Type B communication (similar to iso14443a_setup)
@@ -997,23 +1103,23 @@ void iso14443b_setup() {
 
 	FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
 
-	BigBuf_free();
+	BigBuf_free(); BigBuf_Clear_ext(false);
+	DemodReset();
+	UartReset();
+	
 	// Set up the synchronous serial port
 	FpgaSetupSsc();
+
 	// connect Demodulated Signal to ADC:
 	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
 
 	// Signal field is on with the appropriate LED
     LED_D_ON();
 	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD);
-	
-	SpinDelay(100);
+	SpinDelay(400);
 
 	// Start the timer
-	//StartCountSspClk();
-
-	DemodReset();
-	UartReset();
+	StartCountSspClk();
 }
 
 //-----------------------------------------------------------------------------
@@ -1025,11 +1131,9 @@ void iso14443b_setup() {
 //
 // I tried to be systematic and check every answer of the tag, every CRC, etc...
 //-----------------------------------------------------------------------------
-void ReadSTMemoryIso14443b(uint32_t dwLast)
+void ReadSTMemoryIso14443b(uint8_t numofblocks)
 {
 	FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
-	BigBuf_free();
-
 	clear_trace();
 	set_tracing(TRUE);
 
@@ -1048,15 +1152,16 @@ void ReadSTMemoryIso14443b(uint32_t dwLast)
 	// Signal field is on with the appropriate LED
 	LED_D_ON();
 	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ);
-	SpinDelay(200);
+	SpinDelay(300);
 
 	// First command: wake up the tag using the INITIATE command
-	uint8_t cmd1[] = {0x06, 0x00, 0x97, 0x5b};
+	uint8_t cmd1[] = {ISO14443B_INITIATE, 0x00, 0x97, 0x5b};
 	CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1));
 	GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
 
 	if (Demod.len == 0) {
 		DbpString("No response from tag");
+		set_tracing(FALSE);	
 		return;
 	} else {
 		Dbprintf("Randomly generated Chip ID (+ 2 byte CRC): %02x %02x %02x",
@@ -1065,35 +1170,39 @@ void ReadSTMemoryIso14443b(uint32_t dwLast)
 
 	// There is a response, SELECT the uid
 	DbpString("Now SELECT tag:");
-	cmd1[0] = 0x0E; // 0x0E is SELECT
+	cmd1[0] = ISO14443B_SELECT; // 0x0E is SELECT
 	cmd1[1] = Demod.output[0];
 	ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]);
 	CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1));
 	GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
 	if (Demod.len != 3) {
 		Dbprintf("Expected 3 bytes from tag, got %d", Demod.len);
+		set_tracing(FALSE);	
 		return;
 	}
 	// Check the CRC of the answer:
 	ComputeCrc14443(CRC_14443_B, Demod.output, 1 , &cmd1[2], &cmd1[3]);
 	if(cmd1[2] != Demod.output[1] || cmd1[3] != Demod.output[2]) {
 		DbpString("CRC Error reading select response.");
+		set_tracing(FALSE);	
 		return;
 	}
 	// Check response from the tag: should be the same UID as the command we just sent:
 	if (cmd1[1] != Demod.output[0]) {
 		Dbprintf("Bad response to SELECT from Tag, aborting: %02x %02x", cmd1[1], Demod.output[0]);
+		set_tracing(FALSE);	
 		return;
 	}
 
 	// Tag is now selected,
 	// First get the tag's UID:
-	cmd1[0] = 0x0B;
+	cmd1[0] = ISO14443B_GET_UID;
 	ComputeCrc14443(CRC_14443_B, cmd1, 1 , &cmd1[1], &cmd1[2]);
 	CodeAndTransmit14443bAsReader(cmd1, 3); // Only first three bytes for this one
 	GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
 	if (Demod.len != 10) {
 		Dbprintf("Expected 10 bytes from tag, got %d", Demod.len);
+		set_tracing(FALSE);	
 		return;
 	}
 	// The check the CRC of the answer (use cmd1 as temporary variable):
@@ -1108,12 +1217,13 @@ void ReadSTMemoryIso14443b(uint32_t dwLast)
 			(Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0]);
 
 	// Now loop to read all 16 blocks, address from 0 to last block
-	Dbprintf("Tag memory dump, block 0 to %d", dwLast);
+	Dbprintf("Tag memory dump, block 0 to %d", numofblocks);
 	cmd1[0] = 0x08;
 	i = 0x00;
-	dwLast++;
+	++numofblocks;
+	
 	for (;;) {
-		   if (i == dwLast) {
+		if (i == numofblocks) {
 			DbpString("System area block (0xff):");
 			i = 0xff;
 		}
@@ -1121,9 +1231,10 @@ void ReadSTMemoryIso14443b(uint32_t dwLast)
 		ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]);
 		CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1));
 		GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
+		
 		if (Demod.len != 6) { // Check if we got an answer from the tag
-		DbpString("Expected 6 bytes from tag, got less...");
-		return;
+			DbpString("Expected 6 bytes from tag, got less...");
+			return;
 		}
 		// The check the CRC of the answer (use cmd1 as temporary variable):
 		ComputeCrc14443(CRC_14443_B, Demod.output, 4, &cmd1[2], &cmd1[3]);
@@ -1136,14 +1247,14 @@ void ReadSTMemoryIso14443b(uint32_t dwLast)
 		Dbprintf("Address=%02x, Contents=%08x, CRC=%04x", i,
 				(Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0],
 				(Demod.output[4]<<8)+Demod.output[5]);
-		if (i == 0xff) {
-			break;
-		}
-		i++;
+
+		if (i == 0xff) break;
+		++i;
 	}
+	
+	set_tracing(FALSE);
 }
 
-
 //=============================================================================
 // Finally, the `sniffer' combines elements from both the reader and
 // simulated tag, to show both sides of the conversation.
@@ -1169,7 +1280,7 @@ void RAMFUNC SnoopIso14443b(void)
 	int triggered = TRUE;			// TODO: set and evaluate trigger condition
 
 	FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
-	BigBuf_free();
+	BigBuf_free(); BigBuf_Clear_ext(false);
 
 	clear_trace();
 	set_tracing(TRUE);
@@ -1207,7 +1318,6 @@ void RAMFUNC SnoopIso14443b(void)
 	upTo = dmaBuf;
 	lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
 	FpgaSetupSscDma((uint8_t*) dmaBuf, ISO14443B_DMA_BUFFER_SIZE);
-	uint8_t parity[MAX_PARITY_SIZE];
 
 	bool TagIsActive = FALSE;
 	bool ReaderIsActive = FALSE;
@@ -1216,10 +1326,8 @@ void RAMFUNC SnoopIso14443b(void)
 	for(;;) {
 		int behindBy = (lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR) &
 								(ISO14443B_DMA_BUFFER_SIZE-1);
-		if(behindBy > maxBehindBy) {
-			maxBehindBy = behindBy;
-		}
 
+		if(behindBy > maxBehindBy) maxBehindBy = behindBy;
 		if(behindBy < 2) continue;
 
 		ci = upTo[0];
@@ -1236,10 +1344,12 @@ void RAMFUNC SnoopIso14443b(void)
 				Dbprintf("blew circular buffer! behindBy=%d", behindBy);
 				break;
 			}
+			
 			if(!tracing) {
-				DbpString("Reached trace limit");
+				DbpString("Trace full");
 				break;
 			}
+			
 			if(BUTTON_PRESS()) {
 				DbpString("cancelled");
 				break;
@@ -1249,26 +1359,28 @@ void RAMFUNC SnoopIso14443b(void)
 		samples += 2;
 
 		if (!TagIsActive) {							// no need to try decoding reader data if the tag is sending
-			if(Handle14443bUartBit(ci & 0x01)) {
-			if(triggered && tracing) {
-					LogTrace(Uart.output, Uart.byteCnt, samples, samples, parity, TRUE);
+			if (Handle14443bUartBit(ci & 0x01)) {
+
+				if(triggered && tracing)
+					LogTrace(Uart.output, Uart.byteCnt, samples, samples, NULL, TRUE);
+
+				/* And ready to receive another command. */
+				UartReset();
+				/* And also reset the demod code, which might have been */
+				/* false-triggered by the commands from the reader. */
+				DemodReset();
 			}
-			/* And ready to receive another command. */
-			UartReset();
-			/* And also reset the demod code, which might have been */
-			/* false-triggered by the commands from the reader. */
-			DemodReset();
-		}
-			if(Handle14443bUartBit(cq & 0x01)) {
-			if(triggered && tracing) {
-					LogTrace(Uart.output, Uart.byteCnt, samples, samples, parity, TRUE);
+			
+			if (Handle14443bUartBit(cq & 0x01)) {
+				if(triggered && tracing)
+					LogTrace(Uart.output, Uart.byteCnt, samples, samples, NULL, TRUE);
+
+					/* And ready to receive another command. */
+					UartReset();
+					/* And also reset the demod code, which might have been */
+					/* false-triggered by the commands from the reader. */
+					DemodReset();
 			}
-			/* And ready to receive another command. */
-			UartReset();
-			/* And also reset the demod code, which might have been */
-			/* false-triggered by the commands from the reader. */
-			DemodReset();
-		}
 			ReaderIsActive = (Uart.state > STATE_GOT_FALLING_EDGE_OF_SOF);
 		}
 
@@ -1276,24 +1388,22 @@ void RAMFUNC SnoopIso14443b(void)
 			// is this | 0x01 the error?   & 0xfe  in https://github.com/Proxmark/proxmark3/issues/103
 			if(Handle14443bSamplesDemod(ci | 0x01, cq | 0x01)) {
 
-			//Use samples as a time measurement
-			if(tracing)
-			{
-				//uint8_t parity[MAX_PARITY_SIZE];
-				LogTrace(Demod.output, Demod.len, samples, samples, parity, FALSE);
-			}
-			triggered = TRUE;
+				//Use samples as a time measurement
+				if(tracing)
+					LogTrace(Demod.output, Demod.len, samples, samples, NULL, FALSE);
 
-			// And ready to receive another response.
-			DemodReset();
-		}
+				triggered = TRUE;
+
+				// And ready to receive another response.
+				DemodReset();
+			}
 			TagIsActive = (Demod.state > DEMOD_GOT_FALLING_EDGE_OF_SOF);
 		}
-
 	}
 
 	FpgaDisableSscDma();
 	LEDsoff();
+	
 	AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS;
 	DbpString("Snoop statistics:");
 	Dbprintf("  Max behind by: %i", maxBehindBy);
@@ -1301,42 +1411,97 @@ void RAMFUNC SnoopIso14443b(void)
 	Dbprintf("  Uart ByteCnt: %i", Uart.byteCnt);
 	Dbprintf("  Uart ByteCntMax: %i", Uart.byteCntMax);
 	Dbprintf("  Trace length: %i", BigBuf_get_traceLen());
+	set_tracing(FALSE);	
 }
 
+void iso14b_set_trigger(bool enable) {
+	trigger = enable;
+}
 
 /*
  * Send raw command to tag ISO14443B
  * @Input
- * datalen     len of buffer data
- * recv        bool when true wait for data from tag and send to client
- * powerfield  bool leave the field on when true
- * data        buffer with byte to send
+ * param   flags enum ISO14B_COMMAND.  (mifare.h)
+ * len     len of buffer data
+ * data    buffer with bytes to send
  *
  * @Output
  * none
  *
  */
-void SendRawCommand14443B(uint32_t datalen, uint32_t recv, uint8_t powerfield, uint8_t data[])
+void SendRawCommand14443B_Ex(UsbCommand *c)
 {
-	iso14443b_setup();
+	iso14b_command_t param = c->arg[0];
+	size_t len = c->arg[1] & 0xffff;
+	uint8_t *cmd = c->d.asBytes;
+	uint8_t status = 0;
+	uint32_t sendlen = sizeof(iso14b_card_select_t);
+	uint8_t buf[USB_CMD_DATA_SIZE] = {0x00};
+
+	if (MF_DBGLEVEL > 3) Dbprintf("param, %04x", param );
 	
-	if ( datalen == 0 && recv == 0 && powerfield == 0){
-		
-	} else {		
-		set_tracing(TRUE);
-		CodeAndTransmit14443bAsReader(data, datalen);
+	// turn on trigger (LED_A)
+	if (param & ISO14B_REQUEST_TRIGGER)
+		iso14b_set_trigger(TRUE);
+	
+	if (param & ISO14B_CONNECT) {
+		// Make sure that we start from off, since the tags are stateful;
+		// confusing things will happen if we don't reset them between reads.
+		LED_D_OFF();
+		FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+		SpinDelay(200);
+		clear_trace();
+		iso14443b_setup();
 	}
+	
+	set_tracing(TRUE);
 
-	if(recv) {
-		GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, FALSE);
-		uint16_t iLen = MIN(Demod.len, USB_CMD_DATA_SIZE);
-		cmd_send(CMD_ACK, iLen, 0, 0, Demod.output, iLen);
+	if ( param & ISO14B_SELECT_STD) {
+		iso14b_card_select_t *card = (iso14b_card_select_t*)buf;
+		status = iso14443b_select_card(card);	
+		cmd_send(CMD_ACK, status, sendlen, 0, buf, sendlen);
+		// 0: OK 2: attrib fail, 3:crc fail,
+		if ( status > 0 ) return;
+	} 
+	
+	if ( param & ISO14B_SELECT_SR) {
+		iso14b_card_select_t *card = (iso14b_card_select_t*)buf;
+		status = iso14443b_select_srx_card(card);
+		cmd_send(CMD_ACK, status, sendlen, 0, buf, sendlen);
+		// 0: OK 2: attrib fail, 3:crc fail,
+		if ( status > 0 ) return;
+	} 
+	
+	if (param & ISO14B_APDU) {
+		status = iso14443b_apdu(cmd, len, buf);
+		cmd_send(CMD_ACK, status, status, 0, buf, status);
+	}
+	
+	if (param & ISO14B_RAW) {
+		if(param & ISO14B_APPEND_CRC) {
+			AppendCrc14443b(cmd, len);
+			len += 2;
+		}
+	
+		CodeAndTransmit14443bAsReader(cmd, len);
+		GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
+		
+		sendlen = MIN(Demod.len, USB_CMD_DATA_SIZE);
+		status =  (Demod.len > 0) ? 0 : 1;
+		cmd_send(CMD_ACK, status, sendlen, 0, Demod.output, sendlen);
 	}
 	
-	if(!powerfield) {
+	// turn off trigger (LED_A)
+	if (param & ISO14B_REQUEST_TRIGGER)
+		iso14a_set_trigger(FALSE);
+
+	// turn off antenna et al
+	// we don't send a HALT command.
+	if ( param & ISO14B_DISCONNECT) {
+		if (MF_DBGLEVEL > 3) Dbprintf("disconnect");
 		FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
 		FpgaDisableSscDma();
-		LED_D_OFF();
+		set_tracing(FALSE);
+		LEDsoff();
 	}
-}
-
+}
\ No newline at end of file