Added tiread command to demod TI tags on the PM3

armsrc/appmain.c

@@ -597,10 +597,6 @@ void UsbPacketReceived(BYTE *packet, int len)
 			LED_D_OFF(); // LED D indicates field ON or OFF
 			break;
 
-		case CMD_ACQUIRE_RAW_BITS_TI_TYPE:
-			AcquireRawBitsTI();
-			break;
-
 		case CMD_READ_TI_TYPE:
 			ReadTItag();
 			break;
@@ -609,8 +605,7 @@ void UsbPacketReceived(BYTE *packet, int len)
 			WriteTItag(c->ext1,c->ext2,c->ext3);
 			break;
 
-		case CMD_DOWNLOAD_RAW_ADC_SAMPLES_125K:
+		case CMD_DOWNLOAD_RAW_ADC_SAMPLES_125K: {
-		case CMD_DOWNLOAD_RAW_BITS_TI_TYPE: {
 			UsbCommand n;
 			if(c->cmd == CMD_DOWNLOAD_RAW_ADC_SAMPLES_125K) {
 				n.cmd = CMD_DOWNLOADED_RAW_ADC_SAMPLES_125K;
@@ -632,11 +627,6 @@ void UsbPacketReceived(BYTE *packet, int len)
 			SimulateTagLowFrequency(c->ext1, 1);
 			LED_A_OFF();
 			break;
-#ifdef WITH_LCD
-		case CMD_LCD_RESET:
-			LCDReset();
-			break;
-#endif
 		case CMD_READ_MEM:
 			ReadMem(c->ext1);
 			break;
@@ -644,6 +634,9 @@ void UsbPacketReceived(BYTE *packet, int len)
 			FpgaSendCommand(FPGA_CMD_SET_DIVISOR, c->ext1);
 			break;
 #ifdef WITH_LCD
+		case CMD_LCD_RESET:
+			LCDReset();
+			break;
 		case CMD_LCD:
 			LCDSend(c->ext1);
 			break;
@@ -660,7 +653,6 @@ void UsbPacketReceived(BYTE *packet, int len)
 			}
 			break;
 
-
 		default:
 			DbpString("unknown command");
 			break;

armsrc/apps.h

@@ -9,7 +9,7 @@
 
 // The large multi-purpose buffer, typically used to hold A/D samples,
 // maybe processed in some way.
-DWORD BigBuf[10000];
+DWORD BigBuf[12000];
 
 /// appmain.h
 void ReadMem(int addr);

armsrc/lfops.c

@@ -115,15 +115,181 @@ void ModThenAcquireRawAdcSamples125k(int delay_off,int period_0,int period_1,BYT
 	DoAcquisition125k(at134khz);
 }
 
+/* blank r/w tag data stream
+...0000000000000000 01111111
+1010101010101010101010101010101010101010101010101010101010101010
+0011010010100001
+01111111
+101010101010101[0]000...
+
+[5555fe852c5555555555555555fe0000]
+*/
+void ReadTItag()
+{
+	// some hardcoded initial params
+	// when we read a TI tag we sample the zerocross line at 2Mhz
+	// TI tags modulate a 1 as 16 cycles of 123.2Khz
+	// TI tags modulate a 0 as 16 cycles of 134.2Khz
+	#define FSAMPLE 2000000
+	#define FREQLO 123200
+	#define FREQHI 134200
+
+	signed char *dest = (signed char *)BigBuf;
+	int n = sizeof(BigBuf);
+//	int *dest = GraphBuffer;
+//	int n = GraphTraceLen;
+
+	// 128 bit shift register [shift3:shift2:shift1:shift0]
+	DWORD shift3 = 0, shift2 = 0, shift1 = 0, shift0 = 0;
+
+	int i, cycles=0, samples=0;
+	// how many sample points fit in 16 cycles of each frequency
+	DWORD sampleslo = (FSAMPLE<<4)/FREQLO, sampleshi = (FSAMPLE<<4)/FREQHI;
+	// when to tell if we're close enough to one freq or another
+	DWORD threshold = (sampleslo - sampleshi + 1)>>1;
+
+	// TI tags charge at 134.2Khz
+	FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
+
+	// Place FPGA in passthrough mode, in this mode the CROSS_LO line
+	// connects to SSP_DIN and the SSP_DOUT logic level controls
+	// whether we're modulating the antenna (high)
+	// or listening to the antenna (low)
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU);
+
+	// get TI tag data into the buffer
+	AcquireTiType();
+
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+
+	for (i=0; i<n-1; i++) {
+		// count cycles by looking for lo to hi zero crossings
+		if ( (dest[i]<0) && (dest[i+1]>0) ) {
+			cycles++;
+			// after 16 cycles, measure the frequency
+			if (cycles>15) {
+				cycles=0;
+				samples=i-samples; // number of samples in these 16 cycles
+
+				// TI bits are coming to us lsb first so shift them
+				// right through our 128 bit right shift register
+			  shift0 = (shift0>>1) | (shift1 << 31);
+			  shift1 = (shift1>>1) | (shift2 << 31);
+			  shift2 = (shift2>>1) | (shift3 << 31);
+			  shift3 >>= 1;
+
+				// check if the cycles fall close to the number
+				// expected for either the low or high frequency
+				if ( (samples>(sampleslo-threshold)) && (samples<(sampleslo+threshold)) ) {
+					// low frequency represents a 1
+					shift3 |= (1<<31);
+				} else if ( (samples>(sampleshi-threshold)) && (samples<(sampleshi+threshold)) ) {
+					// high frequency represents a 0
+				} else {
+					// probably detected a gay waveform or noise
+					// use this as gaydar or discard shift register and start again
+					shift3 = shift2 = shift1 = shift0 = 0;
+				}
+				samples = i;
+
+				// for each bit we receive, test if we've detected a valid tag
+
+				// if we see 17 zeroes followed by 6 ones, we might have a tag
+				// remember the bits are backwards
+				if ( ((shift0 & 0x7fffff) == 0x7e0000) ) {
+					// if start and end bytes match, we have a tag so break out of the loop
+					if ( ((shift0>>16)&0xff) == ((shift3>>8)&0xff) ) {
+						cycles = 0xF0B; //use this as a flag (ugly but whatever)
+						break;
+					}
+				}
+			}
+		}
+	}
+
+	// if flag is set we have a tag
+	if (cycles!=0xF0B) {
+		DbpString("Info: No valid tag detected.");
+	} else {
+	  // put 64 bit data into shift1 and shift0
+	  shift0 = (shift0>>24) | (shift1 << 8);
+	  shift1 = (shift1>>24) | (shift2 << 8);
+
+		// align 16 bit crc into lower half of shift2
+	  shift2 = ((shift2>>24) | (shift3 << 8)) & 0x0ffff;
+
+		// if r/w tag, check ident match
+		if ( shift3&(1<<15) ) {
+			DbpString("Info: TI tag is rewriteable");
+			// only 15 bits compare, last bit of ident is not valid
+			if ( ((shift3>>16)^shift0)&0x7fff ) {
+				DbpString("Error: Ident mismatch!");
+			} else {
+				DbpString("Info: TI tag ident is valid");
+			}
+		} else {
+			DbpString("Info: TI tag is readonly");
+		}
+
+		// WARNING the order of the bytes in which we calc crc below needs checking
+		// i'm 99% sure the crc algorithm is correct, but it may need to eat the
+		// bytes in reverse or something
+		// calculate CRC
+		DWORD crc=0;
+
+	 	crc = update_crc16(crc, (shift0)&0xff);
+		crc = update_crc16(crc, (shift0>>8)&0xff);
+		crc = update_crc16(crc, (shift0>>16)&0xff);
+		crc = update_crc16(crc, (shift0>>24)&0xff);
+		crc = update_crc16(crc, (shift1)&0xff);
+		crc = update_crc16(crc, (shift1>>8)&0xff);
+		crc = update_crc16(crc, (shift1>>16)&0xff);
+		crc = update_crc16(crc, (shift1>>24)&0xff);
+
+		DbpString("Info: Tag data_hi, data_lo, crc = ");
+		DbpIntegers(shift1, shift0, shift2&0xffff);
+		if (crc != (shift2&0xffff)) {
+			DbpString("Error: CRC mismatch, expected");
+			DbpIntegers(0, 0, crc);
+		} else {
+			DbpString("Info: CRC is good");
+		}
+	}
+}
+
+void WriteTIbyte(BYTE b)
+{
+	int i = 0;
+
+	// modulate 8 bits out to the antenna
+	for (i=0; i<8; i++)
+	{
+		if (b&(1<<i)) {
+			// stop modulating antenna
+			PIO_OUTPUT_DATA_CLEAR = (1<<GPIO_SSC_DOUT);
+			SpinDelayUs(1000);
+			// modulate antenna
+			PIO_OUTPUT_DATA_SET = (1<<GPIO_SSC_DOUT);
+			SpinDelayUs(1000);
+		} else {
+			// stop modulating antenna
+			PIO_OUTPUT_DATA_CLEAR = (1<<GPIO_SSC_DOUT);
+			SpinDelayUs(300);
+			// modulate antenna
+			PIO_OUTPUT_DATA_SET = (1<<GPIO_SSC_DOUT);
+			SpinDelayUs(1700);
+		}
+	}
+}
+
 void AcquireTiType(void)
 {
-	int i;
+	int i, j, n;
 	// tag transmission is <20ms, sampling at 2M gives us 40K samples max
 	// each sample is 1 bit stuffed into a DWORD so we need 1250 DWORDS
-	int n = 1250;
+	#define TIBUFLEN 1250
 
 	// clear buffer
-	DbpIntegers((DWORD)BigBuf, sizeof(BigBuf), 0x12345678);
 	memset(BigBuf,0,sizeof(BigBuf));
 
 	// Set up the synchronous serial port
@@ -163,7 +329,7 @@ void AcquireTiType(void)
 	for(;;) {
 			if(SSC_STATUS & SSC_STATUS_RX_READY) {
 					BigBuf[i] = SSC_RECEIVE_HOLDING;	// store 32 bit values in buffer
-					i++; if(i >= n) return;
+					i++; if(i >= TIBUFLEN) break;
 			}
 			WDT_HIT();
 	}
@@ -171,54 +337,22 @@ void AcquireTiType(void)
 	// return stolen pin to SSP
 	PIO_DISABLE = (1<<GPIO_SSC_DOUT);
 	PIO_PERIPHERAL_A_SEL = (1<<GPIO_SSC_DIN) | (1<<GPIO_SSC_DOUT);
-}
 
-void ReadTItag()
+	char *dest = (char *)BigBuf;
-{
+	n = TIBUFLEN*32;
-}
+	// unpack buffer
-
+	for (i=TIBUFLEN-1; i>=0; i--) {
-void WriteTIbyte(BYTE b)
+//		DbpIntegers(0, 0, BigBuf[i]);
-{
+		for (j=0; j<32; j++) {
-	int i = 0;
+			if(BigBuf[i] & (1 << j)) {
-
+				dest[--n] = 1;
-	// modulate 8 bits out to the antenna
+			} else {
-	for (i=0; i<8; i++)
+				dest[--n] = -1;
-	{
+			}
-		if (b&(1<<i)) {
-			// stop modulating antenna
-			PIO_OUTPUT_DATA_CLEAR = (1<<GPIO_SSC_DOUT);
-			SpinDelayUs(1000);
-			// modulate antenna
-			PIO_OUTPUT_DATA_SET = (1<<GPIO_SSC_DOUT);
-			SpinDelayUs(1000);
-		} else {
-			// stop modulating antenna
-			PIO_OUTPUT_DATA_CLEAR = (1<<GPIO_SSC_DOUT);
-			SpinDelayUs(300);
-			// modulate antenna
-			PIO_OUTPUT_DATA_SET = (1<<GPIO_SSC_DOUT);
-			SpinDelayUs(1700);
 		}
 	}
 }
 
-void AcquireRawBitsTI(void)
-{
-	// TI tags charge at 134.2Khz
-	FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
-
-	// Place FPGA in passthrough mode, in this mode the CROSS_LO line
-	// connects to SSP_DIN and the SSP_DOUT logic level controls
-	// whether we're modulating the antenna (high)
-	// or listening to the antenna (low)
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU);
-
-	// get TI tag data into the buffer
-	AcquireTiType();
-
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-}
-
 // arguments: 64bit data split into 32bit idhi:idlo and optional 16bit crc
 // if crc provided, it will be written with the data verbatim (even if bogus)
 // if not provided a valid crc will be computed from the data and written.
@@ -292,7 +426,7 @@ void WriteTItag(DWORD idhi, DWORD idlo, WORD crc)
 	AcquireTiType();
 
 	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-	DbpString("Now use tibits and tidemod");
+	DbpString("Now use tiread to check");
 }
 
 void SimulateTagLowFrequency(int period, int ledcontrol)

include/usb_cmd.h

@@ -37,8 +37,6 @@ typedef struct {
 #define CMD_READ_MEM																	0x0106
 
 // For low-frequency tags
-#define CMD_ACQUIRE_RAW_BITS_TI_TYPE									0x0200
-#define CMD_DOWNLOAD_RAW_BITS_TI_TYPE									0x0201
 #define CMD_READ_TI_TYPE															0x0202
 #define CMD_WRITE_TI_TYPE															0x0203
 #define CMD_DOWNLOADED_RAW_BITS_TI_TYPE								0x0204

winsrc/command.cpp

@@ -1397,45 +1397,6 @@ static void CmdHi15demod(char *str)
 	PrintToScrollback("CRC=%04x", Iso15693Crc(outBuf, k-2));
 }
 
-static void CmdTIReadRaw(char *str)
-{
-	UsbCommand c;
-	c.cmd = CMD_ACQUIRE_RAW_BITS_TI_TYPE;
-	SendCommand(&c, FALSE);
-}
-
-static void CmdTIBits(char *str)
-{
-	int cnt = 0;
-	int i;
-//	for(i = 0; i < 1536; i += 12) {
-	for(i = 0; i < 4000; i += 12) {
-		UsbCommand c;
-		c.cmd = CMD_DOWNLOAD_RAW_BITS_TI_TYPE;
-		c.ext1 = i;
-		SendCommand(&c, FALSE);
-		ReceiveCommand(&c);
-		if(c.cmd != CMD_DOWNLOADED_RAW_BITS_TI_TYPE) {
-			PrintToScrollback("bad resp");
-			return;
-		}
-		int j;
-		for(j = 0; j < 12; j++) {
-			int k;
-			for(k = 31; k >= 0; k--) {
-				if(c.d.asDwords[j] & (1 << k)) {
-					GraphBuffer[cnt++] = 1;
-				} else {
-					GraphBuffer[cnt++] = -1;
-				}
-			}
-		}
-	}
-//	GraphTraceLen = 1536*32;
-	GraphTraceLen = 4000*32;
-	RepaintGraphWindow();
-}
-
 static void CmdFSKdemod(char *cmdline)
 {
 	static const int LowTone[]  = {
@@ -1454,13 +1415,13 @@ static void CmdFSKdemod(char *cmdline)
 		1,  1,  1,  1,     -1, -1, -1, -1, -1,
 	};
 
-	int convLen = max(arraylen(HighTone), arraylen(LowTone));
+	int lowLen = sizeof(LowTone)/sizeof(int);
+	int highLen = sizeof(HighTone)/sizeof(int);
+	int convLen = (highLen>lowLen)?highLen:lowLen;
 	DWORD hi = 0, lo = 0;
 
 	int i, j;
 	int minMark=0, maxMark=0;
-	int lowLen = arraylen(LowTone);
-	int highLen = arraylen(HighTone);
 
 	for(i = 0; i < GraphTraceLen - convLen; i++) {
 		int lowSum = 0, highSum = 0;
@@ -1499,10 +1460,10 @@ static void CmdFSKdemod(char *cmdline)
 	int max = 0, maxPos = 0;
 	for(i = 0; i < 6000; i++) {
 		int dec = 0;
-		for(j = 0; j < 3*arraylen(LowTone); j++) {
+		for(j = 0; j < 3*lowLen; j++) {
 			dec -= GraphBuffer[i+j];
 		}
-		for(; j < 3*(arraylen(LowTone) + arraylen(HighTone) ); j++) {
+		for(; j < 3*(lowLen + highLen ); j++) {
 			dec += GraphBuffer[i+j];
 		}
 		if(dec > max) {
@@ -1522,7 +1483,7 @@ static void CmdFSKdemod(char *cmdline)
 	GraphBuffer[maxPos+1] = minMark;
 
 	PrintToScrollback("actual data bits start at sample %d", maxPos);
-	PrintToScrollback("length %d/%d", arraylen(HighTone), arraylen(LowTone));
+	PrintToScrollback("length %d/%d", highLen, lowLen);
 
 	BYTE bits[46];
 	bits[sizeof(bits)-1] = '\0';
@@ -1530,10 +1491,10 @@ static void CmdFSKdemod(char *cmdline)
 	// find bit pairs and manchester decode them
 	for(i = 0; i < arraylen(bits)-1; i++) {
 		int dec = 0;
-		for(j = 0; j < arraylen(LowTone); j++) {
+		for(j = 0; j < lowLen; j++) {
 			dec -= GraphBuffer[maxPos+j];
 		}
-		for(; j < arraylen(LowTone) + arraylen(HighTone); j++) {
+		for(; j < lowLen + highLen; j++) {
 			dec += GraphBuffer[maxPos+j];
 		}
 		maxPos += j;
@@ -1574,7 +1535,7 @@ static void CmdTIWrite(char *str)
 	res = sscanf(str, "0x%x 0x%x 0x%x ", &c.ext1, &c.ext2, &c.ext3);
 	if (res == 2) c.ext3=0;
 	if (res<2)
-		PrintToScrollback("Please specify 2 or three hex strings, eg 0x1234 0x5678");
+		PrintToScrollback("Please specify the data as two hex strings, optionally the CRC as a third");
 	else
 		SendCommand(&c, FALSE);
 }
@@ -1595,52 +1556,57 @@ h = 2*pi*ones(1, floor(f_s*T_h))*(f_h/f_s);
 l = sign(sin(cumsum(l)));
 h = sign(sin(cumsum(h)));
 	*/
- static const int LowTone[] = {
-  1,  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1,  1, -1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1,
- };
- static const int HighTone[] = {
-  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,  1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,     -1, -1, -1, -1, -1, -1, -1, -1,
-  1,  1,  1,  1,  1,  1,  1,
- };
 
-	int convLen = max(arraylen(HighTone), arraylen(LowTone));
+// 2M*16/134.2k = 238
+ static const int LowTone[] = {
+	1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1, 1,		 -1, -1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1, 1,		 -1, -1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1, 1,		 -1, -1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1, 1,		 -1, -1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1, 1,		 -1, -1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1, 1,		 -1, -1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1, 1,		 -1, -1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1, 1,		 -1, -1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1, 1,		 -1, -1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1, 1,		 -1, -1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1, 1,		 -1, -1
+ };
+// 2M*16/123.2k = 260
+ static const int HighTone[] = {
+	1, 1, 1, 1, 1, 1, 1, 1,		-1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1, 1,		-1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1,			-1, -1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1,			-1, -1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1,			-1, -1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1,			-1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1, 1,		-1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1, 1,		-1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1,			-1, -1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1,			-1, -1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1,			-1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1, 1,		-1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1, 1,		-1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1, 1,		-1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1,			-1, -1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1,			-1, -1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1,			-1, -1, -1, -1, -1, -1, -1,
+	1, 1, 1, 1, 1, 1, 1, 1
+ };
+	int lowLen = sizeof(LowTone)/sizeof(int);
+	int highLen = sizeof(HighTone)/sizeof(int);
+	int convLen = (highLen>lowLen)?highLen:lowLen;
 	WORD crc;
-	int i, TagType;
+	int i, j, TagType;
+	int lowSum = 0, highSum = 0;;
+	int lowTot = 0, highTot = 0;
+
 	for(i = 0; i < GraphTraceLen - convLen; i++) {
-		int j;
+		lowSum = 0;
-		int lowSum = 0, highSum = 0;;
+		highSum = 0;;
-		int lowLen = arraylen(LowTone);
-		int highLen = arraylen(HighTone);
 
 		for(j = 0; j < lowLen; j++) {
 			lowSum += LowTone[j]*GraphBuffer[i+j];
@@ -1650,12 +1616,15 @@ h = sign(sin(cumsum(h)));
 		}
 		lowSum = abs((100*lowSum) / lowLen);
 		highSum = abs((100*highSum) / highLen);
+		lowSum = (lowSum<0)?-lowSum:lowSum;
+		highSum = (highSum<0)?-highSum:highSum;
+
 		GraphBuffer[i] = (highSum << 16) | lowSum;
 	}
 
 	for(i = 0; i < GraphTraceLen - convLen - 16; i++) {
-		int j;
+		lowTot = 0;
-		int lowTot = 0, highTot = 0;
+		highTot = 0;
 		// 16 and 15 are f_s divided by f_l and f_h, rounded
 		for(j = 0; j < 16; j++) {
 			lowTot += (GraphBuffer[i+j] & 0xffff);
@@ -1688,11 +1657,11 @@ h = sign(sin(cumsum(h)));
 		int j;
 		int dec = 0;
 		// searching 17 consecutive lows
-		for(j = 0; j < 17*arraylen(LowTone); j++) {
+		for(j = 0; j < 17*lowLen; j++) {
 			dec -= GraphBuffer[i+j];
 		}
 		// searching 7 consecutive highs
-		for(; j < 17*arraylen(LowTone) + 6*arraylen(HighTone); j++) {
+		for(; j < 17*lowLen + 6*highLen; j++) {
 			dec += GraphBuffer[i+j];
 		}
 		if(dec > max) {
@@ -1707,8 +1676,8 @@ h = sign(sin(cumsum(h)));
 	GraphBuffer[maxPos+1] = -800;
 
 	// advance pointer to start of actual data stream (after 16 pre and 8 start bits)
-	maxPos += 17*arraylen(LowTone);
+	maxPos += 17*lowLen;
-	maxPos += 6*arraylen(HighTone);
+	maxPos += 6*highLen;
 
 	// place a marker in the buffer to visually aid location
 	// of the end of sync
@@ -1717,7 +1686,7 @@ h = sign(sin(cumsum(h)));
 
 	PrintToScrollback("actual data bits start at sample %d", maxPos);
 
-	PrintToScrollback("length %d/%d", arraylen(HighTone), arraylen(LowTone));
+	PrintToScrollback("length %d/%d", highLen, lowLen);
 
 	BYTE bits[1+64+16+8+16];
 	bits[sizeof(bits)-1] = '\0';
@@ -1728,21 +1697,21 @@ h = sign(sin(cumsum(h)));
 		int high = 0;
 		int low = 0;
 		int j;
-		for(j = 0; j < arraylen(LowTone); j++) {
+		for(j = 0; j < lowLen; j++) {
 			low -= GraphBuffer[maxPos+j];
 		}
-		for(j = 0; j < arraylen(HighTone); j++) {
+		for(j = 0; j < highLen; j++) {
 			high += GraphBuffer[maxPos+j];
 		}
 
 		if(high > low) {
 			bits[i] = '1';
-			maxPos += arraylen(HighTone);
+			maxPos += highLen;
 			// bitstream arrives lsb first so shift right
 			shift3 |= (1<<31);
 		} else {
 			bits[i] = '.';
-			maxPos += arraylen(LowTone);
+			maxPos += lowLen;
 		}
 
 		// 128 bit right shift register
@@ -2870,9 +2839,7 @@ static struct {
 	{"scale",					CmdScale,						1, "<int> -- Set cursor display scale"},
 	{"setlfdivisor",	CmdSetDivisor,			0, "<19 - 255> -- Drive LF antenna at 12Mhz/(divisor+1)"},
 	{"sri512read",		CmdSri512read,			0, "<int> -- Read contents of a SRI512 tag"},
-	{"tibits",				CmdTIBits,					0, "Get raw bits for TI-type LF tag"},
 	{"tidemod",				CmdTIDemod,					1, "Demodulate raw bits for TI-type LF tag"},
-	{"tireadraw",			CmdTIReadRaw,				0, "Read a TI-type 134 kHz tag in raw mode"},
 	{"tiread",				CmdTIRead,					0, "Read and decode a TI 134 kHz tag"},
 	{"tiwrite",				CmdTIWrite,					0, "Write new data to a r/w TI 134 kHz tag"},
 	{"threshold",			CmdThreshold,				1, "Maximize/minimize every value in the graph window depending on threshold"},