//-----------------------------------------------------------------------------
// The main application code. This is the first thing called after start.c
// executes.
// Jonathan Westhues, Mar 2006
// Edits by Gerhard de Koning Gans, Sep 2007 (##)
//-----------------------------------------------------------------------------


#include <proxmark3.h>
#include <stdlib.h>
#include "apps.h"
#ifdef WITH_LCD
#include "fonts.h"
#include "LCD.h"
#endif

// The large multi-purpose buffer, typically used to hold A/D samples,
// maybe pre-processed in some way.
DWORD BigBuf[16000];
int usbattached = 0;

//=============================================================================
// A buffer where we can queue things up to be sent through the FPGA, for
// any purpose (fake tag, as reader, whatever). We go MSB first, since that
// is the order in which they go out on the wire.
//=============================================================================

BYTE ToSend[256];
int ToSendMax;
static int ToSendBit;


void BufferClear(void)
{
	memset(BigBuf,0,sizeof(BigBuf));
	DbpString("Buffer cleared");
}

void ToSendReset(void)
{
	ToSendMax = -1;
	ToSendBit = 8;
}

void ToSendStuffBit(int b)
{
	if(ToSendBit >= 8) {
		ToSendMax++;
		ToSend[ToSendMax] = 0;
		ToSendBit = 0;
	}

	if(b) {
		ToSend[ToSendMax] |= (1 << (7 - ToSendBit));
	}

	ToSendBit++;

	if(ToSendBit >= sizeof(ToSend)) {
		ToSendBit = 0;
		DbpString("ToSendStuffBit overflowed!");
	}
}

//=============================================================================
// Debug print functions, to go out over USB, to the usual PC-side client.
//=============================================================================

void DbpString(char *str)
{
	/* this holds up stuff unless we're connected to usb */
//	if (!usbattached)
//		return;

	UsbCommand c;
	c.cmd = CMD_DEBUG_PRINT_STRING;
	c.ext1 = strlen(str);
	memcpy(c.d.asBytes, str, c.ext1);

	UsbSendPacket((BYTE *)&c, sizeof(c));
	// TODO fix USB so stupid things like this aren't req'd
	SpinDelay(50);
}

void DbpIntegers(int x1, int x2, int x3)
{
	/* this holds up stuff unless we're connected to usb */
//	if (!usbattached)
//		return;

	UsbCommand c;
	c.cmd = CMD_DEBUG_PRINT_INTEGERS;
	c.ext1 = x1;
	c.ext2 = x2;
	c.ext3 = x3;

	UsbSendPacket((BYTE *)&c, sizeof(c));
	// XXX
	SpinDelay(50);
}

void AcquireRawAdcSamples125k(BOOL at134khz)
{
	if(at134khz) {
		FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
		FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
	} else {
		FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
		FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
	}

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

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

	// Now set up the SSC to get the ADC samples that are now streaming at us.
	FpgaSetupSsc();

	// Now call the acquisition routine
	DoAcquisition125k(at134khz);
}

// split into two routines so we can avoid timing issues after sending commands //
void DoAcquisition125k(BOOL at134khz)
{
	BYTE *dest = (BYTE *)BigBuf;
	int n = sizeof(BigBuf);
	int i;

	memset(dest,0,n);
	i = 0;
	for(;;) {
		if(SSC_STATUS & (SSC_STATUS_TX_READY)) {
			SSC_TRANSMIT_HOLDING = 0x43;
			LED_D_ON();
		}
		if(SSC_STATUS & (SSC_STATUS_RX_READY)) {
			dest[i] = (BYTE)SSC_RECEIVE_HOLDING;
			i++;
			LED_D_OFF();
			if(i >= n) {
				break;
			}
		}
	}
	DbpIntegers(dest[0], dest[1], at134khz);
}

void ModThenAcquireRawAdcSamples125k(int delay_off,int period_0,int period_1,BYTE *command)
{
	BOOL at134khz;

	// 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
		FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
	} else {
		FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
		FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
	}

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

	// Now set up the SSC to get the ADC samples that are now streaming at us.
	FpgaSetupSsc();

	// now modulate the reader field
	while(*command != '\0' && *command != ' ')
		{
		FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
		LED_D_OFF();
		SpinDelayUs(delay_off);
		if(at134khz) {
			FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
			FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
		} else {
			FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
			FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
		}
		LED_D_ON();
		if(*(command++) == '0')
			SpinDelayUs(period_0);
		else
			SpinDelayUs(period_1);
		}
	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
	LED_D_OFF();
	SpinDelayUs(delay_off);
	if(at134khz) {
		FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
		FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
	} else {
		FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
		FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
	}

	// now do the read
	DoAcquisition125k(at134khz);
}

void AcquireTiType(void)
{
	int i;
	int n = 5000;

	// clear buffer
	memset(BigBuf,0,sizeof(BigBuf));

	// Set up the synchronous serial port
  PIO_DISABLE = (1<<GPIO_SSC_DIN);
  PIO_PERIPHERAL_A_SEL = (1<<GPIO_SSC_DIN);

	// steal this pin from the SSP and use it to control the modulation
  PIO_ENABLE = (1<<GPIO_SSC_DOUT);
	PIO_OUTPUT_ENABLE	= (1<<GPIO_SSC_DOUT);

  SSC_CONTROL = SSC_CONTROL_RESET;
  SSC_CONTROL = SSC_CONTROL_RX_ENABLE | SSC_CONTROL_TX_ENABLE;

  // Sample at 2 Mbit/s, so TI tags are 16.2 vs. 14.9 clocks long
  // 48/2 = 24 MHz clock must be divided by 12
  SSC_CLOCK_DIVISOR = 12;

  SSC_RECEIVE_CLOCK_MODE = SSC_CLOCK_MODE_SELECT(0);
	SSC_RECEIVE_FRAME_MODE = SSC_FRAME_MODE_BITS_IN_WORD(32) | SSC_FRAME_MODE_MSB_FIRST;
	SSC_TRANSMIT_CLOCK_MODE = 0;
	SSC_TRANSMIT_FRAME_MODE = 0;

	LED_D_ON();

	// modulate antenna
	PIO_OUTPUT_DATA_SET = (1<<GPIO_SSC_DOUT);

	// Charge TI tag for 50ms.
	SpinDelay(50);

	// stop modulating antenna and listen
	PIO_OUTPUT_DATA_CLEAR = (1<<GPIO_SSC_DOUT);

	LED_D_OFF();

	i = 0;
	for(;;) {
			if(SSC_STATUS & SSC_STATUS_RX_READY) {
					BigBuf[i] = SSC_RECEIVE_HOLDING;	// store 32 bit values in buffer
					i++; if(i >= n) return;
			}
			WDT_HIT();
	}

	// return stolen pin to SSP
	PIO_DISABLE = (1<<GPIO_SSC_DOUT);
	PIO_PERIPHERAL_A_SEL = (1<<GPIO_SSC_DIN) | (1<<GPIO_SSC_DOUT);
}

void AcquireRawBitsTI(void)
{
	LED_D_ON();
	// 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);
}

//-----------------------------------------------------------------------------
// Read an ADC channel and block till it completes, then return the result
// in ADC units (0 to 1023). Also a routine to average 32 samples and
// return that.
//-----------------------------------------------------------------------------
static int ReadAdc(int ch)
{
	DWORD d;

	ADC_CONTROL = ADC_CONTROL_RESET;
	ADC_MODE = ADC_MODE_PRESCALE(32) | ADC_MODE_STARTUP_TIME(16) |
		ADC_MODE_SAMPLE_HOLD_TIME(8);
	ADC_CHANNEL_ENABLE = ADC_CHANNEL(ch);

	ADC_CONTROL = ADC_CONTROL_START;
	while(!(ADC_STATUS & ADC_END_OF_CONVERSION(ch)))
		;
	d = ADC_CHANNEL_DATA(ch);

	return d;
}

static int AvgAdc(int ch)
{
	int i;
	int a = 0;

	for(i = 0; i < 32; i++) {
		a += ReadAdc(ch);
	}

	return (a + 15) >> 5;
}

void MeasureAntennaTuning(void)
{
	BYTE *dest = (BYTE *)BigBuf;
	int i, ptr = 0, adcval = 0, peak = 0, peakv = 0, peakf = 0;;
	int vLf125 = 0, vLf134 = 0, vHf = 0;	// in mV

	UsbCommand c;

	DbpString("Measuring antenna characteristics, please wait.");
	memset(BigBuf,0,sizeof(BigBuf));

/*
 * Sweeps the useful LF range of the proxmark from
 * 46.8kHz (divisor=255) to 600kHz (divisor=19) and
 * read the voltage in the antenna, the result left
 * in the buffer is a graph which should clearly show
 * the resonating frequency of your LF antenna
 * ( hopefully around 95 if it is tuned to 125kHz!)
 */
	FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
	for (i=255; i>19; i--) {
		FpgaSendCommand(FPGA_CMD_SET_DIVISOR, i);
		SpinDelay(20);
		// Vref = 3.3V, and a 10000:240 voltage divider on the input
		// can measure voltages up to 137500 mV
		adcval = ((137500 * AvgAdc(ADC_CHAN_LF)) >> 10);
		if (i==95) 	vLf125 = adcval; // voltage at 125Khz
		if (i==89) 	vLf134 = adcval; // voltage at 134Khz

		dest[i] = adcval>>8; // scale int to fit in byte for graphing purposes
		if(dest[i] > peak) {
			peakv = adcval;
			peak = dest[i];
			peakf = i;
			ptr = i;
		}
	}

	// Let the FPGA drive the high-frequency antenna around 13.56 MHz.
	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR);
	SpinDelay(20);
	// Vref = 3300mV, and an 10:1 voltage divider on the input
	// can measure voltages up to 33000 mV
	vHf = (33000 * AvgAdc(ADC_CHAN_HF)) >> 10;

	c.cmd = CMD_MEASURED_ANTENNA_TUNING;
	c.ext1 = (vLf125 << 0) | (vLf134 << 16);
	c.ext2 = vHf;
	c.ext3 = peakf | (peakv << 16);
	UsbSendPacket((BYTE *)&c, sizeof(c));
}

void SimulateTagLowFrequency(int period, int ledcontrol)
{
	int i;
	BYTE *tab = (BYTE *)BigBuf;

	FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_SIMULATOR);

	PIO_ENABLE = (1 << GPIO_SSC_DOUT) | (1 << GPIO_SSC_CLK);

	PIO_OUTPUT_ENABLE = (1 << GPIO_SSC_DOUT);
	PIO_OUTPUT_DISABLE = (1 << GPIO_SSC_CLK);

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

	i = 0;
	for(;;) {
		while(!(PIO_PIN_DATA_STATUS & (1<<GPIO_SSC_CLK))) {
			if(BUTTON_PRESS()) {
				DbpString("Stopped");
				return;
			}
			WDT_HIT();
		}

		if (ledcontrol)
			LED_D_ON();

		if(tab[i])
			OPEN_COIL();
		else
			SHORT_COIL();

		if (ledcontrol)
			LED_D_OFF();

		while(PIO_PIN_DATA_STATUS & (1<<GPIO_SSC_CLK)) {
			if(BUTTON_PRESS()) {
				DbpString("Stopped");
				return;
			}
			WDT_HIT();
		}

		i++;
		if(i == period) i = 0;
	}
}

// compose fc/8 fc/10 waveform
static void fc(int c, int *n) {
	BYTE *dest = (BYTE *)BigBuf;
	int idx;

	// for when we want an fc8 pattern every 4 logical bits
	if(c==0) {
		dest[((*n)++)]=1;
		dest[((*n)++)]=1;
		dest[((*n)++)]=0;
		dest[((*n)++)]=0;
		dest[((*n)++)]=0;
		dest[((*n)++)]=0;
		dest[((*n)++)]=0;
		dest[((*n)++)]=0;
	}
	//	an fc/8  encoded bit is a bit pattern of  11000000  x6 = 48 samples
	if(c==8) {
		for (idx=0; idx<6; idx++) {
			dest[((*n)++)]=1;
			dest[((*n)++)]=1;
			dest[((*n)++)]=0;
			dest[((*n)++)]=0;
			dest[((*n)++)]=0;
			dest[((*n)++)]=0;
			dest[((*n)++)]=0;
			dest[((*n)++)]=0;
		}
	}

	//	an fc/10 encoded bit is a bit pattern of 1110000000 x5 = 50 samples
	if(c==10) {
		for (idx=0; idx<5; idx++) {
			dest[((*n)++)]=1;
			dest[((*n)++)]=1;
			dest[((*n)++)]=1;
			dest[((*n)++)]=0;
			dest[((*n)++)]=0;
			dest[((*n)++)]=0;
			dest[((*n)++)]=0;
			dest[((*n)++)]=0;
			dest[((*n)++)]=0;
			dest[((*n)++)]=0;
		}
	}
}

// prepare a waveform pattern in the buffer based on the ID given then
// simulate a HID tag until the button is pressed
static void CmdHIDsimTAG(int hi, int lo, int ledcontrol)
{
	int n=0, i=0;
	/*
	 HID tag bitstream format
	 The tag contains a 44bit unique code. This is sent out MSB first in sets of 4 bits
	 A 1 bit is represented as 6 fc8 and 5 fc10 patterns
	 A 0 bit is represented as 5 fc10 and 6 fc8 patterns
	 A fc8 is inserted before every 4 bits
	 A special start of frame pattern is used consisting a0b0 where a and b are neither 0
	 nor 1 bits, they are special patterns (a = set of 12 fc8 and b = set of 10 fc10)
	*/

	if (hi>0xFFF) {
		DbpString("Tags can only have 44 bits.");
		return;
	}
	fc(0,&n);
	// special start of frame marker containing invalid bit sequences
	fc(8,  &n);	fc(8,  &n);	// invalid
	fc(8,  &n);	fc(10, &n); // logical 0
	fc(10, &n);	fc(10, &n); // invalid
	fc(8,  &n);	fc(10, &n); // logical 0

	WDT_HIT();
	// manchester encode bits 43 to 32
	for (i=11; i>=0; i--) {
		if ((i%4)==3) fc(0,&n);
		if ((hi>>i)&1) {
			fc(10, &n);	fc(8,  &n);		// low-high transition
		} else {
			fc(8,  &n);	fc(10, &n);		// high-low transition
		}
	}

	WDT_HIT();
	// manchester encode bits 31 to 0
	for (i=31; i>=0; i--) {
		if ((i%4)==3) fc(0,&n);
		if ((lo>>i)&1) {
			fc(10, &n);	fc(8,  &n);		// low-high transition
		} else {
			fc(8,  &n);	fc(10, &n);		// high-low transition
		}
	}

	if (ledcontrol)
		LED_A_ON();
	SimulateTagLowFrequency(n, ledcontrol);

	if (ledcontrol)
		LED_A_OFF();
}

// loop to capture raw HID waveform then FSK demodulate the TAG ID from it
static void CmdHIDdemodFSK(int findone, int *high, int *low, int ledcontrol)
{
	BYTE *dest = (BYTE *)BigBuf;
	int m=0, n=0, i=0, idx=0, found=0, lastval=0;
	DWORD hi=0, lo=0;

	FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
	FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);

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

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

	// Now set up the SSC to get the ADC samples that are now streaming at us.
	FpgaSetupSsc();

	for(;;) {
		WDT_HIT();
		if (ledcontrol)
			LED_A_ON();
		if(BUTTON_PRESS()) {
			DbpString("Stopped");
			if (ledcontrol)
				LED_A_OFF();
			return;
		}

		i = 0;
		m = sizeof(BigBuf);
		memset(dest,128,m);
		for(;;) {
			if(SSC_STATUS & (SSC_STATUS_TX_READY)) {
				SSC_TRANSMIT_HOLDING = 0x43;
				if (ledcontrol)
					LED_D_ON();
			}
			if(SSC_STATUS & (SSC_STATUS_RX_READY)) {
				dest[i] = (BYTE)SSC_RECEIVE_HOLDING;
				// 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;
				}
			}
		}

		// FSK demodulator

		// sync to first lo-hi transition
		for( idx=1; idx<m; idx++) {
			if (dest[idx-1]<dest[idx])
				lastval=idx;
				break;
		}
		WDT_HIT();

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

				lastval=idx;
				i++;
			}
		}
		m=i;
		WDT_HIT();

		// we now have a set of cycle counts, loop over previous results and aggregate data into bit patterns
		lastval=dest[0];
		idx=0;
		i=0;
		n=0;
		for( idx=0; idx<m; idx++) {
			if (dest[idx]==lastval) {
				n++;
			} else {
				// a bit time is five fc/10 or six fc/8 cycles so figure out how many bits a pattern width represents,
				// an extra fc/8 pattern preceeds every 4 bits (about 200 cycles) just to complicate things but it gets
				// swallowed up by rounding
				// expected results are 1 or 2 bits, any more and it's an invalid manchester encoding
				// special start of frame markers use invalid manchester states (no transitions) by using sequences
				// like 111000
				if (dest[idx-1]) {
					n=(n+1)/6;			// fc/8 in sets of 6
				} else {
					n=(n+1)/5;			// fc/10 in sets of 5
				}
				switch (n) {			// stuff appropriate bits in buffer
					case 0:
					case 1:	// one bit
						dest[i++]=dest[idx-1];
						break;
					case 2: // two bits
						dest[i++]=dest[idx-1];
						dest[i++]=dest[idx-1];
						break;
					case 3: // 3 bit start of frame markers
						dest[i++]=dest[idx-1];
						dest[i++]=dest[idx-1];
						dest[i++]=dest[idx-1];
						break;
					// When a logic 0 is immediately followed by the start of the next transmisson
					// (special pattern) a pattern of 4 bit duration lengths is created.
					case 4:
						dest[i++]=dest[idx-1];
						dest[i++]=dest[idx-1];
						dest[i++]=dest[idx-1];
						dest[i++]=dest[idx-1];
						break;
					default:	// this shouldn't happen, don't stuff any bits
						break;
				}
				n=0;
				lastval=dest[idx];
			}
		}
		m=i;
		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++) {
			// 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 && (hi|lo)) {
					DbpString("TAG ID");
					DbpIntegers(hi, lo, (lo>>1)&0xffff);
					/* if we're only looking for one tag */
					if (findone)
					{
						*high = hi;
						*low = lo;
						return;
					}
					hi=0;
					lo=0;
					found=0;
				}
			}
			if (found) {
				if (dest[idx] && (!dest[idx+1]) ) {
					hi=(hi<<1)|(lo>>31);
					lo=(lo<<1)|0;
				} else if ( (!dest[idx]) && dest[idx+1]) {
					hi=(hi<<1)|(lo>>31);
					lo=(lo<<1)|1;
				} else {
					found=0;
					hi=0;
					lo=0;
				}
				idx++;
			}
			if ( dest[idx] && dest[idx+1] && dest[idx+2] && (!dest[idx+3]) && (!dest[idx+4]) && (!dest[idx+5]) )
			{
				found=1;
				idx+=6;
				if (found && (hi|lo)) {
					DbpString("TAG ID");
					DbpIntegers(hi, lo, (lo>>1)&0xffff);
					/* if we're only looking for one tag */
					if (findone)
					{
						*high = hi;
						*low = lo;
						return;
					}
					hi=0;
					lo=0;
					found=0;
				}
			}
		}
		WDT_HIT();
	}
}

void SimulateTagHfListen(void)
{
	BYTE *dest = (BYTE *)BigBuf;
	int n = sizeof(BigBuf);
	BYTE v = 0;
	int i;
	int p = 0;

	// We're using this mode just so that I can test it out; the simulated
	// tag mode would work just as well and be simpler.
	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ | FPGA_HF_READER_RX_XCORR_SNOOP);

	// We need to listen to the high-frequency, peak-detected path.
	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);

	FpgaSetupSsc();

	i = 0;
	for(;;) {
		if(SSC_STATUS & (SSC_STATUS_TX_READY)) {
			SSC_TRANSMIT_HOLDING = 0xff;
		}
		if(SSC_STATUS & (SSC_STATUS_RX_READY)) {
			BYTE r = (BYTE)SSC_RECEIVE_HOLDING;

			v <<= 1;
			if(r & 1) {
				v |= 1;
			}
			p++;

			if(p >= 8) {
				dest[i] = v;
				v = 0;
				p = 0;
				i++;

				if(i >= n) {
					break;
				}
			}
		}
	}
	DbpString("simulate tag (now type bitsamples)");
}

void UsbPacketReceived(BYTE *packet, int len)
{
	UsbCommand *c = (UsbCommand *)packet;

	switch(c->cmd) {
		case CMD_ACQUIRE_RAW_ADC_SAMPLES_125K:
			AcquireRawAdcSamples125k(c->ext1);
			break;

		case CMD_MOD_THEN_ACQUIRE_RAW_ADC_SAMPLES_125K:
			ModThenAcquireRawAdcSamples125k(c->ext1,c->ext2,c->ext3,c->d.asBytes);
			break;

		case CMD_ACQUIRE_RAW_BITS_TI_TYPE:
			AcquireRawBitsTI();
			break;

		case CMD_ACQUIRE_RAW_ADC_SAMPLES_ISO_15693:
			AcquireRawAdcSamplesIso15693();
			break;

		case CMD_BUFF_CLEAR:
			BufferClear();
			break;

		case CMD_READER_ISO_15693:
			ReaderIso15693(c->ext1);
			break;

		case CMD_SIMTAG_ISO_15693:
			SimTagIso15693(c->ext1);
			break;

		case CMD_ACQUIRE_RAW_ADC_SAMPLES_ISO_14443:
			AcquireRawAdcSamplesIso14443(c->ext1);
			break;

		case CMD_READ_SRI512_TAG:
			ReadSRI512Iso14443(c->ext1);
			break;

		case CMD_READER_ISO_14443a:
			ReaderIso14443a(c->ext1);
			break;

		case CMD_SNOOP_ISO_14443:
			SnoopIso14443();
			break;

		case CMD_SNOOP_ISO_14443a:
			SnoopIso14443a();
			break;

		case CMD_SIMULATE_TAG_HF_LISTEN:
			SimulateTagHfListen();
			break;

		case CMD_SIMULATE_TAG_ISO_14443:
			SimulateIso14443Tag();
			break;

		case CMD_SIMULATE_TAG_ISO_14443a:
			SimulateIso14443aTag(c->ext1, c->ext2);  // ## Simulate iso14443a tag - pass tag type & UID
			break;

		case CMD_MEASURE_ANTENNA_TUNING:
			MeasureAntennaTuning();
			break;

		case CMD_LISTEN_READER_FIELD:
			ListenReaderField(c->ext1);
			break;

		case CMD_HID_DEMOD_FSK:
			CmdHIDdemodFSK(0, 0, 0, 1);				// Demodulate HID tag
			break;

		case CMD_HID_SIM_TAG:
			CmdHIDsimTAG(c->ext1, c->ext2, 1);					// Simulate HID tag by ID
			break;

		case CMD_FPGA_MAJOR_MODE_OFF:		// ## FPGA Control
			FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
			SpinDelay(200);
			LED_D_OFF(); // LED D indicates field ON or OFF
			break;

		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;
			} else {
				n.cmd = CMD_DOWNLOADED_RAW_BITS_TI_TYPE;
			}
			n.ext1 = c->ext1;
			memcpy(n.d.asDwords, BigBuf+c->ext1, 12*sizeof(DWORD));
			UsbSendPacket((BYTE *)&n, sizeof(n));
			break;
		}
		case CMD_DOWNLOADED_SIM_SAMPLES_125K: {
			BYTE *b = (BYTE *)BigBuf;
			memcpy(b+c->ext1, c->d.asBytes, 48);
			break;
		}
		case CMD_SIMULATE_TAG_125K:
			LED_A_ON();
			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;
		case CMD_SET_LF_DIVISOR:
			FpgaSendCommand(FPGA_CMD_SET_DIVISOR, c->ext1);
			break;
#ifdef WITH_LCD
		case CMD_LCD:
			LCDSend(c->ext1);
			break;
#endif
        case CMD_SETUP_WRITE:
		case CMD_FINISH_WRITE:
		case CMD_HARDWARE_RESET:
			USB_D_PLUS_PULLUP_OFF();
			SpinDelay(1000);
			SpinDelay(1000);
			RSTC_CONTROL = RST_CONTROL_KEY | RST_CONTROL_PROCESSOR_RESET;
			for(;;) {
				// We're going to reset, and the bootrom will take control.
			}
			break;


		default:
			DbpString("unknown command");
			break;
	}
}

void ReadMem(int addr)
{
	const DWORD *data = ((DWORD *)addr);
	int i;

	DbpString("Reading memory at address");
	DbpIntegers(0, 0, addr);
	for (i = 0; i < 8; i+= 2)
		DbpIntegers(0, data[i], data[i+1]);
}

void AppMain(void)
{
	memset(BigBuf,0,sizeof(BigBuf));
	SpinDelay(100);

	LED_D_OFF();
	LED_C_OFF();
	LED_B_OFF();
	LED_A_OFF();

	UsbStart();

	// The FPGA gets its clock from us from PCK0 output, so set that up.
	PIO_PERIPHERAL_B_SEL = (1 << GPIO_PCK0);
	PIO_DISABLE = (1 << GPIO_PCK0);
	PMC_SYS_CLK_ENABLE = PMC_SYS_CLK_PROGRAMMABLE_CLK_0;
	// PCK0 is PLL clock / 4 = 96Mhz / 4 = 24Mhz
	PMC_PROGRAMMABLE_CLK_0 = PMC_CLK_SELECTION_PLL_CLOCK |
		PMC_CLK_PRESCALE_DIV_4;
	PIO_OUTPUT_ENABLE = (1 << GPIO_PCK0);

	// Reset SPI
	SPI_CONTROL = SPI_CONTROL_RESET;
	// Reset SSC
	SSC_CONTROL = SSC_CONTROL_RESET;

	// Load the FPGA image, which we have stored in our flash.
	FpgaDownloadAndGo();

#ifdef WITH_LCD

	LCDInit();

	// test text on different colored backgrounds
	LCDString(" The quick brown fox  ",	&FONT6x8,1,1+8*0,WHITE  ,BLACK );
	LCDString("  jumped over the     ",	&FONT6x8,1,1+8*1,BLACK  ,WHITE );
	LCDString("     lazy dog.        ",	&FONT6x8,1,1+8*2,YELLOW ,RED   );
	LCDString(" AaBbCcDdEeFfGgHhIiJj ",	&FONT6x8,1,1+8*3,RED    ,GREEN );
	LCDString(" KkLlMmNnOoPpQqRrSsTt ",	&FONT6x8,1,1+8*4,MAGENTA,BLUE  );
	LCDString("UuVvWwXxYyZz0123456789",	&FONT6x8,1,1+8*5,BLUE   ,YELLOW);
	LCDString("`-=[]_;',./~!@#$%^&*()",	&FONT6x8,1,1+8*6,BLACK  ,CYAN  );
	LCDString("     _+{}|:\\\"<>?     ",&FONT6x8,1,1+8*7,BLUE  ,MAGENTA);

	// color bands
	LCDFill(0, 1+8* 8, 132, 8, BLACK);
	LCDFill(0, 1+8* 9, 132, 8, WHITE);
	LCDFill(0, 1+8*10, 132, 8, RED);
	LCDFill(0, 1+8*11, 132, 8, GREEN);
	LCDFill(0, 1+8*12, 132, 8, BLUE);
	LCDFill(0, 1+8*13, 132, 8, YELLOW);
	LCDFill(0, 1+8*14, 132, 8, CYAN);
	LCDFill(0, 1+8*15, 132, 8, MAGENTA);

#endif

	for(;;) {
		usbattached = UsbPoll(FALSE);
		WDT_HIT();

		if (BUTTON_HELD(1000) > 0)
			SamyRun();
	}
}


// samy's sniff and repeat routine
void SamyRun()
{
	DbpString("Stand-alone mode! No PC necessary.");

	// 3 possible options? no just 2 for now
#define OPTS 2

	int high[OPTS], low[OPTS];

	// Oooh pretty -- notify user we're in elite samy mode now
	LED(LED_RED,	200);
	LED(LED_ORANGE, 200);
	LED(LED_GREEN,	200);
	LED(LED_ORANGE, 200);
	LED(LED_RED,	200);
	LED(LED_ORANGE, 200);
	LED(LED_GREEN,	200);
	LED(LED_ORANGE, 200);
	LED(LED_RED,	200);

	int selected = 0;
	int playing = 0;

	// Turn on selected LED
	LED(selected + 1, 0);

	for (;;)
	{
		usbattached = UsbPoll(FALSE);
		WDT_HIT();

		// Was our button held down or pressed?
		int button_pressed = BUTTON_HELD(1000);
		SpinDelay(300);

		// Button was held for a second, begin recording
		if (button_pressed > 0)
		{
			LEDsoff();
			LED(selected + 1, 0);
			LED(LED_RED2, 0);

			// record
			DbpString("Starting recording");

			// wait for button to be released
			while(BUTTON_PRESS())
				WDT_HIT();

			/* need this delay to prevent catching some weird data */
			SpinDelay(500);

			CmdHIDdemodFSK(1, &high[selected], &low[selected], 0);
			DbpString("Recorded");
			DbpIntegers(selected, high[selected], low[selected]);

			LEDsoff();
			LED(selected + 1, 0);
			// Finished recording

			// If we were previously playing, set playing off
			// so next button push begins playing what we recorded
			playing = 0;
		}

		// Change where to record (or begin playing)
		else if (button_pressed)
		{
			// Next option if we were previously playing
			if (playing)
				selected = (selected + 1) % OPTS;
			playing = !playing;

			LEDsoff();
			LED(selected + 1, 0);

			// Begin transmitting
			if (playing)
			{
				LED(LED_GREEN, 0);
				DbpString("Playing");
				// wait for button to be released
				while(BUTTON_PRESS())
					WDT_HIT();
				DbpIntegers(selected, high[selected], low[selected]);
				CmdHIDsimTAG(high[selected], low[selected], 0);
				DbpString("Done playing");
				if (BUTTON_HELD(1000) > 0)
					{
					DbpString("Exiting");
					LEDsoff();
					return;
					}

				/* We pressed a button so ignore it here with a delay */
				SpinDelay(300);

				// when done, we're done playing, move to next option
				selected = (selected + 1) % OPTS;
				playing = !playing;
				LEDsoff();
				LED(selected + 1, 0);
			}
			else
				while(BUTTON_PRESS())
					WDT_HIT();
		}
	}
}


/* 
OBJECTIVE
Listen and detect an external reader. Determine the best location
for the antenna.

INSTRUCTIONS:
Inside the ListenReaderField() function, there is two mode. 
By default, when you call the function, you will enter mode 1.
If you press the PM3 button one time, you will enter mode 2.
If you press the PM3 button a second time, you will exit the function.

DESCRIPTION OF MODE 1:
This mode just listens for an external reader field and lights up green 
for HF and/or red for LF. This is the original mode of the detectreader
function.

DESCRIPTION OF MODE 2:
This mode will visually represent, using the LEDs, the actual strength of the
current compared to the maximum current detected. Basically, once you know 
what kind of external reader is present, it will help you spot the best location to place
your antenna. You will probably not get some good results if there is a LF and a HF reader
at the same place! :-)

LIGHT SCHEME USED:

Light scheme | Descriptiong
----------------------------------------------------
    ----     | No field detected
    X---     | 14% of maximum current detected
    -X--     | 29% of maximum current detected
    --X-     | 43% of maximum current detected
    ---X     | 57% of maximum current detected
    --XX     | 71% of maximum current detected
    -XXX     | 86% of maximum current detected
    XXXX     | 100% of maximum current detected

TODO:
Add the LF part for MODE 2

*/
void ListenReaderField(int limit)
{
	int lf_av, lf_av_new, lf_baseline= 0, lf_count= 0;
	int hf_av, hf_av_new,  hf_baseline= 0, hf_count= 0, hf_max;
	int mode=1;

#define LF_ONLY		1
#define HF_ONLY		2

	LED_A_OFF();
	LED_B_OFF();
	LED_C_OFF();
	LED_D_OFF();

	lf_av= ReadAdc(ADC_CHAN_LF);

	if(limit != HF_ONLY) 
		{
		DbpString("LF 125/134 Baseline:");
		DbpIntegers(lf_av,0,0);
		lf_baseline= lf_av;
		}

	hf_av=hf_max=ReadAdc(ADC_CHAN_HF);

	if (limit != LF_ONLY) 
		{
		DbpString("HF 13.56 Baseline:");
		DbpIntegers(hf_av,0,0);
		hf_baseline= hf_av;
		}

	for(;;) 
		{
		if (BUTTON_PRESS()) {
			SpinDelay(500);
			switch (mode) {
				case 1:
					mode=2;
					DbpString("Signal Strength Mode");
					break;
				case 2:
				default:
					DbpString("Stopped");
					LED_A_OFF();
					LED_B_OFF();
					LED_C_OFF();
					LED_D_OFF();
					return;
					break;
			}
		}
		WDT_HIT();

		if (limit != HF_ONLY) 
			{
			if (abs(lf_av - lf_baseline) > 10)
				LED_D_ON();
			else
				LED_D_OFF();
			++lf_count;
			lf_av_new= ReadAdc(ADC_CHAN_LF);
			// see if there's a significant change
			if(abs(lf_av - lf_av_new) > 10) 
				{
				DbpString("LF 125/134 Field Change:");
				DbpIntegers(lf_av,lf_av_new,lf_count);
				lf_av= lf_av_new;
				lf_count= 0;
				}
			}

		if (limit != LF_ONLY) 
			{
			if (abs(hf_av - hf_baseline) > 10) {
				if (mode == 1)
					LED_B_ON();
				if (mode == 2) {
					if ( hf_av>(hf_max/7)*6) {
						LED_A_ON();	LED_B_ON();	LED_C_ON();	LED_D_ON();
					}
					if ( (hf_av>(hf_max/7)*5) && (hf_av<=(hf_max/7)*6) ) {
						LED_A_ON();	LED_B_ON();	LED_C_OFF(); LED_D_ON();
					}
					if ( (hf_av>(hf_max/7)*4) && (hf_av<=(hf_max/7)*5) ) {
						LED_A_OFF(); LED_B_ON(); LED_C_OFF(); LED_D_ON();
					}
					if ( (hf_av>(hf_max/7)*3) && (hf_av<=(hf_max/7)*4) ) {
						LED_A_OFF(); LED_B_OFF(); LED_C_OFF(); LED_D_ON();
					}
					if ( (hf_av>(hf_max/7)*2) && (hf_av<=(hf_max/7)*3) ) {
						LED_A_OFF(); LED_B_ON(); LED_C_OFF(); LED_D_OFF();
					}
					if ( (hf_av>(hf_max/7)*1) && (hf_av<=(hf_max/7)*2) ) {
						LED_A_ON();	LED_B_OFF(); LED_C_OFF(); LED_D_OFF();
					}
					if ( (hf_av>(hf_max/7)*0) && (hf_av<=(hf_max/7)*1) ) {
						LED_A_OFF(); LED_B_OFF(); LED_C_ON(); LED_D_OFF();
					}
				} 
			} else {
				if (mode == 1) {
					LED_B_OFF();
				}
				if (mode == 2) {
					LED_A_OFF(); LED_B_OFF(); LED_C_OFF(); LED_D_OFF();
				}
			}

			++hf_count;
			hf_av_new= ReadAdc(ADC_CHAN_HF);
			// see if there's a significant change
			if(abs(hf_av - hf_av_new) > 10) 
				{
				DbpString("HF 13.56 Field Change:");
				DbpIntegers(hf_av,hf_av_new,hf_count);
				hf_av= hf_av_new;
				if (hf_av > hf_max)
					hf_max = hf_av;
				hf_count= 0;
				}
			}
		}
}