[proxmark3-svn] / armsrc / lfsampling.c

//-----------------------------------------------------------------------------
// This code is licensed to you under the terms of the GNU GPL, version 2 or,
// at your option, any later version. See the LICENSE.txt file for the text of
// the license.
//-----------------------------------------------------------------------------
// Miscellaneous routines for low frequency sampling.
//-----------------------------------------------------------------------------

#include "proxmark3.h"
#include "apps.h"
#include "util.h"
#include "string.h"
#include "lfsampling.h"
#include "usb_cdc.h"	// for usb_poll_validate_length
//#include "ticks.h"		// for StartTicks

sample_config config = { 1, 8, 1, 95, 0 } ;

void printConfig()
{
	Dbprintf("LF Sampling config: ");
	Dbprintf("  [q] divisor:           %d ", config.divisor);
	Dbprintf("  [b] bps:               %d ", config.bits_per_sample);
	Dbprintf("  [d] decimation:        %d ", config.decimation);
	Dbprintf("  [a] averaging:         %d ", config.averaging);
	Dbprintf("  [t] trigger threshold: %d ", config.trigger_threshold);
}


/**
 * Called from the USB-handler to set the sampling configuration
 * The sampling config is used for std reading and snooping.
 *
 * Other functions may read samples and ignore the sampling config,
 * such as functions to read the UID from a prox tag or similar.
 *
 * Values set to '0' implies no change (except for averaging)
 * @brief setSamplingConfig
 * @param sc
 */
void setSamplingConfig(sample_config *sc)
{
	if(sc->divisor != 0) config.divisor = sc->divisor;
	if(sc->bits_per_sample!= 0) config.bits_per_sample= sc->bits_per_sample;
	if(sc->decimation!= 0) config.decimation= sc->decimation;
	if(sc->trigger_threshold != -1) config.trigger_threshold= sc->trigger_threshold;

	config.averaging= sc->averaging;
	if(config.bits_per_sample > 8)	config.bits_per_sample = 8;
	if(config.decimation < 1)	config.decimation = 1;

	printConfig();
}

sample_config* getSamplingConfig()
{
	return &config;
}

typedef struct {
	uint8_t * buffer;
	uint32_t numbits;
	uint32_t position;
} BitstreamOut;

/**
 * @brief Pushes bit onto the stream
 * @param stream
 * @param bit
 */
void pushBit( BitstreamOut* stream, uint8_t bit)
{
	int bytepos = stream->position >> 3; // divide by 8
	int bitpos = stream->position & 7;
	*(stream->buffer+bytepos) |= (bit > 0) <<  (7 - bitpos);
	stream->position++;
	stream->numbits++;
}

/**
* Setup the FPGA to listen for samples. This method downloads the FPGA bitstream
* if not already loaded, sets divisor and starts up the antenna.
* @param divisor : 1, 88> 255 or negative ==> 134.8 KHz
* 				   0 or 95 ==> 125 KHz
*
**/
void LFSetupFPGAForADC(int divisor, bool lf_field)
{
	FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
	if ( (divisor == 1) || (divisor < 0) || (divisor > 255) )
		FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
	else if (divisor == 0)
		FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
	else
		FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor);

	FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | (lf_field ? FPGA_LF_ADC_READER_FIELD : 0));

	// 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();
}

/**
 * Does the sample acquisition. If threshold is specified, the actual sampling
 * is not commenced until the threshold has been reached.
 * This method implements decimation and quantization in order to
 * be able to provide longer sample traces.
 * Uses the following global settings:
 * @param decimation - how much should the signal be decimated. A decimation of N means we keep 1 in N samples, etc.
 * @param bits_per_sample - bits per sample. Max 8, min 1 bit per sample.
 * @param averaging If set to true, decimation will use averaging, so that if e.g. decimation is 3, the sample
 * value that will be used is the average value of the three samples.
 * @param trigger_threshold - a threshold. The sampling won't commence until this threshold has been reached. Set
 * to -1 to ignore threshold.
 * @param silent - is true, now outputs are made. If false, dbprints the status
 * @return the number of bits occupied by the samples.
 */
uint32_t DoAcquisition(uint8_t decimation, uint32_t bits_per_sample, bool averaging, int trigger_threshold, bool silent, int bufsize, int cancel_after)
{
	//.
	uint8_t *dest = BigBuf_get_addr();
	bufsize = (bufsize > 0 && bufsize < BigBuf_max_traceLen()) ? bufsize : BigBuf_max_traceLen();

	//memset(dest, 0, bufsize); //creates issues with cmdread (marshmellow)

	if(bits_per_sample < 1) bits_per_sample = 1;
	if(bits_per_sample > 8) bits_per_sample = 8;

	if(decimation < 1) decimation = 1;

	// Use a bit stream to handle the output
	BitstreamOut data = { dest , 0, 0};
	int sample_counter = 0;
	uint8_t sample = 0;
	//If we want to do averaging
	uint32_t sample_sum =0 ;
	uint32_t sample_total_numbers =0 ;
	uint32_t sample_total_saved =0 ;
	uint32_t cancel_counter = 0;

	while(!BUTTON_PRESS() && !usb_poll_validate_length() ) {
		WDT_HIT();
		if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
			AT91C_BASE_SSC->SSC_THR = 0x43;
			LED_D_ON();
		}
		if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
			sample = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
			LED_D_OFF();
			// threshold either high or low values 128 = center 0.  if trigger = 178 
			if ((trigger_threshold > 0) && (sample < (trigger_threshold+128)) && (sample > (128-trigger_threshold))) { // 
				if (cancel_after > 0) cancel_counter++;
				if (cancel_after == cancel_counter) break;
				continue;
			}
			trigger_threshold = 0;
			sample_total_numbers++;

			if(averaging)
			{
				sample_sum += sample;
			}
			//Check decimation
			if(decimation > 1)
			{
				sample_counter++;
				if(sample_counter < decimation) continue;
				sample_counter = 0;
			}
			//Averaging
			if(averaging && decimation > 1) {
				sample = sample_sum / decimation;
				sample_sum =0;
			}
			//Store the sample
			sample_total_saved ++;
			if(bits_per_sample == 8){
				dest[sample_total_saved-1] = sample;
				data.numbits = sample_total_saved << 3;//Get the return value correct
				if(sample_total_saved >= bufsize) break;
			}
			else{
				pushBit(&data, sample & 0x80);
				if(bits_per_sample > 1)	pushBit(&data, sample & 0x40);
				if(bits_per_sample > 2)	pushBit(&data, sample & 0x20);
				if(bits_per_sample > 3)	pushBit(&data, sample & 0x10);
				if(bits_per_sample > 4)	pushBit(&data, sample & 0x08);
				if(bits_per_sample > 5)	pushBit(&data, sample & 0x04);
				if(bits_per_sample > 6)	pushBit(&data, sample & 0x02);
				//Not needed, 8bps is covered above
				//if(bits_per_sample > 7)	pushBit(&data, sample & 0x01);
				if((data.numbits >> 3) +1  >= bufsize) break;
			}
		}
	}

	if(!silent)
	{
		Dbprintf("Done, saved %d out of %d seen samples at %d bits/sample",sample_total_saved, sample_total_numbers,bits_per_sample);
		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]);
	}
	return data.numbits;
}
/**
 * @brief Does sample acquisition, ignoring the config values set in the sample_config.
 * This method is typically used by tag-specific readers who just wants to read the samples
 * the normal way
 * @param trigger_threshold
 * @param silent
 * @return number of bits sampled
 */
uint32_t DoAcquisition_default(int trigger_threshold, bool silent)
{
	return DoAcquisition(1,8,0,trigger_threshold,silent,0,0);
}
uint32_t DoAcquisition_config(bool silent, int sample_size)
{
	return DoAcquisition(config.decimation
				  ,config.bits_per_sample
				  ,config.averaging
				  ,config.trigger_threshold
				  ,silent
				  ,sample_size
				  ,0);
}

uint32_t DoPartialAcquisition(int trigger_threshold, bool silent, int sample_size, int cancel_after) {
	return DoAcquisition(1,8,0,trigger_threshold,silent,sample_size,cancel_after);
}

uint32_t ReadLF(bool activeField, bool silent, int sample_size)
{
	if (!silent) printConfig();
	LFSetupFPGAForADC(config.divisor, activeField);
	// Now call the acquisition routine
	return DoAcquisition_config(silent, sample_size);
}

/**
* Initializes the FPGA for reader-mode (field on), and acquires the samples.
* @return number of bits sampled
**/
uint32_t SampleLF(bool printCfg, int sample_size)
{
	uint32_t ret = ReadLF(true, printCfg, sample_size);
	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
	return ret;
}
/**
* Initializes the FPGA for snoop-mode (field off), and acquires the samples.
* @return number of bits sampled
**/

uint32_t SnoopLF()
{
	uint32_t ret = ReadLF(false, true, 0);
	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
	return ret;
}

/**
* acquisition of Cotag LF signal. Similart to other LF,  since the Cotag has such long datarate RF/384
* and is Manchester?,  we directly gather the manchester data into bigbuff
**/
#define COTAG_T1 384
#define COTAG_T2 (COTAG_T1>>1)
#define COTAG_ONE_THRESHOLD 128+30
#define COTAG_ZERO_THRESHOLD 128-30
#ifndef COTAG_BITS
#define COTAG_BITS 264
#endif
void doCotagAcquisition(size_t sample_size) {

	uint8_t *dest = BigBuf_get_addr();
	uint16_t bufsize = BigBuf_max_traceLen();
	
	if ( bufsize > sample_size )
		bufsize = sample_size;

	dest[0] = 0;
	uint8_t sample = 0, firsthigh = 0, firstlow = 0; 
	uint16_t i = 0;

	while (!BUTTON_PRESS() && !usb_poll_validate_length() && (i < bufsize) ) {
		WDT_HIT();
		if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
			AT91C_BASE_SSC->SSC_THR = 0x43;
			LED_D_ON();
		}
		
		if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
			sample = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
			LED_D_OFF();
		
			// find first peak
			if ( !firsthigh ) {
				if (sample < COTAG_ONE_THRESHOLD) 
					continue;
				firsthigh = 1;
			}
			if ( !firstlow ){
				if (sample > COTAG_ZERO_THRESHOLD )
					continue;
				firstlow = 1;
			}

			++i;
	
			if ( sample > COTAG_ONE_THRESHOLD)
				dest[i] = 255;
			else if ( sample < COTAG_ZERO_THRESHOLD)
				dest[i] = 0;
			else 
				dest[i] = dest[i-1];
		}
	}
}

uint32_t doCotagAcquisitionManchester() {

	uint8_t *dest = BigBuf_get_addr();
	uint16_t bufsize = BigBuf_max_traceLen();
	
	if ( bufsize > COTAG_BITS )
		bufsize = COTAG_BITS;

	dest[0] = 0;
	uint8_t sample = 0, firsthigh = 0, firstlow = 0; 
	uint16_t sample_counter = 0, period = 0;
	uint8_t curr = 0, prev = 0;
	uint16_t noise_counter = 0;
	while (!BUTTON_PRESS() && !usb_poll_validate_length() && (sample_counter < bufsize) && (noise_counter < (COTAG_T1<<1)) ) {
		WDT_HIT();
		if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
			AT91C_BASE_SSC->SSC_THR = 0x43;
			LED_D_ON();
		}

		if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
			sample = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
			LED_D_OFF();

			// find first peak
			if ( !firsthigh ) {
				if (sample < COTAG_ONE_THRESHOLD) {
					noise_counter++;
					continue;
				}
				noise_counter = 0;
				firsthigh = 1;
			}

			if ( !firstlow ){
				if (sample > COTAG_ZERO_THRESHOLD ) {
					noise_counter++;
					continue;
				}
				noise_counter=0;
				firstlow = 1;
			}

			// set sample 255, 0,  or previous
			if ( sample > COTAG_ONE_THRESHOLD){
				prev = curr;
				curr = 1;
			}
			else if ( sample < COTAG_ZERO_THRESHOLD) {
				prev = curr;
				curr = 0;
			}
			else {
				curr = prev;
			}

			// full T1 periods, 
			if ( period > 0 ) {
				--period;
				continue;
			}

			dest[sample_counter] = curr;
			++sample_counter;
			period = COTAG_T1;
		}
	}
	return sample_counter;
}
Commit	Line	Data
31abe49f MHS	1	//-----------------------------------------------------------------------------
	2	// This code is licensed to you under the terms of the GNU GPL, version 2 or,
	3	// at your option, any later version. See the LICENSE.txt file for the text of
	4	// the license.
	5	//-----------------------------------------------------------------------------
	6	// Miscellaneous routines for low frequency sampling.
	7	//-----------------------------------------------------------------------------
	8
	9	#include "proxmark3.h"
	10	#include "apps.h"
	11	#include "util.h"
	12	#include "string.h"
31abe49f	13	#include "lfsampling.h"
e04475c4	14	#include "usb_cdc.h" // for usb_poll_validate_length
e04475c4	15	//#include "ticks.h" // for StartTicks
10a8875c	16
0cd2a41a	17	sample_config config = { 1, 8, 1, 95, 0 } ;
31abe49f MHS	18
	19	void printConfig()
	20	{
e2012d1b	21	Dbprintf("LF Sampling config: ");
31abe49f MHS	22	Dbprintf(" [q] divisor: %d ", config.divisor);
	23	Dbprintf(" [b] bps: %d ", config.bits_per_sample);
	24	Dbprintf(" [d] decimation: %d ", config.decimation);
	25	Dbprintf(" [a] averaging: %d ", config.averaging);
	26	Dbprintf(" [t] trigger threshold: %d ", config.trigger_threshold);
	27	}
	28
	29
	30	/**
	31	* Called from the USB-handler to set the sampling configuration
	32	* The sampling config is used for std reading and snooping.
	33	*
	34	* Other functions may read samples and ignore the sampling config,
	35	* such as functions to read the UID from a prox tag or similar.
	36	*
	37	* Values set to '0' implies no change (except for averaging)
	38	* @brief setSamplingConfig
	39	* @param sc
	40	*/
	41	void setSamplingConfig(sample_config *sc)
	42	{
	43	if(sc->divisor != 0) config.divisor = sc->divisor;
	44	if(sc->bits_per_sample!= 0) config.bits_per_sample= sc->bits_per_sample;
	45	if(sc->decimation!= 0) config.decimation= sc->decimation;
	46	if(sc->trigger_threshold != -1) config.trigger_threshold= sc->trigger_threshold;
	47
	48	config.averaging= sc->averaging;
	49	if(config.bits_per_sample > 8) config.bits_per_sample = 8;
	50	if(config.decimation < 1) config.decimation = 1;
	51
	52	printConfig();
	53	}
	54
	55	sample_config* getSamplingConfig()
	56	{
	57	return &config;
	58	}
10a8875c	59
31abe49f MHS	60	typedef struct {
	61	uint8_t * buffer;
	62	uint32_t numbits;
	63	uint32_t position;
	64	} BitstreamOut;
	65
31abe49f MHS	66	/**
	67	* @brief Pushes bit onto the stream
	68	* @param stream
	69	* @param bit
	70	*/
10a8875c	71	void pushBit( BitstreamOut* stream, uint8_t bit)
31abe49f MHS	72	{
	73	int bytepos = stream->position >> 3; // divide by 8
	74	int bitpos = stream->position & 7;
	75	*(stream->buffer+bytepos) \|= (bit > 0) << (7 - bitpos);
	76	stream->position++;
	77	stream->numbits++;
	78	}
10a8875c	79
31abe49f MHS	80	/**
	81	* Setup the FPGA to listen for samples. This method downloads the FPGA bitstream
	82	* if not already loaded, sets divisor and starts up the antenna.
	83	* @param divisor : 1, 88> 255 or negative ==> 134.8 KHz
	84	* 0 or 95 ==> 125 KHz
	85	*
	86	**/
	87	void LFSetupFPGAForADC(int divisor, bool lf_field)
	88	{
	89	FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
	90	if ( (divisor == 1) \|\| (divisor < 0) \|\| (divisor > 255) )
	91	FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
	92	else if (divisor == 0)
	93	FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
	94	else
	95	FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor);
	96
	97	FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC \| (lf_field ? FPGA_LF_ADC_READER_FIELD : 0));
	98
	99	// Connect the A/D to the peak-detected low-frequency path.
	100	SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
	101	// Give it a bit of time for the resonant antenna to settle.
	102	SpinDelay(50);
	103	// Now set up the SSC to get the ADC samples that are now streaming at us.
	104	FpgaSetupSsc();
	105	}
	106
31abe49f MHS	107	/**
	108	* Does the sample acquisition. If threshold is specified, the actual sampling
	109	* is not commenced until the threshold has been reached.
	110	* This method implements decimation and quantization in order to
	111	* be able to provide longer sample traces.
	112	* Uses the following global settings:
	113	* @param decimation - how much should the signal be decimated. A decimation of N means we keep 1 in N samples, etc.
	114	* @param bits_per_sample - bits per sample. Max 8, min 1 bit per sample.
	115	* @param averaging If set to true, decimation will use averaging, so that if e.g. decimation is 3, the sample
	116	* value that will be used is the average value of the three samples.
	117	* @param trigger_threshold - a threshold. The sampling won't commence until this threshold has been reached. Set
	118	* to -1 to ignore threshold.
	119	* @param silent - is true, now outputs are made. If false, dbprints the status
	120	* @return the number of bits occupied by the samples.
	121	*/
217cfb6b	122	uint32_t DoAcquisition(uint8_t decimation, uint32_t bits_per_sample, bool averaging, int trigger_threshold, bool silent, int bufsize, int cancel_after)
31abe49f MHS	123	{
31abe49f MHS	124	//.
0644d5e3	125	uint8_t *dest = BigBuf_get_addr();
a37228c8	126	bufsize = (bufsize > 0 && bufsize < BigBuf_max_traceLen()) ? bufsize : BigBuf_max_traceLen();
0644d5e3	127
3cec7061	128	//memset(dest, 0, bufsize); //creates issues with cmdread (marshmellow)
31abe49f MHS	129
	130	if(bits_per_sample < 1) bits_per_sample = 1;
	131	if(bits_per_sample > 8) bits_per_sample = 8;
	132
	133	if(decimation < 1) decimation = 1;
	134
	135	// Use a bit stream to handle the output
	136	BitstreamOut data = { dest , 0, 0};
	137	int sample_counter = 0;
	138	uint8_t sample = 0;
	139	//If we want to do averaging
	140	uint32_t sample_sum =0 ;
	141	uint32_t sample_total_numbers =0 ;
	142	uint32_t sample_total_saved =0 ;
217cfb6b	143	uint32_t cancel_counter = 0;
31abe49f	144
e04475c4	145	while(!BUTTON_PRESS() && !usb_poll_validate_length() ) {
31abe49f MHS	146	WDT_HIT();
	147	if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
	148	AT91C_BASE_SSC->SSC_THR = 0x43;
	149	LED_D_ON();
	150	}
	151	if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
	152	sample = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
	153	LED_D_OFF();
b29d55f2	154	// threshold either high or low values 128 = center 0. if trigger = 178
217cfb6b	155	if ((trigger_threshold > 0) && (sample < (trigger_threshold+128)) && (sample > (128-trigger_threshold))) { //
	156	if (cancel_after > 0) cancel_counter++;
	157	if (cancel_after == cancel_counter) break;
31abe49f	158	continue;
217cfb6b	159	}
31abe49f MHS	160	trigger_threshold = 0;
	161	sample_total_numbers++;
	162
	163	if(averaging)
	164	{
	165	sample_sum += sample;
	166	}
	167	//Check decimation
	168	if(decimation > 1)
	169	{
	170	sample_counter++;
	171	if(sample_counter < decimation) continue;
	172	sample_counter = 0;
	173	}
	174	//Averaging
	175	if(averaging && decimation > 1) {
	176	sample = sample_sum / decimation;
	177	sample_sum =0;
	178	}
	179	//Store the sample
	180	sample_total_saved ++;
	181	if(bits_per_sample == 8){
	182	dest[sample_total_saved-1] = sample;
	183	data.numbits = sample_total_saved << 3;//Get the return value correct
	184	if(sample_total_saved >= bufsize) break;
	185	}
	186	else{
	187	pushBit(&data, sample & 0x80);
	188	if(bits_per_sample > 1) pushBit(&data, sample & 0x40);
	189	if(bits_per_sample > 2) pushBit(&data, sample & 0x20);
	190	if(bits_per_sample > 3) pushBit(&data, sample & 0x10);
	191	if(bits_per_sample > 4) pushBit(&data, sample & 0x08);
	192	if(bits_per_sample > 5) pushBit(&data, sample & 0x04);
	193	if(bits_per_sample > 6) pushBit(&data, sample & 0x02);
	194	//Not needed, 8bps is covered above
	195	//if(bits_per_sample > 7) pushBit(&data, sample & 0x01);
	196	if((data.numbits >> 3) +1 >= bufsize) break;
	197	}
	198	}
	199	}
	200
	201	if(!silent)
	202	{
	203	Dbprintf("Done, saved %d out of %d seen samples at %d bits/sample",sample_total_saved, sample_total_numbers,bits_per_sample);
	204	Dbprintf("buffer samples: %02x %02x %02x %02x %02x %02x %02x %02x ...",
	205	dest[0], dest[1], dest[2], dest[3], dest[4], dest[5], dest[6], dest[7]);
	206	}
	207	return data.numbits;
	208	}
	209	/**
	210	* @brief Does sample acquisition, ignoring the config values set in the sample_config.
	211	* This method is typically used by tag-specific readers who just wants to read the samples
	212	* the normal way
	213	* @param trigger_threshold
	214	* @param silent
	215	* @return number of bits sampled
	216	*/
	217	uint32_t DoAcquisition_default(int trigger_threshold, bool silent)
	218	{
217cfb6b	219	return DoAcquisition(1,8,0,trigger_threshold,silent,0,0);
31abe49f	220	}
b9957414	221	uint32_t DoAcquisition_config(bool silent, int sample_size)
31abe49f MHS	222	{
	223	return DoAcquisition(config.decimation
	224	,config.bits_per_sample
	225	,config.averaging
	226	,config.trigger_threshold
a37228c8	227	,silent
217cfb6b	228	,sample_size
217cfb6b	229	,0);
a37228c8	230	}
a37228c8	231
217cfb6b	232	uint32_t DoPartialAcquisition(int trigger_threshold, bool silent, int sample_size, int cancel_after) {
217cfb6b	233	return DoAcquisition(1,8,0,trigger_threshold,silent,sample_size,cancel_after);
31abe49f MHS	234	}
31abe49f MHS	235
b9957414	236	uint32_t ReadLF(bool activeField, bool silent, int sample_size)
31abe49f	237	{
1fbf8956	238	if (!silent) printConfig();
31abe49f MHS	239	LFSetupFPGAForADC(config.divisor, activeField);
31abe49f MHS	240	// Now call the acquisition routine
b9957414	241	return DoAcquisition_config(silent, sample_size);
31abe49f MHS	242	}
	243
	244	/**
	245	* Initializes the FPGA for reader-mode (field on), and acquires the samples.
	246	* @return number of bits sampled
	247	**/
b9957414	248	uint32_t SampleLF(bool printCfg, int sample_size)
31abe49f	249	{
b9957414	250	uint32_t ret = ReadLF(true, printCfg, sample_size);
e04475c4	251	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
e04475c4	252	return ret;
31abe49f MHS	253	}
	254	/**
	255	* Initializes the FPGA for snoop-mode (field off), and acquires the samples.
	256	* @return number of bits sampled
	257	**/
	258
	259	uint32_t SnoopLF()
	260	{
b9957414	261	uint32_t ret = ReadLF(false, true, 0);
e04475c4	262	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
e04475c4	263	return ret;
31abe49f	264	}
7cfc777b	265
e04475c4	266	/**
	267	* acquisition of Cotag LF signal. Similart to other LF, since the Cotag has such long datarate RF/384
	268	* and is Manchester?, we directly gather the manchester data into bigbuff
	269	**/
	270	#define COTAG_T1 384
	271	#define COTAG_T2 (COTAG_T1>>1)
	272	#define COTAG_ONE_THRESHOLD 128+30
	273	#define COTAG_ZERO_THRESHOLD 128-30
	274	#ifndef COTAG_BITS
	275	#define COTAG_BITS 264
	276	#endif
	277	void doCotagAcquisition(size_t sample_size) {
	278
	279	uint8_t *dest = BigBuf_get_addr();
	280	uint16_t bufsize = BigBuf_max_traceLen();
	281
	282	if ( bufsize > sample_size )
	283	bufsize = sample_size;
	284
	285	dest[0] = 0;
	286	uint8_t sample = 0, firsthigh = 0, firstlow = 0;
	287	uint16_t i = 0;
	288
	289	while (!BUTTON_PRESS() && !usb_poll_validate_length() && (i < bufsize) ) {
	290	WDT_HIT();
	291	if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
	292	AT91C_BASE_SSC->SSC_THR = 0x43;
	293	LED_D_ON();
	294	}
	295
	296	if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
	297	sample = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
	298	LED_D_OFF();
	299
	300	// find first peak
	301	if ( !firsthigh ) {
	302	if (sample < COTAG_ONE_THRESHOLD)
	303	continue;
	304	firsthigh = 1;
	305	}
	306	if ( !firstlow ){
	307	if (sample > COTAG_ZERO_THRESHOLD )
	308	continue;
	309	firstlow = 1;
	310	}
	311
	312	++i;
	313
	314	if ( sample > COTAG_ONE_THRESHOLD)
	315	dest[i] = 255;
	316	else if ( sample < COTAG_ZERO_THRESHOLD)
	317	dest[i] = 0;
	318	else
	319	dest[i] = dest[i-1];
	320	}
	321	}
	322	}
	323
	324	uint32_t doCotagAcquisitionManchester() {
	325
	326	uint8_t *dest = BigBuf_get_addr();
	327	uint16_t bufsize = BigBuf_max_traceLen();
	328
	329	if ( bufsize > COTAG_BITS )
330	bufsize = COTAG_BITS;
331
332	dest[0] = 0;
333	uint8_t sample = 0, firsthigh = 0, firstlow = 0;
334	uint16_t sample_counter = 0, period = 0;
335	uint8_t curr = 0, prev = 0;
217cfb6b	336	uint16_t noise_counter = 0;
cb593491	337	while (!BUTTON_PRESS() && !usb_poll_validate_length() && (sample_counter < bufsize) && (noise_counter < (COTAG_T1<<1)) ) {
e04475c4	338	WDT_HIT();
	339	if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
	340	AT91C_BASE_SSC->SSC_THR = 0x43;
	341	LED_D_ON();
	342	}
	343
	344	if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
	345	sample = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
	346	LED_D_OFF();
	347
	348	// find first peak
	349	if ( !firsthigh ) {
217cfb6b	350	if (sample < COTAG_ONE_THRESHOLD) {
217cfb6b	351	noise_counter++;
e04475c4	352	continue;
217cfb6b	353	}
217cfb6b	354	noise_counter = 0;
e04475c4	355	firsthigh = 1;
	356	}
	357
	358	if ( !firstlow ){
217cfb6b	359	if (sample > COTAG_ZERO_THRESHOLD ) {
217cfb6b	360	noise_counter++;
e04475c4	361	continue;
217cfb6b	362	}
217cfb6b	363	noise_counter=0;
e04475c4	364	firstlow = 1;
	365	}
	366
	367	// set sample 255, 0, or previous
	368	if ( sample > COTAG_ONE_THRESHOLD){
	369	prev = curr;
	370	curr = 1;
	371	}
	372	else if ( sample < COTAG_ZERO_THRESHOLD) {
	373	prev = curr;
	374	curr = 0;
	375	}
	376	else {
	377	curr = prev;
	378	}
	379
	380	// full T1 periods,
	381	if ( period > 0 ) {
	382	--period;
	383	continue;
	384	}
	385
	386	dest[sample_counter] = curr;
	387	++sample_counter;
	388	period = COTAG_T1;
	389	}
	390	}
	391	return sample_counter;
	392	}