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Merge pull request #81 from mdp/fixguard
[proxmark3-svn] / armsrc / lfsampling.c
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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
31abe49f 9#include "lfsampling.h"
10a8875c 10
507afbf3 11/*
12Default LF config is set to:
13 decimation = 1 (we keep 1 out of 1 samples)
14 bits_per_sample = 8
15 averaging = YES
16 divisor = 95 (125khz)
17 trigger_threshold = 0
18 */
0cd2a41a 19sample_config config = { 1, 8, 1, 95, 0 } ;
31abe49f 20
24c49d36 21void printConfig() {
7838f4be 22 Dbprintf("LF Sampling config: ");
5f5b83b7 23 Dbprintf(" [q] divisor: %d (%d KHz)", config.divisor, 12000 / (config.divisor+1));
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24 Dbprintf(" [b] bps: %d ", config.bits_per_sample);
25 Dbprintf(" [d] decimation: %d ", config.decimation);
507afbf3 26 Dbprintf(" [a] averaging: %s ", (config.averaging) ? "Yes" : "No");
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27 Dbprintf(" [t] trigger threshold: %d ", config.trigger_threshold);
28}
29
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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 */
24c49d36 41void setSamplingConfig(sample_config *sc) {
31abe49f 42 if(sc->divisor != 0) config.divisor = sc->divisor;
9974991e 43 if(sc->bits_per_sample != 0) config.bits_per_sample = sc->bits_per_sample;
9974991e 44 if(sc->trigger_threshold != -1) config.trigger_threshold = sc->trigger_threshold;
507afbf3 45
46 config.decimation = (sc->decimation != 0) ? sc->decimation : 1;
9974991e 47 config.averaging = sc->averaging;
31abe49f 48 if(config.bits_per_sample > 8) config.bits_per_sample = 8;
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49
50 printConfig();
51}
52
24c49d36 53sample_config* getSamplingConfig() {
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54 return &config;
55}
10a8875c 56
53d5dc64 57struct BitstreamOut {
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58 uint8_t * buffer;
59 uint32_t numbits;
60 uint32_t position;
53d5dc64 61};
31abe49f 62
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63/**
64 * @brief Pushes bit onto the stream
65 * @param stream
66 * @param bit
67 */
24c49d36 68void pushBit( BitstreamOut* stream, uint8_t bit) {
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69 int bytepos = stream->position >> 3; // divide by 8
70 int bitpos = stream->position & 7;
71 *(stream->buffer+bytepos) |= (bit > 0) << (7 - bitpos);
72 stream->position++;
73 stream->numbits++;
74}
10a8875c 75
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76/**
77* Setup the FPGA to listen for samples. This method downloads the FPGA bitstream
78* if not already loaded, sets divisor and starts up the antenna.
79* @param divisor : 1, 88> 255 or negative ==> 134.8 KHz
80* 0 or 95 ==> 125 KHz
81*
82**/
24c49d36 83void LFSetupFPGAForADC(int divisor, bool lf_field) {
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84 FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
85 if ( (divisor == 1) || (divisor < 0) || (divisor > 255) )
86 FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
87 else if (divisor == 0)
88 FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
89 else
90 FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor);
91
92 FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | (lf_field ? FPGA_LF_ADC_READER_FIELD : 0));
93
94 // Connect the A/D to the peak-detected low-frequency path.
95 SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
8255e1a6 96 // 50ms for the resonant antenna to settle.
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97 SpinDelay(50);
98 // Now set up the SSC to get the ADC samples that are now streaming at us.
99 FpgaSetupSsc();
24c49d36 100 // start a 1.5ticks is 1us
101 StartTicks();
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102}
103
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104/**
105 * Does the sample acquisition. If threshold is specified, the actual sampling
106 * is not commenced until the threshold has been reached.
107 * This method implements decimation and quantization in order to
108 * be able to provide longer sample traces.
109 * Uses the following global settings:
110 * @param decimation - how much should the signal be decimated. A decimation of N means we keep 1 in N samples, etc.
111 * @param bits_per_sample - bits per sample. Max 8, min 1 bit per sample.
112 * @param averaging If set to true, decimation will use averaging, so that if e.g. decimation is 3, the sample
113 * value that will be used is the average value of the three samples.
114 * @param trigger_threshold - a threshold. The sampling won't commence until this threshold has been reached. Set
115 * to -1 to ignore threshold.
116 * @param silent - is true, now outputs are made. If false, dbprints the status
117 * @return the number of bits occupied by the samples.
118 */
b828a4e1 119uint32_t DoAcquisition(uint8_t decimation, uint32_t bits_per_sample, bool averaging, int trigger_threshold, bool silent) {
1c8fbeb9 120 //bigbuf, to hold the aquired raw data signal
0644d5e3 121 uint8_t *dest = BigBuf_get_addr();
1c8fbeb9 122 uint16_t bufsize = BigBuf_max_traceLen();
0644d5e3 123
c0f15a05 124 //BigBuf_Clear_ext(false); //creates issues with cmdread (marshmellow)
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125
126 if(bits_per_sample < 1) bits_per_sample = 1;
127 if(bits_per_sample > 8) bits_per_sample = 8;
128
129 if(decimation < 1) decimation = 1;
130
131 // Use a bit stream to handle the output
132 BitstreamOut data = { dest , 0, 0};
133 int sample_counter = 0;
134 uint8_t sample = 0;
135 //If we want to do averaging
136 uint32_t sample_sum =0 ;
137 uint32_t sample_total_numbers =0 ;
138 uint32_t sample_total_saved =0 ;
139
edaf10af 140 while(!BUTTON_PRESS() && !usb_poll_validate_length() ) {
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141 WDT_HIT();
142 if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
5f5b83b7 143 AT91C_BASE_SSC->SSC_THR = 0x43;
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144 LED_D_ON();
145 }
146 if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
147 sample = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
148 LED_D_OFF();
99cf19d9 149 // threshold either high or low values 128 = center 0. if trigger = 178
150 if ((trigger_threshold > 0) && (sample < (trigger_threshold+128)) && (sample > (128-trigger_threshold))) //
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151 continue;
152
153 trigger_threshold = 0;
154 sample_total_numbers++;
155
156 if(averaging)
157 {
158 sample_sum += sample;
159 }
160 //Check decimation
161 if(decimation > 1)
162 {
163 sample_counter++;
164 if(sample_counter < decimation) continue;
165 sample_counter = 0;
166 }
167 //Averaging
168 if(averaging && decimation > 1) {
169 sample = sample_sum / decimation;
170 sample_sum =0;
171 }
172 //Store the sample
173 sample_total_saved ++;
174 if(bits_per_sample == 8){
175 dest[sample_total_saved-1] = sample;
176 data.numbits = sample_total_saved << 3;//Get the return value correct
177 if(sample_total_saved >= bufsize) break;
178 }
179 else{
180 pushBit(&data, sample & 0x80);
181 if(bits_per_sample > 1) pushBit(&data, sample & 0x40);
182 if(bits_per_sample > 2) pushBit(&data, sample & 0x20);
183 if(bits_per_sample > 3) pushBit(&data, sample & 0x10);
184 if(bits_per_sample > 4) pushBit(&data, sample & 0x08);
185 if(bits_per_sample > 5) pushBit(&data, sample & 0x04);
186 if(bits_per_sample > 6) pushBit(&data, sample & 0x02);
187 //Not needed, 8bps is covered above
188 //if(bits_per_sample > 7) pushBit(&data, sample & 0x01);
189 if((data.numbits >> 3) +1 >= bufsize) break;
190 }
191 }
192 }
193
194 if(!silent)
195 {
196 Dbprintf("Done, saved %d out of %d seen samples at %d bits/sample",sample_total_saved, sample_total_numbers,bits_per_sample);
197 Dbprintf("buffer samples: %02x %02x %02x %02x %02x %02x %02x %02x ...",
198 dest[0], dest[1], dest[2], dest[3], dest[4], dest[5], dest[6], dest[7]);
199 }
200 return data.numbits;
201}
202/**
203 * @brief Does sample acquisition, ignoring the config values set in the sample_config.
204 * This method is typically used by tag-specific readers who just wants to read the samples
205 * the normal way
206 * @param trigger_threshold
207 * @param silent
208 * @return number of bits sampled
209 */
24c49d36 210uint32_t DoAcquisition_default(int trigger_threshold, bool silent) {
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211 return DoAcquisition(1,8,0,trigger_threshold,silent);
212}
24c49d36 213uint32_t DoAcquisition_config( bool silent) {
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214 return DoAcquisition(config.decimation
215 ,config.bits_per_sample
216 ,config.averaging
217 ,config.trigger_threshold
218 ,silent);
219}
220
24c49d36 221uint32_t ReadLF(bool activeField, bool silent) {
222 if (!silent)
223 printConfig();
31abe49f 224 LFSetupFPGAForADC(config.divisor, activeField);
1fbf8956 225 return DoAcquisition_config(silent);
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226}
227
228/**
229* Initializes the FPGA for reader-mode (field on), and acquires the samples.
230* @return number of bits sampled
231**/
24c49d36 232uint32_t SampleLF(bool printCfg) {
b828a4e1 233 BigBuf_Clear_ext(false);
234 uint32_t ret = ReadLF(true, printCfg);
235 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
236 return ret;
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237}
238/**
239* Initializes the FPGA for snoop-mode (field off), and acquires the samples.
240* @return number of bits sampled
241**/
ac2df346 242uint32_t SnoopLF() {
b828a4e1 243 BigBuf_Clear_ext(false);
244 uint32_t ret = ReadLF(false, true);
245 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
246 return ret;
31abe49f 247}
ac2df346 248
249/**
250* acquisition of T55x7 LF signal. Similart to other LF, but adjusted with @marshmellows thresholds
251* the data is collected in BigBuf.
252**/
94422fa2 253void doT55x7Acquisition(size_t sample_size) {
ac2df346 254
24c49d36 255 #define T55xx_READ_UPPER_THRESHOLD 128+40 // 60 grph
256 #define T55xx_READ_LOWER_THRESHOLD 128-40 // -60 grph
257 #define T55xx_READ_TOL 2
258
ac2df346 259 uint8_t *dest = BigBuf_get_addr();
260 uint16_t bufsize = BigBuf_max_traceLen();
261
94422fa2 262 if ( bufsize > sample_size )
263 bufsize = sample_size;
ac2df346 264
24c49d36 265 uint8_t curSample = 0, lastSample = 0;
266 uint16_t i = 0, skipCnt = 0;
ac2df346 267 bool startFound = false;
268 bool highFound = false;
6426f6ba 269 bool lowFound = false;
24c49d36 270
3f267966 271 while(!BUTTON_PRESS() && !usb_poll_validate_length() && skipCnt < 1000 && (i < bufsize) ) {
1c8fbeb9 272 WDT_HIT();
ac2df346 273 if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
53d5dc64 274 AT91C_BASE_SSC->SSC_THR = 0x43; //43
ac2df346 275 LED_D_ON();
276 }
277 if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
1d0ccbe0 278 curSample = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1c8fbeb9 279 LED_D_OFF();
280
94422fa2 281 // skip until the first high sample above threshold
1d0ccbe0 282 if (!startFound && curSample > T55xx_READ_UPPER_THRESHOLD) {
6426f6ba 283 //if (curSample > lastSample)
284 // lastSample = curSample;
1d0ccbe0 285 highFound = true;
ac2df346 286 } else if (!highFound) {
1d0ccbe0 287 skipCnt++;
ac2df346 288 continue;
289 }
53d5dc64 290 // skip until the first low sample below threshold
6426f6ba 291 if (!startFound && curSample < T55xx_READ_LOWER_THRESHOLD) {
292 //if (curSample > lastSample)
293 lastSample = curSample;
294 lowFound = true;
295 } else if (!lowFound) {
296 skipCnt++;
297 continue;
298 }
299
94422fa2 300 // skip until first high samples begin to change
24c49d36 301 if (startFound || curSample > T55xx_READ_LOWER_THRESHOLD + T55xx_READ_TOL){
94422fa2 302 // if just found start - recover last sample
303 if (!startFound) {
6426f6ba 304 dest[i++] = lastSample;
3f267966 305 startFound = true;
94422fa2 306 }
307 // collect samples
1d0ccbe0 308 dest[i++] = curSample;
ac2df346 309 }
310 }
311 }
1d0ccbe0 312}
5f5b83b7 313/**
314* acquisition of Cotag LF signal. Similart to other LF, since the Cotag has such long datarate RF/384
315* and is Manchester?, we directly gather the manchester data into bigbuff
316**/
317
318#define COTAG_T1 384
319#define COTAG_T2 (COTAG_T1>>1)
320#define COTAG_ONE_THRESHOLD 128+30
321#define COTAG_ZERO_THRESHOLD 128-30
322void doCotagAcquisition(size_t sample_size) {
323
324 uint8_t *dest = BigBuf_get_addr();
325 uint16_t bufsize = BigBuf_max_traceLen();
326
327 if ( bufsize > sample_size )
328 bufsize = sample_size;
329
330 dest[0] = 0;
331 uint8_t sample = 0, firsthigh = 0, firstlow = 0;
332 uint16_t i = 0;
333
334 while (!BUTTON_PRESS() && !usb_poll_validate_length() && (i < bufsize) ) {
335 WDT_HIT();
336 if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
337 AT91C_BASE_SSC->SSC_THR = 0x43;
338 LED_D_ON();
339 }
340
341 if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
342 sample = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
343 LED_D_OFF();
344
345 // find first peak
346 if ( !firsthigh ) {
347 if (sample < COTAG_ONE_THRESHOLD)
348 continue;
349 firsthigh = 1;
350 }
351 if ( !firstlow ){
352 if (sample > COTAG_ZERO_THRESHOLD )
353 continue;
354 firstlow = 1;
355 }
356
357 ++i;
358
359 if ( sample > COTAG_ONE_THRESHOLD)
360 dest[i] = 255;
361 else if ( sample < COTAG_ZERO_THRESHOLD)
362 dest[i] = 0;
363 else
364 dest[i] = dest[i-1];
365 }
366 }
367}
368
369uint32_t doCotagAcquisitionManchester() {
370
371 uint8_t *dest = BigBuf_get_addr();
372 uint16_t bufsize = BigBuf_max_traceLen();
373
a330987d 374 if ( bufsize > COTAG_BITS )
375 bufsize = COTAG_BITS;
5f5b83b7 376
377 dest[0] = 0;
378 uint8_t sample = 0, firsthigh = 0, firstlow = 0;
379 uint16_t sample_counter = 0, period = 0;
380 uint8_t curr = 0, prev = 0;
381
382 while (!BUTTON_PRESS() && !usb_poll_validate_length() && (sample_counter < bufsize) ) {
383 WDT_HIT();
384 if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
385 AT91C_BASE_SSC->SSC_THR = 0x43;
386 LED_D_ON();
387 }
388
389 if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
390 sample = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
391 LED_D_OFF();
392
393 // find first peak
394 if ( !firsthigh ) {
395 if (sample < COTAG_ONE_THRESHOLD)
396 continue;
397 firsthigh = 1;
398 }
399
400 if ( !firstlow ){
401 if (sample > COTAG_ZERO_THRESHOLD )
402 continue;
403 firstlow = 1;
404 }
405
406 // set sample 255, 0, or previous
407 if ( sample > COTAG_ONE_THRESHOLD){
408 prev = curr;
409 curr = 1;
410 }
411 else if ( sample < COTAG_ZERO_THRESHOLD) {
412 prev = curr;
413 curr = 0;
414 }
415 else {
416 curr = prev;
417 }
418
419 // full T1 periods,
420 if ( period > 0 ) {
421 --period;
422 continue;
423 }
424
425 dest[sample_counter] = curr;
426 ++sample_counter;
427 period = COTAG_T1;
428 }
429 }
430 return sample_counter;
431}
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