fix incorrect variable name
[proxmark3-svn] / armsrc / lfsampling.c
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"
13 #include "lfsampling.h"
14 #include "usb_cdc.h" // for usb_poll_validate_length
15 //#include "ticks.h" // for StartTicks
16
17 sample_config config = { 1, 8, 1, 95, 0 } ;
18
19 void printConfig()
20 {
21 Dbprintf("LF Sampling config: ");
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 }
59
60 typedef struct {
61 uint8_t * buffer;
62 uint32_t numbits;
63 uint32_t position;
64 } BitstreamOut;
65
66 /**
67 * @brief Pushes bit onto the stream
68 * @param stream
69 * @param bit
70 */
71 void pushBit( BitstreamOut* stream, uint8_t bit)
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 }
79
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
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 */
122 uint32_t DoAcquisition(uint8_t decimation, uint32_t bits_per_sample, bool averaging, int trigger_threshold, bool silent, int bufsize, int cancel_after)
123 {
124 //.
125 uint8_t *dest = BigBuf_get_addr();
126 bufsize = (bufsize > 0 && bufsize < BigBuf_max_traceLen()) ? bufsize : BigBuf_max_traceLen();
127
128 //memset(dest, 0, bufsize); //creates issues with cmdread (marshmellow)
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 ;
143 uint32_t cancel_counter = 0;
144
145 while(!BUTTON_PRESS() && !usb_poll_validate_length() ) {
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();
154 // threshold either high or low values 128 = center 0. if trigger = 178
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;
158 continue;
159 }
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 {
219 return DoAcquisition(1,8,0,trigger_threshold,silent,0,0);
220 }
221 uint32_t DoAcquisition_config(bool silent, int sample_size)
222 {
223 return DoAcquisition(config.decimation
224 ,config.bits_per_sample
225 ,config.averaging
226 ,config.trigger_threshold
227 ,silent
228 ,sample_size
229 ,0);
230 }
231
232 uint32_t DoPartialAcquisition(int trigger_threshold, bool silent, int sample_size, int cancel_after) {
233 return DoAcquisition(1,8,0,trigger_threshold,silent,sample_size,cancel_after);
234 }
235
236 uint32_t ReadLF(bool activeField, bool silent, int sample_size)
237 {
238 if (!silent) printConfig();
239 LFSetupFPGAForADC(config.divisor, activeField);
240 // Now call the acquisition routine
241 return DoAcquisition_config(silent, sample_size);
242 }
243
244 /**
245 * Initializes the FPGA for reader-mode (field on), and acquires the samples.
246 * @return number of bits sampled
247 **/
248 uint32_t SampleLF(bool printCfg, int sample_size)
249 {
250 uint32_t ret = ReadLF(true, printCfg, sample_size);
251 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
252 return ret;
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 {
261 uint32_t ret = ReadLF(false, true, 0);
262 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
263 return ret;
264 }
265
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;
336 uint16_t noise_counter = 0;
337 while (!BUTTON_PRESS() && !usb_poll_validate_length() && (sample_counter < bufsize) && (noise_counter < (COTAG_T1<<1)) ) {
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 ) {
350 if (sample < COTAG_ONE_THRESHOLD) {
351 noise_counter++;
352 continue;
353 }
354 noise_counter = 0;
355 firsthigh = 1;
356 }
357
358 if ( !firstlow ){
359 if (sample > COTAG_ZERO_THRESHOLD ) {
360 noise_counter++;
361 continue;
362 }
363 noise_counter=0;
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 }
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