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git.zerfleddert.de Git - proxmark3-svn/blob - 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
5 //-----------------------------------------------------------------------------
6 // Miscellaneous routines for low frequency sampling.
7 //-----------------------------------------------------------------------------
13 #include "lfsampling.h"
14 #include "usb_cdc.h" // for usb_poll_validate_length
15 #include "fpgaloader.h"
17 sample_config config
= { 1, 8, 1, 95, 0, 0 } ;
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 Dbprintf(" [s] samples to skip: %d ", config
.samples_to_skip
);
32 * Called from the USB-handler to set the sampling configuration
33 * The sampling config is used for std reading and snooping.
35 * Other functions may read samples and ignore the sampling config,
36 * such as functions to read the UID from a prox tag or similar.
38 * Values set to '0' implies no change (except for averaging, threshold, samples_to_skip)
39 * @brief setSamplingConfig
42 void setSamplingConfig(uint8_t *config_data
) {
43 sample_config
*sc
= (sample_config
*)config_data
;
44 if (sc
->divisor
!= 0) config
.divisor
= sc
->divisor
;
45 if (sc
->bits_per_sample
!= 0) config
.bits_per_sample
= sc
->bits_per_sample
;
46 if (sc
->decimation
!= 0) config
.decimation
= sc
->decimation
;
47 if (sc
->trigger_threshold
!= -1) config
.trigger_threshold
= sc
->trigger_threshold
;
48 if (sc
->samples_to_skip
!= -1) config
.samples_to_skip
= sc
->samples_to_skip
;
50 config
.averaging
= sc
->averaging
;
51 if (config
.bits_per_sample
> 8) config
.bits_per_sample
= 8;
52 if (config
.decimation
< 1) config
.decimation
= 1;
57 sample_config
* getSamplingConfig()
69 * @brief Pushes bit onto the stream
73 void pushBit( BitstreamOut
* stream
, uint8_t bit
)
75 int bytepos
= stream
->position
>> 3; // divide by 8
76 int bitpos
= stream
->position
& 7;
77 *(stream
->buffer
+bytepos
) |= (bit
> 0) << (7 - bitpos
);
83 * Setup the FPGA to listen for samples. This method downloads the FPGA bitstream
84 * if not already loaded, sets divisor and starts up the antenna.
85 * @param divisor : 1, 88> 255 or negative ==> 134.8 KHz
89 void LFSetupFPGAForADC(int divisor
, bool lf_field
)
91 FpgaDownloadAndGo(FPGA_BITSTREAM_LF
);
92 if ( (divisor
== 1) || (divisor
< 0) || (divisor
> 255) )
93 FpgaSendCommand(FPGA_CMD_SET_DIVISOR
, 88); //134.8Khz
94 else if (divisor
== 0)
95 FpgaSendCommand(FPGA_CMD_SET_DIVISOR
, 95); //125Khz
97 FpgaSendCommand(FPGA_CMD_SET_DIVISOR
, divisor
);
99 FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC
| (lf_field
? FPGA_LF_ADC_READER_FIELD
: 0));
101 // Connect the A/D to the peak-detected low-frequency path.
102 SetAdcMuxFor(GPIO_MUXSEL_LOPKD
);
103 // Give it a bit of time for the resonant antenna to settle.
105 // Now set up the SSC to get the ADC samples that are now streaming at us.
106 FpgaSetupSsc(FPGA_MAJOR_MODE_LF_ADC
);
110 * Does the sample acquisition. If threshold is specified, the actual sampling
111 * is not commenced until the threshold has been reached.
112 * This method implements decimation and quantization in order to
113 * be able to provide longer sample traces.
114 * Uses the following global settings:
115 * @param decimation - how much should the signal be decimated. A decimation of N means we keep 1 in N samples, etc.
116 * @param bits_per_sample - bits per sample. Max 8, min 1 bit per sample.
117 * @param averaging If set to true, decimation will use averaging, so that if e.g. decimation is 3, the sample
118 * value that will be used is the average value of the three samples.
119 * @param trigger_threshold - a threshold. The sampling won't commence until this threshold has been reached. Set
120 * to -1 to ignore threshold.
121 * @param silent - is true, now outputs are made. If false, dbprints the status
122 * @return the number of bits occupied by the samples.
124 uint32_t DoAcquisition(uint8_t decimation
, uint32_t bits_per_sample
, bool averaging
, int trigger_threshold
, bool silent
, int bufsize
, int cancel_after
, int samples_to_skip
)
127 uint8_t *dest
= BigBuf_get_addr();
128 bufsize
= (bufsize
> 0 && bufsize
< BigBuf_max_traceLen()) ? bufsize
: BigBuf_max_traceLen();
130 //memset(dest, 0, bufsize); //creates issues with cmdread (marshmellow)
132 if(bits_per_sample
< 1) bits_per_sample
= 1;
133 if(bits_per_sample
> 8) bits_per_sample
= 8;
135 if(decimation
< 1) decimation
= 1;
137 // Use a bit stream to handle the output
138 BitstreamOut data
= { dest
, 0, 0};
139 int sample_counter
= 0;
141 //If we want to do averaging
142 uint32_t sample_sum
=0 ;
143 uint32_t sample_total_numbers
=0 ;
144 uint32_t sample_total_saved
=0 ;
145 uint32_t cancel_counter
= 0;
146 uint32_t samples_skipped
= 0;
148 while(!BUTTON_PRESS() && !usb_poll_validate_length() ) {
150 if (AT91C_BASE_SSC
->SSC_SR
& AT91C_SSC_TXRDY
) {
151 AT91C_BASE_SSC
->SSC_THR
= 0x43;
154 if (AT91C_BASE_SSC
->SSC_SR
& AT91C_SSC_RXRDY
) {
155 sample
= (uint8_t)AT91C_BASE_SSC
->SSC_RHR
;
157 // threshold either high or low values 128 = center 0. if trigger = 178
158 if ((trigger_threshold
> 0) && (sample
< (trigger_threshold
+128)) && (sample
> (128-trigger_threshold
))) { //
159 if (cancel_after
> 0) {
161 if (cancel_after
== cancel_counter
) break;
165 trigger_threshold
= 0;
166 if (samples_to_skip
> samples_skipped
) {
170 sample_total_numbers
++;
174 sample_sum
+= sample
;
180 if(sample_counter
< decimation
) continue;
184 if(averaging
&& decimation
> 1) {
185 sample
= sample_sum
/ decimation
;
189 sample_total_saved
++;
190 if(bits_per_sample
== 8){
191 dest
[sample_total_saved
-1] = sample
;
192 data
.numbits
= sample_total_saved
<< 3;//Get the return value correct
193 if(sample_total_saved
>= bufsize
) break;
196 pushBit(&data
, sample
& 0x80);
197 if(bits_per_sample
> 1) pushBit(&data
, sample
& 0x40);
198 if(bits_per_sample
> 2) pushBit(&data
, sample
& 0x20);
199 if(bits_per_sample
> 3) pushBit(&data
, sample
& 0x10);
200 if(bits_per_sample
> 4) pushBit(&data
, sample
& 0x08);
201 if(bits_per_sample
> 5) pushBit(&data
, sample
& 0x04);
202 if(bits_per_sample
> 6) pushBit(&data
, sample
& 0x02);
203 //Not needed, 8bps is covered above
204 //if(bits_per_sample > 7) pushBit(&data, sample & 0x01);
205 if((data
.numbits
>> 3) +1 >= bufsize
) break;
212 Dbprintf("Done, saved %d out of %d seen samples at %d bits/sample",sample_total_saved
, sample_total_numbers
,bits_per_sample
);
213 Dbprintf("buffer samples: %02x %02x %02x %02x %02x %02x %02x %02x ...",
214 dest
[0], dest
[1], dest
[2], dest
[3], dest
[4], dest
[5], dest
[6], dest
[7]);
219 * @brief Does sample acquisition, ignoring the config values set in the sample_config.
220 * This method is typically used by tag-specific readers who just wants to read the samples
222 * @param trigger_threshold
224 * @return number of bits sampled
226 uint32_t DoAcquisition_default(int trigger_threshold
, bool silent
)
228 return DoAcquisition(1,8,0,trigger_threshold
,silent
,0,0,0);
230 uint32_t DoAcquisition_config(bool silent
, int sample_size
)
232 return DoAcquisition(config
.decimation
233 ,config
.bits_per_sample
235 ,config
.trigger_threshold
239 ,config
.samples_to_skip
);
242 uint32_t DoPartialAcquisition(int trigger_threshold
, bool silent
, int sample_size
, int cancel_after
) {
243 return DoAcquisition(1,8,0,trigger_threshold
,silent
,sample_size
,cancel_after
,0);
246 uint32_t ReadLF(bool activeField
, bool silent
, int sample_size
)
248 if (!silent
) printConfig();
249 LFSetupFPGAForADC(config
.divisor
, activeField
);
250 // Now call the acquisition routine
251 return DoAcquisition_config(silent
, sample_size
);
255 * Initializes the FPGA for reader-mode (field on), and acquires the samples.
256 * @return number of bits sampled
258 uint32_t SampleLF(bool printCfg
, int sample_size
)
260 uint32_t ret
= ReadLF(true, printCfg
, sample_size
);
261 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF
);
265 * Initializes the FPGA for snoop-mode (field off), and acquires the samples.
266 * @return number of bits sampled
271 uint32_t ret
= ReadLF(false, true, 0);
272 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF
);
277 * acquisition of Cotag LF signal. Similar to other LF, since the Cotag has such long datarate RF/384
278 * and is Manchester?, we directly gather the manchester data into bigbuff
281 #define COTAG_T2 (COTAG_T1>>1)
282 #define COTAG_ONE_THRESHOLD 128+30
283 #define COTAG_ZERO_THRESHOLD 128-30
285 #define COTAG_BITS 264
287 void doCotagAcquisition(size_t sample_size
) {
289 uint8_t *dest
= BigBuf_get_addr();
290 uint16_t bufsize
= BigBuf_max_traceLen();
292 if ( bufsize
> sample_size
)
293 bufsize
= sample_size
;
296 uint8_t sample
= 0, firsthigh
= 0, firstlow
= 0;
299 while (!BUTTON_PRESS() && !usb_poll_validate_length() && (i
< bufsize
) ) {
301 if (AT91C_BASE_SSC
->SSC_SR
& AT91C_SSC_TXRDY
) {
302 AT91C_BASE_SSC
->SSC_THR
= 0x43;
306 if (AT91C_BASE_SSC
->SSC_SR
& AT91C_SSC_RXRDY
) {
307 sample
= (uint8_t)AT91C_BASE_SSC
->SSC_RHR
;
312 if (sample
< COTAG_ONE_THRESHOLD
)
317 if (sample
> COTAG_ZERO_THRESHOLD
)
324 if ( sample
> COTAG_ONE_THRESHOLD
)
326 else if ( sample
< COTAG_ZERO_THRESHOLD
)
334 uint32_t doCotagAcquisitionManchester() {
336 uint8_t *dest
= BigBuf_get_addr();
337 uint16_t bufsize
= BigBuf_max_traceLen();
339 if ( bufsize
> COTAG_BITS
)
340 bufsize
= COTAG_BITS
;
343 uint8_t sample
= 0, firsthigh
= 0, firstlow
= 0;
344 uint16_t sample_counter
= 0, period
= 0;
345 uint8_t curr
= 0, prev
= 0;
346 uint16_t noise_counter
= 0;
347 while (!BUTTON_PRESS() && !usb_poll_validate_length() && (sample_counter
< bufsize
) && (noise_counter
< (COTAG_T1
<<1)) ) {
349 if (AT91C_BASE_SSC
->SSC_SR
& AT91C_SSC_TXRDY
) {
350 AT91C_BASE_SSC
->SSC_THR
= 0x43;
354 if (AT91C_BASE_SSC
->SSC_SR
& AT91C_SSC_RXRDY
) {
355 sample
= (uint8_t)AT91C_BASE_SSC
->SSC_RHR
;
360 if (sample
< COTAG_ONE_THRESHOLD
) {
369 if (sample
> COTAG_ZERO_THRESHOLD
) {
377 // set sample 255, 0, or previous
378 if ( sample
> COTAG_ONE_THRESHOLD
){
382 else if ( sample
< COTAG_ZERO_THRESHOLD
) {
396 dest
[sample_counter
] = curr
;
401 return sample_counter
;