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1 | //----------------------------------------------------------------------------- | |
2 | // Copyright (C) 2014 | |
3 | // | |
4 | // This code is licensed to you under the terms of the GNU GPL, version 2 or, | |
5 | // at your option, any later version. See the LICENSE.txt file for the text of | |
6 | // the license. | |
7 | //----------------------------------------------------------------------------- | |
8 | // Low frequency demod/decode commands | |
9 | //----------------------------------------------------------------------------- | |
10 | ||
11 | #include <stdlib.h> | |
12 | #include <string.h> | |
13 | #include "lfdemod.h" | |
14 | ||
15 | ||
16 | uint8_t justNoise(uint8_t *BitStream, size_t size) | |
17 | { | |
18 | static const uint8_t THRESHOLD = 123; | |
19 | //test samples are not just noise | |
20 | uint8_t justNoise1 = 1; | |
21 | for(size_t idx=0; idx < size && justNoise1 ;idx++){ | |
22 | justNoise1 = BitStream[idx] < THRESHOLD; | |
23 | } | |
24 | return justNoise1; | |
25 | } | |
26 | ||
27 | //by marshmellow | |
28 | //get high and low values of a wave with passed in fuzz factor. also return noise test = 1 for passed or 0 for only noise | |
29 | int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi, uint8_t fuzzLo) | |
30 | { | |
31 | *high=0; | |
32 | *low=255; | |
33 | // get high and low thresholds | |
34 | for (int i=0; i < size; i++){ | |
35 | if (BitStream[i] > *high) *high = BitStream[i]; | |
36 | if (BitStream[i] < *low) *low = BitStream[i]; | |
37 | } | |
38 | if (*high < 123) return -1; // just noise | |
39 | *high = (int)(((*high-128)*(((float)fuzzHi)/100))+128); | |
40 | *low = (int)(((*low-128)*(((float)fuzzLo)/100))+128); | |
41 | return 1; | |
42 | } | |
43 | ||
44 | // by marshmellow | |
45 | // pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType | |
46 | // returns 1 if passed | |
47 | uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType) | |
48 | { | |
49 | uint8_t ans = 0; | |
50 | for (uint8_t i = 0; i < bitLen; i++){ | |
51 | ans ^= ((bits >> i) & 1); | |
52 | } | |
53 | //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType); | |
54 | return (ans == pType); | |
55 | } | |
56 | ||
57 | //by marshmellow | |
58 | //search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length | |
59 | uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx) | |
60 | { | |
61 | uint8_t foundCnt=0; | |
62 | for (int idx=0; idx < *size - pLen; idx++){ | |
63 | if (memcmp(BitStream+idx, preamble, pLen) == 0){ | |
64 | //first index found | |
65 | foundCnt++; | |
66 | if (foundCnt == 1){ | |
67 | *startIdx = idx; | |
68 | } | |
69 | if (foundCnt == 2){ | |
70 | *size = idx - *startIdx; | |
71 | return 1; | |
72 | } | |
73 | } | |
74 | } | |
75 | return 0; | |
76 | } | |
77 | ||
78 | //by marshmellow | |
79 | //takes 1s and 0s and searches for EM410x format - output EM ID | |
80 | uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo) | |
81 | { | |
82 | //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future | |
83 | // otherwise could be a void with no arguments | |
84 | //set defaults | |
85 | uint32_t i = 0; | |
86 | if (BitStream[1]>1){ //allow only 1s and 0s | |
87 | // PrintAndLog("no data found"); | |
88 | return 0; | |
89 | } | |
90 | // 111111111 bit pattern represent start of frame | |
91 | uint8_t preamble[] = {1,1,1,1,1,1,1,1,1}; | |
92 | uint32_t idx = 0; | |
93 | uint32_t parityBits = 0; | |
94 | uint8_t errChk = 0; | |
95 | uint8_t FmtLen = 10; | |
96 | *startIdx = 0; | |
97 | for (uint8_t extraBitChk=0; extraBitChk<5; extraBitChk++){ | |
98 | errChk = preambleSearch(BitStream+extraBitChk+*startIdx, preamble, sizeof(preamble), size, startIdx); | |
99 | if (errChk == 0) return 0; | |
100 | if (*size>64) FmtLen = 22; | |
101 | if (*size<64) return 0; | |
102 | idx = *startIdx + 9; | |
103 | for (i=0; i<FmtLen; i++){ //loop through 10 or 22 sets of 5 bits (50-10p = 40 bits or 88 bits) | |
104 | parityBits = bytebits_to_byte(BitStream+(i*5)+idx,5); | |
105 | //check even parity | |
106 | if (parityTest(parityBits, 5, 0) == 0){ | |
107 | //parity failed try next bit (in the case of 1111111111) but last 9 = preamble | |
108 | startIdx++; | |
109 | errChk = 0; | |
110 | break; | |
111 | } | |
112 | //set uint64 with ID from BitStream | |
113 | for (uint8_t ii=0; ii<4; ii++){ | |
114 | *hi = (*hi << 1) | (*lo >> 63); | |
115 | *lo = (*lo << 1) | (BitStream[(i*5)+ii+idx]); | |
116 | } | |
117 | } | |
118 | if (errChk != 0) return 1; | |
119 | //skip last 5 bit parity test for simplicity. | |
120 | // *size = 64 | 128; | |
121 | } | |
122 | return 0; | |
123 | } | |
124 | ||
125 | //by marshmellow | |
126 | //takes 3 arguments - clock, invert, maxErr as integers | |
127 | //attempts to demodulate ask while decoding manchester | |
128 | //prints binary found and saves in graphbuffer for further commands | |
129 | int askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr) | |
130 | { | |
131 | int i; | |
132 | //int clk2=*clk; | |
133 | int start = DetectASKClock(BinStream, *size, clk, 20); //clock default | |
134 | if (*clk==0) return -3; | |
135 | if (start < 0) return -3; | |
136 | // if autodetected too low then adjust //MAY NEED ADJUSTMENT | |
137 | //if (clk2==0 && *clk<8) *clk =64; | |
138 | //if (clk2==0 && *clk<32) *clk=32; | |
139 | if (*invert != 0 && *invert != 1) *invert=0; | |
140 | uint32_t initLoopMax = 200; | |
141 | if (initLoopMax > *size) initLoopMax=*size; | |
142 | // Detect high and lows | |
143 | // 25% fuzz in case highs and lows aren't clipped [marshmellow] | |
144 | int high, low, ans; | |
145 | ans = getHiLo(BinStream, initLoopMax, &high, &low, 75, 75); | |
146 | if (ans<1) return -2; //just noise | |
147 | ||
148 | // PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low); | |
149 | int lastBit = 0; //set first clock check | |
150 | uint32_t bitnum = 0; //output counter | |
151 | int tol = 0; //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave | |
152 | if (*clk<=32) tol=1; //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely | |
153 | int iii = 0; | |
154 | uint32_t gLen = *size; | |
155 | if (gLen > 3000) gLen=3000; | |
156 | //if 0 errors allowed then only try first 2 clock cycles as we want a low tolerance | |
157 | if (!maxErr) gLen=*clk*2; | |
158 | uint8_t errCnt =0; | |
159 | uint16_t MaxBits = 500; | |
160 | uint32_t bestStart = *size; | |
161 | int bestErrCnt = maxErr+1; | |
162 | // PrintAndLog("DEBUG - lastbit - %d",lastBit); | |
163 | // loop to find first wave that works | |
164 | for (iii=0; iii < gLen; ++iii){ | |
165 | if ((BinStream[iii] >= high) || (BinStream[iii] <= low)){ | |
166 | lastBit=iii-*clk; | |
167 | errCnt=0; | |
168 | // loop through to see if this start location works | |
169 | for (i = iii; i < *size; ++i) { | |
170 | if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){ | |
171 | lastBit+=*clk; | |
172 | } else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){ | |
173 | //low found and we are expecting a bar | |
174 | lastBit+=*clk; | |
175 | } else { | |
176 | //mid value found or no bar supposed to be here | |
177 | if ((i-lastBit)>(*clk+tol)){ | |
178 | //should have hit a high or low based on clock!! | |
179 | ||
180 | //debug | |
181 | //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit); | |
182 | ||
183 | errCnt++; | |
184 | lastBit+=*clk;//skip over until hit too many errors | |
185 | if (errCnt>(maxErr)) break; //allow 1 error for every 1000 samples else start over | |
186 | } | |
187 | } | |
188 | if ((i-iii) >(MaxBits * *clk)) break; //got plenty of bits | |
189 | } | |
190 | //we got more than 64 good bits and not all errors | |
191 | if ((((i-iii)/ *clk) > (64)) && (errCnt<=maxErr)) { | |
192 | //possible good read | |
193 | if (errCnt==0){ | |
194 | bestStart=iii; | |
195 | bestErrCnt=errCnt; | |
196 | break; //great read - finish | |
197 | } | |
198 | if (errCnt<bestErrCnt){ //set this as new best run | |
199 | bestErrCnt=errCnt; | |
200 | bestStart = iii; | |
201 | } | |
202 | } | |
203 | } | |
204 | } | |
205 | if (bestErrCnt<=maxErr){ | |
206 | //best run is good enough set to best run and set overwrite BinStream | |
207 | iii=bestStart; | |
208 | lastBit = bestStart - *clk; | |
209 | bitnum=0; | |
210 | for (i = iii; i < *size; ++i) { | |
211 | if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){ | |
212 | lastBit += *clk; | |
213 | BinStream[bitnum] = *invert; | |
214 | bitnum++; | |
215 | } else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){ | |
216 | //low found and we are expecting a bar | |
217 | lastBit+=*clk; | |
218 | BinStream[bitnum] = 1-*invert; | |
219 | bitnum++; | |
220 | } else { | |
221 | //mid value found or no bar supposed to be here | |
222 | if ((i-lastBit)>(*clk+tol)){ | |
223 | //should have hit a high or low based on clock!! | |
224 | ||
225 | //debug | |
226 | //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit); | |
227 | if (bitnum > 0){ | |
228 | BinStream[bitnum]=77; | |
229 | bitnum++; | |
230 | } | |
231 | ||
232 | lastBit+=*clk;//skip over error | |
233 | } | |
234 | } | |
235 | if (bitnum >=MaxBits) break; | |
236 | } | |
237 | *size=bitnum; | |
238 | } else{ | |
239 | *invert=bestStart; | |
240 | *clk=iii; | |
241 | return -1; | |
242 | } | |
243 | return bestErrCnt; | |
244 | } | |
245 | ||
246 | //by marshmellow | |
247 | //encode binary data into binary manchester | |
248 | int ManchesterEncode(uint8_t *BitStream, size_t size) | |
249 | { | |
250 | size_t modIdx=20000, i=0; | |
251 | if (size>modIdx) return -1; | |
252 | for (size_t idx=0; idx < size; idx++){ | |
253 | BitStream[idx+modIdx++] = BitStream[idx]; | |
254 | BitStream[idx+modIdx++] = BitStream[idx]^1; | |
255 | } | |
256 | for (; i<(size*2); i++){ | |
257 | BitStream[i] = BitStream[i+20000]; | |
258 | } | |
259 | return i; | |
260 | } | |
261 | ||
262 | //by marshmellow | |
263 | //take 10 and 01 and manchester decode | |
264 | //run through 2 times and take least errCnt | |
265 | int manrawdecode(uint8_t * BitStream, size_t *size) | |
266 | { | |
267 | uint16_t bitnum=0, MaxBits = 512, errCnt = 0; | |
268 | size_t i, ii; | |
269 | uint16_t bestErr = 1000, bestRun = 0; | |
270 | if (size == 0) return -1; | |
271 | for (ii=0;ii<2;++ii){ | |
272 | i=0; | |
273 | for (i=i+ii;i<*size-2;i+=2){ | |
274 | if(BitStream[i]==1 && (BitStream[i+1]==0)){ | |
275 | } else if((BitStream[i]==0)&& BitStream[i+1]==1){ | |
276 | } else { | |
277 | errCnt++; | |
278 | } | |
279 | if(bitnum>MaxBits) break; | |
280 | } | |
281 | if (bestErr>errCnt){ | |
282 | bestErr=errCnt; | |
283 | bestRun=ii; | |
284 | } | |
285 | errCnt=0; | |
286 | } | |
287 | errCnt=bestErr; | |
288 | if (errCnt<20){ | |
289 | ii=bestRun; | |
290 | i=0; | |
291 | for (i=i+ii; i < *size-2; i+=2){ | |
292 | if(BitStream[i] == 1 && (BitStream[i+1] == 0)){ | |
293 | BitStream[bitnum++]=0; | |
294 | } else if((BitStream[i] == 0) && BitStream[i+1] == 1){ | |
295 | BitStream[bitnum++]=1; | |
296 | } else { | |
297 | BitStream[bitnum++]=77; | |
298 | //errCnt++; | |
299 | } | |
300 | if(bitnum>MaxBits) break; | |
301 | } | |
302 | *size=bitnum; | |
303 | } | |
304 | return errCnt; | |
305 | } | |
306 | ||
307 | //by marshmellow | |
308 | //take 01 or 10 = 1 and 11 or 00 = 0 | |
309 | //check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010 | |
310 | //decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding | |
311 | int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert) | |
312 | { | |
313 | uint16_t bitnum=0; | |
314 | uint32_t errCnt =0; | |
315 | size_t i=offset; | |
316 | uint16_t MaxBits=512; | |
317 | //if not enough samples - error | |
318 | if (*size < 51) return -1; | |
319 | //check for phase change faults - skip one sample if faulty | |
320 | uint8_t offsetA = 1, offsetB = 1; | |
321 | for (; i<48; i+=2){ | |
322 | if (BitStream[i+1]==BitStream[i+2]) offsetA=0; | |
323 | if (BitStream[i+2]==BitStream[i+3]) offsetB=0; | |
324 | } | |
325 | if (!offsetA && offsetB) offset++; | |
326 | for (i=offset; i<*size-3; i+=2){ | |
327 | //check for phase error | |
328 | if (BitStream[i+1]==BitStream[i+2]) { | |
329 | BitStream[bitnum++]=77; | |
330 | errCnt++; | |
331 | } | |
332 | if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){ | |
333 | BitStream[bitnum++]=1^invert; | |
334 | } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){ | |
335 | BitStream[bitnum++]=invert; | |
336 | } else { | |
337 | BitStream[bitnum++]=77; | |
338 | errCnt++; | |
339 | } | |
340 | if(bitnum>MaxBits) break; | |
341 | } | |
342 | *size=bitnum; | |
343 | return errCnt; | |
344 | } | |
345 | ||
346 | //by marshmellow | |
347 | void askAmp(uint8_t *BitStream, size_t size) | |
348 | { | |
349 | int shift = 127; | |
350 | int shiftedVal=0; | |
351 | for(int i = 1; i<size; i++){ | |
352 | if (BitStream[i]-BitStream[i-1]>=30) //large jump up | |
353 | shift=127; | |
354 | else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down | |
355 | shift=-127; | |
356 | ||
357 | shiftedVal=BitStream[i]+shift; | |
358 | ||
359 | if (shiftedVal>255) | |
360 | shiftedVal=255; | |
361 | else if (shiftedVal<0) | |
362 | shiftedVal=0; | |
363 | BitStream[i-1] = shiftedVal; | |
364 | } | |
365 | return; | |
366 | } | |
367 | ||
368 | int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low) | |
369 | { | |
370 | size_t bitCnt=0, smplCnt=0, errCnt=0; | |
371 | uint8_t waveHigh = 0; | |
372 | //PrintAndLog("clk: %d", clk); | |
373 | for (size_t i=0; i < *size; i++){ | |
374 | if (BinStream[i] >= high && waveHigh){ | |
375 | smplCnt++; | |
376 | } else if (BinStream[i] <= low && !waveHigh){ | |
377 | smplCnt++; | |
378 | } else { //transition | |
379 | if ((BinStream[i] >= high && !waveHigh) || (BinStream[i] <= low && waveHigh)){ | |
380 | if (smplCnt > clk-(clk/4)-1) { //full clock | |
381 | if (smplCnt > clk + (clk/4)+1) { //too many samples | |
382 | errCnt++; | |
383 | BinStream[bitCnt++]=77; | |
384 | } else if (waveHigh) { | |
385 | BinStream[bitCnt++] = invert; | |
386 | BinStream[bitCnt++] = invert; | |
387 | } else if (!waveHigh) { | |
388 | BinStream[bitCnt++] = invert ^ 1; | |
389 | BinStream[bitCnt++] = invert ^ 1; | |
390 | } | |
391 | waveHigh ^= 1; | |
392 | smplCnt = 0; | |
393 | } else if (smplCnt > (clk/2) - (clk/4)-1) { | |
394 | if (waveHigh) { | |
395 | BinStream[bitCnt++] = invert; | |
396 | } else if (!waveHigh) { | |
397 | BinStream[bitCnt++] = invert ^ 1; | |
398 | } | |
399 | waveHigh ^= 1; | |
400 | smplCnt = 0; | |
401 | } else if (!bitCnt) { | |
402 | //first bit | |
403 | waveHigh = (BinStream[i] >= high); | |
404 | smplCnt = 1; | |
405 | } else { | |
406 | smplCnt++; | |
407 | //transition bit oops | |
408 | } | |
409 | } else { //haven't hit new high or new low yet | |
410 | smplCnt++; | |
411 | } | |
412 | } | |
413 | } | |
414 | *size = bitCnt; | |
415 | return errCnt; | |
416 | } | |
417 | ||
418 | //by marshmellow | |
419 | //takes 3 arguments - clock, invert and maxErr as integers | |
420 | //attempts to demodulate ask only | |
421 | int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp) | |
422 | { | |
423 | uint32_t i; | |
424 | if (*size==0) return -1; | |
425 | int start = DetectASKClock(BinStream, *size, clk, 20); //clock default | |
426 | if (*clk==0) return -1; | |
427 | if (start<0) return -1; | |
428 | if (*invert != 0 && *invert != 1) *invert =0; | |
429 | if (amp==1) askAmp(BinStream, *size); | |
430 | ||
431 | uint32_t initLoopMax = 200; | |
432 | if (initLoopMax > *size) initLoopMax=*size; | |
433 | // Detect high and lows | |
434 | //25% clip in case highs and lows aren't clipped [marshmellow] | |
435 | uint8_t clip = 75; | |
436 | int high, low, ans; | |
437 | ans = getHiLo(BinStream, initLoopMax, &high, &low, clip, clip); | |
438 | if (ans<1) return -1; //just noise | |
439 | ||
440 | if (DetectCleanAskWave(BinStream, *size, high, low)) { | |
441 | //PrintAndLog("Clean"); | |
442 | return cleanAskRawDemod(BinStream, size, *clk, *invert, high, low); | |
443 | } | |
444 | ||
445 | //PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low); | |
446 | int lastBit = 0; //set first clock check | |
447 | uint32_t bitnum = 0; //output counter | |
448 | uint8_t tol = 0; //clock tolerance adjust - waves will be accepted as within the clock | |
449 | // if they fall + or - this value + clock from last valid wave | |
450 | if (*clk == 32) tol=0; //clock tolerance may not be needed anymore currently set to | |
451 | // + or - 1 but could be increased for poor waves or removed entirely | |
452 | uint32_t iii = 0; | |
453 | uint32_t gLen = *size; | |
454 | if (gLen > 500) gLen=500; | |
455 | //if 0 errors allowed then only try first 2 clock cycles as we want a low tolerance | |
456 | if (!maxErr) gLen = *clk * 2; | |
457 | uint8_t errCnt =0; | |
458 | uint32_t bestStart = *size; | |
459 | uint32_t bestErrCnt = maxErr; //(*size/1000); | |
460 | uint8_t midBit=0; | |
461 | uint16_t MaxBits=1000; | |
462 | ||
463 | //PrintAndLog("DEBUG - lastbit - %d",lastBit); | |
464 | //loop to find first wave that works | |
465 | for (iii=start; iii < gLen; ++iii){ | |
466 | if ((BinStream[iii]>=high) || (BinStream[iii]<=low)){ | |
467 | lastBit=iii-*clk; | |
468 | errCnt=0; | |
469 | //loop through to see if this start location works | |
470 | for (i = iii; i < *size; ++i) { | |
471 | if ((BinStream[i] >= high) && ((i-lastBit)>(*clk-tol))){ | |
472 | lastBit+=*clk; | |
473 | midBit=0; | |
474 | } else if ((BinStream[i] <= low) && ((i-lastBit)>(*clk-tol))){ | |
475 | //low found and we are expecting a bar | |
476 | lastBit+=*clk; | |
477 | midBit=0; | |
478 | } else if ((BinStream[i]<=low) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){ | |
479 | //mid bar? | |
480 | midBit=1; | |
481 | } else if ((BinStream[i]>=high) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){ | |
482 | //mid bar? | |
483 | midBit=1; | |
484 | } else if ((i-lastBit)>((*clk/2)+tol) && (midBit==0)){ | |
485 | //no mid bar found | |
486 | midBit=1; | |
487 | } else { | |
488 | //mid value found or no bar supposed to be here | |
489 | ||
490 | if ((i-lastBit)>(*clk+tol)){ | |
491 | //should have hit a high or low based on clock!! | |
492 | //debug | |
493 | //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit); | |
494 | ||
495 | errCnt++; | |
496 | lastBit+=*clk;//skip over until hit too many errors | |
497 | if (errCnt > maxErr){ | |
498 | //errCnt=0; | |
499 | break; | |
500 | } | |
501 | } | |
502 | } | |
503 | if ((i-iii)>(MaxBits * *clk)) break; //got enough bits | |
504 | } | |
505 | //we got more than 64 good bits and not all errors | |
506 | if ((((i-iii)/ *clk) > (64)) && (errCnt<=maxErr)) { | |
507 | //possible good read | |
508 | if (errCnt==0){ | |
509 | bestStart=iii; | |
510 | bestErrCnt=errCnt; | |
511 | break; //great read - finish | |
512 | } | |
513 | if (errCnt<bestErrCnt){ //set this as new best run | |
514 | bestErrCnt=errCnt; | |
515 | bestStart = iii; | |
516 | } | |
517 | } | |
518 | } | |
519 | } | |
520 | if (bestErrCnt<=maxErr){ | |
521 | //best run is good enough - set to best run and overwrite BinStream | |
522 | iii = bestStart; | |
523 | lastBit = bestStart - *clk; | |
524 | bitnum=0; | |
525 | for (i = iii; i < *size; ++i) { | |
526 | if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){ | |
527 | lastBit += *clk; | |
528 | BinStream[bitnum] = *invert; | |
529 | bitnum++; | |
530 | midBit=0; | |
531 | } else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){ | |
532 | //low found and we are expecting a bar | |
533 | lastBit+=*clk; | |
534 | BinStream[bitnum] = 1 - *invert; | |
535 | bitnum++; | |
536 | midBit=0; | |
537 | } else if ((BinStream[i]<=low) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){ | |
538 | //mid bar? | |
539 | midBit=1; | |
540 | BinStream[bitnum] = 1 - *invert; | |
541 | bitnum++; | |
542 | } else if ((BinStream[i]>=high) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){ | |
543 | //mid bar? | |
544 | midBit=1; | |
545 | BinStream[bitnum] = *invert; | |
546 | bitnum++; | |
547 | } else if ((i-lastBit)>((*clk/2)+tol) && (midBit==0)){ | |
548 | //no mid bar found | |
549 | midBit=1; | |
550 | if (bitnum!=0) BinStream[bitnum] = BinStream[bitnum-1]; | |
551 | bitnum++; | |
552 | ||
553 | } else { | |
554 | //mid value found or no bar supposed to be here | |
555 | if ((i-lastBit)>(*clk+tol)){ | |
556 | //should have hit a high or low based on clock!! | |
557 | ||
558 | //debug | |
559 | //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit); | |
560 | if (bitnum > 0){ | |
561 | BinStream[bitnum]=77; | |
562 | bitnum++; | |
563 | } | |
564 | lastBit+=*clk;//skip over error | |
565 | } | |
566 | } | |
567 | if (bitnum >= MaxBits) break; | |
568 | } | |
569 | *size=bitnum; | |
570 | } else{ | |
571 | *invert=bestStart; | |
572 | *clk=iii; | |
573 | return -1; | |
574 | } | |
575 | return bestErrCnt; | |
576 | } | |
577 | ||
578 | // demod gProxIIDemod | |
579 | // error returns as -x | |
580 | // success returns start position in BitStream | |
581 | // BitStream must contain previously askrawdemod and biphasedemoded data | |
582 | int gProxII_Demod(uint8_t BitStream[], size_t *size) | |
583 | { | |
584 | size_t startIdx=0; | |
585 | uint8_t preamble[] = {1,1,1,1,1,0}; | |
586 | ||
587 | uint8_t errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, &startIdx); | |
588 | if (errChk == 0) return -3; //preamble not found | |
589 | if (*size != 96) return -2; //should have found 96 bits | |
590 | //check first 6 spacer bits to verify format | |
591 | if (!BitStream[startIdx+5] && !BitStream[startIdx+10] && !BitStream[startIdx+15] && !BitStream[startIdx+20] && !BitStream[startIdx+25] && !BitStream[startIdx+30]){ | |
592 | //confirmed proper separator bits found | |
593 | //return start position | |
594 | return (int) startIdx; | |
595 | } | |
596 | return -5; | |
597 | } | |
598 | ||
599 | //translate wave to 11111100000 (1 for each short wave 0 for each long wave) | |
600 | size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow) | |
601 | { | |
602 | uint32_t last_transition = 0; | |
603 | uint32_t idx = 1; | |
604 | //uint32_t maxVal=0; | |
605 | if (fchigh==0) fchigh=10; | |
606 | if (fclow==0) fclow=8; | |
607 | //set the threshold close to 0 (graph) or 128 std to avoid static | |
608 | uint8_t threshold_value = 123; | |
609 | ||
610 | // sync to first lo-hi transition, and threshold | |
611 | ||
612 | // Need to threshold first sample | |
613 | ||
614 | if(dest[0] < threshold_value) dest[0] = 0; | |
615 | else dest[0] = 1; | |
616 | ||
617 | size_t numBits = 0; | |
618 | // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8) | |
619 | // or 10 (fc/10) cycles but in practice due to noise etc we may end up with with anywhere | |
620 | // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10 | |
621 | for(idx = 1; idx < size; idx++) { | |
622 | // threshold current value | |
623 | ||
624 | if (dest[idx] < threshold_value) dest[idx] = 0; | |
625 | else dest[idx] = 1; | |
626 | ||
627 | // Check for 0->1 transition | |
628 | if (dest[idx-1] < dest[idx]) { // 0 -> 1 transition | |
629 | if ((idx-last_transition)<(fclow-2)){ //0-5 = garbage noise | |
630 | //do nothing with extra garbage | |
631 | } else if ((idx-last_transition) < (fchigh-1)) { //6-8 = 8 waves | |
632 | dest[numBits]=1; | |
633 | } else if ((idx-last_transition) > (fchigh+1) && !numBits) { //12 + and first bit = garbage | |
634 | //do nothing with beginning garbage | |
635 | } else { //9+ = 10 waves | |
636 | dest[numBits]=0; | |
637 | } | |
638 | last_transition = idx; | |
639 | numBits++; | |
640 | } | |
641 | } | |
642 | return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0 | |
643 | } | |
644 | ||
645 | uint32_t myround2(float f) | |
646 | { | |
647 | if (f >= 2000) return 2000;//something bad happened | |
648 | return (uint32_t) (f + (float)0.5); | |
649 | } | |
650 | ||
651 | //translate 11111100000 to 10 | |
652 | size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t maxConsequtiveBits, | |
653 | uint8_t invert, uint8_t fchigh, uint8_t fclow) | |
654 | { | |
655 | uint8_t lastval=dest[0]; | |
656 | uint32_t idx=0; | |
657 | size_t numBits=0; | |
658 | uint32_t n=1; | |
659 | float lowWaves = (((float)(rfLen))/((float)fclow)); | |
660 | float highWaves = (((float)(rfLen))/((float)fchigh)); | |
661 | for( idx=1; idx < size; idx++) { | |
662 | ||
663 | if (dest[idx]==lastval) { | |
664 | n++; | |
665 | continue; | |
666 | } | |
667 | n++; | |
668 | //if lastval was 1, we have a 1->0 crossing | |
669 | if (dest[idx-1]==1) { | |
670 | if (!numBits && n < (uint8_t)lowWaves) { | |
671 | n=0; | |
672 | lastval = dest[idx]; | |
673 | continue; | |
674 | } | |
675 | n=myround2(((float)n)/lowWaves); | |
676 | } else {// 0->1 crossing | |
677 | //test first bitsample too small | |
678 | if (!numBits && n < (uint8_t)highWaves) { | |
679 | n=0; | |
680 | lastval = dest[idx]; | |
681 | continue; | |
682 | } | |
683 | n = myround2(((float)n)/highWaves); //-1 for fudge factor | |
684 | } | |
685 | if (n == 0) n = 1; | |
686 | ||
687 | if(n < maxConsequtiveBits) //Consecutive | |
688 | { | |
689 | if(invert==0){ //invert bits | |
690 | memset(dest+numBits, dest[idx-1] , n); | |
691 | }else{ | |
692 | memset(dest+numBits, dest[idx-1]^1 , n); | |
693 | } | |
694 | numBits += n; | |
695 | } | |
696 | n=0; | |
697 | lastval=dest[idx]; | |
698 | }//end for | |
699 | ||
700 | // if valid extra bits at the end were all the same frequency - add them in | |
701 | if (n > lowWaves && n > highWaves) { | |
702 | if (dest[idx-2]==1) { | |
703 | n=myround2((float)(n+1)/((float)(rfLen)/(float)fclow)); | |
704 | } else { | |
705 | n=myround2((float)(n+1)/((float)(rfLen-1)/(float)fchigh)); //-1 for fudge factor | |
706 | } | |
707 | memset(dest, dest[idx-1]^invert , n); | |
708 | numBits += n; | |
709 | } | |
710 | return numBits; | |
711 | } | |
712 | //by marshmellow (from holiman's base) | |
713 | // full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod) | |
714 | int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow) | |
715 | { | |
716 | // FSK demodulator | |
717 | size = fsk_wave_demod(dest, size, fchigh, fclow); | |
718 | size = aggregate_bits(dest, size, rfLen, 192, invert, fchigh, fclow); | |
719 | return size; | |
720 | } | |
721 | ||
722 | // loop to get raw HID waveform then FSK demodulate the TAG ID from it | |
723 | int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo) | |
724 | { | |
725 | if (justNoise(dest, *size)) return -1; | |
726 | ||
727 | size_t numStart=0, size2=*size, startIdx=0; | |
728 | // FSK demodulator | |
729 | *size = fskdemod(dest, size2,50,1,10,8); //fsk2a | |
730 | if (*size < 96) return -2; | |
731 | // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1 | |
732 | uint8_t preamble[] = {0,0,0,1,1,1,0,1}; | |
733 | // find bitstring in array | |
734 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); | |
735 | if (errChk == 0) return -3; //preamble not found | |
736 | ||
737 | numStart = startIdx + sizeof(preamble); | |
738 | // final loop, go over previously decoded FSK data and manchester decode into usable tag ID | |
739 | for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){ | |
740 | if (dest[idx] == dest[idx+1]){ | |
741 | return -4; //not manchester data | |
742 | } | |
743 | *hi2 = (*hi2<<1)|(*hi>>31); | |
744 | *hi = (*hi<<1)|(*lo>>31); | |
745 | //Then, shift in a 0 or one into low | |
746 | if (dest[idx] && !dest[idx+1]) // 1 0 | |
747 | *lo=(*lo<<1)|1; | |
748 | else // 0 1 | |
749 | *lo=(*lo<<1)|0; | |
750 | } | |
751 | return (int)startIdx; | |
752 | } | |
753 | ||
754 | // loop to get raw paradox waveform then FSK demodulate the TAG ID from it | |
755 | int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo) | |
756 | { | |
757 | if (justNoise(dest, *size)) return -1; | |
758 | ||
759 | size_t numStart=0, size2=*size, startIdx=0; | |
760 | // FSK demodulator | |
761 | *size = fskdemod(dest, size2,50,1,10,8); //fsk2a | |
762 | if (*size < 96) return -2; | |
763 | ||
764 | // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1 | |
765 | uint8_t preamble[] = {0,0,0,0,1,1,1,1}; | |
766 | ||
767 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); | |
768 | if (errChk == 0) return -3; //preamble not found | |
769 | ||
770 | numStart = startIdx + sizeof(preamble); | |
771 | // final loop, go over previously decoded FSK data and manchester decode into usable tag ID | |
772 | for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){ | |
773 | if (dest[idx] == dest[idx+1]) | |
774 | return -4; //not manchester data | |
775 | *hi2 = (*hi2<<1)|(*hi>>31); | |
776 | *hi = (*hi<<1)|(*lo>>31); | |
777 | //Then, shift in a 0 or one into low | |
778 | if (dest[idx] && !dest[idx+1]) // 1 0 | |
779 | *lo=(*lo<<1)|1; | |
780 | else // 0 1 | |
781 | *lo=(*lo<<1)|0; | |
782 | } | |
783 | return (int)startIdx; | |
784 | } | |
785 | ||
786 | uint32_t bytebits_to_byte(uint8_t* src, size_t numbits) | |
787 | { | |
788 | uint32_t num = 0; | |
789 | for(int i = 0 ; i < numbits ; i++) | |
790 | { | |
791 | num = (num << 1) | (*src); | |
792 | src++; | |
793 | } | |
794 | return num; | |
795 | } | |
796 | ||
797 | int IOdemodFSK(uint8_t *dest, size_t size) | |
798 | { | |
799 | if (justNoise(dest, size)) return -1; | |
800 | //make sure buffer has data | |
801 | if (size < 66*64) return -2; | |
802 | // FSK demodulator | |
803 | size = fskdemod(dest, size, 64, 1, 10, 8); // FSK2a RF/64 | |
804 | if (size < 65) return -3; //did we get a good demod? | |
805 | //Index map | |
806 | //0 10 20 30 40 50 60 | |
807 | //| | | | | | | | |
808 | //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23 | |
809 | //----------------------------------------------------------------------------- | |
810 | //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11 | |
811 | // | |
812 | //XSF(version)facility:codeone+codetwo | |
813 | //Handle the data | |
814 | size_t startIdx = 0; | |
815 | uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,1}; | |
816 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), &size, &startIdx); | |
817 | if (errChk == 0) return -4; //preamble not found | |
818 | ||
819 | if (!dest[startIdx+8] && dest[startIdx+17]==1 && dest[startIdx+26]==1 && dest[startIdx+35]==1 && dest[startIdx+44]==1 && dest[startIdx+53]==1){ | |
820 | //confirmed proper separator bits found | |
821 | //return start position | |
822 | return (int) startIdx; | |
823 | } | |
824 | return -5; | |
825 | } | |
826 | ||
827 | // by marshmellow | |
828 | // takes a array of binary values, start position, length of bits per parity (includes parity bit), | |
829 | // Parity Type (1 for odd 0 for even), and binary Length (length to run) | |
830 | size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen) | |
831 | { | |
832 | uint32_t parityWd = 0; | |
833 | size_t j = 0, bitCnt = 0; | |
834 | for (int word = 0; word < (bLen); word+=pLen){ | |
835 | for (int bit=0; bit < pLen; bit++){ | |
836 | parityWd = (parityWd << 1) | BitStream[startIdx+word+bit]; | |
837 | BitStream[j++] = (BitStream[startIdx+word+bit]); | |
838 | } | |
839 | j--; | |
840 | // if parity fails then return 0 | |
841 | if (parityTest(parityWd, pLen, pType) == 0) return -1; | |
842 | bitCnt+=(pLen-1); | |
843 | parityWd = 0; | |
844 | } | |
845 | // if we got here then all the parities passed | |
846 | //return ID start index and size | |
847 | return bitCnt; | |
848 | } | |
849 | ||
850 | // by marshmellow | |
851 | // FSK Demod then try to locate an AWID ID | |
852 | int AWIDdemodFSK(uint8_t *dest, size_t *size) | |
853 | { | |
854 | //make sure buffer has enough data | |
855 | if (*size < 96*50) return -1; | |
856 | ||
857 | if (justNoise(dest, *size)) return -2; | |
858 | ||
859 | // FSK demodulator | |
860 | *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50 | |
861 | if (*size < 96) return -3; //did we get a good demod? | |
862 | ||
863 | uint8_t preamble[] = {0,0,0,0,0,0,0,1}; | |
864 | size_t startIdx = 0; | |
865 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); | |
866 | if (errChk == 0) return -4; //preamble not found | |
867 | if (*size != 96) return -5; | |
868 | return (int)startIdx; | |
869 | } | |
870 | ||
871 | // by marshmellow | |
872 | // FSK Demod then try to locate an Farpointe Data (pyramid) ID | |
873 | int PyramiddemodFSK(uint8_t *dest, size_t *size) | |
874 | { | |
875 | //make sure buffer has data | |
876 | if (*size < 128*50) return -5; | |
877 | ||
878 | //test samples are not just noise | |
879 | if (justNoise(dest, *size)) return -1; | |
880 | ||
881 | // FSK demodulator | |
882 | *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50 | |
883 | if (*size < 128) return -2; //did we get a good demod? | |
884 | ||
885 | uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1}; | |
886 | size_t startIdx = 0; | |
887 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); | |
888 | if (errChk == 0) return -4; //preamble not found | |
889 | if (*size != 128) return -3; | |
890 | return (int)startIdx; | |
891 | } | |
892 | ||
893 | ||
894 | uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, int high, int low) | |
895 | { | |
896 | uint16_t allPeaks=1; | |
897 | uint16_t cntPeaks=0; | |
898 | size_t loopEnd = 572; | |
899 | if (loopEnd > size) loopEnd = size; | |
900 | for (size_t i=60; i<loopEnd; i++){ | |
901 | if (dest[i]>low && dest[i]<high) | |
902 | allPeaks=0; | |
903 | else | |
904 | cntPeaks++; | |
905 | } | |
906 | if (allPeaks == 0){ | |
907 | if (cntPeaks > 300) return 1; | |
908 | } | |
909 | return allPeaks; | |
910 | } | |
911 | ||
912 | int DetectStrongAskClock(uint8_t dest[], size_t size) | |
913 | { | |
914 | int clk[]={0,8,16,32,40,50,64,100,128,256}; | |
915 | size_t idx = 40; | |
916 | uint8_t high=0; | |
917 | size_t cnt = 0; | |
918 | size_t highCnt = 0; | |
919 | size_t highCnt2 = 0; | |
920 | for (;idx < size; idx++){ | |
921 | if (dest[idx]>128) { | |
922 | if (!high){ | |
923 | high=1; | |
924 | if (cnt > highCnt){ | |
925 | if (highCnt != 0) highCnt2 = highCnt; | |
926 | highCnt = cnt; | |
927 | } else if (cnt > highCnt2) { | |
928 | highCnt2 = cnt; | |
929 | } | |
930 | cnt=1; | |
931 | } else { | |
932 | cnt++; | |
933 | } | |
934 | } else if (dest[idx] <= 128){ | |
935 | if (high) { | |
936 | high=0; | |
937 | if (cnt > highCnt) { | |
938 | if (highCnt != 0) highCnt2 = highCnt; | |
939 | highCnt = cnt; | |
940 | } else if (cnt > highCnt2) { | |
941 | highCnt2 = cnt; | |
942 | } | |
943 | cnt=1; | |
944 | } else { | |
945 | cnt++; | |
946 | } | |
947 | } | |
948 | } | |
949 | uint8_t tol; | |
950 | for (idx=8; idx>0; idx--){ | |
951 | tol = clk[idx]/8; | |
952 | if (clk[idx] >= highCnt - tol && clk[idx] <= highCnt + tol) | |
953 | return clk[idx]; | |
954 | if (clk[idx] >= highCnt2 - tol && clk[idx] <= highCnt2 + tol) | |
955 | return clk[idx]; | |
956 | } | |
957 | return -1; | |
958 | } | |
959 | ||
960 | // by marshmellow | |
961 | // not perfect especially with lower clocks or VERY good antennas (heavy wave clipping) | |
962 | // maybe somehow adjust peak trimming value based on samples to fix? | |
963 | // return start index of best starting position for that clock and return clock (by reference) | |
964 | int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr) | |
965 | { | |
966 | int i=0; | |
967 | int clk[]={8,16,32,40,50,64,100,128,256}; | |
968 | int loopCnt = 256; //don't need to loop through entire array... | |
969 | if (size == 0) return -1; | |
970 | if (size<loopCnt) loopCnt = size; | |
971 | //if we already have a valid clock quit | |
972 | ||
973 | for (;i<8;++i) | |
974 | if (clk[i] == *clock) return 0; | |
975 | ||
976 | //get high and low peak | |
977 | int peak, low; | |
978 | getHiLo(dest, loopCnt, &peak, &low, 75, 75); | |
979 | ||
980 | //test for large clean peaks | |
981 | if (DetectCleanAskWave(dest, size, peak, low)==1){ | |
982 | int ans = DetectStrongAskClock(dest, size); | |
983 | for (i=7; i>0; i--){ | |
984 | if (clk[i] == ans) { | |
985 | *clock=ans; | |
986 | return 0; | |
987 | } | |
988 | } | |
989 | } | |
990 | int ii; | |
991 | int clkCnt; | |
992 | int tol = 0; | |
993 | int bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000}; | |
994 | int bestStart[]={0,0,0,0,0,0,0,0,0}; | |
995 | int errCnt=0; | |
996 | //test each valid clock from smallest to greatest to see which lines up | |
997 | for(clkCnt=0; clkCnt < 8; clkCnt++){ | |
998 | if (clk[clkCnt] == 32){ | |
999 | tol=1; | |
1000 | }else{ | |
1001 | tol=0; | |
1002 | } | |
1003 | if (!maxErr) loopCnt=clk[clkCnt]*2; | |
1004 | bestErr[clkCnt]=1000; | |
1005 | //try lining up the peaks by moving starting point (try first 256) | |
1006 | for (ii=0; ii < loopCnt; ii++){ | |
1007 | if ((dest[ii] >= peak) || (dest[ii] <= low)){ | |
1008 | errCnt=0; | |
1009 | // now that we have the first one lined up test rest of wave array | |
1010 | for (i=0; i<((int)((size-ii-tol)/clk[clkCnt])-1); ++i){ | |
1011 | if (dest[ii+(i*clk[clkCnt])]>=peak || dest[ii+(i*clk[clkCnt])]<=low){ | |
1012 | }else if(dest[ii+(i*clk[clkCnt])-tol]>=peak || dest[ii+(i*clk[clkCnt])-tol]<=low){ | |
1013 | }else if(dest[ii+(i*clk[clkCnt])+tol]>=peak || dest[ii+(i*clk[clkCnt])+tol]<=low){ | |
1014 | }else{ //error no peak detected | |
1015 | errCnt++; | |
1016 | } | |
1017 | } | |
1018 | //if we found no errors then we can stop here | |
1019 | // this is correct one - return this clock | |
1020 | //PrintAndLog("DEBUG: clk %d, err %d, ii %d, i %d",clk[clkCnt],errCnt,ii,i); | |
1021 | if(errCnt==0 && clkCnt<6) { | |
1022 | *clock = clk[clkCnt]; | |
1023 | return ii; | |
1024 | } | |
1025 | //if we found errors see if it is lowest so far and save it as best run | |
1026 | if(errCnt<bestErr[clkCnt]){ | |
1027 | bestErr[clkCnt]=errCnt; | |
1028 | bestStart[clkCnt]=ii; | |
1029 | } | |
1030 | } | |
1031 | } | |
1032 | } | |
1033 | uint8_t iii=0; | |
1034 | uint8_t best=0; | |
1035 | for (iii=0; iii<8; ++iii){ | |
1036 | if (bestErr[iii]<bestErr[best]){ | |
1037 | if (bestErr[iii]==0) bestErr[iii]=1; | |
1038 | // current best bit to error ratio vs new bit to error ratio | |
1039 | if (((size/clk[best])/bestErr[best] < (size/clk[iii])/bestErr[iii]) ){ | |
1040 | best = iii; | |
1041 | } | |
1042 | } | |
1043 | } | |
1044 | if (bestErr[best]>maxErr) return -1; | |
1045 | *clock=clk[best]; | |
1046 | return bestStart[best]; | |
1047 | } | |
1048 | ||
1049 | //by marshmellow | |
1050 | //detect psk clock by reading each phase shift | |
1051 | // a phase shift is determined by measuring the sample length of each wave | |
1052 | int DetectPSKClock(uint8_t dest[], size_t size, int clock) | |
1053 | { | |
1054 | uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock | |
1055 | uint16_t loopCnt = 4096; //don't need to loop through entire array... | |
1056 | if (size == 0) return 0; | |
1057 | if (size<loopCnt) loopCnt = size; | |
1058 | ||
1059 | //if we already have a valid clock quit | |
1060 | size_t i=1; | |
1061 | for (; i < 8; ++i) | |
1062 | if (clk[i] == clock) return clock; | |
1063 | ||
1064 | size_t waveStart=0, waveEnd=0, firstFullWave=0, lastClkBit=0; | |
1065 | uint8_t clkCnt, fc=0, fullWaveLen=0, tol=1; | |
1066 | uint16_t peakcnt=0, errCnt=0, waveLenCnt=0; | |
1067 | uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000}; | |
1068 | uint16_t peaksdet[]={0,0,0,0,0,0,0,0,0}; | |
1069 | countFC(dest, size, &fc); | |
1070 | //PrintAndLog("DEBUG: FC: %d",fc); | |
1071 | ||
1072 | //find first full wave | |
1073 | for (i=0; i<loopCnt; i++){ | |
1074 | if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){ | |
1075 | if (waveStart == 0) { | |
1076 | waveStart = i+1; | |
1077 | //PrintAndLog("DEBUG: waveStart: %d",waveStart); | |
1078 | } else { | |
1079 | waveEnd = i+1; | |
1080 | //PrintAndLog("DEBUG: waveEnd: %d",waveEnd); | |
1081 | waveLenCnt = waveEnd-waveStart; | |
1082 | if (waveLenCnt > fc){ | |
1083 | firstFullWave = waveStart; | |
1084 | fullWaveLen=waveLenCnt; | |
1085 | break; | |
1086 | } | |
1087 | waveStart=0; | |
1088 | } | |
1089 | } | |
1090 | } | |
1091 | //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen); | |
1092 | ||
1093 | //test each valid clock from greatest to smallest to see which lines up | |
1094 | for(clkCnt=7; clkCnt >= 1 ; clkCnt--){ | |
1095 | lastClkBit = firstFullWave; //set end of wave as clock align | |
1096 | waveStart = 0; | |
1097 | errCnt=0; | |
1098 | peakcnt=0; | |
1099 | //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit); | |
1100 | ||
1101 | for (i = firstFullWave+fullWaveLen-1; i < loopCnt-2; i++){ | |
1102 | //top edge of wave = start of new wave | |
1103 | if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){ | |
1104 | if (waveStart == 0) { | |
1105 | waveStart = i+1; | |
1106 | waveLenCnt=0; | |
1107 | } else { //waveEnd | |
1108 | waveEnd = i+1; | |
1109 | waveLenCnt = waveEnd-waveStart; | |
1110 | if (waveLenCnt > fc){ | |
1111 | //if this wave is a phase shift | |
1112 | //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, ii: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+clk[clkCnt]-tol,ii+1,fc); | |
1113 | if (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit | |
1114 | peakcnt++; | |
1115 | lastClkBit+=clk[clkCnt]; | |
1116 | } else if (i<lastClkBit+8){ | |
1117 | //noise after a phase shift - ignore | |
1118 | } else { //phase shift before supposed to based on clock | |
1119 | errCnt++; | |
1120 | } | |
1121 | } else if (i+1 > lastClkBit + clk[clkCnt] + tol + fc){ | |
1122 | lastClkBit+=clk[clkCnt]; //no phase shift but clock bit | |
1123 | } | |
1124 | waveStart=i+1; | |
1125 | } | |
1126 | } | |
1127 | } | |
1128 | if (errCnt == 0){ | |
1129 | return clk[clkCnt]; | |
1130 | } | |
1131 | if (errCnt <= bestErr[clkCnt]) bestErr[clkCnt]=errCnt; | |
1132 | if (peakcnt > peaksdet[clkCnt]) peaksdet[clkCnt]=peakcnt; | |
1133 | } | |
1134 | //all tested with errors | |
1135 | //return the highest clk with the most peaks found | |
1136 | uint8_t best=7; | |
1137 | for (i=7; i>=1; i--){ | |
1138 | if (peaksdet[i] > peaksdet[best]) { | |
1139 | best = i; | |
1140 | } | |
1141 | //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]); | |
1142 | } | |
1143 | return clk[best]; | |
1144 | } | |
1145 | ||
1146 | //by marshmellow | |
1147 | //detect nrz clock by reading #peaks vs no peaks(or errors) | |
1148 | int DetectNRZClock(uint8_t dest[], size_t size, int clock) | |
1149 | { | |
1150 | int i=0; | |
1151 | int clk[]={8,16,32,40,50,64,100,128,256}; | |
1152 | int loopCnt = 4096; //don't need to loop through entire array... | |
1153 | if (size == 0) return 0; | |
1154 | if (size<loopCnt) loopCnt = size; | |
1155 | ||
1156 | //if we already have a valid clock quit | |
1157 | for (; i < 8; ++i) | |
1158 | if (clk[i] == clock) return clock; | |
1159 | ||
1160 | //get high and low peak | |
1161 | int peak, low; | |
1162 | getHiLo(dest, loopCnt, &peak, &low, 75, 75); | |
1163 | ||
1164 | //PrintAndLog("DEBUG: peak: %d, low: %d",peak,low); | |
1165 | int ii; | |
1166 | uint8_t clkCnt; | |
1167 | uint8_t tol = 0; | |
1168 | int peakcnt=0; | |
1169 | int peaksdet[]={0,0,0,0,0,0,0,0}; | |
1170 | int maxPeak=0; | |
1171 | //test for large clipped waves | |
1172 | for (i=0; i<loopCnt; i++){ | |
1173 | if (dest[i] >= peak || dest[i] <= low){ | |
1174 | peakcnt++; | |
1175 | } else { | |
1176 | if (peakcnt>0 && maxPeak < peakcnt){ | |
1177 | maxPeak = peakcnt; | |
1178 | } | |
1179 | peakcnt=0; | |
1180 | } | |
1181 | } | |
1182 | peakcnt=0; | |
1183 | //test each valid clock from smallest to greatest to see which lines up | |
1184 | for(clkCnt=0; clkCnt < 8; ++clkCnt){ | |
1185 | //ignore clocks smaller than largest peak | |
1186 | if (clk[clkCnt]<maxPeak) continue; | |
1187 | ||
1188 | //try lining up the peaks by moving starting point (try first 256) | |
1189 | for (ii=0; ii< loopCnt; ++ii){ | |
1190 | if ((dest[ii] >= peak) || (dest[ii] <= low)){ | |
1191 | peakcnt=0; | |
1192 | // now that we have the first one lined up test rest of wave array | |
1193 | for (i=0; i < ((int)((size-ii-tol)/clk[clkCnt])-1); ++i){ | |
1194 | if (dest[ii+(i*clk[clkCnt])]>=peak || dest[ii+(i*clk[clkCnt])]<=low){ | |
1195 | peakcnt++; | |
1196 | } | |
1197 | } | |
1198 | if(peakcnt>peaksdet[clkCnt]) { | |
1199 | peaksdet[clkCnt]=peakcnt; | |
1200 | } | |
1201 | } | |
1202 | } | |
1203 | } | |
1204 | int iii=7; | |
1205 | int best=0; | |
1206 | for (iii=7; iii > 0; iii--){ | |
1207 | if (peaksdet[iii] > peaksdet[best]){ | |
1208 | best = iii; | |
1209 | } | |
1210 | //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]); | |
1211 | } | |
1212 | return clk[best]; | |
1213 | } | |
1214 | ||
1215 | // by marshmellow | |
1216 | // convert psk1 demod to psk2 demod | |
1217 | // only transition waves are 1s | |
1218 | void psk1TOpsk2(uint8_t *BitStream, size_t size) | |
1219 | { | |
1220 | size_t i=1; | |
1221 | uint8_t lastBit=BitStream[0]; | |
1222 | for (; i<size; i++){ | |
1223 | if (BitStream[i]==77){ | |
1224 | //ignore errors | |
1225 | } else if (lastBit!=BitStream[i]){ | |
1226 | lastBit=BitStream[i]; | |
1227 | BitStream[i]=1; | |
1228 | } else { | |
1229 | BitStream[i]=0; | |
1230 | } | |
1231 | } | |
1232 | return; | |
1233 | } | |
1234 | ||
1235 | // by marshmellow | |
1236 | // convert psk2 demod to psk1 demod | |
1237 | // from only transition waves are 1s to phase shifts change bit | |
1238 | void psk2TOpsk1(uint8_t *BitStream, size_t size) | |
1239 | { | |
1240 | uint8_t phase=0; | |
1241 | for (size_t i=0; i<size; i++){ | |
1242 | if (BitStream[i]==1){ | |
1243 | phase ^=1; | |
1244 | } | |
1245 | BitStream[i]=phase; | |
1246 | } | |
1247 | return; | |
1248 | } | |
1249 | ||
1250 | // redesigned by marshmellow adjusted from existing decode functions | |
1251 | // indala id decoding - only tested on 26 bit tags, but attempted to make it work for more | |
1252 | int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert) | |
1253 | { | |
1254 | //26 bit 40134 format (don't know other formats) | |
1255 | int i; | |
1256 | int long_wait=29;//29 leading zeros in format | |
1257 | int start; | |
1258 | int first = 0; | |
1259 | int first2 = 0; | |
1260 | int bitCnt = 0; | |
1261 | int ii; | |
1262 | // Finding the start of a UID | |
1263 | for (start = 0; start <= *size - 250; start++) { | |
1264 | first = bitStream[start]; | |
1265 | for (i = start; i < start + long_wait; i++) { | |
1266 | if (bitStream[i] != first) { | |
1267 | break; | |
1268 | } | |
1269 | } | |
1270 | if (i == (start + long_wait)) { | |
1271 | break; | |
1272 | } | |
1273 | } | |
1274 | if (start == *size - 250 + 1) { | |
1275 | // did not find start sequence | |
1276 | return -1; | |
1277 | } | |
1278 | // Inverting signal if needed | |
1279 | if (first == 1) { | |
1280 | for (i = start; i < *size; i++) { | |
1281 | bitStream[i] = !bitStream[i]; | |
1282 | } | |
1283 | *invert = 1; | |
1284 | }else *invert=0; | |
1285 | ||
1286 | int iii; | |
1287 | //found start once now test length by finding next one | |
1288 | for (ii=start+29; ii <= *size - 250; ii++) { | |
1289 | first2 = bitStream[ii]; | |
1290 | for (iii = ii; iii < ii + long_wait; iii++) { | |
1291 | if (bitStream[iii] != first2) { | |
1292 | break; | |
1293 | } | |
1294 | } | |
1295 | if (iii == (ii + long_wait)) { | |
1296 | break; | |
1297 | } | |
1298 | } | |
1299 | if (ii== *size - 250 + 1){ | |
1300 | // did not find second start sequence | |
1301 | return -2; | |
1302 | } | |
1303 | bitCnt=ii-start; | |
1304 | ||
1305 | // Dumping UID | |
1306 | i = start; | |
1307 | for (ii = 0; ii < bitCnt; ii++) { | |
1308 | bitStream[ii] = bitStream[i++]; | |
1309 | } | |
1310 | *size=bitCnt; | |
1311 | return 1; | |
1312 | } | |
1313 | ||
1314 | // by marshmellow - demodulate NRZ wave (both similar enough) | |
1315 | // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak | |
1316 | // there probably is a much simpler way to do this.... | |
1317 | int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert, int maxErr) | |
1318 | { | |
1319 | if (justNoise(dest, *size)) return -1; | |
1320 | *clk = DetectNRZClock(dest, *size, *clk); | |
1321 | if (*clk==0) return -2; | |
1322 | uint32_t i; | |
1323 | uint32_t gLen = 4096; | |
1324 | if (gLen>*size) gLen = *size; | |
1325 | int high, low; | |
1326 | if (getHiLo(dest, gLen, &high, &low, 75, 75) < 1) return -3; //25% fuzz on high 25% fuzz on low | |
1327 | int lastBit = 0; //set first clock check | |
1328 | uint32_t bitnum = 0; //output counter | |
1329 | uint8_t tol = 1; //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave | |
1330 | uint32_t iii = 0; | |
1331 | uint16_t errCnt =0; | |
1332 | uint16_t MaxBits = 1000; | |
1333 | uint32_t bestErrCnt = maxErr+1; | |
1334 | uint32_t bestPeakCnt = 0; | |
1335 | uint32_t bestPeakStart=0; | |
1336 | uint8_t bestFirstPeakHigh=0; | |
1337 | uint8_t firstPeakHigh=0; | |
1338 | uint8_t curBit=0; | |
1339 | uint8_t bitHigh=0; | |
1340 | uint8_t errBitHigh=0; | |
1341 | uint16_t peakCnt=0; | |
1342 | uint8_t ignoreWindow=4; | |
1343 | uint8_t ignoreCnt=ignoreWindow; //in case of noice near peak | |
1344 | //loop to find first wave that works - align to clock | |
1345 | for (iii=0; iii < gLen; ++iii){ | |
1346 | if ((dest[iii]>=high) || (dest[iii]<=low)){ | |
1347 | if (dest[iii]>=high) firstPeakHigh=1; | |
1348 | else firstPeakHigh=0; | |
1349 | lastBit=iii-*clk; | |
1350 | peakCnt=0; | |
1351 | errCnt=0; | |
1352 | bitnum=0; | |
1353 | //loop through to see if this start location works | |
1354 | for (i = iii; i < *size; ++i) { | |
1355 | //if we found a high bar and we are at a clock bit | |
1356 | if ((dest[i]>=high ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){ | |
1357 | bitHigh=1; | |
1358 | lastBit+=*clk; | |
1359 | bitnum++; | |
1360 | peakCnt++; | |
1361 | errBitHigh=0; | |
1362 | ignoreCnt=ignoreWindow; | |
1363 | //else if low bar found and we are at a clock point | |
1364 | }else if ((dest[i]<=low ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){ | |
1365 | bitHigh=1; | |
1366 | lastBit+=*clk; | |
1367 | bitnum++; | |
1368 | peakCnt++; | |
1369 | errBitHigh=0; | |
1370 | ignoreCnt=ignoreWindow; | |
1371 | //else if no bars found | |
1372 | }else if(dest[i] < high && dest[i] > low) { | |
1373 | if (ignoreCnt==0){ | |
1374 | bitHigh=0; | |
1375 | if (errBitHigh==1){ | |
1376 | errCnt++; | |
1377 | } | |
1378 | errBitHigh=0; | |
1379 | } else { | |
1380 | ignoreCnt--; | |
1381 | } | |
1382 | //if we are past a clock point | |
1383 | if (i >= lastBit+*clk+tol){ //clock val | |
1384 | lastBit+=*clk; | |
1385 | bitnum++; | |
1386 | } | |
1387 | //else if bar found but we are not at a clock bit and we did not just have a clock bit | |
1388 | }else if ((dest[i]>=high || dest[i]<=low) && (i<lastBit+*clk-tol || i>lastBit+*clk+tol) && (bitHigh==0)){ | |
1389 | //error bar found no clock... | |
1390 | errBitHigh=1; | |
1391 | } | |
1392 | if (bitnum>=MaxBits) break; | |
1393 | } | |
1394 | //we got more than 64 good bits and not all errors | |
1395 | if (bitnum > (64) && (errCnt <= (maxErr))) { | |
1396 | //possible good read | |
1397 | if (errCnt == 0){ | |
1398 | //bestStart = iii; | |
1399 | bestFirstPeakHigh=firstPeakHigh; | |
1400 | bestErrCnt = errCnt; | |
1401 | bestPeakCnt = peakCnt; | |
1402 | bestPeakStart = iii; | |
1403 | break; //great read - finish | |
1404 | } | |
1405 | if (errCnt < bestErrCnt){ //set this as new best run | |
1406 | bestErrCnt = errCnt; | |
1407 | //bestStart = iii; | |
1408 | } | |
1409 | if (peakCnt > bestPeakCnt){ | |
1410 | bestFirstPeakHigh=firstPeakHigh; | |
1411 | bestPeakCnt=peakCnt; | |
1412 | bestPeakStart=iii; | |
1413 | } | |
1414 | } | |
1415 | } | |
1416 | } | |
1417 | //PrintAndLog("DEBUG: bestErrCnt: %d, maxErr: %d, bestStart: %d, bestPeakCnt: %d, bestPeakStart: %d",bestErrCnt,maxErr,bestStart,bestPeakCnt,bestPeakStart); | |
1418 | if (bestErrCnt <= maxErr){ | |
1419 | //best run is good enough set to best run and set overwrite BinStream | |
1420 | iii=bestPeakStart; | |
1421 | lastBit=bestPeakStart-*clk; | |
1422 | bitnum=0; | |
1423 | memset(dest, bestFirstPeakHigh^1, bestPeakStart / *clk); | |
1424 | bitnum += (bestPeakStart / *clk); | |
1425 | for (i = iii; i < *size; ++i) { | |
1426 | //if we found a high bar and we are at a clock bit | |
1427 | if ((dest[i] >= high ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){ | |
1428 | bitHigh=1; | |
1429 | lastBit+=*clk; | |
1430 | curBit=1-*invert; | |
1431 | dest[bitnum]=curBit; | |
1432 | bitnum++; | |
1433 | errBitHigh=0; | |
1434 | ignoreCnt=ignoreWindow; | |
1435 | //else if low bar found and we are at a clock point | |
1436 | }else if ((dest[i]<=low ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){ | |
1437 | bitHigh=1; | |
1438 | lastBit+=*clk; | |
1439 | curBit=*invert; | |
1440 | dest[bitnum]=curBit; | |
1441 | bitnum++; | |
1442 | errBitHigh=0; | |
1443 | ignoreCnt=ignoreWindow; | |
1444 | //else if no bars found | |
1445 | }else if(dest[i]<high && dest[i]>low) { | |
1446 | if (ignoreCnt==0){ | |
1447 | bitHigh=0; | |
1448 | //if peak is done was it an error peak? | |
1449 | if (errBitHigh==1){ | |
1450 | dest[bitnum]=77; | |
1451 | bitnum++; | |
1452 | errCnt++; | |
1453 | } | |
1454 | errBitHigh=0; | |
1455 | } else { | |
1456 | ignoreCnt--; | |
1457 | } | |
1458 | //if we are past a clock point | |
1459 | if (i>=lastBit+*clk+tol){ //clock val | |
1460 | lastBit+=*clk; | |
1461 | dest[bitnum]=curBit; | |
1462 | bitnum++; | |
1463 | } | |
1464 | //else if bar found but we are not at a clock bit and we did not just have a clock bit | |
1465 | }else if ((dest[i]>=high || dest[i]<=low) && ((i<lastBit+*clk-tol) || (i>lastBit+*clk+tol)) && (bitHigh==0)){ | |
1466 | //error bar found no clock... | |
1467 | errBitHigh=1; | |
1468 | } | |
1469 | if (bitnum >= MaxBits) break; | |
1470 | } | |
1471 | *size=bitnum; | |
1472 | } else{ | |
1473 | *size=bitnum; | |
1474 | return bestErrCnt; | |
1475 | } | |
1476 | ||
1477 | if (bitnum>16){ | |
1478 | *size=bitnum; | |
1479 | } else return -5; | |
1480 | return errCnt; | |
1481 | } | |
1482 | ||
1483 | //by marshmellow | |
1484 | //detects the bit clock for FSK given the high and low Field Clocks | |
1485 | uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow) | |
1486 | { | |
1487 | uint8_t clk[] = {8,16,32,40,50,64,100,128,0}; | |
1488 | uint16_t rfLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; | |
1489 | uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; | |
1490 | uint8_t rfLensFnd = 0; | |
1491 | uint8_t lastFCcnt=0; | |
1492 | uint32_t fcCounter = 0; | |
1493 | uint16_t rfCounter = 0; | |
1494 | uint8_t firstBitFnd = 0; | |
1495 | size_t i; | |
1496 | if (size == 0) return 0; | |
1497 | ||
1498 | uint8_t fcTol = (uint8_t)(0.5+(float)(fcHigh-fcLow)/2); | |
1499 | rfLensFnd=0; | |
1500 | fcCounter=0; | |
1501 | rfCounter=0; | |
1502 | firstBitFnd=0; | |
1503 | //PrintAndLog("DEBUG: fcTol: %d",fcTol); | |
1504 | // prime i to first up transition | |
1505 | for (i = 1; i < size-1; i++) | |
1506 | if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1]) | |
1507 | break; | |
1508 | ||
1509 | for (; i < size-1; i++){ | |
1510 | if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1]){ | |
1511 | // new peak | |
1512 | fcCounter++; | |
1513 | rfCounter++; | |
1514 | // if we got less than the small fc + tolerance then set it to the small fc | |
1515 | if (fcCounter < fcLow+fcTol) | |
1516 | fcCounter = fcLow; | |
1517 | else //set it to the large fc | |
1518 | fcCounter = fcHigh; | |
1519 | ||
1520 | //look for bit clock (rf/xx) | |
1521 | if ((fcCounter<lastFCcnt || fcCounter>lastFCcnt)){ | |
1522 | //not the same size as the last wave - start of new bit sequence | |
1523 | ||
1524 | if (firstBitFnd>1){ //skip first wave change - probably not a complete bit | |
1525 | for (int ii=0; ii<15; ii++){ | |
1526 | if (rfLens[ii]==rfCounter){ | |
1527 | rfCnts[ii]++; | |
1528 | rfCounter=0; | |
1529 | break; | |
1530 | } | |
1531 | } | |
1532 | if (rfCounter>0 && rfLensFnd<15){ | |
1533 | //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter); | |
1534 | rfCnts[rfLensFnd]++; | |
1535 | rfLens[rfLensFnd++]=rfCounter; | |
1536 | } | |
1537 | } else { | |
1538 | firstBitFnd++; | |
1539 | } | |
1540 | rfCounter=0; | |
1541 | lastFCcnt=fcCounter; | |
1542 | } | |
1543 | fcCounter=0; | |
1544 | } else { | |
1545 | // count sample | |
1546 | fcCounter++; | |
1547 | rfCounter++; | |
1548 | } | |
1549 | } | |
1550 | uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15; | |
1551 | ||
1552 | for (i=0; i<15; i++){ | |
1553 | //PrintAndLog("DEBUG: RF %d, cnts %d",rfLens[i], rfCnts[i]); | |
1554 | //get highest 2 RF values (might need to get more values to compare or compare all?) | |
1555 | if (rfCnts[i]>rfCnts[rfHighest]){ | |
1556 | rfHighest3=rfHighest2; | |
1557 | rfHighest2=rfHighest; | |
1558 | rfHighest=i; | |
1559 | } else if(rfCnts[i]>rfCnts[rfHighest2]){ | |
1560 | rfHighest3=rfHighest2; | |
1561 | rfHighest2=i; | |
1562 | } else if(rfCnts[i]>rfCnts[rfHighest3]){ | |
1563 | rfHighest3=i; | |
1564 | } | |
1565 | } | |
1566 | // set allowed clock remainder tolerance to be 1 large field clock length+1 | |
1567 | // we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off | |
1568 | uint8_t tol1 = fcHigh+1; | |
1569 | ||
1570 | //PrintAndLog("DEBUG: hightest: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]); | |
1571 | ||
1572 | // loop to find the highest clock that has a remainder less than the tolerance | |
1573 | // compare samples counted divided by | |
1574 | int ii=7; | |
1575 | for (; ii>=0; ii--){ | |
1576 | if (rfLens[rfHighest] % clk[ii] < tol1 || rfLens[rfHighest] % clk[ii] > clk[ii]-tol1){ | |
1577 | if (rfLens[rfHighest2] % clk[ii] < tol1 || rfLens[rfHighest2] % clk[ii] > clk[ii]-tol1){ | |
1578 | if (rfLens[rfHighest3] % clk[ii] < tol1 || rfLens[rfHighest3] % clk[ii] > clk[ii]-tol1){ | |
1579 | break; | |
1580 | } | |
1581 | } | |
1582 | } | |
1583 | } | |
1584 | ||
1585 | if (ii<0) return 0; // oops we went too far | |
1586 | ||
1587 | return clk[ii]; | |
1588 | } | |
1589 | ||
1590 | //by marshmellow | |
1591 | //countFC is to detect the field clock lengths. | |
1592 | //counts and returns the 2 most common wave lengths | |
1593 | //mainly used for FSK field clock detection | |
1594 | uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t *mostFC) | |
1595 | { | |
1596 | uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0}; | |
1597 | uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0}; | |
1598 | uint8_t fcLensFnd = 0; | |
1599 | uint8_t lastFCcnt=0; | |
1600 | uint32_t fcCounter = 0; | |
1601 | size_t i; | |
1602 | if (size == 0) return 0; | |
1603 | ||
1604 | // prime i to first up transition | |
1605 | for (i = 1; i < size-1; i++) | |
1606 | if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]) | |
1607 | break; | |
1608 | ||
1609 | for (; i < size-1; i++){ | |
1610 | if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){ | |
1611 | // new up transition | |
1612 | fcCounter++; | |
1613 | ||
1614 | //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8) | |
1615 | if (lastFCcnt==5 && fcCounter==9) fcCounter--; | |
1616 | //if odd and not rc/5 add one (for when we get a fc 9 instead of 10) | |
1617 | if ((fcCounter==9 && fcCounter & 1) || fcCounter==4) fcCounter++; | |
1618 | ||
1619 | // save last field clock count (fc/xx) | |
1620 | // find which fcLens to save it to: | |
1621 | for (int ii=0; ii<10; ii++){ | |
1622 | if (fcLens[ii]==fcCounter){ | |
1623 | fcCnts[ii]++; | |
1624 | fcCounter=0; | |
1625 | break; | |
1626 | } | |
1627 | } | |
1628 | if (fcCounter>0 && fcLensFnd<10){ | |
1629 | //add new fc length | |
1630 | fcCnts[fcLensFnd]++; | |
1631 | fcLens[fcLensFnd++]=fcCounter; | |
1632 | } | |
1633 | fcCounter=0; | |
1634 | } else { | |
1635 | // count sample | |
1636 | fcCounter++; | |
1637 | } | |
1638 | } | |
1639 | ||
1640 | uint8_t best1=9, best2=9, best3=9; | |
1641 | uint16_t maxCnt1=0; | |
1642 | // go through fclens and find which ones are bigest 2 | |
1643 | for (i=0; i<10; i++){ | |
1644 | // PrintAndLog("DEBUG: FC %d, Cnt %d, Errs %d",fcLens[i],fcCnts[i],errCnt); | |
1645 | // get the 3 best FC values | |
1646 | if (fcCnts[i]>maxCnt1) { | |
1647 | best3=best2; | |
1648 | best2=best1; | |
1649 | maxCnt1=fcCnts[i]; | |
1650 | best1=i; | |
1651 | } else if(fcCnts[i]>fcCnts[best2]){ | |
1652 | best3=best2; | |
1653 | best2=i; | |
1654 | } else if(fcCnts[i]>fcCnts[best3]){ | |
1655 | best3=i; | |
1656 | } | |
1657 | } | |
1658 | uint8_t fcH=0, fcL=0; | |
1659 | if (fcLens[best1]>fcLens[best2]){ | |
1660 | fcH=fcLens[best1]; | |
1661 | fcL=fcLens[best2]; | |
1662 | } else{ | |
1663 | fcH=fcLens[best2]; | |
1664 | fcL=fcLens[best1]; | |
1665 | } | |
1666 | ||
1667 | *mostFC=fcLens[best1]; | |
1668 | // TODO: take top 3 answers and compare to known Field clocks to get top 2 | |
1669 | ||
1670 | uint16_t fcs = (((uint16_t)fcH)<<8) | fcL; | |
1671 | // PrintAndLog("DEBUG: Best %d best2 %d best3 %d",fcLens[best1],fcLens[best2],fcLens[best3]); | |
1672 | ||
1673 | return fcs; | |
1674 | } | |
1675 | ||
1676 | //by marshmellow | |
1677 | //countPSK_FC is to detect the psk carrier clock length. | |
1678 | //counts and returns the 1 most common wave length | |
1679 | uint8_t countPSK_FC(uint8_t *BitStream, size_t size) | |
1680 | { | |
1681 | uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0}; | |
1682 | uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0}; | |
1683 | uint8_t fcLensFnd = 0; | |
1684 | uint32_t fcCounter = 0; | |
1685 | size_t i; | |
1686 | if (size == 0) return 0; | |
1687 | ||
1688 | // prime i to first up transition | |
1689 | for (i = 1; i < size-1; i++) | |
1690 | if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]) | |
1691 | break; | |
1692 | ||
1693 | for (; i < size-1; i++){ | |
1694 | if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){ | |
1695 | // new up transition | |
1696 | fcCounter++; | |
1697 | ||
1698 | // save last field clock count (fc/xx) | |
1699 | // find which fcLens to save it to: | |
1700 | for (int ii=0; ii<10; ii++){ | |
1701 | if (fcLens[ii]==fcCounter){ | |
1702 | fcCnts[ii]++; | |
1703 | fcCounter=0; | |
1704 | break; | |
1705 | } | |
1706 | } | |
1707 | if (fcCounter>0 && fcLensFnd<10){ | |
1708 | //add new fc length | |
1709 | fcCnts[fcLensFnd]++; | |
1710 | fcLens[fcLensFnd++]=fcCounter; | |
1711 | } | |
1712 | fcCounter=0; | |
1713 | } else { | |
1714 | // count sample | |
1715 | fcCounter++; | |
1716 | } | |
1717 | } | |
1718 | ||
1719 | uint8_t best1=9; | |
1720 | uint16_t maxCnt1=0; | |
1721 | // go through fclens and find which ones are bigest | |
1722 | for (i=0; i<10; i++){ | |
1723 | //PrintAndLog("DEBUG: FC %d, Cnt %d",fcLens[i],fcCnts[i]); | |
1724 | // get the best FC value | |
1725 | if (fcCnts[i]>maxCnt1) { | |
1726 | maxCnt1=fcCnts[i]; | |
1727 | best1=i; | |
1728 | } | |
1729 | } | |
1730 | return fcLens[best1]; | |
1731 | } | |
1732 | ||
1733 | //by marshmellow - demodulate PSK1 wave | |
1734 | //uses wave lengths (# Samples) | |
1735 | int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) | |
1736 | { | |
1737 | uint16_t loopCnt = 4096; //don't need to loop through entire array... | |
1738 | if (size == 0) return -1; | |
1739 | if (*size<loopCnt) loopCnt = *size; | |
1740 | ||
1741 | uint8_t curPhase = *invert; | |
1742 | size_t i, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0; | |
1743 | uint8_t fc=0, fullWaveLen=0, tol=1; | |
1744 | uint16_t errCnt=0, waveLenCnt=0; | |
1745 | fc = countPSK_FC(dest, *size); | |
1746 | if (fc!=2 && fc!=4 && fc!=8) return -1; | |
1747 | //PrintAndLog("DEBUG: FC: %d",fc); | |
1748 | *clock = DetectPSKClock(dest, *size, *clock); | |
1749 | if (*clock==0) return -1; | |
1750 | int avgWaveVal=0, lastAvgWaveVal=0; | |
1751 | //find first phase shift | |
1752 | for (i=0; i<loopCnt; i++){ | |
1753 | if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){ | |
1754 | waveEnd = i+1; | |
1755 | //PrintAndLog("DEBUG: waveEnd: %d",waveEnd); | |
1756 | waveLenCnt = waveEnd-waveStart; | |
1757 | if (waveLenCnt > fc && waveStart > fc){ //not first peak and is a large wave | |
1758 | lastAvgWaveVal = avgWaveVal/(waveLenCnt); | |
1759 | firstFullWave = waveStart; | |
1760 | fullWaveLen=waveLenCnt; | |
1761 | //if average wave value is > graph 0 then it is an up wave or a 1 | |
1762 | if (lastAvgWaveVal > 123) curPhase^=1; //fudge graph 0 a little 123 vs 128 | |
1763 | break; | |
1764 | } | |
1765 | waveStart = i+1; | |
1766 | avgWaveVal = 0; | |
1767 | } | |
1768 | avgWaveVal+=dest[i+2]; | |
1769 | } | |
1770 | //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen); | |
1771 | lastClkBit = firstFullWave; //set start of wave as clock align | |
1772 | //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d", *clock, lastClkBit); | |
1773 | waveStart = 0; | |
1774 | errCnt=0; | |
1775 | size_t numBits=0; | |
1776 | //set skipped bits | |
1777 | memset(dest,curPhase^1,firstFullWave / *clock); | |
1778 | numBits += (firstFullWave / *clock); | |
1779 | dest[numBits++] = curPhase; //set first read bit | |
1780 | for (i = firstFullWave+fullWaveLen-1; i < *size-3; i++){ | |
1781 | //top edge of wave = start of new wave | |
1782 | if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){ | |
1783 | if (waveStart == 0) { | |
1784 | waveStart = i+1; | |
1785 | waveLenCnt=0; | |
1786 | avgWaveVal = dest[i+1]; | |
1787 | } else { //waveEnd | |
1788 | waveEnd = i+1; | |
1789 | waveLenCnt = waveEnd-waveStart; | |
1790 | lastAvgWaveVal = avgWaveVal/waveLenCnt; | |
1791 | if (waveLenCnt > fc){ | |
1792 | //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal); | |
1793 | //if this wave is a phase shift | |
1794 | //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc); | |
1795 | if (i+1 >= lastClkBit + *clock - tol){ //should be a clock bit | |
1796 | curPhase^=1; | |
1797 | dest[numBits++] = curPhase; | |
1798 | lastClkBit += *clock; | |
1799 | } else if (i<lastClkBit+10+fc){ | |
1800 | //noise after a phase shift - ignore | |
1801 | } else { //phase shift before supposed to based on clock | |
1802 | errCnt++; | |
1803 | dest[numBits++] = 77; | |
1804 | } | |
1805 | } else if (i+1 > lastClkBit + *clock + tol + fc){ | |
1806 | lastClkBit += *clock; //no phase shift but clock bit | |
1807 | dest[numBits++] = curPhase; | |
1808 | } | |
1809 | avgWaveVal=0; | |
1810 | waveStart=i+1; | |
1811 | } | |
1812 | } | |
1813 | avgWaveVal+=dest[i+1]; | |
1814 | } | |
1815 | *size = numBits; | |
1816 | return errCnt; | |
1817 | } |