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eb191de6 | 1 | //----------------------------------------------------------------------------- |
ba1a299c | 2 | // Copyright (C) 2014 |
eb191de6 | 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 | //----------------------------------------------------------------------------- | |
1e090a61 | 8 | // Low frequency demod/decode commands |
eb191de6 | 9 | //----------------------------------------------------------------------------- |
10 | ||
eb191de6 | 11 | #include <stdlib.h> |
12 | #include <string.h> | |
eb191de6 | 13 | #include "lfdemod.h" |
a1d17964 | 14 | uint8_t justNoise(uint8_t *BitStream, size_t size) |
15 | { | |
16 | static const uint8_t THRESHOLD = 123; | |
17 | //test samples are not just noise | |
18 | uint8_t justNoise1 = 1; | |
19 | for(size_t idx=0; idx < size && justNoise1 ;idx++){ | |
20 | justNoise1 = BitStream[idx] < THRESHOLD; | |
21 | } | |
22 | return justNoise1; | |
23 | } | |
24 | ||
1e090a61 | 25 | //by marshmellow |
872e3d4d | 26 | //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 |
1e090a61 | 27 | int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi, uint8_t fuzzLo) |
28 | { | |
29 | *high=0; | |
30 | *low=255; | |
31 | // get high and low thresholds | |
2eec55c8 | 32 | for (size_t i=0; i < size; i++){ |
1e090a61 | 33 | if (BitStream[i] > *high) *high = BitStream[i]; |
34 | if (BitStream[i] < *low) *low = BitStream[i]; | |
35 | } | |
36 | if (*high < 123) return -1; // just noise | |
75cbbe9a | 37 | *high = ((*high-128)*fuzzHi + 12800)/100; |
38 | *low = ((*low-128)*fuzzLo + 12800)/100; | |
1e090a61 | 39 | return 1; |
40 | } | |
41 | ||
a1d17964 | 42 | // by marshmellow |
43 | // pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType | |
44 | // returns 1 if passed | |
45 | uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType) | |
46 | { | |
47 | uint8_t ans = 0; | |
48 | for (uint8_t i = 0; i < bitLen; i++){ | |
49 | ans ^= ((bits >> i) & 1); | |
50 | } | |
f3bf15e4 | 51 | //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType); |
a1d17964 | 52 | return (ans == pType); |
53 | } | |
54 | ||
55 | //by marshmellow | |
2147c307 | 56 | //search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length |
a1d17964 | 57 | uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx) |
58 | { | |
e0165dcf | 59 | uint8_t foundCnt=0; |
60 | for (int idx=0; idx < *size - pLen; idx++){ | |
61 | if (memcmp(BitStream+idx, preamble, pLen) == 0){ | |
62 | //first index found | |
63 | foundCnt++; | |
64 | if (foundCnt == 1){ | |
65 | *startIdx = idx; | |
66 | } | |
67 | if (foundCnt == 2){ | |
68 | *size = idx - *startIdx; | |
69 | return 1; | |
70 | } | |
71 | } | |
72 | } | |
73 | return 0; | |
a1d17964 | 74 | } |
75 | ||
2147c307 | 76 | //by marshmellow |
77 | //takes 1s and 0s and searches for EM410x format - output EM ID | |
78 | uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo) | |
79 | { | |
e0165dcf | 80 | //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future |
81 | // otherwise could be a void with no arguments | |
82 | //set defaults | |
83 | uint32_t i = 0; | |
84 | if (BitStream[1]>1){ //allow only 1s and 0s | |
85 | // PrintAndLog("no data found"); | |
86 | return 0; | |
87 | } | |
88 | // 111111111 bit pattern represent start of frame | |
89 | // include 0 in front to help get start pos | |
90 | uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1}; | |
91 | uint32_t idx = 0; | |
92 | uint32_t parityBits = 0; | |
93 | uint8_t errChk = 0; | |
94 | uint8_t FmtLen = 10; | |
95 | *startIdx = 0; | |
96 | errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx); | |
97 | if (errChk == 0 || *size < 64) return 0; | |
98 | if (*size > 64) FmtLen = 22; | |
99 | *startIdx += 1; //get rid of 0 from preamble | |
100 | idx = *startIdx + 9; | |
101 | for (i=0; i<FmtLen; i++){ //loop through 10 or 22 sets of 5 bits (50-10p = 40 bits or 88 bits) | |
102 | parityBits = bytebits_to_byte(BitStream+(i*5)+idx,5); | |
2eec55c8 | 103 | //check even parity - quit if failed |
104 | if (parityTest(parityBits, 5, 0) == 0) return 0; | |
e0165dcf | 105 | //set uint64 with ID from BitStream |
106 | for (uint8_t ii=0; ii<4; ii++){ | |
107 | *hi = (*hi << 1) | (*lo >> 63); | |
108 | *lo = (*lo << 1) | (BitStream[(i*5)+ii+idx]); | |
109 | } | |
110 | } | |
111 | if (errChk != 0) return 1; | |
112 | //skip last 5 bit parity test for simplicity. | |
113 | // *size = 64 | 128; | |
114 | return 0; | |
2147c307 | 115 | } |
116 | ||
23f0a7d8 | 117 | // demodulates strong heavily clipped samples |
118 | int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low) | |
119 | { | |
120 | size_t bitCnt=0, smplCnt=0, errCnt=0; | |
121 | uint8_t waveHigh = 0; | |
122 | //PrintAndLog("clk: %d", clk); | |
123 | for (size_t i=0; i < *size; i++){ | |
124 | if (BinStream[i] >= high && waveHigh){ | |
125 | smplCnt++; | |
126 | } else if (BinStream[i] <= low && !waveHigh){ | |
127 | smplCnt++; | |
128 | } else { //transition | |
129 | if ((BinStream[i] >= high && !waveHigh) || (BinStream[i] <= low && waveHigh)){ | |
130 | if (smplCnt > clk-(clk/4)-1) { //full clock | |
131 | if (smplCnt > clk + (clk/4)+1) { //too many samples | |
132 | errCnt++; | |
133 | BinStream[bitCnt++]=77; | |
134 | } else if (waveHigh) { | |
135 | BinStream[bitCnt++] = invert; | |
136 | BinStream[bitCnt++] = invert; | |
137 | } else if (!waveHigh) { | |
138 | BinStream[bitCnt++] = invert ^ 1; | |
139 | BinStream[bitCnt++] = invert ^ 1; | |
140 | } | |
141 | waveHigh ^= 1; | |
142 | smplCnt = 0; | |
143 | } else if (smplCnt > (clk/2) - (clk/4)-1) { | |
144 | if (waveHigh) { | |
145 | BinStream[bitCnt++] = invert; | |
146 | } else if (!waveHigh) { | |
147 | BinStream[bitCnt++] = invert ^ 1; | |
148 | } | |
149 | waveHigh ^= 1; | |
150 | smplCnt = 0; | |
151 | } else if (!bitCnt) { | |
152 | //first bit | |
153 | waveHigh = (BinStream[i] >= high); | |
154 | smplCnt = 1; | |
155 | } else { | |
156 | smplCnt++; | |
157 | //transition bit oops | |
158 | } | |
159 | } else { //haven't hit new high or new low yet | |
160 | smplCnt++; | |
161 | } | |
162 | } | |
163 | } | |
164 | *size = bitCnt; | |
165 | return errCnt; | |
166 | } | |
167 | ||
eb191de6 | 168 | //by marshmellow |
6de43508 | 169 | //takes 3 arguments - clock, invert, maxErr as integers |
ba1a299c | 170 | //attempts to demodulate ask while decoding manchester |
eb191de6 | 171 | //prints binary found and saves in graphbuffer for further commands |
6de43508 | 172 | int askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr) |
eb191de6 | 173 | { |
2eec55c8 | 174 | size_t i; |
6de43508 | 175 | int start = DetectASKClock(BinStream, *size, clk, 20); //clock default |
2eec55c8 | 176 | if (*clk==0 || start < 0) return -3; |
177 | if (*invert != 1) *invert=0; | |
178 | uint8_t initLoopMax = 255; | |
179 | if (initLoopMax > *size) initLoopMax = *size; | |
ba1a299c | 180 | // Detect high and lows |
1e090a61 | 181 | // 25% fuzz in case highs and lows aren't clipped [marshmellow] |
2eec55c8 | 182 | int high, low; |
183 | if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1) return -2; //just noise | |
ba1a299c | 184 | |
23f0a7d8 | 185 | // if clean clipped waves detected run alternate demod |
186 | if (DetectCleanAskWave(BinStream, *size, high, low)) { | |
187 | cleanAskRawDemod(BinStream, size, *clk, *invert, high, low); | |
188 | return manrawdecode(BinStream, size); | |
189 | } | |
190 | ||
191 | ||
1e090a61 | 192 | // PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low); |
ba1a299c | 193 | int lastBit = 0; //set first clock check |
2eec55c8 | 194 | uint16_t bitnum = 0; //output counter |
195 | uint8_t tol = 0; //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave | |
196 | 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 | |
197 | size_t iii = 0; | |
2147c307 | 198 | //if 0 errors allowed then only try first 2 clock cycles as we want a low tolerance |
23f0a7d8 | 199 | if (!maxErr && initLoopMax > *clk*3) initLoopMax = *clk * 3; |
2eec55c8 | 200 | uint16_t errCnt = 0, MaxBits = 512; |
201 | uint16_t bestStart = start; | |
202 | uint16_t bestErrCnt = 0; | |
1e090a61 | 203 | // PrintAndLog("DEBUG - lastbit - %d",lastBit); |
2eec55c8 | 204 | // if best start position not already found by detect clock then |
205 | if (start <= 0 || start > initLoopMax){ | |
206 | bestErrCnt = maxErr+1; | |
207 | // loop to find first wave that works | |
23f0a7d8 | 208 | for (iii=0; iii < initLoopMax-tol-*clk; ++iii){ |
2eec55c8 | 209 | // if no peak skip |
210 | if (BinStream[iii] < high && BinStream[iii] > low) continue; | |
211 | ||
212 | lastBit = iii - *clk; | |
1e090a61 | 213 | // loop through to see if this start location works |
ba1a299c | 214 | for (i = iii; i < *size; ++i) { |
2eec55c8 | 215 | if ((i-lastBit) > (*clk-tol) && (BinStream[i] >= high || BinStream[i] <= low)) { |
216 | lastBit += *clk; | |
217 | } else if ((i-lastBit) > (*clk+tol)) { | |
218 | errCnt++; | |
219 | lastBit += *clk; | |
ba1a299c | 220 | } |
2eec55c8 | 221 | if ((i-iii) > (MaxBits * *clk) || errCnt > maxErr) break; //got plenty of bits or too many errors |
ba1a299c | 222 | } |
223 | //we got more than 64 good bits and not all errors | |
23f0a7d8 | 224 | if ((((i-iii)/ *clk) > (32)) && (errCnt<=maxErr)) { |
ba1a299c | 225 | //possible good read |
2eec55c8 | 226 | if (!errCnt || errCnt < bestErrCnt){ |
227 | bestStart = iii; //set this as new best run | |
228 | bestErrCnt = errCnt; | |
229 | if (!errCnt) break; //great read - finish | |
ba1a299c | 230 | } |
231 | } | |
2eec55c8 | 232 | errCnt = 0; |
ba1a299c | 233 | } |
234 | } | |
2eec55c8 | 235 | if (bestErrCnt > maxErr){ |
236 | *invert = bestStart; | |
237 | *clk = iii; | |
ba1a299c | 238 | return -1; |
2eec55c8 | 239 | } |
240 | //best run is good enough set to best run and set overwrite BinStream | |
241 | lastBit = bestStart - *clk; | |
242 | errCnt = 0; | |
243 | for (i = bestStart; i < *size; ++i) { | |
244 | if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){ | |
245 | //high found and we are expecting a bar | |
246 | lastBit += *clk; | |
247 | BinStream[bitnum++] = *invert; | |
248 | } else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){ | |
249 | //low found and we are expecting a bar | |
250 | lastBit += *clk; | |
251 | BinStream[bitnum++] = *invert ^ 1; | |
252 | } else if ((i-lastBit)>(*clk+tol)){ | |
253 | //should have hit a high or low based on clock!! | |
254 | //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); | |
255 | if (bitnum > 0) { | |
256 | BinStream[bitnum++] = 77; | |
257 | errCnt++; | |
258 | } | |
259 | lastBit += *clk;//skip over error | |
260 | } | |
261 | if (bitnum >= MaxBits) break; | |
ba1a299c | 262 | } |
2eec55c8 | 263 | *size = bitnum; |
ba1a299c | 264 | return bestErrCnt; |
eb191de6 | 265 | } |
266 | ||
ec75f5c1 | 267 | //by marshmellow |
268 | //encode binary data into binary manchester | |
269 | int ManchesterEncode(uint8_t *BitStream, size_t size) | |
270 | { | |
271 | size_t modIdx=20000, i=0; | |
272 | if (size>modIdx) return -1; | |
f3bf15e4 | 273 | for (size_t idx=0; idx < size; idx++){ |
274 | BitStream[idx+modIdx++] = BitStream[idx]; | |
275 | BitStream[idx+modIdx++] = BitStream[idx]^1; | |
276 | } | |
277 | for (; i<(size*2); i++){ | |
278 | BitStream[i] = BitStream[i+20000]; | |
279 | } | |
280 | return i; | |
ec75f5c1 | 281 | } |
282 | ||
eb191de6 | 283 | //by marshmellow |
284 | //take 10 and 01 and manchester decode | |
285 | //run through 2 times and take least errCnt | |
ba1a299c | 286 | int manrawdecode(uint8_t * BitStream, size_t *size) |
eb191de6 | 287 | { |
13d77ef9 | 288 | uint16_t bitnum=0, MaxBits = 512, errCnt = 0; |
289 | size_t i, ii; | |
290 | uint16_t bestErr = 1000, bestRun = 0; | |
6de43508 | 291 | if (size == 0) return -1; |
13d77ef9 | 292 | for (ii=0;ii<2;++ii){ |
2eec55c8 | 293 | for (i=ii; i<*size-2; i+=2) |
294 | if (BitStream[i]==BitStream[i+1]) | |
ba1a299c | 295 | errCnt++; |
2eec55c8 | 296 | |
ba1a299c | 297 | if (bestErr>errCnt){ |
298 | bestErr=errCnt; | |
299 | bestRun=ii; | |
300 | } | |
301 | errCnt=0; | |
302 | } | |
23f0a7d8 | 303 | for (i=bestRun; i < *size-2; i+=2){ |
304 | if(BitStream[i] == 1 && (BitStream[i+1] == 0)){ | |
305 | BitStream[bitnum++]=0; | |
306 | } else if((BitStream[i] == 0) && BitStream[i+1] == 1){ | |
307 | BitStream[bitnum++]=1; | |
308 | } else { | |
309 | BitStream[bitnum++]=77; | |
ba1a299c | 310 | } |
23f0a7d8 | 311 | if(bitnum>MaxBits) break; |
ba1a299c | 312 | } |
23f0a7d8 | 313 | *size=bitnum; |
2eec55c8 | 314 | return bestErr; |
f822a063 | 315 | } |
316 | ||
f822a063 | 317 | //by marshmellow |
2147c307 | 318 | //take 01 or 10 = 1 and 11 or 00 = 0 |
319 | //check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010 | |
13d77ef9 | 320 | //decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding |
1e090a61 | 321 | int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert) |
f822a063 | 322 | { |
2eec55c8 | 323 | uint16_t bitnum = 0; |
324 | uint16_t errCnt = 0; | |
325 | size_t i = offset; | |
2147c307 | 326 | uint16_t MaxBits=512; |
327 | //if not enough samples - error | |
328 | if (*size < 51) return -1; | |
329 | //check for phase change faults - skip one sample if faulty | |
330 | uint8_t offsetA = 1, offsetB = 1; | |
331 | for (; i<48; i+=2){ | |
332 | if (BitStream[i+1]==BitStream[i+2]) offsetA=0; | |
333 | if (BitStream[i+2]==BitStream[i+3]) offsetB=0; | |
334 | } | |
335 | if (!offsetA && offsetB) offset++; | |
336 | for (i=offset; i<*size-3; i+=2){ | |
337 | //check for phase error | |
13d77ef9 | 338 | if (BitStream[i+1]==BitStream[i+2]) { |
2147c307 | 339 | BitStream[bitnum++]=77; |
340 | errCnt++; | |
341 | } | |
ba1a299c | 342 | if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){ |
1e090a61 | 343 | BitStream[bitnum++]=1^invert; |
ba1a299c | 344 | } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){ |
1e090a61 | 345 | BitStream[bitnum++]=invert; |
ba1a299c | 346 | } else { |
347 | BitStream[bitnum++]=77; | |
348 | errCnt++; | |
349 | } | |
6de43508 | 350 | if(bitnum>MaxBits) break; |
ba1a299c | 351 | } |
352 | *size=bitnum; | |
353 | return errCnt; | |
eb191de6 | 354 | } |
355 | ||
356 | //by marshmellow | |
6de43508 | 357 | void askAmp(uint8_t *BitStream, size_t size) |
358 | { | |
f3bf15e4 | 359 | int shift = 127; |
360 | int shiftedVal=0; | |
2eec55c8 | 361 | for(size_t i = 1; i<size; i++){ |
f3bf15e4 | 362 | if (BitStream[i]-BitStream[i-1]>=30) //large jump up |
363 | shift=127; | |
364 | else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down | |
365 | shift=-127; | |
366 | ||
367 | shiftedVal=BitStream[i]+shift; | |
368 | ||
369 | if (shiftedVal>255) | |
370 | shiftedVal=255; | |
371 | else if (shiftedVal<0) | |
372 | shiftedVal=0; | |
373 | BitStream[i-1] = shiftedVal; | |
374 | } | |
375 | return; | |
6de43508 | 376 | } |
377 | ||
378 | //by marshmellow | |
379 | //takes 3 arguments - clock, invert and maxErr as integers | |
eb191de6 | 380 | //attempts to demodulate ask only |
6de43508 | 381 | int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp) |
eb191de6 | 382 | { |
6de43508 | 383 | if (*size==0) return -1; |
384 | int start = DetectASKClock(BinStream, *size, clk, 20); //clock default | |
2eec55c8 | 385 | if (*clk==0 || start < 0) return -1; |
386 | if (*invert != 1) *invert = 0; | |
13d77ef9 | 387 | if (amp==1) askAmp(BinStream, *size); |
388 | ||
2eec55c8 | 389 | uint8_t initLoopMax = 255; |
c12512e9 | 390 | if (initLoopMax > *size) initLoopMax=*size; |
ba1a299c | 391 | // Detect high and lows |
13d77ef9 | 392 | //25% clip in case highs and lows aren't clipped [marshmellow] |
2eec55c8 | 393 | int high, low; |
394 | if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1) | |
395 | return -1; //just noise | |
ba1a299c | 396 | |
2eec55c8 | 397 | // if clean clipped waves detected run alternate demod |
398 | if (DetectCleanAskWave(BinStream, *size, high, low)) | |
13d77ef9 | 399 | return cleanAskRawDemod(BinStream, size, *clk, *invert, high, low); |
13d77ef9 | 400 | |
2eec55c8 | 401 | int lastBit = 0; //set first clock check - can go negative |
402 | size_t i, iii = 0; | |
403 | size_t errCnt = 0, bitnum = 0; //output counter | |
404 | uint8_t midBit = 0; | |
405 | size_t bestStart = start, bestErrCnt = 0; //(*size/1000); | |
406 | size_t MaxBits = 1024; | |
ba1a299c | 407 | |
2eec55c8 | 408 | //if 0 errors allowed then only try first 2 clock cycles as we want a low tolerance |
23f0a7d8 | 409 | if (!maxErr && initLoopMax > *clk*3) initLoopMax = *clk * 3; |
2eec55c8 | 410 | //if best start not already found by detectclock |
411 | if (start <= 0 || start > initLoopMax){ | |
412 | bestErrCnt = maxErr+1; | |
413 | //PrintAndLog("DEBUG - lastbit - %d",lastBit); | |
414 | //loop to find first wave that works | |
23f0a7d8 | 415 | for (iii=0; iii < initLoopMax - *clk; ++iii){ |
2eec55c8 | 416 | if ((BinStream[iii] >= high) || (BinStream[iii] <= low)){ |
417 | lastBit = iii - *clk; | |
418 | //loop through to see if this start location works | |
419 | for (i = iii; i < *size; ++i) { | |
420 | if (i-lastBit > *clk && (BinStream[i] >= high || BinStream[i] <= low)){ | |
421 | lastBit += *clk; | |
422 | midBit = 0; | |
423 | } else if (i-lastBit > (*clk/2) && midBit == 0) { | |
424 | midBit = 1; | |
425 | } else if ((i-lastBit) > *clk) { | |
ba1a299c | 426 | //should have hit a high or low based on clock!! |
ba1a299c | 427 | //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); |
ba1a299c | 428 | errCnt++; |
2eec55c8 | 429 | lastBit += *clk;//skip over until hit too many errors |
430 | if (errCnt > maxErr) | |
ba1a299c | 431 | break; |
ba1a299c | 432 | } |
2eec55c8 | 433 | if ((i-iii)>(MaxBits * *clk)) break; //got enough bits |
ba1a299c | 434 | } |
23f0a7d8 | 435 | //we got more than 32 good bits and not all errors |
436 | if ((((i-iii)/ *clk) > 32) && (errCnt<=maxErr)) { | |
2eec55c8 | 437 | //possible good read |
438 | if (errCnt==0){ | |
439 | bestStart=iii; | |
440 | bestErrCnt=errCnt; | |
441 | break; //great read - finish | |
442 | } | |
443 | if (errCnt<bestErrCnt){ //set this as new best run | |
444 | bestErrCnt=errCnt; | |
445 | bestStart = iii; | |
446 | } | |
ba1a299c | 447 | } |
2eec55c8 | 448 | errCnt=0; |
ba1a299c | 449 | } |
450 | } | |
ba1a299c | 451 | } |
2eec55c8 | 452 | if (bestErrCnt > maxErr){ |
453 | *invert = bestStart; | |
454 | *clk = iii; | |
455 | return -1; | |
456 | } | |
457 | //best run is good enough - set to best run and overwrite BinStream | |
458 | lastBit = bestStart - *clk - 1; | |
459 | errCnt = 0; | |
460 | ||
461 | for (i = bestStart; i < *size; ++i) { | |
462 | if (i - lastBit > *clk){ | |
463 | if (BinStream[i] >= high) { | |
464 | BinStream[bitnum++] = *invert; | |
465 | } else if (BinStream[i] <= low) { | |
466 | BinStream[bitnum++] = *invert ^ 1; | |
1e090a61 | 467 | } else { |
2eec55c8 | 468 | if (bitnum > 0) { |
469 | BinStream[bitnum++]=77; | |
470 | errCnt++; | |
471 | } | |
472 | } | |
473 | midBit = 0; | |
474 | lastBit += *clk; | |
475 | } else if (i-lastBit > (*clk/2) && midBit == 0){ | |
476 | if (BinStream[i] >= high) { | |
477 | BinStream[bitnum++] = *invert; | |
478 | } else if (BinStream[i] <= low) { | |
479 | BinStream[bitnum++] = *invert ^ 1; | |
480 | } else { | |
481 | ||
482 | BinStream[bitnum] = BinStream[bitnum-1]; | |
483 | bitnum++; | |
1e090a61 | 484 | } |
2eec55c8 | 485 | midBit = 1; |
ba1a299c | 486 | } |
2eec55c8 | 487 | if (bitnum >= MaxBits) break; |
1e090a61 | 488 | } |
2eec55c8 | 489 | *size = bitnum; |
490 | return errCnt; | |
eb191de6 | 491 | } |
11081e04 | 492 | |
493 | // demod gProxIIDemod | |
494 | // error returns as -x | |
495 | // success returns start position in BitStream | |
496 | // BitStream must contain previously askrawdemod and biphasedemoded data | |
497 | int gProxII_Demod(uint8_t BitStream[], size_t *size) | |
498 | { | |
499 | size_t startIdx=0; | |
500 | uint8_t preamble[] = {1,1,1,1,1,0}; | |
501 | ||
502 | uint8_t errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, &startIdx); | |
503 | if (errChk == 0) return -3; //preamble not found | |
504 | if (*size != 96) return -2; //should have found 96 bits | |
505 | //check first 6 spacer bits to verify format | |
506 | if (!BitStream[startIdx+5] && !BitStream[startIdx+10] && !BitStream[startIdx+15] && !BitStream[startIdx+20] && !BitStream[startIdx+25] && !BitStream[startIdx+30]){ | |
507 | //confirmed proper separator bits found | |
508 | //return start position | |
509 | return (int) startIdx; | |
510 | } | |
511 | return -5; | |
512 | } | |
513 | ||
ba1a299c | 514 | //translate wave to 11111100000 (1 for each short wave 0 for each long wave) |
f822a063 | 515 | size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow) |
eb191de6 | 516 | { |
2eec55c8 | 517 | size_t last_transition = 0; |
518 | size_t idx = 1; | |
ac3ba7ee | 519 | //uint32_t maxVal=0; |
ba1a299c | 520 | if (fchigh==0) fchigh=10; |
521 | if (fclow==0) fclow=8; | |
84871873 | 522 | //set the threshold close to 0 (graph) or 128 std to avoid static |
523 | uint8_t threshold_value = 123; | |
ba1a299c | 524 | |
525 | // sync to first lo-hi transition, and threshold | |
526 | ||
527 | // Need to threshold first sample | |
528 | ||
529 | if(dest[0] < threshold_value) dest[0] = 0; | |
530 | else dest[0] = 1; | |
531 | ||
532 | size_t numBits = 0; | |
533 | // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8) | |
534 | // or 10 (fc/10) cycles but in practice due to noise etc we may end up with with anywhere | |
535 | // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10 | |
536 | for(idx = 1; idx < size; idx++) { | |
537 | // threshold current value | |
538 | ||
539 | if (dest[idx] < threshold_value) dest[idx] = 0; | |
540 | else dest[idx] = 1; | |
541 | ||
542 | // Check for 0->1 transition | |
543 | if (dest[idx-1] < dest[idx]) { // 0 -> 1 transition | |
544 | if ((idx-last_transition)<(fclow-2)){ //0-5 = garbage noise | |
545 | //do nothing with extra garbage | |
546 | } else if ((idx-last_transition) < (fchigh-1)) { //6-8 = 8 waves | |
2eec55c8 | 547 | dest[numBits++]=1; |
13d77ef9 | 548 | } else if ((idx-last_transition) > (fchigh+1) && !numBits) { //12 + and first bit = garbage |
549 | //do nothing with beginning garbage | |
550 | } else { //9+ = 10 waves | |
2eec55c8 | 551 | dest[numBits++]=0; |
ba1a299c | 552 | } |
553 | last_transition = idx; | |
ba1a299c | 554 | } |
555 | } | |
556 | return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0 | |
eb191de6 | 557 | } |
558 | ||
ba1a299c | 559 | //translate 11111100000 to 10 |
2eec55c8 | 560 | size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, |
e0165dcf | 561 | uint8_t invert, uint8_t fchigh, uint8_t fclow) |
eb191de6 | 562 | { |
ba1a299c | 563 | uint8_t lastval=dest[0]; |
2eec55c8 | 564 | size_t idx=0; |
ba1a299c | 565 | size_t numBits=0; |
566 | uint32_t n=1; | |
ba1a299c | 567 | for( idx=1; idx < size; idx++) { |
13d77ef9 | 568 | n++; |
2eec55c8 | 569 | if (dest[idx]==lastval) continue; |
570 | ||
ba1a299c | 571 | //if lastval was 1, we have a 1->0 crossing |
13d77ef9 | 572 | if (dest[idx-1]==1) { |
75cbbe9a | 573 | if (!numBits && n < rfLen/fclow) { |
13d77ef9 | 574 | n=0; |
575 | lastval = dest[idx]; | |
576 | continue; | |
577 | } | |
75cbbe9a | 578 | n = (n * fclow + rfLen/2) / rfLen; |
13d77ef9 | 579 | } else {// 0->1 crossing |
580 | //test first bitsample too small | |
75cbbe9a | 581 | if (!numBits && n < rfLen/fchigh) { |
13d77ef9 | 582 | n=0; |
583 | lastval = dest[idx]; | |
584 | continue; | |
585 | } | |
75cbbe9a | 586 | n = (n * fchigh + rfLen/2) / rfLen; |
ba1a299c | 587 | } |
588 | if (n == 0) n = 1; | |
589 | ||
2eec55c8 | 590 | memset(dest+numBits, dest[idx-1]^invert , n); |
591 | numBits += n; | |
ba1a299c | 592 | n=0; |
593 | lastval=dest[idx]; | |
594 | }//end for | |
13d77ef9 | 595 | // if valid extra bits at the end were all the same frequency - add them in |
75cbbe9a | 596 | if (n > rfLen/fchigh) { |
13d77ef9 | 597 | if (dest[idx-2]==1) { |
75cbbe9a | 598 | n = (n * fclow + rfLen/2) / rfLen; |
13d77ef9 | 599 | } else { |
75cbbe9a | 600 | n = (n * fchigh + rfLen/2) / rfLen; |
13d77ef9 | 601 | } |
2eec55c8 | 602 | memset(dest+numBits, dest[idx-1]^invert , n); |
13d77ef9 | 603 | numBits += n; |
604 | } | |
ba1a299c | 605 | return numBits; |
eb191de6 | 606 | } |
607 | //by marshmellow (from holiman's base) | |
608 | // full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod) | |
f822a063 | 609 | int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow) |
eb191de6 | 610 | { |
ba1a299c | 611 | // FSK demodulator |
612 | size = fsk_wave_demod(dest, size, fchigh, fclow); | |
2eec55c8 | 613 | size = aggregate_bits(dest, size, rfLen, invert, fchigh, fclow); |
ba1a299c | 614 | return size; |
eb191de6 | 615 | } |
a1d17964 | 616 | |
eb191de6 | 617 | // loop to get raw HID waveform then FSK demodulate the TAG ID from it |
ec75f5c1 | 618 | int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo) |
eb191de6 | 619 | { |
e0165dcf | 620 | if (justNoise(dest, *size)) return -1; |
621 | ||
622 | size_t numStart=0, size2=*size, startIdx=0; | |
623 | // FSK demodulator | |
624 | *size = fskdemod(dest, size2,50,1,10,8); //fsk2a | |
2eec55c8 | 625 | if (*size < 96*2) return -2; |
e0165dcf | 626 | // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1 |
627 | uint8_t preamble[] = {0,0,0,1,1,1,0,1}; | |
628 | // find bitstring in array | |
629 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); | |
630 | if (errChk == 0) return -3; //preamble not found | |
631 | ||
632 | numStart = startIdx + sizeof(preamble); | |
633 | // final loop, go over previously decoded FSK data and manchester decode into usable tag ID | |
634 | for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){ | |
635 | if (dest[idx] == dest[idx+1]){ | |
636 | return -4; //not manchester data | |
637 | } | |
638 | *hi2 = (*hi2<<1)|(*hi>>31); | |
639 | *hi = (*hi<<1)|(*lo>>31); | |
640 | //Then, shift in a 0 or one into low | |
641 | if (dest[idx] && !dest[idx+1]) // 1 0 | |
642 | *lo=(*lo<<1)|1; | |
643 | else // 0 1 | |
644 | *lo=(*lo<<1)|0; | |
645 | } | |
646 | return (int)startIdx; | |
eb191de6 | 647 | } |
648 | ||
ec75f5c1 | 649 | // loop to get raw paradox waveform then FSK demodulate the TAG ID from it |
a1d17964 | 650 | int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo) |
ec75f5c1 | 651 | { |
a1d17964 | 652 | if (justNoise(dest, *size)) return -1; |
653 | ||
654 | size_t numStart=0, size2=*size, startIdx=0; | |
ec75f5c1 | 655 | // FSK demodulator |
a1d17964 | 656 | *size = fskdemod(dest, size2,50,1,10,8); //fsk2a |
657 | if (*size < 96) return -2; | |
ec75f5c1 | 658 | |
a1d17964 | 659 | // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1 |
660 | uint8_t preamble[] = {0,0,0,0,1,1,1,1}; | |
661 | ||
662 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); | |
663 | if (errChk == 0) return -3; //preamble not found | |
664 | ||
665 | numStart = startIdx + sizeof(preamble); | |
666 | // final loop, go over previously decoded FSK data and manchester decode into usable tag ID | |
667 | for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){ | |
668 | if (dest[idx] == dest[idx+1]) | |
669 | return -4; //not manchester data | |
670 | *hi2 = (*hi2<<1)|(*hi>>31); | |
671 | *hi = (*hi<<1)|(*lo>>31); | |
672 | //Then, shift in a 0 or one into low | |
673 | if (dest[idx] && !dest[idx+1]) // 1 0 | |
674 | *lo=(*lo<<1)|1; | |
675 | else // 0 1 | |
676 | *lo=(*lo<<1)|0; | |
ec75f5c1 | 677 | } |
a1d17964 | 678 | return (int)startIdx; |
ec75f5c1 | 679 | } |
680 | ||
ba1a299c | 681 | uint32_t bytebits_to_byte(uint8_t* src, size_t numbits) |
eb191de6 | 682 | { |
ba1a299c | 683 | uint32_t num = 0; |
684 | for(int i = 0 ; i < numbits ; i++) | |
685 | { | |
686 | num = (num << 1) | (*src); | |
687 | src++; | |
688 | } | |
689 | return num; | |
eb191de6 | 690 | } |
691 | ||
692 | int IOdemodFSK(uint8_t *dest, size_t size) | |
693 | { | |
a1d17964 | 694 | if (justNoise(dest, size)) return -1; |
ba1a299c | 695 | //make sure buffer has data |
a1d17964 | 696 | if (size < 66*64) return -2; |
ba1a299c | 697 | // FSK demodulator |
a1d17964 | 698 | size = fskdemod(dest, size, 64, 1, 10, 8); // FSK2a RF/64 |
699 | if (size < 65) return -3; //did we get a good demod? | |
ba1a299c | 700 | //Index map |
701 | //0 10 20 30 40 50 60 | |
702 | //| | | | | | | | |
703 | //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23 | |
704 | //----------------------------------------------------------------------------- | |
705 | //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11 | |
706 | // | |
707 | //XSF(version)facility:codeone+codetwo | |
708 | //Handle the data | |
a1d17964 | 709 | size_t startIdx = 0; |
710 | uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,1}; | |
711 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), &size, &startIdx); | |
712 | if (errChk == 0) return -4; //preamble not found | |
eb191de6 | 713 | |
a1d17964 | 714 | if (!dest[startIdx+8] && dest[startIdx+17]==1 && dest[startIdx+26]==1 && dest[startIdx+35]==1 && dest[startIdx+44]==1 && dest[startIdx+53]==1){ |
715 | //confirmed proper separator bits found | |
716 | //return start position | |
717 | return (int) startIdx; | |
1e090a61 | 718 | } |
a1d17964 | 719 | return -5; |
1e090a61 | 720 | } |
721 | ||
722 | // by marshmellow | |
723 | // takes a array of binary values, start position, length of bits per parity (includes parity bit), | |
724 | // Parity Type (1 for odd 0 for even), and binary Length (length to run) | |
725 | size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen) | |
726 | { | |
727 | uint32_t parityWd = 0; | |
728 | size_t j = 0, bitCnt = 0; | |
729 | for (int word = 0; word < (bLen); word+=pLen){ | |
730 | for (int bit=0; bit < pLen; bit++){ | |
731 | parityWd = (parityWd << 1) | BitStream[startIdx+word+bit]; | |
f3bf15e4 | 732 | BitStream[j++] = (BitStream[startIdx+word+bit]); |
1e090a61 | 733 | } |
734 | j--; | |
735 | // if parity fails then return 0 | |
736 | if (parityTest(parityWd, pLen, pType) == 0) return -1; | |
737 | bitCnt+=(pLen-1); | |
738 | parityWd = 0; | |
739 | } | |
740 | // if we got here then all the parities passed | |
741 | //return ID start index and size | |
742 | return bitCnt; | |
743 | } | |
744 | ||
745 | // by marshmellow | |
746 | // FSK Demod then try to locate an AWID ID | |
a1d17964 | 747 | int AWIDdemodFSK(uint8_t *dest, size_t *size) |
1e090a61 | 748 | { |
a1d17964 | 749 | //make sure buffer has enough data |
750 | if (*size < 96*50) return -1; | |
751 | ||
752 | if (justNoise(dest, *size)) return -2; | |
1e090a61 | 753 | |
754 | // FSK demodulator | |
a1d17964 | 755 | *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50 |
756 | if (*size < 96) return -3; //did we get a good demod? | |
757 | ||
758 | uint8_t preamble[] = {0,0,0,0,0,0,0,1}; | |
759 | size_t startIdx = 0; | |
760 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); | |
761 | if (errChk == 0) return -4; //preamble not found | |
762 | if (*size != 96) return -5; | |
763 | return (int)startIdx; | |
1e090a61 | 764 | } |
765 | ||
766 | // by marshmellow | |
767 | // FSK Demod then try to locate an Farpointe Data (pyramid) ID | |
a1d17964 | 768 | int PyramiddemodFSK(uint8_t *dest, size_t *size) |
1e090a61 | 769 | { |
f3bf15e4 | 770 | //make sure buffer has data |
771 | if (*size < 128*50) return -5; | |
a1d17964 | 772 | |
f3bf15e4 | 773 | //test samples are not just noise |
774 | if (justNoise(dest, *size)) return -1; | |
1e090a61 | 775 | |
f3bf15e4 | 776 | // FSK demodulator |
777 | *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50 | |
778 | if (*size < 128) return -2; //did we get a good demod? | |
a1d17964 | 779 | |
f3bf15e4 | 780 | uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1}; |
a1d17964 | 781 | size_t startIdx = 0; |
782 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); | |
783 | if (errChk == 0) return -4; //preamble not found | |
784 | if (*size != 128) return -3; | |
785 | return (int)startIdx; | |
1e090a61 | 786 | } |
787 | ||
6de43508 | 788 | |
789 | uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, int high, int low) | |
790 | { | |
1fbf8956 | 791 | uint16_t allPeaks=1; |
6de43508 | 792 | uint16_t cntPeaks=0; |
1fbf8956 | 793 | size_t loopEnd = 572; |
794 | if (loopEnd > size) loopEnd = size; | |
795 | for (size_t i=60; i<loopEnd; i++){ | |
6de43508 | 796 | if (dest[i]>low && dest[i]<high) |
797 | allPeaks=0; | |
798 | else | |
799 | cntPeaks++; | |
800 | } | |
1fbf8956 | 801 | if (allPeaks == 0){ |
802 | if (cntPeaks > 300) return 1; | |
6de43508 | 803 | } |
804 | return allPeaks; | |
805 | } | |
806 | ||
2eec55c8 | 807 | // by marshmellow |
808 | // to help detect clocks on heavily clipped samples | |
809 | // based on counts between zero crossings | |
13d77ef9 | 810 | int DetectStrongAskClock(uint8_t dest[], size_t size) |
811 | { | |
2eec55c8 | 812 | int clk[]={0,8,16,32,40,50,64,100,128}; |
e0165dcf | 813 | size_t idx = 40; |
13d77ef9 | 814 | uint8_t high=0; |
815 | size_t cnt = 0; | |
816 | size_t highCnt = 0; | |
817 | size_t highCnt2 = 0; | |
818 | for (;idx < size; idx++){ | |
819 | if (dest[idx]>128) { | |
820 | if (!high){ | |
821 | high=1; | |
822 | if (cnt > highCnt){ | |
823 | if (highCnt != 0) highCnt2 = highCnt; | |
824 | highCnt = cnt; | |
825 | } else if (cnt > highCnt2) { | |
826 | highCnt2 = cnt; | |
827 | } | |
828 | cnt=1; | |
829 | } else { | |
830 | cnt++; | |
831 | } | |
832 | } else if (dest[idx] <= 128){ | |
833 | if (high) { | |
834 | high=0; | |
835 | if (cnt > highCnt) { | |
836 | if (highCnt != 0) highCnt2 = highCnt; | |
837 | highCnt = cnt; | |
838 | } else if (cnt > highCnt2) { | |
839 | highCnt2 = cnt; | |
840 | } | |
841 | cnt=1; | |
842 | } else { | |
843 | cnt++; | |
844 | } | |
845 | } | |
846 | } | |
1fbf8956 | 847 | uint8_t tol; |
13d77ef9 | 848 | for (idx=8; idx>0; idx--){ |
1fbf8956 | 849 | tol = clk[idx]/8; |
850 | if (clk[idx] >= highCnt - tol && clk[idx] <= highCnt + tol) | |
13d77ef9 | 851 | return clk[idx]; |
1fbf8956 | 852 | if (clk[idx] >= highCnt2 - tol && clk[idx] <= highCnt2 + tol) |
13d77ef9 | 853 | return clk[idx]; |
854 | } | |
855 | return -1; | |
856 | } | |
857 | ||
eb191de6 | 858 | // by marshmellow |
859 | // not perfect especially with lower clocks or VERY good antennas (heavy wave clipping) | |
860 | // maybe somehow adjust peak trimming value based on samples to fix? | |
6de43508 | 861 | // return start index of best starting position for that clock and return clock (by reference) |
862 | int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr) | |
eb191de6 | 863 | { |
2eec55c8 | 864 | size_t i=0; |
865 | uint8_t clk[]={8,16,32,40,50,64,100,128,255}; | |
866 | uint8_t loopCnt = 255; //don't need to loop through entire array... | |
23f0a7d8 | 867 | if (size==0) return -1; |
868 | if (size <= loopCnt) loopCnt = size-1; //not enough samples | |
e0165dcf | 869 | //if we already have a valid clock quit |
870 | ||
871 | for (;i<8;++i) | |
872 | if (clk[i] == *clock) return 0; | |
873 | ||
874 | //get high and low peak | |
875 | int peak, low; | |
2eec55c8 | 876 | if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return -1; |
e0165dcf | 877 | |
878 | //test for large clean peaks | |
879 | if (DetectCleanAskWave(dest, size, peak, low)==1){ | |
880 | int ans = DetectStrongAskClock(dest, size); | |
881 | for (i=7; i>0; i--){ | |
882 | if (clk[i] == ans) { | |
2eec55c8 | 883 | *clock = ans; |
e0165dcf | 884 | return 0; |
885 | } | |
886 | } | |
887 | } | |
2eec55c8 | 888 | uint8_t ii; |
889 | uint8_t clkCnt, tol = 0; | |
890 | uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000}; | |
891 | uint8_t bestStart[]={0,0,0,0,0,0,0,0,0}; | |
892 | size_t errCnt = 0; | |
893 | size_t arrLoc, loopEnd; | |
e0165dcf | 894 | //test each valid clock from smallest to greatest to see which lines up |
895 | for(clkCnt=0; clkCnt < 8; clkCnt++){ | |
896 | if (clk[clkCnt] == 32){ | |
897 | tol=1; | |
898 | }else{ | |
899 | tol=0; | |
900 | } | |
23f0a7d8 | 901 | if (!maxErr && loopCnt>clk[clkCnt]*2) loopCnt=clk[clkCnt]*2; |
e0165dcf | 902 | bestErr[clkCnt]=1000; |
903 | //try lining up the peaks by moving starting point (try first 256) | |
23f0a7d8 | 904 | for (ii=0; ii < loopCnt-tol-clk[clkCnt]; ii++){ |
2eec55c8 | 905 | if (dest[ii] < peak && dest[ii] > low) continue; |
906 | ||
907 | errCnt=0; | |
908 | // now that we have the first one lined up test rest of wave array | |
909 | loopEnd = ((size-ii-tol) / clk[clkCnt]) - 1; | |
910 | for (i=0; i < loopEnd; ++i){ | |
911 | arrLoc = ii + (i * clk[clkCnt]); | |
912 | if (dest[arrLoc] >= peak || dest[arrLoc] <= low){ | |
913 | }else if (dest[arrLoc-tol] >= peak || dest[arrLoc-tol] <= low){ | |
914 | }else if (dest[arrLoc+tol] >= peak || dest[arrLoc+tol] <= low){ | |
915 | }else{ //error no peak detected | |
916 | errCnt++; | |
e0165dcf | 917 | } |
918 | } | |
2eec55c8 | 919 | //if we found no errors then we can stop here |
920 | // this is correct one - return this clock | |
921 | //PrintAndLog("DEBUG: clk %d, err %d, ii %d, i %d",clk[clkCnt],errCnt,ii,i); | |
922 | if(errCnt==0 && clkCnt<6) { | |
923 | *clock = clk[clkCnt]; | |
924 | return ii; | |
925 | } | |
926 | //if we found errors see if it is lowest so far and save it as best run | |
927 | if(errCnt<bestErr[clkCnt]){ | |
928 | bestErr[clkCnt]=errCnt; | |
929 | bestStart[clkCnt]=ii; | |
930 | } | |
e0165dcf | 931 | } |
932 | } | |
933 | uint8_t iii=0; | |
934 | uint8_t best=0; | |
935 | for (iii=0; iii<8; ++iii){ | |
2eec55c8 | 936 | if (bestErr[iii] < bestErr[best]){ |
937 | if (bestErr[iii] == 0) bestErr[iii]=1; | |
e0165dcf | 938 | // current best bit to error ratio vs new bit to error ratio |
2eec55c8 | 939 | if ( (size/clk[best])/bestErr[best] < (size/clk[iii])/bestErr[iii] ){ |
e0165dcf | 940 | best = iii; |
941 | } | |
942 | } | |
943 | } | |
2eec55c8 | 944 | if (bestErr[best] > maxErr) return -1; |
945 | *clock = clk[best]; | |
e0165dcf | 946 | return bestStart[best]; |
eb191de6 | 947 | } |
ba1a299c | 948 | |
949 | //by marshmellow | |
6de43508 | 950 | //detect psk clock by reading each phase shift |
951 | // a phase shift is determined by measuring the sample length of each wave | |
952 | int DetectPSKClock(uint8_t dest[], size_t size, int clock) | |
ba1a299c | 953 | { |
e0165dcf | 954 | uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock |
955 | uint16_t loopCnt = 4096; //don't need to loop through entire array... | |
956 | if (size == 0) return 0; | |
957 | if (size<loopCnt) loopCnt = size; | |
958 | ||
959 | //if we already have a valid clock quit | |
960 | size_t i=1; | |
961 | for (; i < 8; ++i) | |
962 | if (clk[i] == clock) return clock; | |
963 | ||
964 | size_t waveStart=0, waveEnd=0, firstFullWave=0, lastClkBit=0; | |
965 | uint8_t clkCnt, fc=0, fullWaveLen=0, tol=1; | |
966 | uint16_t peakcnt=0, errCnt=0, waveLenCnt=0; | |
967 | uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000}; | |
968 | uint16_t peaksdet[]={0,0,0,0,0,0,0,0,0}; | |
2eec55c8 | 969 | fc = countFC(dest, size, 0); |
970 | if (fc!=2 && fc!=4 && fc!=8) return -1; | |
e0165dcf | 971 | //PrintAndLog("DEBUG: FC: %d",fc); |
972 | ||
973 | //find first full wave | |
974 | for (i=0; i<loopCnt; i++){ | |
975 | if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){ | |
976 | if (waveStart == 0) { | |
977 | waveStart = i+1; | |
978 | //PrintAndLog("DEBUG: waveStart: %d",waveStart); | |
979 | } else { | |
980 | waveEnd = i+1; | |
981 | //PrintAndLog("DEBUG: waveEnd: %d",waveEnd); | |
982 | waveLenCnt = waveEnd-waveStart; | |
983 | if (waveLenCnt > fc){ | |
984 | firstFullWave = waveStart; | |
985 | fullWaveLen=waveLenCnt; | |
986 | break; | |
987 | } | |
988 | waveStart=0; | |
989 | } | |
990 | } | |
991 | } | |
992 | //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen); | |
993 | ||
994 | //test each valid clock from greatest to smallest to see which lines up | |
995 | for(clkCnt=7; clkCnt >= 1 ; clkCnt--){ | |
996 | lastClkBit = firstFullWave; //set end of wave as clock align | |
997 | waveStart = 0; | |
998 | errCnt=0; | |
999 | peakcnt=0; | |
1000 | //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit); | |
1001 | ||
1002 | for (i = firstFullWave+fullWaveLen-1; i < loopCnt-2; i++){ | |
1003 | //top edge of wave = start of new wave | |
1004 | if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){ | |
1005 | if (waveStart == 0) { | |
1006 | waveStart = i+1; | |
1007 | waveLenCnt=0; | |
1008 | } else { //waveEnd | |
1009 | waveEnd = i+1; | |
1010 | waveLenCnt = waveEnd-waveStart; | |
1011 | if (waveLenCnt > fc){ | |
1012 | //if this wave is a phase shift | |
1013 | //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, ii: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+clk[clkCnt]-tol,ii+1,fc); | |
1014 | if (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit | |
1015 | peakcnt++; | |
1016 | lastClkBit+=clk[clkCnt]; | |
1017 | } else if (i<lastClkBit+8){ | |
1018 | //noise after a phase shift - ignore | |
1019 | } else { //phase shift before supposed to based on clock | |
1020 | errCnt++; | |
1021 | } | |
1022 | } else if (i+1 > lastClkBit + clk[clkCnt] + tol + fc){ | |
1023 | lastClkBit+=clk[clkCnt]; //no phase shift but clock bit | |
1024 | } | |
1025 | waveStart=i+1; | |
1026 | } | |
1027 | } | |
1028 | } | |
1029 | if (errCnt == 0){ | |
1030 | return clk[clkCnt]; | |
1031 | } | |
1032 | if (errCnt <= bestErr[clkCnt]) bestErr[clkCnt]=errCnt; | |
1033 | if (peakcnt > peaksdet[clkCnt]) peaksdet[clkCnt]=peakcnt; | |
1034 | } | |
1035 | //all tested with errors | |
1036 | //return the highest clk with the most peaks found | |
1037 | uint8_t best=7; | |
1038 | for (i=7; i>=1; i--){ | |
1039 | if (peaksdet[i] > peaksdet[best]) { | |
1040 | best = i; | |
1041 | } | |
1042 | //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]); | |
1043 | } | |
1044 | return clk[best]; | |
ba1a299c | 1045 | } |
1046 | ||
6de43508 | 1047 | //by marshmellow |
1048 | //detect nrz clock by reading #peaks vs no peaks(or errors) | |
1049 | int DetectNRZClock(uint8_t dest[], size_t size, int clock) | |
ba1a299c | 1050 | { |
2eec55c8 | 1051 | size_t i=0; |
1052 | uint8_t clk[]={8,16,32,40,50,64,100,128,255}; | |
1053 | size_t loopCnt = 4096; //don't need to loop through entire array... | |
e0165dcf | 1054 | if (size == 0) return 0; |
1055 | if (size<loopCnt) loopCnt = size; | |
1056 | ||
1057 | //if we already have a valid clock quit | |
1058 | for (; i < 8; ++i) | |
1059 | if (clk[i] == clock) return clock; | |
1060 | ||
1061 | //get high and low peak | |
1062 | int peak, low; | |
2eec55c8 | 1063 | if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return 0; |
e0165dcf | 1064 | |
1065 | //PrintAndLog("DEBUG: peak: %d, low: %d",peak,low); | |
2eec55c8 | 1066 | size_t ii; |
e0165dcf | 1067 | uint8_t clkCnt; |
1068 | uint8_t tol = 0; | |
2eec55c8 | 1069 | uint16_t peakcnt=0; |
1070 | uint16_t peaksdet[]={0,0,0,0,0,0,0,0}; | |
1071 | uint16_t maxPeak=0; | |
e0165dcf | 1072 | //test for large clipped waves |
1073 | for (i=0; i<loopCnt; i++){ | |
1074 | if (dest[i] >= peak || dest[i] <= low){ | |
1075 | peakcnt++; | |
1076 | } else { | |
1077 | if (peakcnt>0 && maxPeak < peakcnt){ | |
1078 | maxPeak = peakcnt; | |
1079 | } | |
1080 | peakcnt=0; | |
1081 | } | |
1082 | } | |
1083 | peakcnt=0; | |
1084 | //test each valid clock from smallest to greatest to see which lines up | |
1085 | for(clkCnt=0; clkCnt < 8; ++clkCnt){ | |
1086 | //ignore clocks smaller than largest peak | |
1087 | if (clk[clkCnt]<maxPeak) continue; | |
1088 | ||
1089 | //try lining up the peaks by moving starting point (try first 256) | |
1090 | for (ii=0; ii< loopCnt; ++ii){ | |
1091 | if ((dest[ii] >= peak) || (dest[ii] <= low)){ | |
1092 | peakcnt=0; | |
1093 | // now that we have the first one lined up test rest of wave array | |
1094 | for (i=0; i < ((int)((size-ii-tol)/clk[clkCnt])-1); ++i){ | |
1095 | if (dest[ii+(i*clk[clkCnt])]>=peak || dest[ii+(i*clk[clkCnt])]<=low){ | |
1096 | peakcnt++; | |
1097 | } | |
1098 | } | |
1099 | if(peakcnt>peaksdet[clkCnt]) { | |
1100 | peaksdet[clkCnt]=peakcnt; | |
1101 | } | |
1102 | } | |
1103 | } | |
1104 | } | |
1105 | int iii=7; | |
2eec55c8 | 1106 | uint8_t best=0; |
e0165dcf | 1107 | for (iii=7; iii > 0; iii--){ |
1108 | if (peaksdet[iii] > peaksdet[best]){ | |
1109 | best = iii; | |
1110 | } | |
1111 | //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]); | |
1112 | } | |
1113 | return clk[best]; | |
ba1a299c | 1114 | } |
1115 | ||
04d2721b | 1116 | // by marshmellow |
1117 | // convert psk1 demod to psk2 demod | |
1118 | // only transition waves are 1s | |
1119 | void psk1TOpsk2(uint8_t *BitStream, size_t size) | |
1120 | { | |
1121 | size_t i=1; | |
1122 | uint8_t lastBit=BitStream[0]; | |
1123 | for (; i<size; i++){ | |
7a8a982b | 1124 | if (BitStream[i]==77){ |
1125 | //ignore errors | |
1126 | } else if (lastBit!=BitStream[i]){ | |
04d2721b | 1127 | lastBit=BitStream[i]; |
1128 | BitStream[i]=1; | |
1129 | } else { | |
1130 | BitStream[i]=0; | |
1131 | } | |
1132 | } | |
1133 | return; | |
1134 | } | |
ba1a299c | 1135 | |
3bc66a96 | 1136 | // by marshmellow |
1137 | // convert psk2 demod to psk1 demod | |
1138 | // from only transition waves are 1s to phase shifts change bit | |
1139 | void psk2TOpsk1(uint8_t *BitStream, size_t size) | |
1140 | { | |
712ebfa6 | 1141 | uint8_t phase=0; |
1142 | for (size_t i=0; i<size; i++){ | |
1143 | if (BitStream[i]==1){ | |
3bc66a96 | 1144 | phase ^=1; |
1145 | } | |
1146 | BitStream[i]=phase; | |
1147 | } | |
1148 | return; | |
1149 | } | |
1150 | ||
04d2721b | 1151 | // redesigned by marshmellow adjusted from existing decode functions |
1152 | // indala id decoding - only tested on 26 bit tags, but attempted to make it work for more | |
ba1a299c | 1153 | int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert) |
1154 | { | |
1155 | //26 bit 40134 format (don't know other formats) | |
1156 | int i; | |
84871873 | 1157 | int long_wait=29;//29 leading zeros in format |
ba1a299c | 1158 | int start; |
1159 | int first = 0; | |
1160 | int first2 = 0; | |
1161 | int bitCnt = 0; | |
1162 | int ii; | |
1163 | // Finding the start of a UID | |
1164 | for (start = 0; start <= *size - 250; start++) { | |
1165 | first = bitStream[start]; | |
1166 | for (i = start; i < start + long_wait; i++) { | |
1167 | if (bitStream[i] != first) { | |
1168 | break; | |
1169 | } | |
1170 | } | |
1171 | if (i == (start + long_wait)) { | |
1172 | break; | |
1173 | } | |
1174 | } | |
1175 | if (start == *size - 250 + 1) { | |
1176 | // did not find start sequence | |
1177 | return -1; | |
1178 | } | |
ba1a299c | 1179 | // Inverting signal if needed |
1180 | if (first == 1) { | |
1181 | for (i = start; i < *size; i++) { | |
1182 | bitStream[i] = !bitStream[i]; | |
1183 | } | |
1184 | *invert = 1; | |
1185 | }else *invert=0; | |
1186 | ||
1187 | int iii; | |
84871873 | 1188 | //found start once now test length by finding next one |
ba1a299c | 1189 | for (ii=start+29; ii <= *size - 250; ii++) { |
1190 | first2 = bitStream[ii]; | |
1191 | for (iii = ii; iii < ii + long_wait; iii++) { | |
1192 | if (bitStream[iii] != first2) { | |
1193 | break; | |
1194 | } | |
1195 | } | |
1196 | if (iii == (ii + long_wait)) { | |
1197 | break; | |
1198 | } | |
1199 | } | |
1200 | if (ii== *size - 250 + 1){ | |
1201 | // did not find second start sequence | |
1202 | return -2; | |
1203 | } | |
1204 | bitCnt=ii-start; | |
1205 | ||
1206 | // Dumping UID | |
1207 | i = start; | |
1208 | for (ii = 0; ii < bitCnt; ii++) { | |
1209 | bitStream[ii] = bitStream[i++]; | |
1210 | } | |
1211 | *size=bitCnt; | |
1212 | return 1; | |
1213 | } | |
1214 | ||
6de43508 | 1215 | // by marshmellow - demodulate NRZ wave (both similar enough) |
04d2721b | 1216 | // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak |
6de43508 | 1217 | // there probably is a much simpler way to do this.... |
1218 | int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert, int maxErr) | |
ba1a299c | 1219 | { |
e0165dcf | 1220 | if (justNoise(dest, *size)) return -1; |
1221 | *clk = DetectNRZClock(dest, *size, *clk); | |
1222 | if (*clk==0) return -2; | |
2eec55c8 | 1223 | size_t i, gLen = 4096; |
e0165dcf | 1224 | if (gLen>*size) gLen = *size; |
1225 | int high, low; | |
1226 | if (getHiLo(dest, gLen, &high, &low, 75, 75) < 1) return -3; //25% fuzz on high 25% fuzz on low | |
1227 | int lastBit = 0; //set first clock check | |
2eec55c8 | 1228 | size_t iii = 0, bitnum = 0; //bitnum counter |
1229 | uint16_t errCnt = 0, MaxBits = 1000; | |
1230 | size_t bestErrCnt = maxErr+1; | |
1231 | size_t bestPeakCnt = 0, bestPeakStart = 0; | |
1232 | uint8_t bestFirstPeakHigh=0, firstPeakHigh=0, curBit=0, bitHigh=0, errBitHigh=0; | |
e0165dcf | 1233 | 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 |
e0165dcf | 1234 | uint16_t peakCnt=0; |
1235 | uint8_t ignoreWindow=4; | |
2eec55c8 | 1236 | uint8_t ignoreCnt=ignoreWindow; //in case of noise near peak |
e0165dcf | 1237 | //loop to find first wave that works - align to clock |
1238 | for (iii=0; iii < gLen; ++iii){ | |
1239 | if ((dest[iii]>=high) || (dest[iii]<=low)){ | |
1240 | if (dest[iii]>=high) firstPeakHigh=1; | |
1241 | else firstPeakHigh=0; | |
1242 | lastBit=iii-*clk; | |
1243 | peakCnt=0; | |
1244 | errCnt=0; | |
e0165dcf | 1245 | //loop through to see if this start location works |
1246 | for (i = iii; i < *size; ++i) { | |
2eec55c8 | 1247 | // if we are at a clock bit |
1248 | if ((i >= lastBit + *clk - tol) && (i <= lastBit + *clk + tol)) { | |
1249 | //test high/low | |
1250 | if (dest[i] >= high || dest[i] <= low) { | |
1251 | bitHigh = 1; | |
1252 | peakCnt++; | |
1253 | errBitHigh = 0; | |
1254 | ignoreCnt = ignoreWindow; | |
1255 | lastBit += *clk; | |
1256 | } else if (i == lastBit + *clk + tol) { | |
1257 | lastBit += *clk; | |
1258 | } | |
e0165dcf | 1259 | //else if no bars found |
2eec55c8 | 1260 | } else if (dest[i] < high && dest[i] > low){ |
e0165dcf | 1261 | if (ignoreCnt==0){ |
1262 | bitHigh=0; | |
2eec55c8 | 1263 | if (errBitHigh==1) errCnt++; |
e0165dcf | 1264 | errBitHigh=0; |
1265 | } else { | |
1266 | ignoreCnt--; | |
1267 | } | |
2eec55c8 | 1268 | } else if ((dest[i]>=high || dest[i]<=low) && (bitHigh==0)) { |
e0165dcf | 1269 | //error bar found no clock... |
1270 | errBitHigh=1; | |
1271 | } | |
2eec55c8 | 1272 | if (((i-iii) / *clk)>=MaxBits) break; |
e0165dcf | 1273 | } |
1274 | //we got more than 64 good bits and not all errors | |
2eec55c8 | 1275 | if (((i-iii) / *clk) > 64 && (errCnt <= (maxErr))) { |
e0165dcf | 1276 | //possible good read |
2eec55c8 | 1277 | if (!errCnt || peakCnt > bestPeakCnt){ |
e0165dcf | 1278 | bestFirstPeakHigh=firstPeakHigh; |
1279 | bestErrCnt = errCnt; | |
1280 | bestPeakCnt = peakCnt; | |
1281 | bestPeakStart = iii; | |
2eec55c8 | 1282 | if (!errCnt) break; //great read - finish |
e0165dcf | 1283 | } |
e0165dcf | 1284 | } |
1285 | } | |
1286 | } | |
1287 | //PrintAndLog("DEBUG: bestErrCnt: %d, maxErr: %d, bestStart: %d, bestPeakCnt: %d, bestPeakStart: %d",bestErrCnt,maxErr,bestStart,bestPeakCnt,bestPeakStart); | |
2eec55c8 | 1288 | if (bestErrCnt > maxErr) return bestErrCnt; |
1289 | ||
1290 | //best run is good enough set to best run and set overwrite BinStream | |
1291 | lastBit = bestPeakStart - *clk; | |
1292 | memset(dest, bestFirstPeakHigh^1, bestPeakStart / *clk); | |
1293 | bitnum += (bestPeakStart / *clk); | |
1294 | for (i = bestPeakStart; i < *size; ++i) { | |
1295 | // if expecting a clock bit | |
1296 | if ((i >= lastBit + *clk - tol) && (i <= lastBit + *clk + tol)) { | |
1297 | // test high/low | |
1298 | if (dest[i] >= high || dest[i] <= low) { | |
1299 | peakCnt++; | |
1300 | bitHigh = 1; | |
1301 | errBitHigh = 0; | |
1302 | ignoreCnt = ignoreWindow; | |
1303 | curBit = *invert; | |
1304 | if (dest[i] >= high) curBit ^= 1; | |
1305 | dest[bitnum++] = curBit; | |
1306 | lastBit += *clk; | |
1307 | //else no bars found in clock area | |
1308 | } else if (i == lastBit + *clk + tol) { | |
1309 | dest[bitnum++] = curBit; | |
1310 | lastBit += *clk; | |
1311 | } | |
1312 | //else if no bars found | |
1313 | } else if (dest[i] < high && dest[i] > low){ | |
1314 | if (ignoreCnt == 0){ | |
1315 | bitHigh = 0; | |
1316 | if (errBitHigh == 1){ | |
1317 | dest[bitnum++] = 77; | |
1318 | errCnt++; | |
e0165dcf | 1319 | } |
2eec55c8 | 1320 | errBitHigh=0; |
1321 | } else { | |
1322 | ignoreCnt--; | |
e0165dcf | 1323 | } |
2eec55c8 | 1324 | } else if ((dest[i] >= high || dest[i] <= low) && (bitHigh == 0)) { |
1325 | //error bar found no clock... | |
1326 | errBitHigh=1; | |
e0165dcf | 1327 | } |
2eec55c8 | 1328 | if (bitnum >= MaxBits) break; |
e0165dcf | 1329 | } |
2eec55c8 | 1330 | *size = bitnum; |
1331 | return bestErrCnt; | |
ba1a299c | 1332 | } |
1333 | ||
1e090a61 | 1334 | //by marshmellow |
03e6bb4a | 1335 | //detects the bit clock for FSK given the high and low Field Clocks |
1336 | uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow) | |
1e090a61 | 1337 | { |
e0165dcf | 1338 | uint8_t clk[] = {8,16,32,40,50,64,100,128,0}; |
1339 | uint16_t rfLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; | |
1340 | uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; | |
1341 | uint8_t rfLensFnd = 0; | |
2eec55c8 | 1342 | uint8_t lastFCcnt = 0; |
1343 | uint16_t fcCounter = 0; | |
e0165dcf | 1344 | uint16_t rfCounter = 0; |
1345 | uint8_t firstBitFnd = 0; | |
1346 | size_t i; | |
1347 | if (size == 0) return 0; | |
1348 | ||
1349 | uint8_t fcTol = (uint8_t)(0.5+(float)(fcHigh-fcLow)/2); | |
1350 | rfLensFnd=0; | |
1351 | fcCounter=0; | |
1352 | rfCounter=0; | |
1353 | firstBitFnd=0; | |
1354 | //PrintAndLog("DEBUG: fcTol: %d",fcTol); | |
1355 | // prime i to first up transition | |
1356 | for (i = 1; i < size-1; i++) | |
1357 | if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1]) | |
1358 | break; | |
1359 | ||
1360 | for (; i < size-1; i++){ | |
2eec55c8 | 1361 | fcCounter++; |
1362 | rfCounter++; | |
1363 | ||
1364 | if (BitStream[i] <= BitStream[i-1] || BitStream[i] < BitStream[i+1]) | |
1365 | continue; | |
1366 | // else new peak | |
1367 | // if we got less than the small fc + tolerance then set it to the small fc | |
1368 | if (fcCounter < fcLow+fcTol) | |
1369 | fcCounter = fcLow; | |
1370 | else //set it to the large fc | |
1371 | fcCounter = fcHigh; | |
1372 | ||
1373 | //look for bit clock (rf/xx) | |
1374 | if ((fcCounter < lastFCcnt || fcCounter > lastFCcnt)){ | |
1375 | //not the same size as the last wave - start of new bit sequence | |
1376 | if (firstBitFnd > 1){ //skip first wave change - probably not a complete bit | |
1377 | for (int ii=0; ii<15; ii++){ | |
1378 | if (rfLens[ii] == rfCounter){ | |
1379 | rfCnts[ii]++; | |
1380 | rfCounter = 0; | |
1381 | break; | |
e0165dcf | 1382 | } |
e0165dcf | 1383 | } |
2eec55c8 | 1384 | if (rfCounter > 0 && rfLensFnd < 15){ |
1385 | //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter); | |
1386 | rfCnts[rfLensFnd]++; | |
1387 | rfLens[rfLensFnd++] = rfCounter; | |
1388 | } | |
1389 | } else { | |
1390 | firstBitFnd++; | |
e0165dcf | 1391 | } |
2eec55c8 | 1392 | rfCounter=0; |
1393 | lastFCcnt=fcCounter; | |
e0165dcf | 1394 | } |
2eec55c8 | 1395 | fcCounter=0; |
e0165dcf | 1396 | } |
1397 | uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15; | |
1398 | ||
1399 | for (i=0; i<15; i++){ | |
1400 | //PrintAndLog("DEBUG: RF %d, cnts %d",rfLens[i], rfCnts[i]); | |
1401 | //get highest 2 RF values (might need to get more values to compare or compare all?) | |
1402 | if (rfCnts[i]>rfCnts[rfHighest]){ | |
1403 | rfHighest3=rfHighest2; | |
1404 | rfHighest2=rfHighest; | |
1405 | rfHighest=i; | |
1406 | } else if(rfCnts[i]>rfCnts[rfHighest2]){ | |
1407 | rfHighest3=rfHighest2; | |
1408 | rfHighest2=i; | |
1409 | } else if(rfCnts[i]>rfCnts[rfHighest3]){ | |
1410 | rfHighest3=i; | |
1411 | } | |
1412 | } | |
1413 | // set allowed clock remainder tolerance to be 1 large field clock length+1 | |
1414 | // we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off | |
1415 | uint8_t tol1 = fcHigh+1; | |
1416 | ||
1417 | //PrintAndLog("DEBUG: hightest: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]); | |
1418 | ||
1419 | // loop to find the highest clock that has a remainder less than the tolerance | |
1420 | // compare samples counted divided by | |
1421 | int ii=7; | |
1422 | for (; ii>=0; ii--){ | |
1423 | if (rfLens[rfHighest] % clk[ii] < tol1 || rfLens[rfHighest] % clk[ii] > clk[ii]-tol1){ | |
1424 | if (rfLens[rfHighest2] % clk[ii] < tol1 || rfLens[rfHighest2] % clk[ii] > clk[ii]-tol1){ | |
1425 | if (rfLens[rfHighest3] % clk[ii] < tol1 || rfLens[rfHighest3] % clk[ii] > clk[ii]-tol1){ | |
1426 | break; | |
1427 | } | |
1428 | } | |
1429 | } | |
1430 | } | |
1431 | ||
1432 | if (ii<0) return 0; // oops we went too far | |
1433 | ||
1434 | return clk[ii]; | |
03e6bb4a | 1435 | } |
1e090a61 | 1436 | |
03e6bb4a | 1437 | //by marshmellow |
1438 | //countFC is to detect the field clock lengths. | |
1439 | //counts and returns the 2 most common wave lengths | |
6de43508 | 1440 | //mainly used for FSK field clock detection |
2eec55c8 | 1441 | uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj) |
03e6bb4a | 1442 | { |
e0165dcf | 1443 | uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0}; |
1444 | uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0}; | |
1445 | uint8_t fcLensFnd = 0; | |
1446 | uint8_t lastFCcnt=0; | |
2eec55c8 | 1447 | uint8_t fcCounter = 0; |
e0165dcf | 1448 | size_t i; |
1449 | if (size == 0) return 0; | |
1450 | ||
1451 | // prime i to first up transition | |
1452 | for (i = 1; i < size-1; i++) | |
1453 | if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]) | |
1454 | break; | |
1455 | ||
1456 | for (; i < size-1; i++){ | |
1457 | if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){ | |
1458 | // new up transition | |
1459 | fcCounter++; | |
2eec55c8 | 1460 | if (fskAdj){ |
1461 | //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8) | |
1462 | if (lastFCcnt==5 && fcCounter==9) fcCounter--; | |
1463 | //if fc=9 or 4 add one (for when we get a fc 9 instead of 10 or a 4 instead of a 5) | |
1464 | if ((fcCounter==9) || fcCounter==4) fcCounter++; | |
e0165dcf | 1465 | // save last field clock count (fc/xx) |
2eec55c8 | 1466 | lastFCcnt = fcCounter; |
1467 | } | |
e0165dcf | 1468 | // find which fcLens to save it to: |
1469 | for (int ii=0; ii<10; ii++){ | |
1470 | if (fcLens[ii]==fcCounter){ | |
1471 | fcCnts[ii]++; | |
1472 | fcCounter=0; | |
1473 | break; | |
1474 | } | |
1475 | } | |
1476 | if (fcCounter>0 && fcLensFnd<10){ | |
1477 | //add new fc length | |
1478 | fcCnts[fcLensFnd]++; | |
1479 | fcLens[fcLensFnd++]=fcCounter; | |
1480 | } | |
1481 | fcCounter=0; | |
1482 | } else { | |
1483 | // count sample | |
1484 | fcCounter++; | |
1485 | } | |
1486 | } | |
1487 | ||
1488 | uint8_t best1=9, best2=9, best3=9; | |
1489 | uint16_t maxCnt1=0; | |
1490 | // go through fclens and find which ones are bigest 2 | |
1491 | for (i=0; i<10; i++){ | |
1492 | // PrintAndLog("DEBUG: FC %d, Cnt %d, Errs %d",fcLens[i],fcCnts[i],errCnt); | |
1493 | // get the 3 best FC values | |
1494 | if (fcCnts[i]>maxCnt1) { | |
1495 | best3=best2; | |
1496 | best2=best1; | |
1497 | maxCnt1=fcCnts[i]; | |
1498 | best1=i; | |
1499 | } else if(fcCnts[i]>fcCnts[best2]){ | |
1500 | best3=best2; | |
1501 | best2=i; | |
1502 | } else if(fcCnts[i]>fcCnts[best3]){ | |
1503 | best3=i; | |
1504 | } | |
1505 | } | |
1506 | uint8_t fcH=0, fcL=0; | |
1507 | if (fcLens[best1]>fcLens[best2]){ | |
1508 | fcH=fcLens[best1]; | |
1509 | fcL=fcLens[best2]; | |
1510 | } else{ | |
1511 | fcH=fcLens[best2]; | |
1512 | fcL=fcLens[best1]; | |
1513 | } | |
1514 | ||
e0165dcf | 1515 | // TODO: take top 3 answers and compare to known Field clocks to get top 2 |
1516 | ||
1517 | uint16_t fcs = (((uint16_t)fcH)<<8) | fcL; | |
1518 | // PrintAndLog("DEBUG: Best %d best2 %d best3 %d",fcLens[best1],fcLens[best2],fcLens[best3]); | |
2eec55c8 | 1519 | if (fskAdj) return fcs; |
1520 | return fcLens[best1]; | |
6de43508 | 1521 | } |
1522 | ||
1523 | //by marshmellow - demodulate PSK1 wave | |
1524 | //uses wave lengths (# Samples) | |
1525 | int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) | |
1526 | { | |
e0165dcf | 1527 | if (size == 0) return -1; |
2eec55c8 | 1528 | uint16_t loopCnt = 4096; //don't need to loop through entire array... |
e0165dcf | 1529 | if (*size<loopCnt) loopCnt = *size; |
1530 | ||
1531 | uint8_t curPhase = *invert; | |
1532 | size_t i, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0; | |
1533 | uint8_t fc=0, fullWaveLen=0, tol=1; | |
1534 | uint16_t errCnt=0, waveLenCnt=0; | |
2eec55c8 | 1535 | fc = countFC(dest, *size, 0); |
e0165dcf | 1536 | if (fc!=2 && fc!=4 && fc!=8) return -1; |
1537 | //PrintAndLog("DEBUG: FC: %d",fc); | |
1538 | *clock = DetectPSKClock(dest, *size, *clock); | |
2eec55c8 | 1539 | if (*clock == 0) return -1; |
e0165dcf | 1540 | int avgWaveVal=0, lastAvgWaveVal=0; |
1541 | //find first phase shift | |
1542 | for (i=0; i<loopCnt; i++){ | |
1543 | if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){ | |
1544 | waveEnd = i+1; | |
1545 | //PrintAndLog("DEBUG: waveEnd: %d",waveEnd); | |
1546 | waveLenCnt = waveEnd-waveStart; | |
1547 | if (waveLenCnt > fc && waveStart > fc){ //not first peak and is a large wave | |
1548 | lastAvgWaveVal = avgWaveVal/(waveLenCnt); | |
1549 | firstFullWave = waveStart; | |
1550 | fullWaveLen=waveLenCnt; | |
1551 | //if average wave value is > graph 0 then it is an up wave or a 1 | |
2eec55c8 | 1552 | if (lastAvgWaveVal > 123) curPhase ^= 1; //fudge graph 0 a little 123 vs 128 |
e0165dcf | 1553 | break; |
1554 | } | |
1555 | waveStart = i+1; | |
1556 | avgWaveVal = 0; | |
1557 | } | |
2eec55c8 | 1558 | avgWaveVal += dest[i+2]; |
e0165dcf | 1559 | } |
1560 | //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen); | |
1561 | lastClkBit = firstFullWave; //set start of wave as clock align | |
1562 | //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d", *clock, lastClkBit); | |
1563 | waveStart = 0; | |
e0165dcf | 1564 | size_t numBits=0; |
1565 | //set skipped bits | |
2eec55c8 | 1566 | memset(dest, curPhase^1, firstFullWave / *clock); |
e0165dcf | 1567 | numBits += (firstFullWave / *clock); |
1568 | dest[numBits++] = curPhase; //set first read bit | |
2eec55c8 | 1569 | for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){ |
e0165dcf | 1570 | //top edge of wave = start of new wave |
1571 | if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){ | |
1572 | if (waveStart == 0) { | |
1573 | waveStart = i+1; | |
2eec55c8 | 1574 | waveLenCnt = 0; |
e0165dcf | 1575 | avgWaveVal = dest[i+1]; |
1576 | } else { //waveEnd | |
1577 | waveEnd = i+1; | |
1578 | waveLenCnt = waveEnd-waveStart; | |
1579 | lastAvgWaveVal = avgWaveVal/waveLenCnt; | |
1580 | if (waveLenCnt > fc){ | |
1581 | //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal); | |
2eec55c8 | 1582 | //this wave is a phase shift |
e0165dcf | 1583 | //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc); |
1584 | if (i+1 >= lastClkBit + *clock - tol){ //should be a clock bit | |
2eec55c8 | 1585 | curPhase ^= 1; |
e0165dcf | 1586 | dest[numBits++] = curPhase; |
1587 | lastClkBit += *clock; | |
2eec55c8 | 1588 | } else if (i < lastClkBit+10+fc){ |
e0165dcf | 1589 | //noise after a phase shift - ignore |
1590 | } else { //phase shift before supposed to based on clock | |
1591 | errCnt++; | |
1592 | dest[numBits++] = 77; | |
1593 | } | |
1594 | } else if (i+1 > lastClkBit + *clock + tol + fc){ | |
1595 | lastClkBit += *clock; //no phase shift but clock bit | |
1596 | dest[numBits++] = curPhase; | |
1597 | } | |
2eec55c8 | 1598 | avgWaveVal = 0; |
1599 | waveStart = i+1; | |
e0165dcf | 1600 | } |
1601 | } | |
2eec55c8 | 1602 | avgWaveVal += dest[i+1]; |
e0165dcf | 1603 | } |
1604 | *size = numBits; | |
1605 | return errCnt; | |
6de43508 | 1606 | } |