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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; | |
2767fc02 | 84 | if (BitStream[1]>1) return 0; //allow only 1s and 0s |
85 | ||
e0165dcf | 86 | // 111111111 bit pattern represent start of frame |
87 | // include 0 in front to help get start pos | |
88 | uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1}; | |
89 | uint32_t idx = 0; | |
90 | uint32_t parityBits = 0; | |
91 | uint8_t errChk = 0; | |
92 | uint8_t FmtLen = 10; | |
93 | *startIdx = 0; | |
94 | errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx); | |
95 | if (errChk == 0 || *size < 64) return 0; | |
96 | if (*size > 64) FmtLen = 22; | |
97 | *startIdx += 1; //get rid of 0 from preamble | |
98 | idx = *startIdx + 9; | |
99 | for (i=0; i<FmtLen; i++){ //loop through 10 or 22 sets of 5 bits (50-10p = 40 bits or 88 bits) | |
100 | parityBits = bytebits_to_byte(BitStream+(i*5)+idx,5); | |
2eec55c8 | 101 | //check even parity - quit if failed |
102 | if (parityTest(parityBits, 5, 0) == 0) return 0; | |
e0165dcf | 103 | //set uint64 with ID from BitStream |
104 | for (uint8_t ii=0; ii<4; ii++){ | |
105 | *hi = (*hi << 1) | (*lo >> 63); | |
106 | *lo = (*lo << 1) | (BitStream[(i*5)+ii+idx]); | |
107 | } | |
108 | } | |
109 | if (errChk != 0) return 1; | |
110 | //skip last 5 bit parity test for simplicity. | |
111 | // *size = 64 | 128; | |
112 | return 0; | |
2147c307 | 113 | } |
114 | ||
fef74fdc | 115 | //by marshmellow |
116 | //demodulates strong heavily clipped samples | |
23f0a7d8 | 117 | int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low) |
118 | { | |
119 | size_t bitCnt=0, smplCnt=0, errCnt=0; | |
120 | uint8_t waveHigh = 0; | |
23f0a7d8 | 121 | for (size_t i=0; i < *size; i++){ |
122 | if (BinStream[i] >= high && waveHigh){ | |
123 | smplCnt++; | |
124 | } else if (BinStream[i] <= low && !waveHigh){ | |
125 | smplCnt++; | |
126 | } else { //transition | |
127 | if ((BinStream[i] >= high && !waveHigh) || (BinStream[i] <= low && waveHigh)){ | |
128 | if (smplCnt > clk-(clk/4)-1) { //full clock | |
129 | if (smplCnt > clk + (clk/4)+1) { //too many samples | |
130 | errCnt++; | |
2767fc02 | 131 | BinStream[bitCnt++]=7; |
23f0a7d8 | 132 | } else if (waveHigh) { |
133 | BinStream[bitCnt++] = invert; | |
134 | BinStream[bitCnt++] = invert; | |
135 | } else if (!waveHigh) { | |
136 | BinStream[bitCnt++] = invert ^ 1; | |
137 | BinStream[bitCnt++] = invert ^ 1; | |
138 | } | |
139 | waveHigh ^= 1; | |
140 | smplCnt = 0; | |
141 | } else if (smplCnt > (clk/2) - (clk/4)-1) { | |
142 | if (waveHigh) { | |
143 | BinStream[bitCnt++] = invert; | |
144 | } else if (!waveHigh) { | |
145 | BinStream[bitCnt++] = invert ^ 1; | |
146 | } | |
147 | waveHigh ^= 1; | |
148 | smplCnt = 0; | |
149 | } else if (!bitCnt) { | |
150 | //first bit | |
151 | waveHigh = (BinStream[i] >= high); | |
152 | smplCnt = 1; | |
153 | } else { | |
154 | smplCnt++; | |
155 | //transition bit oops | |
156 | } | |
157 | } else { //haven't hit new high or new low yet | |
158 | smplCnt++; | |
159 | } | |
160 | } | |
161 | } | |
162 | *size = bitCnt; | |
163 | return errCnt; | |
164 | } | |
165 | ||
eb191de6 | 166 | //by marshmellow |
fef74fdc | 167 | void askAmp(uint8_t *BitStream, size_t size) |
168 | { | |
169 | for(size_t i = 1; i<size; i++){ | |
170 | if (BitStream[i]-BitStream[i-1]>=30) //large jump up | |
171 | BitStream[i]=127; | |
172 | else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down | |
173 | BitStream[i]=-127; | |
174 | } | |
175 | return; | |
176 | } | |
177 | ||
178 | //by marshmellow | |
179 | //attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester | |
180 | int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType) | |
eb191de6 | 181 | { |
fef74fdc | 182 | if (*size==0) return -1; |
6e984446 | 183 | int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default |
2eec55c8 | 184 | if (*clk==0 || start < 0) return -3; |
fef74fdc | 185 | if (*invert != 1) *invert = 0; |
186 | if (amp==1) askAmp(BinStream, *size); | |
187 | ||
2eec55c8 | 188 | uint8_t initLoopMax = 255; |
189 | if (initLoopMax > *size) initLoopMax = *size; | |
ba1a299c | 190 | // Detect high and lows |
fef74fdc | 191 | //25% clip in case highs and lows aren't clipped [marshmellow] |
2eec55c8 | 192 | int high, low; |
fef74fdc | 193 | if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1) |
194 | return -2; //just noise | |
ba1a299c | 195 | |
fef74fdc | 196 | size_t errCnt = 0; |
23f0a7d8 | 197 | // if clean clipped waves detected run alternate demod |
198 | if (DetectCleanAskWave(BinStream, *size, high, low)) { | |
fef74fdc | 199 | errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low); |
200 | if (askType) //askman | |
201 | return manrawdecode(BinStream, size, 0); | |
202 | else //askraw | |
203 | return errCnt; | |
23f0a7d8 | 204 | } |
205 | ||
fef74fdc | 206 | int lastBit; //set first clock check - can go negative |
207 | size_t i, bitnum = 0; //output counter | |
208 | uint8_t midBit = 0; | |
2eec55c8 | 209 | 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 |
fef74fdc | 210 | 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 |
211 | size_t MaxBits = 1024; | |
6e984446 | 212 | lastBit = start - *clk; |
fef74fdc | 213 | |
6e984446 | 214 | for (i = start; i < *size; ++i) { |
fef74fdc | 215 | if (i-lastBit >= *clk-tol){ |
216 | if (BinStream[i] >= high) { | |
217 | BinStream[bitnum++] = *invert; | |
218 | } else if (BinStream[i] <= low) { | |
219 | BinStream[bitnum++] = *invert ^ 1; | |
220 | } else if (i-lastBit >= *clk+tol) { | |
221 | if (bitnum > 0) { | |
222 | BinStream[bitnum++]=7; | |
223 | errCnt++; | |
224 | } | |
225 | } else { //in tolerance - looking for peak | |
226 | continue; | |
227 | } | |
228 | midBit = 0; | |
2eec55c8 | 229 | lastBit += *clk; |
fef74fdc | 230 | } else if (i-lastBit >= (*clk/2-tol) && !midBit && !askType){ |
231 | if (BinStream[i] >= high) { | |
232 | BinStream[bitnum++] = *invert; | |
233 | } else if (BinStream[i] <= low) { | |
234 | BinStream[bitnum++] = *invert ^ 1; | |
235 | } else if (i-lastBit >= *clk/2+tol) { | |
236 | BinStream[bitnum] = BinStream[bitnum-1]; | |
237 | bitnum++; | |
238 | } else { //in tolerance - looking for peak | |
239 | continue; | |
240 | } | |
241 | midBit = 1; | |
2eec55c8 | 242 | } |
243 | if (bitnum >= MaxBits) break; | |
ba1a299c | 244 | } |
2eec55c8 | 245 | *size = bitnum; |
6e984446 | 246 | return errCnt; |
eb191de6 | 247 | } |
248 | ||
249 | //by marshmellow | |
250 | //take 10 and 01 and manchester decode | |
251 | //run through 2 times and take least errCnt | |
fef74fdc | 252 | int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert) |
eb191de6 | 253 | { |
13d77ef9 | 254 | uint16_t bitnum=0, MaxBits = 512, errCnt = 0; |
255 | size_t i, ii; | |
256 | uint16_t bestErr = 1000, bestRun = 0; | |
fef74fdc | 257 | if (*size < 16) return -1; |
2767fc02 | 258 | //find correct start position [alignment] |
13d77ef9 | 259 | for (ii=0;ii<2;++ii){ |
fef74fdc | 260 | for (i=ii; i<*size-3; i+=2) |
2eec55c8 | 261 | if (BitStream[i]==BitStream[i+1]) |
ba1a299c | 262 | errCnt++; |
2eec55c8 | 263 | |
ba1a299c | 264 | if (bestErr>errCnt){ |
265 | bestErr=errCnt; | |
266 | bestRun=ii; | |
267 | } | |
268 | errCnt=0; | |
269 | } | |
2767fc02 | 270 | //decode |
fef74fdc | 271 | for (i=bestRun; i < *size-3; i+=2){ |
23f0a7d8 | 272 | if(BitStream[i] == 1 && (BitStream[i+1] == 0)){ |
fef74fdc | 273 | BitStream[bitnum++]=invert; |
23f0a7d8 | 274 | } else if((BitStream[i] == 0) && BitStream[i+1] == 1){ |
fef74fdc | 275 | BitStream[bitnum++]=invert^1; |
23f0a7d8 | 276 | } else { |
2767fc02 | 277 | BitStream[bitnum++]=7; |
ba1a299c | 278 | } |
23f0a7d8 | 279 | if(bitnum>MaxBits) break; |
ba1a299c | 280 | } |
23f0a7d8 | 281 | *size=bitnum; |
2eec55c8 | 282 | return bestErr; |
f822a063 | 283 | } |
284 | ||
3606ac0a | 285 | uint32_t manchesterEncode2Bytes(uint16_t datain) { |
286 | uint32_t output = 0; | |
287 | uint8_t curBit = 0; | |
288 | for (uint8_t i=0; i<16; i++) { | |
289 | curBit = (datain >> (15-i) & 1); | |
290 | output |= (1<<(((15-i)*2)+curBit)); | |
291 | } | |
292 | return output; | |
293 | } | |
294 | ||
fef74fdc | 295 | //by marshmellow |
296 | //encode binary data into binary manchester | |
297 | int ManchesterEncode(uint8_t *BitStream, size_t size) | |
298 | { | |
299 | size_t modIdx=20000, i=0; | |
300 | if (size>modIdx) return -1; | |
301 | for (size_t idx=0; idx < size; idx++){ | |
302 | BitStream[idx+modIdx++] = BitStream[idx]; | |
303 | BitStream[idx+modIdx++] = BitStream[idx]^1; | |
304 | } | |
305 | for (; i<(size*2); i++){ | |
306 | BitStream[i] = BitStream[i+20000]; | |
307 | } | |
308 | return i; | |
309 | } | |
310 | ||
f822a063 | 311 | //by marshmellow |
2147c307 | 312 | //take 01 or 10 = 1 and 11 or 00 = 0 |
313 | //check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010 | |
13d77ef9 | 314 | //decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding |
1e090a61 | 315 | int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert) |
f822a063 | 316 | { |
2eec55c8 | 317 | uint16_t bitnum = 0; |
318 | uint16_t errCnt = 0; | |
319 | size_t i = offset; | |
2147c307 | 320 | uint16_t MaxBits=512; |
321 | //if not enough samples - error | |
322 | if (*size < 51) return -1; | |
323 | //check for phase change faults - skip one sample if faulty | |
324 | uint8_t offsetA = 1, offsetB = 1; | |
325 | for (; i<48; i+=2){ | |
326 | if (BitStream[i+1]==BitStream[i+2]) offsetA=0; | |
327 | if (BitStream[i+2]==BitStream[i+3]) offsetB=0; | |
328 | } | |
329 | if (!offsetA && offsetB) offset++; | |
330 | for (i=offset; i<*size-3; i+=2){ | |
331 | //check for phase error | |
13d77ef9 | 332 | if (BitStream[i+1]==BitStream[i+2]) { |
2767fc02 | 333 | BitStream[bitnum++]=7; |
2147c307 | 334 | errCnt++; |
335 | } | |
ba1a299c | 336 | if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){ |
1e090a61 | 337 | BitStream[bitnum++]=1^invert; |
ba1a299c | 338 | } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){ |
1e090a61 | 339 | BitStream[bitnum++]=invert; |
ba1a299c | 340 | } else { |
2767fc02 | 341 | BitStream[bitnum++]=7; |
ba1a299c | 342 | errCnt++; |
343 | } | |
6de43508 | 344 | if(bitnum>MaxBits) break; |
ba1a299c | 345 | } |
346 | *size=bitnum; | |
347 | return errCnt; | |
eb191de6 | 348 | } |
349 | ||
fef74fdc | 350 | // by marshmellow |
11081e04 | 351 | // demod gProxIIDemod |
352 | // error returns as -x | |
353 | // success returns start position in BitStream | |
354 | // BitStream must contain previously askrawdemod and biphasedemoded data | |
355 | int gProxII_Demod(uint8_t BitStream[], size_t *size) | |
356 | { | |
357 | size_t startIdx=0; | |
358 | uint8_t preamble[] = {1,1,1,1,1,0}; | |
359 | ||
360 | uint8_t errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, &startIdx); | |
361 | if (errChk == 0) return -3; //preamble not found | |
362 | if (*size != 96) return -2; //should have found 96 bits | |
363 | //check first 6 spacer bits to verify format | |
364 | if (!BitStream[startIdx+5] && !BitStream[startIdx+10] && !BitStream[startIdx+15] && !BitStream[startIdx+20] && !BitStream[startIdx+25] && !BitStream[startIdx+30]){ | |
365 | //confirmed proper separator bits found | |
366 | //return start position | |
367 | return (int) startIdx; | |
368 | } | |
369 | return -5; | |
370 | } | |
371 | ||
ba1a299c | 372 | //translate wave to 11111100000 (1 for each short wave 0 for each long wave) |
f822a063 | 373 | size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow) |
eb191de6 | 374 | { |
2eec55c8 | 375 | size_t last_transition = 0; |
376 | size_t idx = 1; | |
ac3ba7ee | 377 | //uint32_t maxVal=0; |
ba1a299c | 378 | if (fchigh==0) fchigh=10; |
379 | if (fclow==0) fclow=8; | |
84871873 | 380 | //set the threshold close to 0 (graph) or 128 std to avoid static |
381 | uint8_t threshold_value = 123; | |
f4eadf8a | 382 | size_t preLastSample = 0; |
383 | size_t LastSample = 0; | |
384 | size_t currSample = 0; | |
ba1a299c | 385 | // sync to first lo-hi transition, and threshold |
386 | ||
387 | // Need to threshold first sample | |
388 | ||
389 | if(dest[0] < threshold_value) dest[0] = 0; | |
390 | else dest[0] = 1; | |
391 | ||
392 | size_t numBits = 0; | |
393 | // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8) | |
394 | // or 10 (fc/10) cycles but in practice due to noise etc we may end up with with anywhere | |
395 | // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10 | |
396 | for(idx = 1; idx < size; idx++) { | |
397 | // threshold current value | |
398 | ||
399 | if (dest[idx] < threshold_value) dest[idx] = 0; | |
400 | else dest[idx] = 1; | |
401 | ||
402 | // Check for 0->1 transition | |
403 | if (dest[idx-1] < dest[idx]) { // 0 -> 1 transition | |
f4eadf8a | 404 | preLastSample = LastSample; |
405 | LastSample = currSample; | |
406 | currSample = idx-last_transition; | |
407 | if (currSample < (fclow-2)){ //0-5 = garbage noise | |
ba1a299c | 408 | //do nothing with extra garbage |
f4eadf8a | 409 | } else if (currSample < (fchigh-1)) { //6-8 = 8 sample waves |
db829602 | 410 | if (LastSample > (fchigh-2) && (preLastSample < (fchigh-1) || preLastSample == 0 )){ |
f4eadf8a | 411 | dest[numBits-1]=1; //correct last 9 wave surrounded by 8 waves |
412 | } | |
2eec55c8 | 413 | dest[numBits++]=1; |
f4eadf8a | 414 | |
db829602 | 415 | } else if (currSample > (fchigh) && !numBits) { //12 + and first bit = garbage |
13d77ef9 | 416 | //do nothing with beginning garbage |
f4eadf8a | 417 | } else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's |
418 | dest[numBits++]=1; | |
419 | } else { //9+ = 10 sample waves | |
2eec55c8 | 420 | dest[numBits++]=0; |
ba1a299c | 421 | } |
422 | last_transition = idx; | |
ba1a299c | 423 | } |
424 | } | |
425 | return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0 | |
eb191de6 | 426 | } |
427 | ||
ba1a299c | 428 | //translate 11111100000 to 10 |
2eec55c8 | 429 | size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, |
e0165dcf | 430 | uint8_t invert, uint8_t fchigh, uint8_t fclow) |
eb191de6 | 431 | { |
ba1a299c | 432 | uint8_t lastval=dest[0]; |
2eec55c8 | 433 | size_t idx=0; |
ba1a299c | 434 | size_t numBits=0; |
435 | uint32_t n=1; | |
ba1a299c | 436 | for( idx=1; idx < size; idx++) { |
13d77ef9 | 437 | n++; |
2eec55c8 | 438 | if (dest[idx]==lastval) continue; |
439 | ||
ba1a299c | 440 | //if lastval was 1, we have a 1->0 crossing |
13d77ef9 | 441 | if (dest[idx-1]==1) { |
db829602 | 442 | if (!numBits) { |
443 | if (n < rfLen/fclow) { | |
444 | n=0; | |
445 | lastval = dest[idx]; | |
446 | continue; | |
447 | } | |
448 | n = (n * fclow + rfLen/4) / rfLen; | |
449 | } else { | |
450 | n = (n * fclow + rfLen/2) / rfLen; | |
13d77ef9 | 451 | } |
13d77ef9 | 452 | } else {// 0->1 crossing |
453 | //test first bitsample too small | |
75cbbe9a | 454 | if (!numBits && n < rfLen/fchigh) { |
13d77ef9 | 455 | n=0; |
456 | lastval = dest[idx]; | |
457 | continue; | |
458 | } | |
75cbbe9a | 459 | n = (n * fchigh + rfLen/2) / rfLen; |
ba1a299c | 460 | } |
461 | if (n == 0) n = 1; | |
462 | ||
2eec55c8 | 463 | memset(dest+numBits, dest[idx-1]^invert , n); |
464 | numBits += n; | |
ba1a299c | 465 | n=0; |
466 | lastval=dest[idx]; | |
467 | }//end for | |
13d77ef9 | 468 | // if valid extra bits at the end were all the same frequency - add them in |
75cbbe9a | 469 | if (n > rfLen/fchigh) { |
13d77ef9 | 470 | if (dest[idx-2]==1) { |
75cbbe9a | 471 | n = (n * fclow + rfLen/2) / rfLen; |
13d77ef9 | 472 | } else { |
75cbbe9a | 473 | n = (n * fchigh + rfLen/2) / rfLen; |
13d77ef9 | 474 | } |
2eec55c8 | 475 | memset(dest+numBits, dest[idx-1]^invert , n); |
13d77ef9 | 476 | numBits += n; |
477 | } | |
ba1a299c | 478 | return numBits; |
eb191de6 | 479 | } |
480 | //by marshmellow (from holiman's base) | |
481 | // full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod) | |
f822a063 | 482 | int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow) |
eb191de6 | 483 | { |
ba1a299c | 484 | // FSK demodulator |
485 | size = fsk_wave_demod(dest, size, fchigh, fclow); | |
2eec55c8 | 486 | size = aggregate_bits(dest, size, rfLen, invert, fchigh, fclow); |
ba1a299c | 487 | return size; |
eb191de6 | 488 | } |
a1d17964 | 489 | |
eb191de6 | 490 | // loop to get raw HID waveform then FSK demodulate the TAG ID from it |
ec75f5c1 | 491 | int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo) |
eb191de6 | 492 | { |
e0165dcf | 493 | if (justNoise(dest, *size)) return -1; |
494 | ||
495 | size_t numStart=0, size2=*size, startIdx=0; | |
496 | // FSK demodulator | |
497 | *size = fskdemod(dest, size2,50,1,10,8); //fsk2a | |
2eec55c8 | 498 | if (*size < 96*2) return -2; |
e0165dcf | 499 | // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1 |
500 | uint8_t preamble[] = {0,0,0,1,1,1,0,1}; | |
501 | // find bitstring in array | |
502 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); | |
503 | if (errChk == 0) return -3; //preamble not found | |
504 | ||
505 | numStart = startIdx + sizeof(preamble); | |
506 | // final loop, go over previously decoded FSK data and manchester decode into usable tag ID | |
507 | for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){ | |
508 | if (dest[idx] == dest[idx+1]){ | |
509 | return -4; //not manchester data | |
510 | } | |
511 | *hi2 = (*hi2<<1)|(*hi>>31); | |
512 | *hi = (*hi<<1)|(*lo>>31); | |
513 | //Then, shift in a 0 or one into low | |
514 | if (dest[idx] && !dest[idx+1]) // 1 0 | |
515 | *lo=(*lo<<1)|1; | |
516 | else // 0 1 | |
517 | *lo=(*lo<<1)|0; | |
518 | } | |
519 | return (int)startIdx; | |
eb191de6 | 520 | } |
521 | ||
ec75f5c1 | 522 | // loop to get raw paradox waveform then FSK demodulate the TAG ID from it |
a1d17964 | 523 | int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo) |
ec75f5c1 | 524 | { |
a1d17964 | 525 | if (justNoise(dest, *size)) return -1; |
526 | ||
527 | size_t numStart=0, size2=*size, startIdx=0; | |
ec75f5c1 | 528 | // FSK demodulator |
a1d17964 | 529 | *size = fskdemod(dest, size2,50,1,10,8); //fsk2a |
530 | if (*size < 96) return -2; | |
ec75f5c1 | 531 | |
a1d17964 | 532 | // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1 |
533 | uint8_t preamble[] = {0,0,0,0,1,1,1,1}; | |
534 | ||
535 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); | |
536 | if (errChk == 0) return -3; //preamble not found | |
537 | ||
538 | numStart = startIdx + sizeof(preamble); | |
539 | // final loop, go over previously decoded FSK data and manchester decode into usable tag ID | |
540 | for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){ | |
541 | if (dest[idx] == dest[idx+1]) | |
542 | return -4; //not manchester data | |
543 | *hi2 = (*hi2<<1)|(*hi>>31); | |
544 | *hi = (*hi<<1)|(*lo>>31); | |
545 | //Then, shift in a 0 or one into low | |
546 | if (dest[idx] && !dest[idx+1]) // 1 0 | |
547 | *lo=(*lo<<1)|1; | |
548 | else // 0 1 | |
549 | *lo=(*lo<<1)|0; | |
ec75f5c1 | 550 | } |
a1d17964 | 551 | return (int)startIdx; |
ec75f5c1 | 552 | } |
553 | ||
fd1d30cb | 554 | uint32_t bytebits_to_byte(uint8_t *src, size_t numbits) |
eb191de6 | 555 | { |
ba1a299c | 556 | uint32_t num = 0; |
557 | for(int i = 0 ; i < numbits ; i++) | |
558 | { | |
559 | num = (num << 1) | (*src); | |
560 | src++; | |
561 | } | |
562 | return num; | |
eb191de6 | 563 | } |
564 | ||
04bb0567 | 565 | //least significant bit first |
fd1d30cb | 566 | uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits) |
04bb0567 | 567 | { |
568 | uint32_t num = 0; | |
569 | for(int i = 0 ; i < numbits ; i++) | |
570 | { | |
fd1d30cb | 571 | num = (num << 1) | *(src + (numbits-(i+1))); |
04bb0567 | 572 | } |
573 | return num; | |
574 | } | |
575 | ||
eb191de6 | 576 | int IOdemodFSK(uint8_t *dest, size_t size) |
577 | { | |
a1d17964 | 578 | if (justNoise(dest, size)) return -1; |
ba1a299c | 579 | //make sure buffer has data |
a1d17964 | 580 | if (size < 66*64) return -2; |
ba1a299c | 581 | // FSK demodulator |
a1d17964 | 582 | size = fskdemod(dest, size, 64, 1, 10, 8); // FSK2a RF/64 |
583 | if (size < 65) return -3; //did we get a good demod? | |
ba1a299c | 584 | //Index map |
585 | //0 10 20 30 40 50 60 | |
586 | //| | | | | | | | |
587 | //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23 | |
588 | //----------------------------------------------------------------------------- | |
589 | //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11 | |
590 | // | |
591 | //XSF(version)facility:codeone+codetwo | |
592 | //Handle the data | |
a1d17964 | 593 | size_t startIdx = 0; |
594 | uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,1}; | |
595 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), &size, &startIdx); | |
596 | if (errChk == 0) return -4; //preamble not found | |
eb191de6 | 597 | |
a1d17964 | 598 | if (!dest[startIdx+8] && dest[startIdx+17]==1 && dest[startIdx+26]==1 && dest[startIdx+35]==1 && dest[startIdx+44]==1 && dest[startIdx+53]==1){ |
599 | //confirmed proper separator bits found | |
600 | //return start position | |
601 | return (int) startIdx; | |
1e090a61 | 602 | } |
a1d17964 | 603 | return -5; |
415274a7 | 604 | } |
605 | ||
606 | // by marshmellow | |
607 | // find viking preamble 0xF200 in already demoded data | |
608 | int VikingDemod_AM(uint8_t *dest, size_t *size) { | |
415274a7 | 609 | //make sure buffer has data |
610 | if (*size < 64*2) return -2; | |
611 | ||
612 | size_t startIdx = 0; | |
613 | uint8_t preamble[] = {1,1,1,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; | |
614 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); | |
615 | if (errChk == 0) return -4; //preamble not found | |
3ea7254a | 616 | uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^ bytebits_to_byte(dest+startIdx+8,8) ^ bytebits_to_byte(dest+startIdx+16,8) |
617 | ^ bytebits_to_byte(dest+startIdx+24,8) ^ bytebits_to_byte(dest+startIdx+32,8) ^ bytebits_to_byte(dest+startIdx+40,8) | |
618 | ^ bytebits_to_byte(dest+startIdx+48,8) ^ bytebits_to_byte(dest+startIdx+56,8); | |
619 | if ( checkCalc != 0xA8 ) return -5; | |
14331320 | 620 | if (*size != 64) return -6; |
415274a7 | 621 | //return start position |
622 | return (int) startIdx; | |
1e090a61 | 623 | } |
624 | ||
625 | // by marshmellow | |
626 | // takes a array of binary values, start position, length of bits per parity (includes parity bit), | |
29b6cacc | 627 | // Parity Type (1 for odd; 0 for even; 2 Always 1's), and binary Length (length to run) |
1e090a61 | 628 | size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen) |
629 | { | |
630 | uint32_t parityWd = 0; | |
631 | size_t j = 0, bitCnt = 0; | |
632 | for (int word = 0; word < (bLen); word+=pLen){ | |
633 | for (int bit=0; bit < pLen; bit++){ | |
634 | parityWd = (parityWd << 1) | BitStream[startIdx+word+bit]; | |
f3bf15e4 | 635 | BitStream[j++] = (BitStream[startIdx+word+bit]); |
1e090a61 | 636 | } |
29b6cacc | 637 | j--; // overwrite parity with next data |
1e090a61 | 638 | // if parity fails then return 0 |
29b6cacc | 639 | if (pType == 2) { // then marker bit which should be a 1 |
640 | if (!BitStream[j]) return 0; | |
641 | } else { | |
642 | if (parityTest(parityWd, pLen, pType) == 0) return 0; | |
fd1d30cb | 643 | } |
1e090a61 | 644 | bitCnt+=(pLen-1); |
645 | parityWd = 0; | |
646 | } | |
647 | // if we got here then all the parities passed | |
648 | //return ID start index and size | |
649 | return bitCnt; | |
650 | } | |
651 | ||
04bb0567 | 652 | // Ask/Biphase Demod then try to locate an ISO 11784/85 ID |
653 | // BitStream must contain previously askrawdemod and biphasedemoded data | |
b2c330b3 | 654 | int FDXBdemodBI(uint8_t *dest, size_t *size) |
04bb0567 | 655 | { |
656 | //make sure buffer has enough data | |
657 | if (*size < 128) return -1; | |
658 | ||
659 | size_t startIdx = 0; | |
660 | uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,1}; | |
661 | ||
662 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); | |
663 | if (errChk == 0) return -2; //preamble not found | |
664 | return (int)startIdx; | |
665 | } | |
666 | ||
1e090a61 | 667 | // by marshmellow |
668 | // FSK Demod then try to locate an AWID ID | |
a1d17964 | 669 | int AWIDdemodFSK(uint8_t *dest, size_t *size) |
1e090a61 | 670 | { |
a1d17964 | 671 | //make sure buffer has enough data |
672 | if (*size < 96*50) return -1; | |
673 | ||
674 | if (justNoise(dest, *size)) return -2; | |
1e090a61 | 675 | |
676 | // FSK demodulator | |
a1d17964 | 677 | *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50 |
678 | if (*size < 96) return -3; //did we get a good demod? | |
679 | ||
680 | uint8_t preamble[] = {0,0,0,0,0,0,0,1}; | |
681 | size_t startIdx = 0; | |
682 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); | |
683 | if (errChk == 0) return -4; //preamble not found | |
684 | if (*size != 96) return -5; | |
685 | return (int)startIdx; | |
1e090a61 | 686 | } |
687 | ||
688 | // by marshmellow | |
689 | // FSK Demod then try to locate an Farpointe Data (pyramid) ID | |
a1d17964 | 690 | int PyramiddemodFSK(uint8_t *dest, size_t *size) |
1e090a61 | 691 | { |
f3bf15e4 | 692 | //make sure buffer has data |
693 | if (*size < 128*50) return -5; | |
a1d17964 | 694 | |
f3bf15e4 | 695 | //test samples are not just noise |
696 | if (justNoise(dest, *size)) return -1; | |
1e090a61 | 697 | |
f3bf15e4 | 698 | // FSK demodulator |
699 | *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50 | |
700 | if (*size < 128) return -2; //did we get a good demod? | |
a1d17964 | 701 | |
f3bf15e4 | 702 | uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1}; |
a1d17964 | 703 | size_t startIdx = 0; |
704 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); | |
705 | if (errChk == 0) return -4; //preamble not found | |
706 | if (*size != 128) return -3; | |
707 | return (int)startIdx; | |
1e090a61 | 708 | } |
709 | ||
db829602 | 710 | /* |
711 | void dummy(char *fmt, ...){} | |
712 | ||
713 | #ifndef ON_DEVICE | |
714 | #include "ui.h" | |
715 | #define prnt PrintAndLog | |
716 | #else | |
717 | ||
718 | #define prnt dummy | |
719 | #endif | |
720 | */ | |
fef74fdc | 721 | // by marshmellow |
722 | // to detect a wave that has heavily clipped (clean) samples | |
cc15a118 | 723 | uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low) |
6de43508 | 724 | { |
1fbf8956 | 725 | uint16_t allPeaks=1; |
6de43508 | 726 | uint16_t cntPeaks=0; |
db829602 | 727 | size_t loopEnd = 512+160; |
1fbf8956 | 728 | if (loopEnd > size) loopEnd = size; |
db829602 | 729 | for (size_t i=160; i<loopEnd; i++){ |
6de43508 | 730 | if (dest[i]>low && dest[i]<high) |
731 | allPeaks=0; | |
732 | else | |
733 | cntPeaks++; | |
734 | } | |
1fbf8956 | 735 | if (allPeaks == 0){ |
736 | if (cntPeaks > 300) return 1; | |
6de43508 | 737 | } |
738 | return allPeaks; | |
739 | } | |
2eec55c8 | 740 | // by marshmellow |
741 | // to help detect clocks on heavily clipped samples | |
cc15a118 | 742 | // based on count of low to low |
743 | int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low) | |
13d77ef9 | 744 | { |
cc15a118 | 745 | uint8_t fndClk[] = {8,16,32,40,50,64,128}; |
746 | size_t startwave; | |
db829602 | 747 | size_t i = 100; |
cc15a118 | 748 | size_t minClk = 255; |
749 | // get to first full low to prime loop and skip incomplete first pulse | |
750 | while ((dest[i] < high) && (i < size)) | |
751 | ++i; | |
752 | while ((dest[i] > low) && (i < size)) | |
753 | ++i; | |
754 | ||
755 | // loop through all samples | |
756 | while (i < size) { | |
757 | // measure from low to low | |
758 | while ((dest[i] > low) && (i < size)) | |
759 | ++i; | |
760 | startwave= i; | |
761 | while ((dest[i] < high) && (i < size)) | |
762 | ++i; | |
763 | while ((dest[i] > low) && (i < size)) | |
764 | ++i; | |
765 | //get minimum measured distance | |
766 | if (i-startwave < minClk && i < size) | |
767 | minClk = i - startwave; | |
13d77ef9 | 768 | } |
cc15a118 | 769 | // set clock |
db829602 | 770 | //prnt("minClk: %d",minClk); |
cc15a118 | 771 | for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) { |
772 | if (minClk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1) | |
773 | return fndClk[clkCnt]; | |
13d77ef9 | 774 | } |
cc15a118 | 775 | return 0; |
13d77ef9 | 776 | } |
777 | ||
eb191de6 | 778 | // by marshmellow |
779 | // not perfect especially with lower clocks or VERY good antennas (heavy wave clipping) | |
780 | // maybe somehow adjust peak trimming value based on samples to fix? | |
6de43508 | 781 | // return start index of best starting position for that clock and return clock (by reference) |
782 | int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr) | |
eb191de6 | 783 | { |
6e984446 | 784 | size_t i=1; |
cc15a118 | 785 | uint8_t clk[] = {255,8,16,32,40,50,64,100,128,255}; |
786 | uint8_t clkEnd = 9; | |
2eec55c8 | 787 | uint8_t loopCnt = 255; //don't need to loop through entire array... |
db829602 | 788 | if (size <= loopCnt+60) return -1; //not enough samples |
789 | size -= 60; //sometimes there is a strange end wave - filter out this.... | |
6e984446 | 790 | //if we already have a valid clock |
791 | uint8_t clockFnd=0; | |
cc15a118 | 792 | for (;i<clkEnd;++i) |
793 | if (clk[i] == *clock) clockFnd = i; | |
6e984446 | 794 | //clock found but continue to find best startpos |
e0165dcf | 795 | |
796 | //get high and low peak | |
797 | int peak, low; | |
2eec55c8 | 798 | if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return -1; |
e0165dcf | 799 | |
800 | //test for large clean peaks | |
cc15a118 | 801 | if (!clockFnd){ |
802 | if (DetectCleanAskWave(dest, size, peak, low)==1){ | |
803 | int ans = DetectStrongAskClock(dest, size, peak, low); | |
804 | for (i=clkEnd-1; i>0; i--){ | |
805 | if (clk[i] == ans) { | |
806 | *clock = ans; | |
807 | //clockFnd = i; | |
808 | return 0; // for strong waves i don't use the 'best start position' yet... | |
809 | //break; //clock found but continue to find best startpos [not yet] | |
810 | } | |
e0165dcf | 811 | } |
812 | } | |
813 | } | |
2eec55c8 | 814 | uint8_t ii; |
815 | uint8_t clkCnt, tol = 0; | |
816 | uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000}; | |
817 | uint8_t bestStart[]={0,0,0,0,0,0,0,0,0}; | |
818 | size_t errCnt = 0; | |
819 | size_t arrLoc, loopEnd; | |
6e984446 | 820 | |
cc15a118 | 821 | if (clockFnd>0) { |
822 | clkCnt = clockFnd; | |
823 | clkEnd = clockFnd+1; | |
824 | } | |
825 | else clkCnt=1; | |
826 | ||
827 | //test each valid clock from smallest to greatest to see which lines up | |
828 | for(; clkCnt < clkEnd; clkCnt++){ | |
fef74fdc | 829 | if (clk[clkCnt] <= 32){ |
e0165dcf | 830 | tol=1; |
831 | }else{ | |
832 | tol=0; | |
833 | } | |
2767fc02 | 834 | //if no errors allowed - keep start within the first clock |
cc15a118 | 835 | if (!maxErr && size > clk[clkCnt]*2 + tol && clk[clkCnt]<128) loopCnt=clk[clkCnt]*2; |
e0165dcf | 836 | bestErr[clkCnt]=1000; |
6e984446 | 837 | //try lining up the peaks by moving starting point (try first few clocks) |
cc15a118 | 838 | for (ii=0; ii < loopCnt; ii++){ |
2eec55c8 | 839 | if (dest[ii] < peak && dest[ii] > low) continue; |
840 | ||
841 | errCnt=0; | |
842 | // now that we have the first one lined up test rest of wave array | |
843 | loopEnd = ((size-ii-tol) / clk[clkCnt]) - 1; | |
844 | for (i=0; i < loopEnd; ++i){ | |
845 | arrLoc = ii + (i * clk[clkCnt]); | |
846 | if (dest[arrLoc] >= peak || dest[arrLoc] <= low){ | |
847 | }else if (dest[arrLoc-tol] >= peak || dest[arrLoc-tol] <= low){ | |
848 | }else if (dest[arrLoc+tol] >= peak || dest[arrLoc+tol] <= low){ | |
849 | }else{ //error no peak detected | |
850 | errCnt++; | |
e0165dcf | 851 | } |
852 | } | |
cc15a118 | 853 | //if we found no errors then we can stop here and a low clock (common clocks) |
2eec55c8 | 854 | // this is correct one - return this clock |
db829602 | 855 | //prnt("DEBUG: clk %d, err %d, ii %d, i %d",clk[clkCnt],errCnt,ii,i); |
cc15a118 | 856 | if(errCnt==0 && clkCnt<7) { |
857 | if (!clockFnd) *clock = clk[clkCnt]; | |
2eec55c8 | 858 | return ii; |
859 | } | |
860 | //if we found errors see if it is lowest so far and save it as best run | |
861 | if(errCnt<bestErr[clkCnt]){ | |
862 | bestErr[clkCnt]=errCnt; | |
863 | bestStart[clkCnt]=ii; | |
864 | } | |
e0165dcf | 865 | } |
866 | } | |
cc15a118 | 867 | uint8_t iii; |
e0165dcf | 868 | uint8_t best=0; |
cc15a118 | 869 | for (iii=1; iii<clkEnd; ++iii){ |
2eec55c8 | 870 | if (bestErr[iii] < bestErr[best]){ |
871 | if (bestErr[iii] == 0) bestErr[iii]=1; | |
e0165dcf | 872 | // current best bit to error ratio vs new bit to error ratio |
2eec55c8 | 873 | if ( (size/clk[best])/bestErr[best] < (size/clk[iii])/bestErr[iii] ){ |
e0165dcf | 874 | best = iii; |
875 | } | |
876 | } | |
877 | } | |
2767fc02 | 878 | //if (bestErr[best] > maxErr) return -1; |
cc15a118 | 879 | if (!clockFnd) *clock = clk[best]; |
e0165dcf | 880 | return bestStart[best]; |
eb191de6 | 881 | } |
ba1a299c | 882 | |
883 | //by marshmellow | |
6de43508 | 884 | //detect psk clock by reading each phase shift |
885 | // a phase shift is determined by measuring the sample length of each wave | |
886 | int DetectPSKClock(uint8_t dest[], size_t size, int clock) | |
ba1a299c | 887 | { |
e0165dcf | 888 | uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock |
889 | uint16_t loopCnt = 4096; //don't need to loop through entire array... | |
890 | if (size == 0) return 0; | |
db829602 | 891 | if (size<loopCnt) loopCnt = size-20; |
e0165dcf | 892 | |
893 | //if we already have a valid clock quit | |
894 | size_t i=1; | |
895 | for (; i < 8; ++i) | |
896 | if (clk[i] == clock) return clock; | |
897 | ||
898 | size_t waveStart=0, waveEnd=0, firstFullWave=0, lastClkBit=0; | |
899 | uint8_t clkCnt, fc=0, fullWaveLen=0, tol=1; | |
900 | uint16_t peakcnt=0, errCnt=0, waveLenCnt=0; | |
901 | uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000}; | |
902 | uint16_t peaksdet[]={0,0,0,0,0,0,0,0,0}; | |
2eec55c8 | 903 | fc = countFC(dest, size, 0); |
904 | if (fc!=2 && fc!=4 && fc!=8) return -1; | |
db829602 | 905 | //prnt("DEBUG: FC: %d",fc); |
e0165dcf | 906 | |
907 | //find first full wave | |
db829602 | 908 | for (i=160; i<loopCnt; i++){ |
e0165dcf | 909 | if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){ |
910 | if (waveStart == 0) { | |
911 | waveStart = i+1; | |
db829602 | 912 | //prnt("DEBUG: waveStart: %d",waveStart); |
e0165dcf | 913 | } else { |
914 | waveEnd = i+1; | |
db829602 | 915 | //prnt("DEBUG: waveEnd: %d",waveEnd); |
e0165dcf | 916 | waveLenCnt = waveEnd-waveStart; |
917 | if (waveLenCnt > fc){ | |
918 | firstFullWave = waveStart; | |
919 | fullWaveLen=waveLenCnt; | |
920 | break; | |
921 | } | |
922 | waveStart=0; | |
923 | } | |
924 | } | |
925 | } | |
db829602 | 926 | //prnt("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen); |
e0165dcf | 927 | |
928 | //test each valid clock from greatest to smallest to see which lines up | |
929 | for(clkCnt=7; clkCnt >= 1 ; clkCnt--){ | |
930 | lastClkBit = firstFullWave; //set end of wave as clock align | |
931 | waveStart = 0; | |
932 | errCnt=0; | |
933 | peakcnt=0; | |
db829602 | 934 | //prnt("DEBUG: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit); |
e0165dcf | 935 | |
936 | for (i = firstFullWave+fullWaveLen-1; i < loopCnt-2; i++){ | |
937 | //top edge of wave = start of new wave | |
938 | if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){ | |
939 | if (waveStart == 0) { | |
940 | waveStart = i+1; | |
941 | waveLenCnt=0; | |
942 | } else { //waveEnd | |
943 | waveEnd = i+1; | |
944 | waveLenCnt = waveEnd-waveStart; | |
945 | if (waveLenCnt > fc){ | |
946 | //if this wave is a phase shift | |
db829602 | 947 | //prnt("DEBUG: phase shift at: %d, len: %d, nextClk: %d, ii: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+clk[clkCnt]-tol,ii+1,fc); |
e0165dcf | 948 | if (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit |
949 | peakcnt++; | |
950 | lastClkBit+=clk[clkCnt]; | |
951 | } else if (i<lastClkBit+8){ | |
952 | //noise after a phase shift - ignore | |
953 | } else { //phase shift before supposed to based on clock | |
954 | errCnt++; | |
955 | } | |
956 | } else if (i+1 > lastClkBit + clk[clkCnt] + tol + fc){ | |
957 | lastClkBit+=clk[clkCnt]; //no phase shift but clock bit | |
958 | } | |
959 | waveStart=i+1; | |
960 | } | |
961 | } | |
962 | } | |
963 | if (errCnt == 0){ | |
964 | return clk[clkCnt]; | |
965 | } | |
966 | if (errCnt <= bestErr[clkCnt]) bestErr[clkCnt]=errCnt; | |
967 | if (peakcnt > peaksdet[clkCnt]) peaksdet[clkCnt]=peakcnt; | |
968 | } | |
969 | //all tested with errors | |
970 | //return the highest clk with the most peaks found | |
971 | uint8_t best=7; | |
972 | for (i=7; i>=1; i--){ | |
973 | if (peaksdet[i] > peaksdet[best]) { | |
974 | best = i; | |
975 | } | |
db829602 | 976 | //prnt("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]); |
e0165dcf | 977 | } |
978 | return clk[best]; | |
ba1a299c | 979 | } |
980 | ||
db829602 | 981 | int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low){ |
982 | //find shortest transition from high to low | |
983 | size_t i = 0; | |
984 | size_t transition1 = 0; | |
985 | int lowestTransition = 255; | |
986 | uint8_t lastWasHigh=0; | |
987 | //find first valid beginning of a high/low wave | |
988 | if (dest[i] >= peak) { | |
989 | for (; i < size; i++) { | |
990 | if (dest[i] <= low) break; | |
991 | } | |
992 | lastWasHigh=0; | |
993 | } else if (dest[i] <= low) { | |
994 | for (; i < size; i++) { | |
995 | if (dest[i] >= peak) break; | |
996 | } | |
997 | lastWasHigh=1; | |
998 | } else { | |
999 | for (; i < size; i++) { | |
1000 | if (dest[i] >= peak || dest[i] <= low) { | |
1001 | lastWasHigh = (dest[i] >= peak); | |
1002 | break; | |
1003 | } | |
1004 | } | |
1005 | } | |
1006 | if (i==size) return 0; | |
1007 | transition1 = i; | |
1008 | ||
1009 | for (;i < size; i++) { | |
1010 | if ((dest[i] >= peak && !lastWasHigh) || (dest[i] <= low && lastWasHigh)) { | |
1011 | lastWasHigh = (dest[i] >= peak); | |
1012 | if (i-transition1 < lowestTransition) lowestTransition = i-transition1; | |
1013 | transition1 = i; | |
1014 | } | |
1015 | } | |
1016 | if (lowestTransition == 255) lowestTransition = 0; | |
1017 | return lowestTransition; | |
1018 | } | |
1019 | ||
6de43508 | 1020 | //by marshmellow |
1021 | //detect nrz clock by reading #peaks vs no peaks(or errors) | |
1022 | int DetectNRZClock(uint8_t dest[], size_t size, int clock) | |
ba1a299c | 1023 | { |
2eec55c8 | 1024 | size_t i=0; |
1025 | uint8_t clk[]={8,16,32,40,50,64,100,128,255}; | |
1026 | size_t loopCnt = 4096; //don't need to loop through entire array... | |
e0165dcf | 1027 | if (size == 0) return 0; |
db829602 | 1028 | if (size<loopCnt) loopCnt = size-20; |
e0165dcf | 1029 | //if we already have a valid clock quit |
1030 | for (; i < 8; ++i) | |
1031 | if (clk[i] == clock) return clock; | |
1032 | ||
1033 | //get high and low peak | |
1034 | int peak, low; | |
2eec55c8 | 1035 | if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return 0; |
e0165dcf | 1036 | |
db829602 | 1037 | int lowestTransition = DetectStrongNRZClk(dest, size-20, peak, low); |
1038 | //prnt("DEBUG: peak: %d, low: %d",peak,low); | |
2eec55c8 | 1039 | size_t ii; |
e0165dcf | 1040 | uint8_t clkCnt; |
1041 | uint8_t tol = 0; | |
db829602 | 1042 | uint16_t smplCnt = 0; |
1043 | int16_t peakcnt = 0; | |
1044 | int16_t peaksdet[] = {0,0,0,0,0,0,0,0}; | |
1045 | uint16_t maxPeak = 255; | |
1046 | uint8_t firstpeak = 0; | |
e0165dcf | 1047 | //test for large clipped waves |
1048 | for (i=0; i<loopCnt; i++){ | |
1049 | if (dest[i] >= peak || dest[i] <= low){ | |
db829602 | 1050 | if (!firstpeak) continue; |
1051 | smplCnt++; | |
e0165dcf | 1052 | } else { |
db829602 | 1053 | firstpeak=1; |
1054 | if (smplCnt > 6 ){ | |
1055 | if (maxPeak > smplCnt){ | |
1056 | maxPeak = smplCnt; | |
1057 | //prnt("maxPk: %d",maxPeak); | |
1058 | } | |
1059 | peakcnt++; | |
1060 | //prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt); | |
1061 | smplCnt=0; | |
e0165dcf | 1062 | } |
e0165dcf | 1063 | } |
1064 | } | |
db829602 | 1065 | uint8_t samePeak=0; |
1066 | uint8_t errBitHigh=0; | |
e0165dcf | 1067 | peakcnt=0; |
1068 | //test each valid clock from smallest to greatest to see which lines up | |
1069 | for(clkCnt=0; clkCnt < 8; ++clkCnt){ | |
db829602 | 1070 | //ignore clocks smaller than smallest peak |
1071 | if (clk[clkCnt] < maxPeak - (clk[clkCnt]/4)) continue; | |
e0165dcf | 1072 | //try lining up the peaks by moving starting point (try first 256) |
db829602 | 1073 | for (ii=20; ii < loopCnt; ++ii){ |
e0165dcf | 1074 | if ((dest[ii] >= peak) || (dest[ii] <= low)){ |
1075 | peakcnt=0; | |
db829602 | 1076 | uint8_t bitHigh =0; |
1077 | uint8_t ignoreCnt = 0; | |
1078 | uint8_t ignoreWindow = 4; | |
1079 | int lastBit = ii-clk[clkCnt]; | |
1080 | //loop through to see if this start location works | |
1081 | for (i = ii; i < size-20; ++i) { | |
1082 | // if we are at a clock bit | |
1083 | if ((i >= lastBit + clk[clkCnt] - tol) && (i <= lastBit + clk[clkCnt] + tol)) { | |
1084 | //test high/low | |
1085 | if (dest[i] >= peak || dest[i] <= low) { | |
1086 | if (samePeak) peakcnt--; | |
1087 | bitHigh=1; | |
1088 | peakcnt++; | |
1089 | errBitHigh = 0; | |
1090 | ignoreCnt = ignoreWindow; | |
1091 | lastBit += clk[clkCnt]; | |
1092 | samePeak = 1; | |
1093 | } else if (i == lastBit + clk[clkCnt] + tol) { | |
1094 | lastBit += clk[clkCnt]; | |
1095 | samePeak = 0; | |
1096 | } | |
1097 | //else if not a clock bit and no peaks | |
1098 | } else if (dest[i] < peak && dest[i] > low){ | |
1099 | samePeak = 0; | |
1100 | if (ignoreCnt==0){ | |
1101 | bitHigh=0; | |
1102 | if (errBitHigh==1) peakcnt--; | |
1103 | errBitHigh=0; | |
1104 | } else { | |
1105 | ignoreCnt--; | |
1106 | } | |
1107 | // else if not a clock bit but we have a peak | |
1108 | } else if ((dest[i]>=peak || dest[i]<=low) && (bitHigh==0)) { | |
1109 | //error bar found no clock... | |
1110 | errBitHigh=1; | |
e0165dcf | 1111 | } |
1112 | } | |
1113 | if(peakcnt>peaksdet[clkCnt]) { | |
1114 | peaksdet[clkCnt]=peakcnt; | |
1115 | } | |
1116 | } | |
1117 | } | |
1118 | } | |
1119 | int iii=7; | |
2eec55c8 | 1120 | uint8_t best=0; |
e0165dcf | 1121 | for (iii=7; iii > 0; iii--){ |
1122 | if (peaksdet[iii] > peaksdet[best]){ | |
1123 | best = iii; | |
db829602 | 1124 | } else if (peaksdet[iii] == peaksdet[best] && lowestTransition){ |
1125 | if (clk[iii] > (lowestTransition - (clk[iii]/8)) && clk[iii] < (lowestTransition + (clk[iii]/8))){ | |
1126 | best = iii; | |
1127 | } | |
e0165dcf | 1128 | } |
db829602 | 1129 | //prnt("DEBUG: Clk: %d, peaks: %d, maxPeak: %d, bestClk: %d, lowestTrs: %d",clk[iii],peaksdet[iii],maxPeak, clk[best], lowestTransition); |
e0165dcf | 1130 | } |
db829602 | 1131 | |
e0165dcf | 1132 | return clk[best]; |
ba1a299c | 1133 | } |
1134 | ||
04d2721b | 1135 | // by marshmellow |
1136 | // convert psk1 demod to psk2 demod | |
1137 | // only transition waves are 1s | |
1138 | void psk1TOpsk2(uint8_t *BitStream, size_t size) | |
1139 | { | |
1140 | size_t i=1; | |
1141 | uint8_t lastBit=BitStream[0]; | |
1142 | for (; i<size; i++){ | |
2767fc02 | 1143 | if (BitStream[i]==7){ |
7a8a982b | 1144 | //ignore errors |
1145 | } else if (lastBit!=BitStream[i]){ | |
04d2721b | 1146 | lastBit=BitStream[i]; |
1147 | BitStream[i]=1; | |
1148 | } else { | |
1149 | BitStream[i]=0; | |
1150 | } | |
1151 | } | |
1152 | return; | |
1153 | } | |
ba1a299c | 1154 | |
3bc66a96 | 1155 | // by marshmellow |
1156 | // convert psk2 demod to psk1 demod | |
1157 | // from only transition waves are 1s to phase shifts change bit | |
1158 | void psk2TOpsk1(uint8_t *BitStream, size_t size) | |
1159 | { | |
712ebfa6 | 1160 | uint8_t phase=0; |
1161 | for (size_t i=0; i<size; i++){ | |
1162 | if (BitStream[i]==1){ | |
3bc66a96 | 1163 | phase ^=1; |
1164 | } | |
1165 | BitStream[i]=phase; | |
1166 | } | |
1167 | return; | |
1168 | } | |
1169 | ||
04d2721b | 1170 | // redesigned by marshmellow adjusted from existing decode functions |
1171 | // indala id decoding - only tested on 26 bit tags, but attempted to make it work for more | |
ba1a299c | 1172 | int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert) |
1173 | { | |
1174 | //26 bit 40134 format (don't know other formats) | |
14331320 | 1175 | uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1}; |
1176 | uint8_t preamble_i[] = {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0}; | |
1177 | size_t startidx = 0; | |
1178 | if (!preambleSearch(bitStream, preamble, sizeof(preamble), size, &startidx)){ | |
1179 | // if didn't find preamble try again inverting | |
1180 | if (!preambleSearch(bitStream, preamble_i, sizeof(preamble_i), size, &startidx)) return -1; | |
1181 | *invert ^= 1; | |
1182 | } | |
1183 | if (*size != 64 && *size != 224) return -2; | |
1184 | if (*invert==1) | |
1185 | for (size_t i = startidx; i < *size; i++) | |
1186 | bitStream[i] ^= 1; | |
ba1a299c | 1187 | |
14331320 | 1188 | return (int) startidx; |
ba1a299c | 1189 | } |
1190 | ||
db829602 | 1191 | // by marshmellow - demodulate NRZ wave |
04d2721b | 1192 | // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak |
db829602 | 1193 | int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert){ |
e0165dcf | 1194 | if (justNoise(dest, *size)) return -1; |
1195 | *clk = DetectNRZClock(dest, *size, *clk); | |
1196 | if (*clk==0) return -2; | |
2eec55c8 | 1197 | size_t i, gLen = 4096; |
db829602 | 1198 | if (gLen>*size) gLen = *size-20; |
e0165dcf | 1199 | int high, low; |
1200 | if (getHiLo(dest, gLen, &high, &low, 75, 75) < 1) return -3; //25% fuzz on high 25% fuzz on low | |
db829602 | 1201 | |
1202 | uint8_t bit=0; | |
1203 | //convert wave samples to 1's and 0's | |
1204 | for(i=20; i < *size-20; i++){ | |
1205 | if (dest[i] >= high) bit = 1; | |
1206 | if (dest[i] <= low) bit = 0; | |
1207 | dest[i] = bit; | |
e0165dcf | 1208 | } |
db829602 | 1209 | //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit) |
1210 | size_t lastBit = 0; | |
1211 | size_t numBits = 0; | |
1212 | for(i=21; i < *size-20; i++) { | |
1213 | //if transition detected or large number of same bits - store the passed bits | |
1214 | if (dest[i] != dest[i-1] || (i-lastBit) == (10 * *clk)) { | |
1215 | memset(dest+numBits, dest[i-1] ^ *invert, (i - lastBit + (*clk/4)) / *clk); | |
1216 | numBits += (i - lastBit + (*clk/4)) / *clk; | |
1217 | lastBit = i-1; | |
e0165dcf | 1218 | } |
e0165dcf | 1219 | } |
db829602 | 1220 | *size = numBits; |
1221 | return 0; | |
ba1a299c | 1222 | } |
1223 | ||
1e090a61 | 1224 | //by marshmellow |
03e6bb4a | 1225 | //detects the bit clock for FSK given the high and low Field Clocks |
1226 | uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow) | |
1e090a61 | 1227 | { |
e0165dcf | 1228 | uint8_t clk[] = {8,16,32,40,50,64,100,128,0}; |
1229 | uint16_t rfLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; | |
1230 | uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; | |
1231 | uint8_t rfLensFnd = 0; | |
2eec55c8 | 1232 | uint8_t lastFCcnt = 0; |
1233 | uint16_t fcCounter = 0; | |
e0165dcf | 1234 | uint16_t rfCounter = 0; |
1235 | uint8_t firstBitFnd = 0; | |
1236 | size_t i; | |
1237 | if (size == 0) return 0; | |
1238 | ||
1239 | uint8_t fcTol = (uint8_t)(0.5+(float)(fcHigh-fcLow)/2); | |
1240 | rfLensFnd=0; | |
1241 | fcCounter=0; | |
1242 | rfCounter=0; | |
1243 | firstBitFnd=0; | |
1244 | //PrintAndLog("DEBUG: fcTol: %d",fcTol); | |
1245 | // prime i to first up transition | |
1246 | for (i = 1; i < size-1; i++) | |
1247 | if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1]) | |
1248 | break; | |
1249 | ||
1250 | for (; i < size-1; i++){ | |
2eec55c8 | 1251 | fcCounter++; |
1252 | rfCounter++; | |
1253 | ||
1254 | if (BitStream[i] <= BitStream[i-1] || BitStream[i] < BitStream[i+1]) | |
1255 | continue; | |
1256 | // else new peak | |
1257 | // if we got less than the small fc + tolerance then set it to the small fc | |
1258 | if (fcCounter < fcLow+fcTol) | |
1259 | fcCounter = fcLow; | |
1260 | else //set it to the large fc | |
1261 | fcCounter = fcHigh; | |
1262 | ||
1263 | //look for bit clock (rf/xx) | |
1264 | if ((fcCounter < lastFCcnt || fcCounter > lastFCcnt)){ | |
1265 | //not the same size as the last wave - start of new bit sequence | |
1266 | if (firstBitFnd > 1){ //skip first wave change - probably not a complete bit | |
1267 | for (int ii=0; ii<15; ii++){ | |
1268 | if (rfLens[ii] == rfCounter){ | |
1269 | rfCnts[ii]++; | |
1270 | rfCounter = 0; | |
1271 | break; | |
e0165dcf | 1272 | } |
e0165dcf | 1273 | } |
2eec55c8 | 1274 | if (rfCounter > 0 && rfLensFnd < 15){ |
1275 | //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter); | |
1276 | rfCnts[rfLensFnd]++; | |
1277 | rfLens[rfLensFnd++] = rfCounter; | |
1278 | } | |
1279 | } else { | |
1280 | firstBitFnd++; | |
e0165dcf | 1281 | } |
2eec55c8 | 1282 | rfCounter=0; |
1283 | lastFCcnt=fcCounter; | |
e0165dcf | 1284 | } |
2eec55c8 | 1285 | fcCounter=0; |
e0165dcf | 1286 | } |
1287 | uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15; | |
1288 | ||
1289 | for (i=0; i<15; i++){ | |
1290 | //PrintAndLog("DEBUG: RF %d, cnts %d",rfLens[i], rfCnts[i]); | |
1291 | //get highest 2 RF values (might need to get more values to compare or compare all?) | |
1292 | if (rfCnts[i]>rfCnts[rfHighest]){ | |
1293 | rfHighest3=rfHighest2; | |
1294 | rfHighest2=rfHighest; | |
1295 | rfHighest=i; | |
1296 | } else if(rfCnts[i]>rfCnts[rfHighest2]){ | |
1297 | rfHighest3=rfHighest2; | |
1298 | rfHighest2=i; | |
1299 | } else if(rfCnts[i]>rfCnts[rfHighest3]){ | |
1300 | rfHighest3=i; | |
1301 | } | |
1302 | } | |
1303 | // set allowed clock remainder tolerance to be 1 large field clock length+1 | |
1304 | // we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off | |
1305 | uint8_t tol1 = fcHigh+1; | |
1306 | ||
1307 | //PrintAndLog("DEBUG: hightest: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]); | |
1308 | ||
1309 | // loop to find the highest clock that has a remainder less than the tolerance | |
1310 | // compare samples counted divided by | |
1311 | int ii=7; | |
1312 | for (; ii>=0; ii--){ | |
1313 | if (rfLens[rfHighest] % clk[ii] < tol1 || rfLens[rfHighest] % clk[ii] > clk[ii]-tol1){ | |
1314 | if (rfLens[rfHighest2] % clk[ii] < tol1 || rfLens[rfHighest2] % clk[ii] > clk[ii]-tol1){ | |
1315 | if (rfLens[rfHighest3] % clk[ii] < tol1 || rfLens[rfHighest3] % clk[ii] > clk[ii]-tol1){ | |
1316 | break; | |
1317 | } | |
1318 | } | |
1319 | } | |
1320 | } | |
1321 | ||
1322 | if (ii<0) return 0; // oops we went too far | |
1323 | ||
1324 | return clk[ii]; | |
03e6bb4a | 1325 | } |
1e090a61 | 1326 | |
03e6bb4a | 1327 | //by marshmellow |
1328 | //countFC is to detect the field clock lengths. | |
1329 | //counts and returns the 2 most common wave lengths | |
6de43508 | 1330 | //mainly used for FSK field clock detection |
2eec55c8 | 1331 | uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj) |
03e6bb4a | 1332 | { |
e0165dcf | 1333 | uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0}; |
1334 | uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0}; | |
1335 | uint8_t fcLensFnd = 0; | |
1336 | uint8_t lastFCcnt=0; | |
2eec55c8 | 1337 | uint8_t fcCounter = 0; |
e0165dcf | 1338 | size_t i; |
1339 | if (size == 0) return 0; | |
1340 | ||
1341 | // prime i to first up transition | |
1342 | for (i = 1; i < size-1; i++) | |
1343 | if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]) | |
1344 | break; | |
1345 | ||
1346 | for (; i < size-1; i++){ | |
1347 | if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){ | |
1348 | // new up transition | |
1349 | fcCounter++; | |
2eec55c8 | 1350 | if (fskAdj){ |
1351 | //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8) | |
1352 | if (lastFCcnt==5 && fcCounter==9) fcCounter--; | |
1353 | //if fc=9 or 4 add one (for when we get a fc 9 instead of 10 or a 4 instead of a 5) | |
1354 | if ((fcCounter==9) || fcCounter==4) fcCounter++; | |
e0165dcf | 1355 | // save last field clock count (fc/xx) |
2eec55c8 | 1356 | lastFCcnt = fcCounter; |
1357 | } | |
e0165dcf | 1358 | // find which fcLens to save it to: |
1359 | for (int ii=0; ii<10; ii++){ | |
1360 | if (fcLens[ii]==fcCounter){ | |
1361 | fcCnts[ii]++; | |
1362 | fcCounter=0; | |
1363 | break; | |
1364 | } | |
1365 | } | |
1366 | if (fcCounter>0 && fcLensFnd<10){ | |
1367 | //add new fc length | |
1368 | fcCnts[fcLensFnd]++; | |
1369 | fcLens[fcLensFnd++]=fcCounter; | |
1370 | } | |
1371 | fcCounter=0; | |
1372 | } else { | |
1373 | // count sample | |
1374 | fcCounter++; | |
1375 | } | |
1376 | } | |
1377 | ||
1378 | uint8_t best1=9, best2=9, best3=9; | |
1379 | uint16_t maxCnt1=0; | |
1380 | // go through fclens and find which ones are bigest 2 | |
1381 | for (i=0; i<10; i++){ | |
1382 | // PrintAndLog("DEBUG: FC %d, Cnt %d, Errs %d",fcLens[i],fcCnts[i],errCnt); | |
1383 | // get the 3 best FC values | |
1384 | if (fcCnts[i]>maxCnt1) { | |
1385 | best3=best2; | |
1386 | best2=best1; | |
1387 | maxCnt1=fcCnts[i]; | |
1388 | best1=i; | |
1389 | } else if(fcCnts[i]>fcCnts[best2]){ | |
1390 | best3=best2; | |
1391 | best2=i; | |
1392 | } else if(fcCnts[i]>fcCnts[best3]){ | |
1393 | best3=i; | |
1394 | } | |
1395 | } | |
1396 | uint8_t fcH=0, fcL=0; | |
1397 | if (fcLens[best1]>fcLens[best2]){ | |
1398 | fcH=fcLens[best1]; | |
1399 | fcL=fcLens[best2]; | |
1400 | } else{ | |
1401 | fcH=fcLens[best2]; | |
1402 | fcL=fcLens[best1]; | |
1403 | } | |
1404 | ||
e0165dcf | 1405 | // TODO: take top 3 answers and compare to known Field clocks to get top 2 |
1406 | ||
1407 | uint16_t fcs = (((uint16_t)fcH)<<8) | fcL; | |
1408 | // PrintAndLog("DEBUG: Best %d best2 %d best3 %d",fcLens[best1],fcLens[best2],fcLens[best3]); | |
2eec55c8 | 1409 | if (fskAdj) return fcs; |
1410 | return fcLens[best1]; | |
6de43508 | 1411 | } |
1412 | ||
1413 | //by marshmellow - demodulate PSK1 wave | |
1414 | //uses wave lengths (# Samples) | |
1415 | int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) | |
1416 | { | |
e0165dcf | 1417 | if (size == 0) return -1; |
2eec55c8 | 1418 | uint16_t loopCnt = 4096; //don't need to loop through entire array... |
e0165dcf | 1419 | if (*size<loopCnt) loopCnt = *size; |
1420 | ||
db829602 | 1421 | size_t numBits=0; |
e0165dcf | 1422 | uint8_t curPhase = *invert; |
1423 | size_t i, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0; | |
1424 | uint8_t fc=0, fullWaveLen=0, tol=1; | |
1425 | uint16_t errCnt=0, waveLenCnt=0; | |
2eec55c8 | 1426 | fc = countFC(dest, *size, 0); |
e0165dcf | 1427 | if (fc!=2 && fc!=4 && fc!=8) return -1; |
1428 | //PrintAndLog("DEBUG: FC: %d",fc); | |
1429 | *clock = DetectPSKClock(dest, *size, *clock); | |
2eec55c8 | 1430 | if (*clock == 0) return -1; |
e0165dcf | 1431 | int avgWaveVal=0, lastAvgWaveVal=0; |
1432 | //find first phase shift | |
1433 | for (i=0; i<loopCnt; i++){ | |
1434 | if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){ | |
1435 | waveEnd = i+1; | |
1436 | //PrintAndLog("DEBUG: waveEnd: %d",waveEnd); | |
1437 | waveLenCnt = waveEnd-waveStart; | |
db829602 | 1438 | if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+2)){ //not first peak and is a large wave but not out of whack |
e0165dcf | 1439 | lastAvgWaveVal = avgWaveVal/(waveLenCnt); |
1440 | firstFullWave = waveStart; | |
1441 | fullWaveLen=waveLenCnt; | |
1442 | //if average wave value is > graph 0 then it is an up wave or a 1 | |
2eec55c8 | 1443 | if (lastAvgWaveVal > 123) curPhase ^= 1; //fudge graph 0 a little 123 vs 128 |
e0165dcf | 1444 | break; |
1445 | } | |
1446 | waveStart = i+1; | |
1447 | avgWaveVal = 0; | |
1448 | } | |
2eec55c8 | 1449 | avgWaveVal += dest[i+2]; |
e0165dcf | 1450 | } |
db829602 | 1451 | if (firstFullWave == 0) { |
1452 | // no phase shift detected - could be all 1's or 0's - doesn't matter where we start | |
1453 | // so skip a little to ensure we are past any Start Signal | |
1454 | firstFullWave = 160; | |
1455 | memset(dest, curPhase, firstFullWave / *clock); | |
1456 | } else { | |
1457 | memset(dest, curPhase^1, firstFullWave / *clock); | |
1458 | } | |
1459 | //advance bits | |
1460 | numBits += (firstFullWave / *clock); | |
1461 | //set start of wave as clock align | |
1462 | lastClkBit = firstFullWave; | |
e0165dcf | 1463 | //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen); |
e0165dcf | 1464 | //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d", *clock, lastClkBit); |
1465 | waveStart = 0; | |
e0165dcf | 1466 | dest[numBits++] = curPhase; //set first read bit |
2eec55c8 | 1467 | for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){ |
e0165dcf | 1468 | //top edge of wave = start of new wave |
1469 | if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){ | |
1470 | if (waveStart == 0) { | |
1471 | waveStart = i+1; | |
2eec55c8 | 1472 | waveLenCnt = 0; |
e0165dcf | 1473 | avgWaveVal = dest[i+1]; |
1474 | } else { //waveEnd | |
1475 | waveEnd = i+1; | |
1476 | waveLenCnt = waveEnd-waveStart; | |
1477 | lastAvgWaveVal = avgWaveVal/waveLenCnt; | |
1478 | if (waveLenCnt > fc){ | |
1479 | //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal); | |
2eec55c8 | 1480 | //this wave is a phase shift |
e0165dcf | 1481 | //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc); |
1482 | if (i+1 >= lastClkBit + *clock - tol){ //should be a clock bit | |
2eec55c8 | 1483 | curPhase ^= 1; |
e0165dcf | 1484 | dest[numBits++] = curPhase; |
1485 | lastClkBit += *clock; | |
2eec55c8 | 1486 | } else if (i < lastClkBit+10+fc){ |
e0165dcf | 1487 | //noise after a phase shift - ignore |
1488 | } else { //phase shift before supposed to based on clock | |
1489 | errCnt++; | |
2767fc02 | 1490 | dest[numBits++] = 7; |
e0165dcf | 1491 | } |
1492 | } else if (i+1 > lastClkBit + *clock + tol + fc){ | |
1493 | lastClkBit += *clock; //no phase shift but clock bit | |
1494 | dest[numBits++] = curPhase; | |
1495 | } | |
2eec55c8 | 1496 | avgWaveVal = 0; |
1497 | waveStart = i+1; | |
e0165dcf | 1498 | } |
1499 | } | |
2eec55c8 | 1500 | avgWaveVal += dest[i+1]; |
e0165dcf | 1501 | } |
1502 | *size = numBits; | |
1503 | return errCnt; | |
6de43508 | 1504 | } |