| 1 | //----------------------------------------------------------------------------- |
| 2 | // Copyright (C) 2014 |
| 3 | // |
| 4 | // This code is licensed to you under the terms of the GNU GPL, version 2 or, |
| 5 | // at your option, any later version. See the LICENSE.txt file for the text of |
| 6 | // the license. |
| 7 | //----------------------------------------------------------------------------- |
| 8 | // Low frequency demod/decode commands |
| 9 | //----------------------------------------------------------------------------- |
| 10 | |
| 11 | #include <stdlib.h> |
| 12 | #include "lfdemod.h" |
| 13 | #include <string.h> |
| 14 | |
| 15 | //to allow debug print calls when used not on device |
| 16 | void dummy(char *fmt, ...){} |
| 17 | |
| 18 | #ifndef ON_DEVICE |
| 19 | #include "ui.h" |
| 20 | #include "cmdparser.h" |
| 21 | #include "cmddata.h" |
| 22 | #define prnt PrintAndLog |
| 23 | #else |
| 24 | uint8_t g_debugMode=0; |
| 25 | #define prnt dummy |
| 26 | #endif |
| 27 | |
| 28 | uint8_t justNoise(uint8_t *BitStream, size_t size) |
| 29 | { |
| 30 | static const uint8_t THRESHOLD = 123; |
| 31 | //test samples are not just noise |
| 32 | uint8_t justNoise1 = 1; |
| 33 | for(size_t idx=0; idx < size && justNoise1 ;idx++){ |
| 34 | justNoise1 = BitStream[idx] < THRESHOLD; |
| 35 | } |
| 36 | return justNoise1; |
| 37 | } |
| 38 | |
| 39 | //by marshmellow |
| 40 | //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 |
| 41 | int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi, uint8_t fuzzLo) |
| 42 | { |
| 43 | *high=0; |
| 44 | *low=255; |
| 45 | // get high and low thresholds |
| 46 | for (size_t i=0; i < size; i++){ |
| 47 | if (BitStream[i] > *high) *high = BitStream[i]; |
| 48 | if (BitStream[i] < *low) *low = BitStream[i]; |
| 49 | } |
| 50 | if (*high < 123) return -1; // just noise |
| 51 | *high = ((*high-128)*fuzzHi + 12800)/100; |
| 52 | *low = ((*low-128)*fuzzLo + 12800)/100; |
| 53 | return 1; |
| 54 | } |
| 55 | |
| 56 | // by marshmellow |
| 57 | // pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType |
| 58 | // returns 1 if passed |
| 59 | uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType) |
| 60 | { |
| 61 | uint8_t ans = 0; |
| 62 | for (uint8_t i = 0; i < bitLen; i++){ |
| 63 | ans ^= ((bits >> i) & 1); |
| 64 | } |
| 65 | if (g_debugMode) prnt("DEBUG: ans: %d, ptype: %d, bits: %08X",ans,pType,bits); |
| 66 | return (ans == pType); |
| 67 | } |
| 68 | |
| 69 | // by marshmellow |
| 70 | // takes a array of binary values, start position, length of bits per parity (includes parity bit), |
| 71 | // Parity Type (1 for odd; 0 for even; 2 for Always 1's; 3 for Always 0's), and binary Length (length to run) |
| 72 | size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen) |
| 73 | { |
| 74 | uint32_t parityWd = 0; |
| 75 | size_t j = 0, bitCnt = 0; |
| 76 | for (int word = 0; word < (bLen); word+=pLen) { |
| 77 | for (int bit=0; bit < pLen; bit++) { |
| 78 | parityWd = (parityWd << 1) | BitStream[startIdx+word+bit]; |
| 79 | BitStream[j++] = (BitStream[startIdx+word+bit]); |
| 80 | } |
| 81 | if (word+pLen >= bLen) break; |
| 82 | |
| 83 | j--; // overwrite parity with next data |
| 84 | // if parity fails then return 0 |
| 85 | switch (pType) { |
| 86 | case 3: if (BitStream[j]==1) {return 0;} break; //should be 0 spacer bit |
| 87 | case 2: if (BitStream[j]==0) {return 0;} break; //should be 1 spacer bit |
| 88 | default: if (parityTest(parityWd, pLen, pType) == 0) {return 0;} break; //test parity |
| 89 | } |
| 90 | bitCnt+=(pLen-1); |
| 91 | parityWd = 0; |
| 92 | } |
| 93 | // if we got here then all the parities passed |
| 94 | //return ID start index and size |
| 95 | return bitCnt; |
| 96 | } |
| 97 | |
| 98 | // by marshmellow |
| 99 | // takes a array of binary values, length of bits per parity (includes parity bit), |
| 100 | // Parity Type (1 for odd; 0 for even; 2 Always 1's; 3 Always 0's), and binary Length (length to run) |
| 101 | // Make sure *dest is long enough to store original sourceLen + #_of_parities_to_be_added |
| 102 | size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t pLen, uint8_t pType) |
| 103 | { |
| 104 | uint32_t parityWd = 0; |
| 105 | size_t j = 0, bitCnt = 0; |
| 106 | for (int word = 0; word < sourceLen; word+=pLen-1) { |
| 107 | for (int bit=0; bit < pLen-1; bit++){ |
| 108 | parityWd = (parityWd << 1) | BitSource[word+bit]; |
| 109 | dest[j++] = (BitSource[word+bit]); |
| 110 | } |
| 111 | // if parity fails then return 0 |
| 112 | switch (pType) { |
| 113 | case 3: dest[j++]=0; break; // marker bit which should be a 0 |
| 114 | case 2: dest[j++]=1; break; // marker bit which should be a 1 |
| 115 | default: |
| 116 | dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1; |
| 117 | break; |
| 118 | } |
| 119 | bitCnt += pLen; |
| 120 | parityWd = 0; |
| 121 | } |
| 122 | // if we got here then all the parities passed |
| 123 | //return ID start index and size |
| 124 | return bitCnt; |
| 125 | } |
| 126 | |
| 127 | uint32_t bytebits_to_byte(uint8_t *src, size_t numbits) |
| 128 | { |
| 129 | uint32_t num = 0; |
| 130 | for(int i = 0 ; i < numbits ; i++) |
| 131 | { |
| 132 | num = (num << 1) | (*src); |
| 133 | src++; |
| 134 | } |
| 135 | return num; |
| 136 | } |
| 137 | |
| 138 | //least significant bit first |
| 139 | uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits) |
| 140 | { |
| 141 | uint32_t num = 0; |
| 142 | for(int i = 0 ; i < numbits ; i++) |
| 143 | { |
| 144 | num = (num << 1) | *(src + (numbits-(i+1))); |
| 145 | } |
| 146 | return num; |
| 147 | } |
| 148 | |
| 149 | //by marshmellow |
| 150 | //search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length |
| 151 | uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx) |
| 152 | { |
| 153 | // Sanity check. If preamble length is bigger than bitstream length. |
| 154 | if ( *size <= pLen ) return 0; |
| 155 | |
| 156 | uint8_t foundCnt=0; |
| 157 | for (int idx=0; idx < *size - pLen; idx++){ |
| 158 | if (memcmp(BitStream+idx, preamble, pLen) == 0){ |
| 159 | //first index found |
| 160 | foundCnt++; |
| 161 | if (foundCnt == 1){ |
| 162 | *startIdx = idx; |
| 163 | } |
| 164 | if (foundCnt == 2){ |
| 165 | *size = idx - *startIdx; |
| 166 | return 1; |
| 167 | } |
| 168 | } |
| 169 | } |
| 170 | return 0; |
| 171 | } |
| 172 | |
| 173 | // search for given preamble in given BitStream and return success=1 or fail=0 and startIndex (where it was found) |
| 174 | // does not look for a repeating preamble |
| 175 | // em4x05/4x69 only sends preamble once, so look for it once in the first pLen bits |
| 176 | // leave it generic so it could be reused later... |
| 177 | bool onePreambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t size, size_t *startIdx) { |
| 178 | // Sanity check. If preamble length is bigger than bitstream length. |
| 179 | if ( size <= pLen ) return false; |
| 180 | for (size_t idx = 0; idx < size - pLen; idx++) { |
| 181 | if (memcmp(BitStream+idx, preamble, pLen) == 0) { |
| 182 | if (g_debugMode) prnt("DEBUG: preamble found at %u", idx); |
| 183 | *startIdx = idx; |
| 184 | return true; |
| 185 | } |
| 186 | } |
| 187 | return false; |
| 188 | } |
| 189 | |
| 190 | //by marshmellow |
| 191 | //takes 1s and 0s and searches for EM410x format - output EM ID |
| 192 | uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo) |
| 193 | { |
| 194 | //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future |
| 195 | // otherwise could be a void with no arguments |
| 196 | //set defaults |
| 197 | uint32_t i = 0; |
| 198 | if (BitStream[1]>1) return 0; //allow only 1s and 0s |
| 199 | |
| 200 | // 111111111 bit pattern represent start of frame |
| 201 | // include 0 in front to help get start pos |
| 202 | uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1}; |
| 203 | uint32_t idx = 0; |
| 204 | uint32_t parityBits = 0; |
| 205 | uint8_t errChk = 0; |
| 206 | uint8_t FmtLen = 10; |
| 207 | *startIdx = 0; |
| 208 | errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx); |
| 209 | if (errChk == 0 || *size < 64) return 0; |
| 210 | if (*size > 64) FmtLen = 22; |
| 211 | *startIdx += 1; //get rid of 0 from preamble |
| 212 | idx = *startIdx + 9; |
| 213 | for (i=0; i<FmtLen; i++){ //loop through 10 or 22 sets of 5 bits (50-10p = 40 bits or 88 bits) |
| 214 | parityBits = bytebits_to_byte(BitStream+(i*5)+idx,5); |
| 215 | //check even parity - quit if failed |
| 216 | if (parityTest(parityBits, 5, 0) == 0) return 0; |
| 217 | //set uint64 with ID from BitStream |
| 218 | for (uint8_t ii=0; ii<4; ii++){ |
| 219 | *hi = (*hi << 1) | (*lo >> 63); |
| 220 | *lo = (*lo << 1) | (BitStream[(i*5)+ii+idx]); |
| 221 | } |
| 222 | } |
| 223 | if (errChk != 0) return 1; |
| 224 | //skip last 5 bit parity test for simplicity. |
| 225 | // *size = 64 | 128; |
| 226 | return 0; |
| 227 | } |
| 228 | |
| 229 | //by marshmellow |
| 230 | //demodulates strong heavily clipped samples |
| 231 | int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low) |
| 232 | { |
| 233 | size_t bitCnt=0, smplCnt=0, errCnt=0; |
| 234 | uint8_t waveHigh = 0; |
| 235 | for (size_t i=0; i < *size; i++){ |
| 236 | if (BinStream[i] >= high && waveHigh){ |
| 237 | smplCnt++; |
| 238 | } else if (BinStream[i] <= low && !waveHigh){ |
| 239 | smplCnt++; |
| 240 | } else { //transition |
| 241 | if ((BinStream[i] >= high && !waveHigh) || (BinStream[i] <= low && waveHigh)){ |
| 242 | if (smplCnt > clk-(clk/4)-1) { //full clock |
| 243 | if (smplCnt > clk + (clk/4)+1) { //too many samples |
| 244 | errCnt++; |
| 245 | if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i); |
| 246 | BinStream[bitCnt++]=7; |
| 247 | } else if (waveHigh) { |
| 248 | BinStream[bitCnt++] = invert; |
| 249 | BinStream[bitCnt++] = invert; |
| 250 | } else if (!waveHigh) { |
| 251 | BinStream[bitCnt++] = invert ^ 1; |
| 252 | BinStream[bitCnt++] = invert ^ 1; |
| 253 | } |
| 254 | waveHigh ^= 1; |
| 255 | smplCnt = 0; |
| 256 | } else if (smplCnt > (clk/2) - (clk/4)-1) { |
| 257 | if (waveHigh) { |
| 258 | BinStream[bitCnt++] = invert; |
| 259 | } else if (!waveHigh) { |
| 260 | BinStream[bitCnt++] = invert ^ 1; |
| 261 | } |
| 262 | waveHigh ^= 1; |
| 263 | smplCnt = 0; |
| 264 | } else if (!bitCnt) { |
| 265 | //first bit |
| 266 | waveHigh = (BinStream[i] >= high); |
| 267 | smplCnt = 1; |
| 268 | } else { |
| 269 | smplCnt++; |
| 270 | //transition bit oops |
| 271 | } |
| 272 | } else { //haven't hit new high or new low yet |
| 273 | smplCnt++; |
| 274 | } |
| 275 | } |
| 276 | } |
| 277 | *size = bitCnt; |
| 278 | return errCnt; |
| 279 | } |
| 280 | |
| 281 | //by marshmellow |
| 282 | void askAmp(uint8_t *BitStream, size_t size) |
| 283 | { |
| 284 | uint8_t Last = 128; |
| 285 | for(size_t i = 1; i<size; i++){ |
| 286 | if (BitStream[i]-BitStream[i-1]>=30) //large jump up |
| 287 | Last = 255; |
| 288 | else if(BitStream[i-1]-BitStream[i]>=20) //large jump down |
| 289 | Last = 0; |
| 290 | |
| 291 | BitStream[i-1] = Last; |
| 292 | } |
| 293 | return; |
| 294 | } |
| 295 | |
| 296 | //by marshmellow |
| 297 | //attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester |
| 298 | int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType) |
| 299 | { |
| 300 | if (*size==0) return -1; |
| 301 | int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default |
| 302 | if (*clk==0 || start < 0) return -3; |
| 303 | if (*invert != 1) *invert = 0; |
| 304 | if (amp==1) askAmp(BinStream, *size); |
| 305 | if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d, amp %d", *clk, start, amp); |
| 306 | |
| 307 | uint8_t initLoopMax = 255; |
| 308 | if (initLoopMax > *size) initLoopMax = *size; |
| 309 | // Detect high and lows |
| 310 | //25% clip in case highs and lows aren't clipped [marshmellow] |
| 311 | int high, low; |
| 312 | if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1) |
| 313 | return -2; //just noise |
| 314 | |
| 315 | size_t errCnt = 0; |
| 316 | // if clean clipped waves detected run alternate demod |
| 317 | if (DetectCleanAskWave(BinStream, *size, high, low)) { |
| 318 | if (g_debugMode==2) prnt("DEBUG ASK: Clean Wave Detected - using clean wave demod"); |
| 319 | errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low); |
| 320 | if (askType) //askman |
| 321 | return manrawdecode(BinStream, size, 0); |
| 322 | else //askraw |
| 323 | return errCnt; |
| 324 | } |
| 325 | if (g_debugMode==2) prnt("DEBUG ASK: Weak Wave Detected - using weak wave demod"); |
| 326 | |
| 327 | int lastBit; //set first clock check - can go negative |
| 328 | size_t i, bitnum = 0; //output counter |
| 329 | uint8_t midBit = 0; |
| 330 | 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 |
| 331 | 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 |
| 332 | size_t MaxBits = 3072; //max bits to collect |
| 333 | lastBit = start - *clk; |
| 334 | |
| 335 | for (i = start; i < *size; ++i) { |
| 336 | if (i-lastBit >= *clk-tol){ |
| 337 | if (BinStream[i] >= high) { |
| 338 | BinStream[bitnum++] = *invert; |
| 339 | } else if (BinStream[i] <= low) { |
| 340 | BinStream[bitnum++] = *invert ^ 1; |
| 341 | } else if (i-lastBit >= *clk+tol) { |
| 342 | if (bitnum > 0) { |
| 343 | if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i); |
| 344 | BinStream[bitnum++]=7; |
| 345 | errCnt++; |
| 346 | } |
| 347 | } else { //in tolerance - looking for peak |
| 348 | continue; |
| 349 | } |
| 350 | midBit = 0; |
| 351 | lastBit += *clk; |
| 352 | } else if (i-lastBit >= (*clk/2-tol) && !midBit && !askType){ |
| 353 | if (BinStream[i] >= high) { |
| 354 | BinStream[bitnum++] = *invert; |
| 355 | } else if (BinStream[i] <= low) { |
| 356 | BinStream[bitnum++] = *invert ^ 1; |
| 357 | } else if (i-lastBit >= *clk/2+tol) { |
| 358 | BinStream[bitnum] = BinStream[bitnum-1]; |
| 359 | bitnum++; |
| 360 | } else { //in tolerance - looking for peak |
| 361 | continue; |
| 362 | } |
| 363 | midBit = 1; |
| 364 | } |
| 365 | if (bitnum >= MaxBits) break; |
| 366 | } |
| 367 | *size = bitnum; |
| 368 | return errCnt; |
| 369 | } |
| 370 | |
| 371 | //by marshmellow |
| 372 | //take 10 and 01 and manchester decode |
| 373 | //run through 2 times and take least errCnt |
| 374 | int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert) |
| 375 | { |
| 376 | uint16_t bitnum=0, MaxBits = 512, errCnt = 0; |
| 377 | size_t i, ii; |
| 378 | uint16_t bestErr = 1000, bestRun = 0; |
| 379 | if (*size < 16) return -1; |
| 380 | //find correct start position [alignment] |
| 381 | for (ii=0;ii<2;++ii){ |
| 382 | for (i=ii; i<*size-3; i+=2) |
| 383 | if (BitStream[i]==BitStream[i+1]) |
| 384 | errCnt++; |
| 385 | |
| 386 | if (bestErr>errCnt){ |
| 387 | bestErr=errCnt; |
| 388 | bestRun=ii; |
| 389 | } |
| 390 | errCnt=0; |
| 391 | } |
| 392 | //decode |
| 393 | for (i=bestRun; i < *size-3; i+=2){ |
| 394 | if(BitStream[i] == 1 && (BitStream[i+1] == 0)){ |
| 395 | BitStream[bitnum++]=invert; |
| 396 | } else if((BitStream[i] == 0) && BitStream[i+1] == 1){ |
| 397 | BitStream[bitnum++]=invert^1; |
| 398 | } else { |
| 399 | BitStream[bitnum++]=7; |
| 400 | } |
| 401 | if(bitnum>MaxBits) break; |
| 402 | } |
| 403 | *size=bitnum; |
| 404 | return bestErr; |
| 405 | } |
| 406 | |
| 407 | uint32_t manchesterEncode2Bytes(uint16_t datain) { |
| 408 | uint32_t output = 0; |
| 409 | uint8_t curBit = 0; |
| 410 | for (uint8_t i=0; i<16; i++) { |
| 411 | curBit = (datain >> (15-i) & 1); |
| 412 | output |= (1<<(((15-i)*2)+curBit)); |
| 413 | } |
| 414 | return output; |
| 415 | } |
| 416 | |
| 417 | //by marshmellow |
| 418 | //encode binary data into binary manchester |
| 419 | int ManchesterEncode(uint8_t *BitStream, size_t size) |
| 420 | { |
| 421 | size_t modIdx=20000, i=0; |
| 422 | if (size>modIdx) return -1; |
| 423 | for (size_t idx=0; idx < size; idx++){ |
| 424 | BitStream[idx+modIdx++] = BitStream[idx]; |
| 425 | BitStream[idx+modIdx++] = BitStream[idx]^1; |
| 426 | } |
| 427 | for (; i<(size*2); i++){ |
| 428 | BitStream[i] = BitStream[i+20000]; |
| 429 | } |
| 430 | return i; |
| 431 | } |
| 432 | |
| 433 | //by marshmellow |
| 434 | //take 01 or 10 = 1 and 11 or 00 = 0 |
| 435 | //check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010 |
| 436 | //decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding |
| 437 | int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert) |
| 438 | { |
| 439 | uint16_t bitnum = 0; |
| 440 | uint16_t errCnt = 0; |
| 441 | size_t i = offset; |
| 442 | uint16_t MaxBits=512; |
| 443 | //if not enough samples - error |
| 444 | if (*size < 51) return -1; |
| 445 | //check for phase change faults - skip one sample if faulty |
| 446 | uint8_t offsetA = 1, offsetB = 1; |
| 447 | for (; i<48; i+=2){ |
| 448 | if (BitStream[i+1]==BitStream[i+2]) offsetA=0; |
| 449 | if (BitStream[i+2]==BitStream[i+3]) offsetB=0; |
| 450 | } |
| 451 | if (!offsetA && offsetB) offset++; |
| 452 | for (i=offset; i<*size-3; i+=2){ |
| 453 | //check for phase error |
| 454 | if (BitStream[i+1]==BitStream[i+2]) { |
| 455 | BitStream[bitnum++]=7; |
| 456 | errCnt++; |
| 457 | } |
| 458 | if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){ |
| 459 | BitStream[bitnum++]=1^invert; |
| 460 | } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){ |
| 461 | BitStream[bitnum++]=invert; |
| 462 | } else { |
| 463 | BitStream[bitnum++]=7; |
| 464 | errCnt++; |
| 465 | } |
| 466 | if(bitnum>MaxBits) break; |
| 467 | } |
| 468 | *size=bitnum; |
| 469 | return errCnt; |
| 470 | } |
| 471 | |
| 472 | // by marshmellow |
| 473 | // demod gProxIIDemod |
| 474 | // error returns as -x |
| 475 | // success returns start position in BitStream |
| 476 | // BitStream must contain previously askrawdemod and biphasedemoded data |
| 477 | int gProxII_Demod(uint8_t BitStream[], size_t *size) |
| 478 | { |
| 479 | size_t startIdx=0; |
| 480 | uint8_t preamble[] = {1,1,1,1,1,0}; |
| 481 | |
| 482 | uint8_t errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, &startIdx); |
| 483 | if (errChk == 0) return -3; //preamble not found |
| 484 | if (*size != 96) return -2; //should have found 96 bits |
| 485 | //check first 6 spacer bits to verify format |
| 486 | if (!BitStream[startIdx+5] && !BitStream[startIdx+10] && !BitStream[startIdx+15] && !BitStream[startIdx+20] && !BitStream[startIdx+25] && !BitStream[startIdx+30]){ |
| 487 | //confirmed proper separator bits found |
| 488 | //return start position |
| 489 | return (int) startIdx; |
| 490 | } |
| 491 | return -5; //spacer bits not found - not a valid gproxII |
| 492 | } |
| 493 | |
| 494 | //translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq]) |
| 495 | size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow) |
| 496 | { |
| 497 | size_t last_transition = 0; |
| 498 | size_t idx = 1; |
| 499 | //uint32_t maxVal=0; |
| 500 | if (fchigh==0) fchigh=10; |
| 501 | if (fclow==0) fclow=8; |
| 502 | //set the threshold close to 0 (graph) or 128 std to avoid static |
| 503 | uint8_t threshold_value = 123; |
| 504 | size_t preLastSample = 0; |
| 505 | size_t LastSample = 0; |
| 506 | size_t currSample = 0; |
| 507 | if ( size < 1024 ) return 0; // not enough samples |
| 508 | |
| 509 | // jump to modulating data by finding the first 4 threshold crossings (or first 2 waves) |
| 510 | // in case you have junk or noise at the beginning of the trace... |
| 511 | uint8_t thresholdCnt = 0; |
| 512 | size_t waveSizeCnt = 0; |
| 513 | bool isAboveThreshold = dest[idx++] >= threshold_value; |
| 514 | for (; idx < size-20; idx++ ) { |
| 515 | if(dest[idx] < threshold_value && isAboveThreshold) { |
| 516 | thresholdCnt++; |
| 517 | if (thresholdCnt > 2 && waveSizeCnt < fchigh+1) break; |
| 518 | isAboveThreshold = false; |
| 519 | waveSizeCnt = 0; |
| 520 | } else if (dest[idx] >= threshold_value && !isAboveThreshold) { |
| 521 | thresholdCnt++; |
| 522 | if (thresholdCnt > 2 && waveSizeCnt < fchigh+1) break; |
| 523 | isAboveThreshold = true; |
| 524 | waveSizeCnt = 0; |
| 525 | } else { |
| 526 | waveSizeCnt++; |
| 527 | } |
| 528 | if (thresholdCnt > 10) break; |
| 529 | } |
| 530 | if (g_debugMode == 2) prnt("threshold Count reached at %u",idx); |
| 531 | |
| 532 | // Need to threshold first sample |
| 533 | if(dest[idx] < threshold_value) dest[0] = 0; |
| 534 | else dest[0] = 1; |
| 535 | idx++; |
| 536 | |
| 537 | size_t numBits = 0; |
| 538 | // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8) |
| 539 | // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere |
| 540 | // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10 |
| 541 | // (could also be fc/5 && fc/7 for fsk1 = 4-9) |
| 542 | for(; idx < size-20; idx++) { |
| 543 | // threshold current value |
| 544 | |
| 545 | if (dest[idx] < threshold_value) dest[idx] = 0; |
| 546 | else dest[idx] = 1; |
| 547 | |
| 548 | // Check for 0->1 transition |
| 549 | if (dest[idx-1] < dest[idx]) { |
| 550 | preLastSample = LastSample; |
| 551 | LastSample = currSample; |
| 552 | currSample = idx-last_transition; |
| 553 | if (currSample < (fclow-2)) { //0-5 = garbage noise (or 0-3) |
| 554 | //do nothing with extra garbage |
| 555 | } else if (currSample < (fchigh-1)) { //6-8 = 8 sample waves (or 3-6 = 5) |
| 556 | //correct previous 9 wave surrounded by 8 waves (or 6 surrounded by 5) |
| 557 | if (LastSample > (fchigh-2) && (preLastSample < (fchigh-1))){ |
| 558 | dest[numBits-1]=1; |
| 559 | } |
| 560 | dest[numBits++]=1; |
| 561 | |
| 562 | } else if (currSample > (fchigh+1) && numBits < 3) { //12 + and first two bit = unusable garbage |
| 563 | //do nothing with beginning garbage and reset.. should be rare.. |
| 564 | numBits = 0; |
| 565 | } else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's (or 4 then a 6 should be two 5's) |
| 566 | dest[numBits++]=1; |
| 567 | } else { //9+ = 10 sample waves (or 6+ = 7) |
| 568 | dest[numBits++]=0; |
| 569 | } |
| 570 | last_transition = idx; |
| 571 | } |
| 572 | } |
| 573 | return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0 |
| 574 | } |
| 575 | |
| 576 | //translate 11111100000 to 10 |
| 577 | //rfLen = clock, fchigh = larger field clock, fclow = smaller field clock |
| 578 | size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, |
| 579 | uint8_t invert, uint8_t fchigh, uint8_t fclow) |
| 580 | { |
| 581 | uint8_t lastval=dest[0]; |
| 582 | size_t idx=0; |
| 583 | size_t numBits=0; |
| 584 | uint32_t n=1; |
| 585 | for( idx=1; idx < size; idx++) { |
| 586 | n++; |
| 587 | if (dest[idx]==lastval) continue; //skip until we hit a transition |
| 588 | |
| 589 | //find out how many bits (n) we collected |
| 590 | //if lastval was 1, we have a 1->0 crossing |
| 591 | if (dest[idx-1]==1) { |
| 592 | n = (n * fclow + rfLen/2) / rfLen; |
| 593 | } else {// 0->1 crossing |
| 594 | n = (n * fchigh + rfLen/2) / rfLen; |
| 595 | } |
| 596 | if (n == 0) n = 1; |
| 597 | |
| 598 | //add to our destination the bits we collected |
| 599 | memset(dest+numBits, dest[idx-1]^invert , n); |
| 600 | numBits += n; |
| 601 | n=0; |
| 602 | lastval=dest[idx]; |
| 603 | }//end for |
| 604 | // if valid extra bits at the end were all the same frequency - add them in |
| 605 | if (n > rfLen/fchigh) { |
| 606 | if (dest[idx-2]==1) { |
| 607 | n = (n * fclow + rfLen/2) / rfLen; |
| 608 | } else { |
| 609 | n = (n * fchigh + rfLen/2) / rfLen; |
| 610 | } |
| 611 | memset(dest+numBits, dest[idx-1]^invert , n); |
| 612 | numBits += n; |
| 613 | } |
| 614 | return numBits; |
| 615 | } |
| 616 | |
| 617 | //by marshmellow (from holiman's base) |
| 618 | // full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod) |
| 619 | int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow) |
| 620 | { |
| 621 | // FSK demodulator |
| 622 | size = fsk_wave_demod(dest, size, fchigh, fclow); |
| 623 | size = aggregate_bits(dest, size, rfLen, invert, fchigh, fclow); |
| 624 | return size; |
| 625 | } |
| 626 | |
| 627 | // loop to get raw HID waveform then FSK demodulate the TAG ID from it |
| 628 | int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo) |
| 629 | { |
| 630 | if (justNoise(dest, *size)) return -1; |
| 631 | |
| 632 | size_t numStart=0, size2=*size, startIdx=0; |
| 633 | // FSK demodulator |
| 634 | *size = fskdemod(dest, size2,50,1,10,8); //fsk2a |
| 635 | if (*size < 96*2) return -2; |
| 636 | // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1 |
| 637 | uint8_t preamble[] = {0,0,0,1,1,1,0,1}; |
| 638 | // find bitstring in array |
| 639 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); |
| 640 | if (errChk == 0) return -3; //preamble not found |
| 641 | |
| 642 | numStart = startIdx + sizeof(preamble); |
| 643 | // final loop, go over previously decoded FSK data and manchester decode into usable tag ID |
| 644 | for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){ |
| 645 | if (dest[idx] == dest[idx+1]){ |
| 646 | return -4; //not manchester data |
| 647 | } |
| 648 | *hi2 = (*hi2<<1)|(*hi>>31); |
| 649 | *hi = (*hi<<1)|(*lo>>31); |
| 650 | //Then, shift in a 0 or one into low |
| 651 | if (dest[idx] && !dest[idx+1]) // 1 0 |
| 652 | *lo=(*lo<<1)|1; |
| 653 | else // 0 1 |
| 654 | *lo=(*lo<<1)|0; |
| 655 | } |
| 656 | return (int)startIdx; |
| 657 | } |
| 658 | |
| 659 | // loop to get raw paradox waveform then FSK demodulate the TAG ID from it |
| 660 | int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo) |
| 661 | { |
| 662 | if (justNoise(dest, *size)) return -1; |
| 663 | |
| 664 | size_t numStart=0, size2=*size, startIdx=0; |
| 665 | // FSK demodulator |
| 666 | *size = fskdemod(dest, size2,50,1,10,8); //fsk2a |
| 667 | if (*size < 96) return -2; |
| 668 | |
| 669 | // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1 |
| 670 | uint8_t preamble[] = {0,0,0,0,1,1,1,1}; |
| 671 | |
| 672 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); |
| 673 | if (errChk == 0) return -3; //preamble not found |
| 674 | |
| 675 | numStart = startIdx + sizeof(preamble); |
| 676 | // final loop, go over previously decoded FSK data and manchester decode into usable tag ID |
| 677 | for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){ |
| 678 | if (dest[idx] == dest[idx+1]) |
| 679 | return -4; //not manchester data |
| 680 | *hi2 = (*hi2<<1)|(*hi>>31); |
| 681 | *hi = (*hi<<1)|(*lo>>31); |
| 682 | //Then, shift in a 0 or one into low |
| 683 | if (dest[idx] && !dest[idx+1]) // 1 0 |
| 684 | *lo=(*lo<<1)|1; |
| 685 | else // 0 1 |
| 686 | *lo=(*lo<<1)|0; |
| 687 | } |
| 688 | return (int)startIdx; |
| 689 | } |
| 690 | |
| 691 | int IOdemodFSK(uint8_t *dest, size_t size) |
| 692 | { |
| 693 | if (justNoise(dest, size)) return -1; |
| 694 | //make sure buffer has data |
| 695 | if (size < 66*64) return -2; |
| 696 | // FSK demodulator |
| 697 | size = fskdemod(dest, size, 64, 1, 10, 8); // FSK2a RF/64 |
| 698 | if (size < 65) return -3; //did we get a good demod? |
| 699 | //Index map |
| 700 | //0 10 20 30 40 50 60 |
| 701 | //| | | | | | | |
| 702 | //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23 |
| 703 | //----------------------------------------------------------------------------- |
| 704 | //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11 |
| 705 | // |
| 706 | //XSF(version)facility:codeone+codetwo |
| 707 | //Handle the data |
| 708 | size_t startIdx = 0; |
| 709 | uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,1}; |
| 710 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), &size, &startIdx); |
| 711 | if (errChk == 0) return -4; //preamble not found |
| 712 | |
| 713 | if (!dest[startIdx+8] && dest[startIdx+17]==1 && dest[startIdx+26]==1 && dest[startIdx+35]==1 && dest[startIdx+44]==1 && dest[startIdx+53]==1){ |
| 714 | //confirmed proper separator bits found |
| 715 | //return start position |
| 716 | return (int) startIdx; |
| 717 | } |
| 718 | return -5; |
| 719 | } |
| 720 | |
| 721 | // by marshmellow |
| 722 | // find viking preamble 0xF200 in already demoded data |
| 723 | int VikingDemod_AM(uint8_t *dest, size_t *size) { |
| 724 | //make sure buffer has data |
| 725 | if (*size < 64*2) return -2; |
| 726 | |
| 727 | size_t startIdx = 0; |
| 728 | 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}; |
| 729 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); |
| 730 | if (errChk == 0) return -4; //preamble not found |
| 731 | uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^ bytebits_to_byte(dest+startIdx+8,8) ^ bytebits_to_byte(dest+startIdx+16,8) |
| 732 | ^ bytebits_to_byte(dest+startIdx+24,8) ^ bytebits_to_byte(dest+startIdx+32,8) ^ bytebits_to_byte(dest+startIdx+40,8) |
| 733 | ^ bytebits_to_byte(dest+startIdx+48,8) ^ bytebits_to_byte(dest+startIdx+56,8); |
| 734 | if ( checkCalc != 0xA8 ) return -5; |
| 735 | if (*size != 64) return -6; |
| 736 | //return start position |
| 737 | return (int) startIdx; |
| 738 | } |
| 739 | |
| 740 | // find presco preamble 0x10D in already demoded data |
| 741 | int PrescoDemod(uint8_t *dest, size_t *size) { |
| 742 | //make sure buffer has data |
| 743 | if (*size < 64*2) return -2; |
| 744 | |
| 745 | size_t startIdx = 0; |
| 746 | uint8_t preamble[] = {1,0,0,0,0,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0}; |
| 747 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); |
| 748 | if (errChk == 0) return -4; //preamble not found |
| 749 | //return start position |
| 750 | return (int) startIdx; |
| 751 | } |
| 752 | |
| 753 | // Ask/Biphase Demod then try to locate an ISO 11784/85 ID |
| 754 | // BitStream must contain previously askrawdemod and biphasedemoded data |
| 755 | int FDXBdemodBI(uint8_t *dest, size_t *size) |
| 756 | { |
| 757 | //make sure buffer has enough data |
| 758 | if (*size < 128) return -1; |
| 759 | |
| 760 | size_t startIdx = 0; |
| 761 | uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,1}; |
| 762 | |
| 763 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); |
| 764 | if (errChk == 0) return -2; //preamble not found |
| 765 | return (int)startIdx; |
| 766 | } |
| 767 | |
| 768 | // by marshmellow |
| 769 | // FSK Demod then try to locate an AWID ID |
| 770 | int AWIDdemodFSK(uint8_t *dest, size_t *size) |
| 771 | { |
| 772 | //make sure buffer has enough data |
| 773 | if (*size < 96*50) return -1; |
| 774 | |
| 775 | if (justNoise(dest, *size)) return -2; |
| 776 | |
| 777 | // FSK demodulator |
| 778 | *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50 |
| 779 | if (*size < 96) return -3; //did we get a good demod? |
| 780 | |
| 781 | uint8_t preamble[] = {0,0,0,0,0,0,0,1}; |
| 782 | size_t startIdx = 0; |
| 783 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); |
| 784 | if (errChk == 0) return -4; //preamble not found |
| 785 | if (*size != 96) return -5; |
| 786 | return (int)startIdx; |
| 787 | } |
| 788 | |
| 789 | // by marshmellow |
| 790 | // FSK Demod then try to locate a Farpointe Data (pyramid) ID |
| 791 | int PyramiddemodFSK(uint8_t *dest, size_t *size) |
| 792 | { |
| 793 | //make sure buffer has data |
| 794 | if (*size < 128*50) return -5; |
| 795 | |
| 796 | //test samples are not just noise |
| 797 | if (justNoise(dest, *size)) return -1; |
| 798 | |
| 799 | // FSK demodulator |
| 800 | *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50 |
| 801 | if (*size < 128) return -2; //did we get a good demod? |
| 802 | |
| 803 | uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1}; |
| 804 | size_t startIdx = 0; |
| 805 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); |
| 806 | if (errChk == 0) return -4; //preamble not found |
| 807 | if (*size != 128) return -3; |
| 808 | return (int)startIdx; |
| 809 | } |
| 810 | |
| 811 | // by marshmellow |
| 812 | // to detect a wave that has heavily clipped (clean) samples |
| 813 | uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low) |
| 814 | { |
| 815 | bool allArePeaks = true; |
| 816 | uint16_t cntPeaks=0; |
| 817 | size_t loopEnd = 512+160; |
| 818 | if (loopEnd > size) loopEnd = size; |
| 819 | for (size_t i=160; i<loopEnd; i++){ |
| 820 | if (dest[i]>low && dest[i]<high) |
| 821 | allArePeaks = false; |
| 822 | else |
| 823 | cntPeaks++; |
| 824 | } |
| 825 | if (!allArePeaks){ |
| 826 | if (cntPeaks > 300) return true; |
| 827 | } |
| 828 | return allArePeaks; |
| 829 | } |
| 830 | // by marshmellow |
| 831 | // to help detect clocks on heavily clipped samples |
| 832 | // based on count of low to low |
| 833 | int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low) |
| 834 | { |
| 835 | uint8_t fndClk[] = {8,16,32,40,50,64,128}; |
| 836 | size_t startwave; |
| 837 | size_t i = 100; |
| 838 | size_t minClk = 255; |
| 839 | // get to first full low to prime loop and skip incomplete first pulse |
| 840 | while ((dest[i] < high) && (i < size)) |
| 841 | ++i; |
| 842 | while ((dest[i] > low) && (i < size)) |
| 843 | ++i; |
| 844 | |
| 845 | // loop through all samples |
| 846 | while (i < size) { |
| 847 | // measure from low to low |
| 848 | while ((dest[i] > low) && (i < size)) |
| 849 | ++i; |
| 850 | startwave= i; |
| 851 | while ((dest[i] < high) && (i < size)) |
| 852 | ++i; |
| 853 | while ((dest[i] > low) && (i < size)) |
| 854 | ++i; |
| 855 | //get minimum measured distance |
| 856 | if (i-startwave < minClk && i < size) |
| 857 | minClk = i - startwave; |
| 858 | } |
| 859 | // set clock |
| 860 | if (g_debugMode==2) prnt("DEBUG ASK: detectstrongASKclk smallest wave: %d",minClk); |
| 861 | for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) { |
| 862 | if (minClk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1) |
| 863 | return fndClk[clkCnt]; |
| 864 | } |
| 865 | return 0; |
| 866 | } |
| 867 | |
| 868 | // by marshmellow |
| 869 | // not perfect especially with lower clocks or VERY good antennas (heavy wave clipping) |
| 870 | // maybe somehow adjust peak trimming value based on samples to fix? |
| 871 | // return start index of best starting position for that clock and return clock (by reference) |
| 872 | int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr) |
| 873 | { |
| 874 | size_t i=1; |
| 875 | uint8_t clk[] = {255,8,16,32,40,50,64,100,128,255}; |
| 876 | uint8_t clkEnd = 9; |
| 877 | uint8_t loopCnt = 255; //don't need to loop through entire array... |
| 878 | if (size <= loopCnt+60) return -1; //not enough samples |
| 879 | size -= 60; //sometimes there is a strange end wave - filter out this.... |
| 880 | //if we already have a valid clock |
| 881 | uint8_t clockFnd=0; |
| 882 | for (;i<clkEnd;++i) |
| 883 | if (clk[i] == *clock) clockFnd = i; |
| 884 | //clock found but continue to find best startpos |
| 885 | |
| 886 | //get high and low peak |
| 887 | int peak, low; |
| 888 | if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return -1; |
| 889 | |
| 890 | //test for large clean peaks |
| 891 | if (!clockFnd){ |
| 892 | if (DetectCleanAskWave(dest, size, peak, low)==1){ |
| 893 | int ans = DetectStrongAskClock(dest, size, peak, low); |
| 894 | if (g_debugMode==2) prnt("DEBUG ASK: detectaskclk Clean Ask Wave Detected: clk %d",ans); |
| 895 | for (i=clkEnd-1; i>0; i--){ |
| 896 | if (clk[i] == ans) { |
| 897 | *clock = ans; |
| 898 | //clockFnd = i; |
| 899 | return 0; // for strong waves i don't use the 'best start position' yet... |
| 900 | //break; //clock found but continue to find best startpos [not yet] |
| 901 | } |
| 902 | } |
| 903 | } |
| 904 | } |
| 905 | uint8_t ii; |
| 906 | uint8_t clkCnt, tol = 0; |
| 907 | uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000}; |
| 908 | uint8_t bestStart[]={0,0,0,0,0,0,0,0,0}; |
| 909 | size_t errCnt = 0; |
| 910 | size_t arrLoc, loopEnd; |
| 911 | |
| 912 | if (clockFnd>0) { |
| 913 | clkCnt = clockFnd; |
| 914 | clkEnd = clockFnd+1; |
| 915 | } |
| 916 | else clkCnt=1; |
| 917 | |
| 918 | //test each valid clock from smallest to greatest to see which lines up |
| 919 | for(; clkCnt < clkEnd; clkCnt++){ |
| 920 | if (clk[clkCnt] <= 32){ |
| 921 | tol=1; |
| 922 | }else{ |
| 923 | tol=0; |
| 924 | } |
| 925 | //if no errors allowed - keep start within the first clock |
| 926 | if (!maxErr && size > clk[clkCnt]*2 + tol && clk[clkCnt]<128) loopCnt=clk[clkCnt]*2; |
| 927 | bestErr[clkCnt]=1000; |
| 928 | //try lining up the peaks by moving starting point (try first few clocks) |
| 929 | for (ii=0; ii < loopCnt; ii++){ |
| 930 | if (dest[ii] < peak && dest[ii] > low) continue; |
| 931 | |
| 932 | errCnt=0; |
| 933 | // now that we have the first one lined up test rest of wave array |
| 934 | loopEnd = ((size-ii-tol) / clk[clkCnt]) - 1; |
| 935 | for (i=0; i < loopEnd; ++i){ |
| 936 | arrLoc = ii + (i * clk[clkCnt]); |
| 937 | if (dest[arrLoc] >= peak || dest[arrLoc] <= low){ |
| 938 | }else if (dest[arrLoc-tol] >= peak || dest[arrLoc-tol] <= low){ |
| 939 | }else if (dest[arrLoc+tol] >= peak || dest[arrLoc+tol] <= low){ |
| 940 | }else{ //error no peak detected |
| 941 | errCnt++; |
| 942 | } |
| 943 | } |
| 944 | //if we found no errors then we can stop here and a low clock (common clocks) |
| 945 | // this is correct one - return this clock |
| 946 | if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, err %d, startpos %d, endpos %d",clk[clkCnt],errCnt,ii,i); |
| 947 | if(errCnt==0 && clkCnt<7) { |
| 948 | if (!clockFnd) *clock = clk[clkCnt]; |
| 949 | return ii; |
| 950 | } |
| 951 | //if we found errors see if it is lowest so far and save it as best run |
| 952 | if(errCnt<bestErr[clkCnt]){ |
| 953 | bestErr[clkCnt]=errCnt; |
| 954 | bestStart[clkCnt]=ii; |
| 955 | } |
| 956 | } |
| 957 | } |
| 958 | uint8_t iii; |
| 959 | uint8_t best=0; |
| 960 | for (iii=1; iii<clkEnd; ++iii){ |
| 961 | if (bestErr[iii] < bestErr[best]){ |
| 962 | if (bestErr[iii] == 0) bestErr[iii]=1; |
| 963 | // current best bit to error ratio vs new bit to error ratio |
| 964 | if ( (size/clk[best])/bestErr[best] < (size/clk[iii])/bestErr[iii] ){ |
| 965 | best = iii; |
| 966 | } |
| 967 | } |
| 968 | if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, # Errors %d, Current Best Clk %d, bestStart %d",clk[iii],bestErr[iii],clk[best],bestStart[best]); |
| 969 | } |
| 970 | if (!clockFnd) *clock = clk[best]; |
| 971 | return bestStart[best]; |
| 972 | } |
| 973 | |
| 974 | //by marshmellow |
| 975 | //detect psk clock by reading each phase shift |
| 976 | // a phase shift is determined by measuring the sample length of each wave |
| 977 | int DetectPSKClock(uint8_t dest[], size_t size, int clock) |
| 978 | { |
| 979 | uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock |
| 980 | uint16_t loopCnt = 4096; //don't need to loop through entire array... |
| 981 | if (size == 0) return 0; |
| 982 | if (size<loopCnt) loopCnt = size-20; |
| 983 | |
| 984 | //if we already have a valid clock quit |
| 985 | size_t i=1; |
| 986 | for (; i < 8; ++i) |
| 987 | if (clk[i] == clock) return clock; |
| 988 | |
| 989 | size_t waveStart=0, waveEnd=0, firstFullWave=0, lastClkBit=0; |
| 990 | uint8_t clkCnt, fc=0, fullWaveLen=0, tol=1; |
| 991 | uint16_t peakcnt=0, errCnt=0, waveLenCnt=0; |
| 992 | uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000}; |
| 993 | uint16_t peaksdet[]={0,0,0,0,0,0,0,0,0}; |
| 994 | fc = countFC(dest, size, 0); |
| 995 | if (fc!=2 && fc!=4 && fc!=8) return -1; |
| 996 | if (g_debugMode==2) prnt("DEBUG PSK: FC: %d",fc); |
| 997 | |
| 998 | //find first full wave |
| 999 | for (i=160; i<loopCnt; i++){ |
| 1000 | if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){ |
| 1001 | if (waveStart == 0) { |
| 1002 | waveStart = i+1; |
| 1003 | //prnt("DEBUG: waveStart: %d",waveStart); |
| 1004 | } else { |
| 1005 | waveEnd = i+1; |
| 1006 | //prnt("DEBUG: waveEnd: %d",waveEnd); |
| 1007 | waveLenCnt = waveEnd-waveStart; |
| 1008 | if (waveLenCnt > fc){ |
| 1009 | firstFullWave = waveStart; |
| 1010 | fullWaveLen=waveLenCnt; |
| 1011 | break; |
| 1012 | } |
| 1013 | waveStart=0; |
| 1014 | } |
| 1015 | } |
| 1016 | } |
| 1017 | if (g_debugMode ==2) prnt("DEBUG PSK: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen); |
| 1018 | |
| 1019 | //test each valid clock from greatest to smallest to see which lines up |
| 1020 | for(clkCnt=7; clkCnt >= 1 ; clkCnt--){ |
| 1021 | lastClkBit = firstFullWave; //set end of wave as clock align |
| 1022 | waveStart = 0; |
| 1023 | errCnt=0; |
| 1024 | peakcnt=0; |
| 1025 | if (g_debugMode == 2) prnt("DEBUG PSK: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit); |
| 1026 | |
| 1027 | for (i = firstFullWave+fullWaveLen-1; i < loopCnt-2; i++){ |
| 1028 | //top edge of wave = start of new wave |
| 1029 | if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){ |
| 1030 | if (waveStart == 0) { |
| 1031 | waveStart = i+1; |
| 1032 | waveLenCnt=0; |
| 1033 | } else { //waveEnd |
| 1034 | waveEnd = i+1; |
| 1035 | waveLenCnt = waveEnd-waveStart; |
| 1036 | if (waveLenCnt > fc){ |
| 1037 | //if this wave is a phase shift |
| 1038 | if (g_debugMode == 2) prnt("DEBUG PSK: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+clk[clkCnt]-tol,i+1,fc); |
| 1039 | if (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit |
| 1040 | peakcnt++; |
| 1041 | lastClkBit+=clk[clkCnt]; |
| 1042 | } else if (i<lastClkBit+8){ |
| 1043 | //noise after a phase shift - ignore |
| 1044 | } else { //phase shift before supposed to based on clock |
| 1045 | errCnt++; |
| 1046 | } |
| 1047 | } else if (i+1 > lastClkBit + clk[clkCnt] + tol + fc){ |
| 1048 | lastClkBit+=clk[clkCnt]; //no phase shift but clock bit |
| 1049 | } |
| 1050 | waveStart=i+1; |
| 1051 | } |
| 1052 | } |
| 1053 | } |
| 1054 | if (errCnt == 0){ |
| 1055 | return clk[clkCnt]; |
| 1056 | } |
| 1057 | if (errCnt <= bestErr[clkCnt]) bestErr[clkCnt]=errCnt; |
| 1058 | if (peakcnt > peaksdet[clkCnt]) peaksdet[clkCnt]=peakcnt; |
| 1059 | } |
| 1060 | //all tested with errors |
| 1061 | //return the highest clk with the most peaks found |
| 1062 | uint8_t best=7; |
| 1063 | for (i=7; i>=1; i--){ |
| 1064 | if (peaksdet[i] > peaksdet[best]) { |
| 1065 | best = i; |
| 1066 | } |
| 1067 | if (g_debugMode == 2) prnt("DEBUG PSK: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[i],peaksdet[i],bestErr[i],clk[best]); |
| 1068 | } |
| 1069 | return clk[best]; |
| 1070 | } |
| 1071 | |
| 1072 | int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low){ |
| 1073 | //find shortest transition from high to low |
| 1074 | size_t i = 0; |
| 1075 | size_t transition1 = 0; |
| 1076 | int lowestTransition = 255; |
| 1077 | bool lastWasHigh = false; |
| 1078 | |
| 1079 | //find first valid beginning of a high or low wave |
| 1080 | while ((dest[i] >= peak || dest[i] <= low) && (i < size)) |
| 1081 | ++i; |
| 1082 | while ((dest[i] < peak && dest[i] > low) && (i < size)) |
| 1083 | ++i; |
| 1084 | lastWasHigh = (dest[i] >= peak); |
| 1085 | |
| 1086 | if (i==size) return 0; |
| 1087 | transition1 = i; |
| 1088 | |
| 1089 | for (;i < size; i++) { |
| 1090 | if ((dest[i] >= peak && !lastWasHigh) || (dest[i] <= low && lastWasHigh)) { |
| 1091 | lastWasHigh = (dest[i] >= peak); |
| 1092 | if (i-transition1 < lowestTransition) lowestTransition = i-transition1; |
| 1093 | transition1 = i; |
| 1094 | } |
| 1095 | } |
| 1096 | if (lowestTransition == 255) lowestTransition = 0; |
| 1097 | if (g_debugMode==2) prnt("DEBUG NRZ: detectstrongNRZclk smallest wave: %d",lowestTransition); |
| 1098 | return lowestTransition; |
| 1099 | } |
| 1100 | |
| 1101 | //by marshmellow |
| 1102 | //detect nrz clock by reading #peaks vs no peaks(or errors) |
| 1103 | int DetectNRZClock(uint8_t dest[], size_t size, int clock) |
| 1104 | { |
| 1105 | size_t i=0; |
| 1106 | uint8_t clk[]={8,16,32,40,50,64,100,128,255}; |
| 1107 | size_t loopCnt = 4096; //don't need to loop through entire array... |
| 1108 | if (size == 0) return 0; |
| 1109 | if (size<loopCnt) loopCnt = size-20; |
| 1110 | //if we already have a valid clock quit |
| 1111 | for (; i < 8; ++i) |
| 1112 | if (clk[i] == clock) return clock; |
| 1113 | |
| 1114 | //get high and low peak |
| 1115 | int peak, low; |
| 1116 | if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return 0; |
| 1117 | |
| 1118 | int lowestTransition = DetectStrongNRZClk(dest, size-20, peak, low); |
| 1119 | size_t ii; |
| 1120 | uint8_t clkCnt; |
| 1121 | uint8_t tol = 0; |
| 1122 | uint16_t smplCnt = 0; |
| 1123 | int16_t peakcnt = 0; |
| 1124 | int16_t peaksdet[] = {0,0,0,0,0,0,0,0}; |
| 1125 | uint16_t maxPeak = 255; |
| 1126 | bool firstpeak = false; |
| 1127 | //test for large clipped waves |
| 1128 | for (i=0; i<loopCnt; i++){ |
| 1129 | if (dest[i] >= peak || dest[i] <= low){ |
| 1130 | if (!firstpeak) continue; |
| 1131 | smplCnt++; |
| 1132 | } else { |
| 1133 | firstpeak=true; |
| 1134 | if (smplCnt > 6 ){ |
| 1135 | if (maxPeak > smplCnt){ |
| 1136 | maxPeak = smplCnt; |
| 1137 | //prnt("maxPk: %d",maxPeak); |
| 1138 | } |
| 1139 | peakcnt++; |
| 1140 | //prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt); |
| 1141 | smplCnt=0; |
| 1142 | } |
| 1143 | } |
| 1144 | } |
| 1145 | bool errBitHigh = 0; |
| 1146 | bool bitHigh = 0; |
| 1147 | uint8_t ignoreCnt = 0; |
| 1148 | uint8_t ignoreWindow = 4; |
| 1149 | bool lastPeakHigh = 0; |
| 1150 | int lastBit = 0; |
| 1151 | peakcnt=0; |
| 1152 | //test each valid clock from smallest to greatest to see which lines up |
| 1153 | for(clkCnt=0; clkCnt < 8; ++clkCnt){ |
| 1154 | //ignore clocks smaller than smallest peak |
| 1155 | if (clk[clkCnt] < maxPeak - (clk[clkCnt]/4)) continue; |
| 1156 | //try lining up the peaks by moving starting point (try first 256) |
| 1157 | for (ii=20; ii < loopCnt; ++ii){ |
| 1158 | if ((dest[ii] >= peak) || (dest[ii] <= low)){ |
| 1159 | peakcnt = 0; |
| 1160 | bitHigh = false; |
| 1161 | ignoreCnt = 0; |
| 1162 | lastBit = ii-clk[clkCnt]; |
| 1163 | //loop through to see if this start location works |
| 1164 | for (i = ii; i < size-20; ++i) { |
| 1165 | //if we are at a clock bit |
| 1166 | if ((i >= lastBit + clk[clkCnt] - tol) && (i <= lastBit + clk[clkCnt] + tol)) { |
| 1167 | //test high/low |
| 1168 | if (dest[i] >= peak || dest[i] <= low) { |
| 1169 | //if same peak don't count it |
| 1170 | if ((dest[i] >= peak && !lastPeakHigh) || (dest[i] <= low && lastPeakHigh)) { |
| 1171 | peakcnt++; |
| 1172 | } |
| 1173 | lastPeakHigh = (dest[i] >= peak); |
| 1174 | bitHigh = true; |
| 1175 | errBitHigh = false; |
| 1176 | ignoreCnt = ignoreWindow; |
| 1177 | lastBit += clk[clkCnt]; |
| 1178 | } else if (i == lastBit + clk[clkCnt] + tol) { |
| 1179 | lastBit += clk[clkCnt]; |
| 1180 | } |
| 1181 | //else if not a clock bit and no peaks |
| 1182 | } else if (dest[i] < peak && dest[i] > low){ |
| 1183 | if (ignoreCnt==0){ |
| 1184 | bitHigh=false; |
| 1185 | if (errBitHigh==true) peakcnt--; |
| 1186 | errBitHigh=false; |
| 1187 | } else { |
| 1188 | ignoreCnt--; |
| 1189 | } |
| 1190 | // else if not a clock bit but we have a peak |
| 1191 | } else if ((dest[i]>=peak || dest[i]<=low) && (!bitHigh)) { |
| 1192 | //error bar found no clock... |
| 1193 | errBitHigh=true; |
| 1194 | } |
| 1195 | } |
| 1196 | if(peakcnt>peaksdet[clkCnt]) { |
| 1197 | peaksdet[clkCnt]=peakcnt; |
| 1198 | } |
| 1199 | } |
| 1200 | } |
| 1201 | } |
| 1202 | int iii=7; |
| 1203 | uint8_t best=0; |
| 1204 | for (iii=7; iii > 0; iii--){ |
| 1205 | if ((peaksdet[iii] >= (peaksdet[best]-1)) && (peaksdet[iii] <= peaksdet[best]+1) && lowestTransition) { |
| 1206 | if (clk[iii] > (lowestTransition - (clk[iii]/8)) && clk[iii] < (lowestTransition + (clk[iii]/8))) { |
| 1207 | best = iii; |
| 1208 | } |
| 1209 | } else if (peaksdet[iii] > peaksdet[best]){ |
| 1210 | best = iii; |
| 1211 | } |
| 1212 | if (g_debugMode==2) prnt("DEBUG NRZ: Clk: %d, peaks: %d, maxPeak: %d, bestClk: %d, lowestTrs: %d",clk[iii],peaksdet[iii],maxPeak, clk[best], lowestTransition); |
| 1213 | } |
| 1214 | |
| 1215 | return clk[best]; |
| 1216 | } |
| 1217 | |
| 1218 | // by marshmellow |
| 1219 | // convert psk1 demod to psk2 demod |
| 1220 | // only transition waves are 1s |
| 1221 | void psk1TOpsk2(uint8_t *BitStream, size_t size) |
| 1222 | { |
| 1223 | size_t i=1; |
| 1224 | uint8_t lastBit=BitStream[0]; |
| 1225 | for (; i<size; i++){ |
| 1226 | if (BitStream[i]==7){ |
| 1227 | //ignore errors |
| 1228 | } else if (lastBit!=BitStream[i]){ |
| 1229 | lastBit=BitStream[i]; |
| 1230 | BitStream[i]=1; |
| 1231 | } else { |
| 1232 | BitStream[i]=0; |
| 1233 | } |
| 1234 | } |
| 1235 | return; |
| 1236 | } |
| 1237 | |
| 1238 | // by marshmellow |
| 1239 | // convert psk2 demod to psk1 demod |
| 1240 | // from only transition waves are 1s to phase shifts change bit |
| 1241 | void psk2TOpsk1(uint8_t *BitStream, size_t size) |
| 1242 | { |
| 1243 | uint8_t phase=0; |
| 1244 | for (size_t i=0; i<size; i++){ |
| 1245 | if (BitStream[i]==1){ |
| 1246 | phase ^=1; |
| 1247 | } |
| 1248 | BitStream[i]=phase; |
| 1249 | } |
| 1250 | return; |
| 1251 | } |
| 1252 | |
| 1253 | // redesigned by marshmellow adjusted from existing decode functions |
| 1254 | // indala id decoding - only tested on 26 bit tags, but attempted to make it work for more |
| 1255 | int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert) |
| 1256 | { |
| 1257 | //26 bit 40134 format (don't know other formats) |
| 1258 | 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}; |
| 1259 | 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}; |
| 1260 | size_t startidx = 0; |
| 1261 | if (!preambleSearch(bitStream, preamble, sizeof(preamble), size, &startidx)){ |
| 1262 | // if didn't find preamble try again inverting |
| 1263 | if (!preambleSearch(bitStream, preamble_i, sizeof(preamble_i), size, &startidx)) return -1; |
| 1264 | *invert ^= 1; |
| 1265 | } |
| 1266 | if (*size != 64 && *size != 224) return -2; |
| 1267 | if (*invert==1) |
| 1268 | for (size_t i = startidx; i < *size; i++) |
| 1269 | bitStream[i] ^= 1; |
| 1270 | |
| 1271 | return (int) startidx; |
| 1272 | } |
| 1273 | |
| 1274 | // by marshmellow - demodulate NRZ wave - requires a read with strong signal |
| 1275 | // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak |
| 1276 | int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert){ |
| 1277 | if (justNoise(dest, *size)) return -1; |
| 1278 | *clk = DetectNRZClock(dest, *size, *clk); |
| 1279 | if (*clk==0) return -2; |
| 1280 | size_t i, gLen = 4096; |
| 1281 | if (gLen>*size) gLen = *size-20; |
| 1282 | int high, low; |
| 1283 | if (getHiLo(dest, gLen, &high, &low, 75, 75) < 1) return -3; //25% fuzz on high 25% fuzz on low |
| 1284 | |
| 1285 | uint8_t bit=0; |
| 1286 | //convert wave samples to 1's and 0's |
| 1287 | for(i=20; i < *size-20; i++){ |
| 1288 | if (dest[i] >= high) bit = 1; |
| 1289 | if (dest[i] <= low) bit = 0; |
| 1290 | dest[i] = bit; |
| 1291 | } |
| 1292 | //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit) |
| 1293 | size_t lastBit = 0; |
| 1294 | size_t numBits = 0; |
| 1295 | for(i=21; i < *size-20; i++) { |
| 1296 | //if transition detected or large number of same bits - store the passed bits |
| 1297 | if (dest[i] != dest[i-1] || (i-lastBit) == (10 * *clk)) { |
| 1298 | memset(dest+numBits, dest[i-1] ^ *invert, (i - lastBit + (*clk/4)) / *clk); |
| 1299 | numBits += (i - lastBit + (*clk/4)) / *clk; |
| 1300 | lastBit = i-1; |
| 1301 | } |
| 1302 | } |
| 1303 | *size = numBits; |
| 1304 | return 0; |
| 1305 | } |
| 1306 | |
| 1307 | //by marshmellow |
| 1308 | //detects the bit clock for FSK given the high and low Field Clocks |
| 1309 | uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow) |
| 1310 | { |
| 1311 | uint8_t clk[] = {8,16,32,40,50,64,100,128,0}; |
| 1312 | uint16_t rfLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; |
| 1313 | uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; |
| 1314 | uint8_t rfLensFnd = 0; |
| 1315 | uint8_t lastFCcnt = 0; |
| 1316 | uint16_t fcCounter = 0; |
| 1317 | uint16_t rfCounter = 0; |
| 1318 | uint8_t firstBitFnd = 0; |
| 1319 | size_t i; |
| 1320 | if (size == 0) return 0; |
| 1321 | |
| 1322 | uint8_t fcTol = ((fcHigh*100 - fcLow*100)/2 + 50)/100; //(uint8_t)(0.5+(float)(fcHigh-fcLow)/2); |
| 1323 | rfLensFnd=0; |
| 1324 | fcCounter=0; |
| 1325 | rfCounter=0; |
| 1326 | firstBitFnd=0; |
| 1327 | //PrintAndLog("DEBUG: fcTol: %d",fcTol); |
| 1328 | // prime i to first peak / up transition |
| 1329 | for (i = 160; i < size-20; i++) |
| 1330 | if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1]) |
| 1331 | break; |
| 1332 | |
| 1333 | for (; i < size-20; i++){ |
| 1334 | fcCounter++; |
| 1335 | rfCounter++; |
| 1336 | |
| 1337 | if (BitStream[i] <= BitStream[i-1] || BitStream[i] < BitStream[i+1]) |
| 1338 | continue; |
| 1339 | // else new peak |
| 1340 | // if we got less than the small fc + tolerance then set it to the small fc |
| 1341 | if (fcCounter < fcLow+fcTol) |
| 1342 | fcCounter = fcLow; |
| 1343 | else //set it to the large fc |
| 1344 | fcCounter = fcHigh; |
| 1345 | |
| 1346 | //look for bit clock (rf/xx) |
| 1347 | if ((fcCounter < lastFCcnt || fcCounter > lastFCcnt)){ |
| 1348 | //not the same size as the last wave - start of new bit sequence |
| 1349 | if (firstBitFnd > 1){ //skip first wave change - probably not a complete bit |
| 1350 | for (int ii=0; ii<15; ii++){ |
| 1351 | if (rfLens[ii] >= (rfCounter-4) && rfLens[ii] <= (rfCounter+4)){ |
| 1352 | rfCnts[ii]++; |
| 1353 | rfCounter = 0; |
| 1354 | break; |
| 1355 | } |
| 1356 | } |
| 1357 | if (rfCounter > 0 && rfLensFnd < 15){ |
| 1358 | //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter); |
| 1359 | rfCnts[rfLensFnd]++; |
| 1360 | rfLens[rfLensFnd++] = rfCounter; |
| 1361 | } |
| 1362 | } else { |
| 1363 | firstBitFnd++; |
| 1364 | } |
| 1365 | rfCounter=0; |
| 1366 | lastFCcnt=fcCounter; |
| 1367 | } |
| 1368 | fcCounter=0; |
| 1369 | } |
| 1370 | uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15; |
| 1371 | |
| 1372 | for (i=0; i<15; i++){ |
| 1373 | //get highest 2 RF values (might need to get more values to compare or compare all?) |
| 1374 | if (rfCnts[i]>rfCnts[rfHighest]){ |
| 1375 | rfHighest3=rfHighest2; |
| 1376 | rfHighest2=rfHighest; |
| 1377 | rfHighest=i; |
| 1378 | } else if(rfCnts[i]>rfCnts[rfHighest2]){ |
| 1379 | rfHighest3=rfHighest2; |
| 1380 | rfHighest2=i; |
| 1381 | } else if(rfCnts[i]>rfCnts[rfHighest3]){ |
| 1382 | rfHighest3=i; |
| 1383 | } |
| 1384 | if (g_debugMode==2) prnt("DEBUG FSK: RF %d, cnts %d",rfLens[i], rfCnts[i]); |
| 1385 | } |
| 1386 | // set allowed clock remainder tolerance to be 1 large field clock length+1 |
| 1387 | // we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off |
| 1388 | uint8_t tol1 = fcHigh+1; |
| 1389 | |
| 1390 | if (g_debugMode==2) prnt("DEBUG FSK: most counted rf values: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]); |
| 1391 | |
| 1392 | // loop to find the highest clock that has a remainder less than the tolerance |
| 1393 | // compare samples counted divided by |
| 1394 | // test 128 down to 32 (shouldn't be possible to have fc/10 & fc/8 and rf/16 or less) |
| 1395 | int ii=7; |
| 1396 | for (; ii>=2; ii--){ |
| 1397 | if (rfLens[rfHighest] % clk[ii] < tol1 || rfLens[rfHighest] % clk[ii] > clk[ii]-tol1){ |
| 1398 | if (rfLens[rfHighest2] % clk[ii] < tol1 || rfLens[rfHighest2] % clk[ii] > clk[ii]-tol1){ |
| 1399 | if (rfLens[rfHighest3] % clk[ii] < tol1 || rfLens[rfHighest3] % clk[ii] > clk[ii]-tol1){ |
| 1400 | if (g_debugMode==2) prnt("DEBUG FSK: clk %d divides into the 3 most rf values within tolerance",clk[ii]); |
| 1401 | break; |
| 1402 | } |
| 1403 | } |
| 1404 | } |
| 1405 | } |
| 1406 | |
| 1407 | if (ii<0) return 0; // oops we went too far |
| 1408 | |
| 1409 | return clk[ii]; |
| 1410 | } |
| 1411 | |
| 1412 | //by marshmellow |
| 1413 | //countFC is to detect the field clock lengths. |
| 1414 | //counts and returns the 2 most common wave lengths |
| 1415 | //mainly used for FSK field clock detection |
| 1416 | uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj) |
| 1417 | { |
| 1418 | uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; |
| 1419 | uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; |
| 1420 | uint8_t fcLensFnd = 0; |
| 1421 | uint8_t lastFCcnt = 0; |
| 1422 | uint8_t fcCounter = 0; |
| 1423 | size_t i; |
| 1424 | if (size < 180) return 0; |
| 1425 | |
| 1426 | // prime i to first up transition |
| 1427 | for (i = 160; i < size-20; i++) |
| 1428 | if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]) |
| 1429 | break; |
| 1430 | |
| 1431 | for (; i < size-20; i++){ |
| 1432 | if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){ |
| 1433 | // new up transition |
| 1434 | fcCounter++; |
| 1435 | if (fskAdj){ |
| 1436 | //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8) |
| 1437 | if (lastFCcnt==5 && fcCounter==9) fcCounter--; |
| 1438 | //if fc=9 or 4 add one (for when we get a fc 9 instead of 10 or a 4 instead of a 5) |
| 1439 | if ((fcCounter==9) || fcCounter==4) fcCounter++; |
| 1440 | // save last field clock count (fc/xx) |
| 1441 | lastFCcnt = fcCounter; |
| 1442 | } |
| 1443 | // find which fcLens to save it to: |
| 1444 | for (int ii=0; ii<15; ii++){ |
| 1445 | if (fcLens[ii]==fcCounter){ |
| 1446 | fcCnts[ii]++; |
| 1447 | fcCounter=0; |
| 1448 | break; |
| 1449 | } |
| 1450 | } |
| 1451 | if (fcCounter>0 && fcLensFnd<15){ |
| 1452 | //add new fc length |
| 1453 | fcCnts[fcLensFnd]++; |
| 1454 | fcLens[fcLensFnd++]=fcCounter; |
| 1455 | } |
| 1456 | fcCounter=0; |
| 1457 | } else { |
| 1458 | // count sample |
| 1459 | fcCounter++; |
| 1460 | } |
| 1461 | } |
| 1462 | |
| 1463 | uint8_t best1=14, best2=14, best3=14; |
| 1464 | uint16_t maxCnt1=0; |
| 1465 | // go through fclens and find which ones are bigest 2 |
| 1466 | for (i=0; i<15; i++){ |
| 1467 | // get the 3 best FC values |
| 1468 | if (fcCnts[i]>maxCnt1) { |
| 1469 | best3=best2; |
| 1470 | best2=best1; |
| 1471 | maxCnt1=fcCnts[i]; |
| 1472 | best1=i; |
| 1473 | } else if(fcCnts[i]>fcCnts[best2]){ |
| 1474 | best3=best2; |
| 1475 | best2=i; |
| 1476 | } else if(fcCnts[i]>fcCnts[best3]){ |
| 1477 | best3=i; |
| 1478 | } |
| 1479 | if (g_debugMode==2) prnt("DEBUG countfc: FC %u, Cnt %u, best fc: %u, best2 fc: %u",fcLens[i],fcCnts[i],fcLens[best1],fcLens[best2]); |
| 1480 | } |
| 1481 | if (fcLens[best1]==0) return 0; |
| 1482 | uint8_t fcH=0, fcL=0; |
| 1483 | if (fcLens[best1]>fcLens[best2]){ |
| 1484 | fcH=fcLens[best1]; |
| 1485 | fcL=fcLens[best2]; |
| 1486 | } else{ |
| 1487 | fcH=fcLens[best2]; |
| 1488 | fcL=fcLens[best1]; |
| 1489 | } |
| 1490 | if ((size-180)/fcH/3 > fcCnts[best1]+fcCnts[best2]) { |
| 1491 | if (g_debugMode==2) prnt("DEBUG countfc: fc is too large: %u > %u. Not psk or fsk",(size-180)/fcH/3,fcCnts[best1]+fcCnts[best2]); |
| 1492 | return 0; //lots of waves not psk or fsk |
| 1493 | } |
| 1494 | // TODO: take top 3 answers and compare to known Field clocks to get top 2 |
| 1495 | |
| 1496 | uint16_t fcs = (((uint16_t)fcH)<<8) | fcL; |
| 1497 | if (fskAdj) return fcs; |
| 1498 | return fcLens[best1]; |
| 1499 | } |
| 1500 | |
| 1501 | //by marshmellow - demodulate PSK1 wave |
| 1502 | //uses wave lengths (# Samples) |
| 1503 | int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) |
| 1504 | { |
| 1505 | if (size == 0) return -1; |
| 1506 | uint16_t loopCnt = 4096; //don't need to loop through entire array... |
| 1507 | if (*size<loopCnt) loopCnt = *size; |
| 1508 | |
| 1509 | size_t numBits=0; |
| 1510 | uint8_t curPhase = *invert; |
| 1511 | size_t i=0, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0; |
| 1512 | uint8_t fc=0, fullWaveLen=0, tol=1; |
| 1513 | uint16_t errCnt=0, waveLenCnt=0; |
| 1514 | fc = countFC(dest, *size, 0); |
| 1515 | if (fc!=2 && fc!=4 && fc!=8) return -1; |
| 1516 | //PrintAndLog("DEBUG: FC: %d",fc); |
| 1517 | *clock = DetectPSKClock(dest, *size, *clock); |
| 1518 | if (*clock == 0) return -1; |
| 1519 | // jump to modulating data by finding the first 2 threshold crossings (or first 1 waves) |
| 1520 | // in case you have junk or noise at the beginning of the trace... |
| 1521 | uint8_t thresholdCnt = 0; |
| 1522 | size_t waveSizeCnt = 0; |
| 1523 | uint8_t threshold_value = 123; //-5 |
| 1524 | bool isAboveThreshold = dest[i++] >= threshold_value; |
| 1525 | for (; i < *size-20; i++ ) { |
| 1526 | if(dest[i] < threshold_value && isAboveThreshold) { |
| 1527 | thresholdCnt++; |
| 1528 | if (thresholdCnt > 2 && waveSizeCnt < fc+1) break; |
| 1529 | isAboveThreshold = false; |
| 1530 | waveSizeCnt = 0; |
| 1531 | } else if (dest[i] >= threshold_value && !isAboveThreshold) { |
| 1532 | thresholdCnt++; |
| 1533 | if (thresholdCnt > 2 && waveSizeCnt < fc+1) break; |
| 1534 | isAboveThreshold = true; |
| 1535 | waveSizeCnt = 0; |
| 1536 | } else { |
| 1537 | waveSizeCnt++; |
| 1538 | } |
| 1539 | if (thresholdCnt > 10) break; |
| 1540 | } |
| 1541 | if (g_debugMode == 2) prnt("DEBUG PSK: threshold Count reached at %u, count: %u",i, thresholdCnt); |
| 1542 | |
| 1543 | |
| 1544 | int avgWaveVal=0, lastAvgWaveVal=0; |
| 1545 | waveStart = i+1; |
| 1546 | //find first phase shift |
| 1547 | for (; i<loopCnt; i++){ |
| 1548 | if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){ |
| 1549 | waveEnd = i+1; |
| 1550 | if (g_debugMode == 2) prnt("DEBUG PSK: waveEnd: %u, waveStart: %u",waveEnd, waveStart); |
| 1551 | waveLenCnt = waveEnd-waveStart; |
| 1552 | if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+3)){ //not first peak and is a large wave but not out of whack |
| 1553 | lastAvgWaveVal = avgWaveVal/(waveLenCnt); |
| 1554 | firstFullWave = waveStart; |
| 1555 | fullWaveLen=waveLenCnt; |
| 1556 | //if average wave value is > graph 0 then it is an up wave or a 1 |
| 1557 | if (lastAvgWaveVal > threshold_value) curPhase ^= 1; //fudge graph 0 a little 123 vs 128 |
| 1558 | break; |
| 1559 | } |
| 1560 | waveStart = i+1; |
| 1561 | avgWaveVal = 0; |
| 1562 | } |
| 1563 | avgWaveVal += dest[i+2]; |
| 1564 | } |
| 1565 | if (firstFullWave == 0) { |
| 1566 | // no phase shift detected - could be all 1's or 0's - doesn't matter where we start |
| 1567 | // so skip a little to ensure we are past any Start Signal |
| 1568 | firstFullWave = 160; |
| 1569 | memset(dest, curPhase, firstFullWave / *clock); |
| 1570 | } else { |
| 1571 | memset(dest, curPhase^1, firstFullWave / *clock); |
| 1572 | } |
| 1573 | //advance bits |
| 1574 | numBits += (firstFullWave / *clock); |
| 1575 | //set start of wave as clock align |
| 1576 | lastClkBit = firstFullWave; |
| 1577 | if (g_debugMode==2) prnt("DEBUG PSK: firstFullWave: %u, waveLen: %u",firstFullWave,fullWaveLen); |
| 1578 | if (g_debugMode==2) prnt("DEBUG: clk: %d, lastClkBit: %u, fc: %u", *clock, lastClkBit,(unsigned int) fc); |
| 1579 | waveStart = 0; |
| 1580 | dest[numBits++] = curPhase; //set first read bit |
| 1581 | for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){ |
| 1582 | //top edge of wave = start of new wave |
| 1583 | if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){ |
| 1584 | if (waveStart == 0) { |
| 1585 | waveStart = i+1; |
| 1586 | waveLenCnt = 0; |
| 1587 | avgWaveVal = dest[i+1]; |
| 1588 | } else { //waveEnd |
| 1589 | waveEnd = i+1; |
| 1590 | waveLenCnt = waveEnd-waveStart; |
| 1591 | lastAvgWaveVal = avgWaveVal/waveLenCnt; |
| 1592 | if (waveLenCnt > fc){ |
| 1593 | //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal); |
| 1594 | //this wave is a phase shift |
| 1595 | //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc); |
| 1596 | if (i+1 >= lastClkBit + *clock - tol){ //should be a clock bit |
| 1597 | curPhase ^= 1; |
| 1598 | dest[numBits++] = curPhase; |
| 1599 | lastClkBit += *clock; |
| 1600 | } else if (i < lastClkBit+10+fc){ |
| 1601 | //noise after a phase shift - ignore |
| 1602 | } else { //phase shift before supposed to based on clock |
| 1603 | errCnt++; |
| 1604 | dest[numBits++] = 7; |
| 1605 | } |
| 1606 | } else if (i+1 > lastClkBit + *clock + tol + fc){ |
| 1607 | lastClkBit += *clock; //no phase shift but clock bit |
| 1608 | dest[numBits++] = curPhase; |
| 1609 | } |
| 1610 | avgWaveVal = 0; |
| 1611 | waveStart = i+1; |
| 1612 | } |
| 1613 | } |
| 1614 | avgWaveVal += dest[i+1]; |
| 1615 | } |
| 1616 | *size = numBits; |
| 1617 | return errCnt; |
| 1618 | } |
| 1619 | |
| 1620 | //by marshmellow |
| 1621 | //attempt to identify a Sequence Terminator in ASK modulated raw wave |
| 1622 | bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) { |
| 1623 | size_t bufsize = *size; |
| 1624 | //need to loop through all samples and identify our clock, look for the ST pattern |
| 1625 | uint8_t fndClk[] = {8,16,32,40,50,64,128}; |
| 1626 | int clk = 0; |
| 1627 | int tol = 0; |
| 1628 | int i, j, skip, start, end, low, high, minClk, waveStart; |
| 1629 | bool complete = false; |
| 1630 | int tmpbuff[bufsize / 32]; //guess rf/32 clock, if click is smaller we will only have room for a fraction of the samples captured |
| 1631 | int waveLen[bufsize / 32]; // if clock is larger then we waste memory in array size that is not needed... |
| 1632 | size_t testsize = (bufsize < 512) ? bufsize : 512; |
| 1633 | int phaseoff = 0; |
| 1634 | high = low = 128; |
| 1635 | memset(tmpbuff, 0, sizeof(tmpbuff)); |
| 1636 | |
| 1637 | if ( getHiLo(buffer, testsize, &high, &low, 80, 80) == -1 ) { |
| 1638 | if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting"); |
| 1639 | return false; //just noise |
| 1640 | } |
| 1641 | i = 0; |
| 1642 | j = 0; |
| 1643 | minClk = 255; |
| 1644 | // get to first full low to prime loop and skip incomplete first pulse |
| 1645 | while ((buffer[i] < high) && (i < bufsize)) |
| 1646 | ++i; |
| 1647 | while ((buffer[i] > low) && (i < bufsize)) |
| 1648 | ++i; |
| 1649 | skip = i; |
| 1650 | |
| 1651 | // populate tmpbuff buffer with pulse lengths |
| 1652 | while (i < bufsize) { |
| 1653 | // measure from low to low |
| 1654 | while ((buffer[i] > low) && (i < bufsize)) |
| 1655 | ++i; |
| 1656 | start= i; |
| 1657 | while ((buffer[i] < high) && (i < bufsize)) |
| 1658 | ++i; |
| 1659 | //first high point for this wave |
| 1660 | waveStart = i; |
| 1661 | while ((buffer[i] > low) && (i < bufsize)) |
| 1662 | ++i; |
| 1663 | if (j >= (bufsize/32)) { |
| 1664 | break; |
| 1665 | } |
| 1666 | waveLen[j] = i - waveStart; //first high to first low |
| 1667 | tmpbuff[j++] = i - start; |
| 1668 | if (i-start < minClk && i < bufsize) { |
| 1669 | minClk = i - start; |
| 1670 | } |
| 1671 | } |
| 1672 | // set clock - might be able to get this externally and remove this work... |
| 1673 | if (!clk) { |
| 1674 | for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) { |
| 1675 | tol = fndClk[clkCnt]/8; |
| 1676 | if (minClk >= fndClk[clkCnt]-tol && minClk <= fndClk[clkCnt]+1) { |
| 1677 | clk=fndClk[clkCnt]; |
| 1678 | break; |
| 1679 | } |
| 1680 | } |
| 1681 | // clock not found - ERROR |
| 1682 | if (!clk) { |
| 1683 | if (g_debugMode==2) prnt("DEBUG STT: clock not found - quitting"); |
| 1684 | return false; |
| 1685 | } |
| 1686 | } else tol = clk/8; |
| 1687 | |
| 1688 | *foundclock = clk; |
| 1689 | |
| 1690 | // look for Sequence Terminator - should be pulses of clk*(1 or 1.5), clk*2, clk*(1.5 or 2) |
| 1691 | start = -1; |
| 1692 | for (i = 0; i < j - 4; ++i) { |
| 1693 | skip += tmpbuff[i]; |
| 1694 | if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol && waveLen[i] < clk+tol) { //1 to 2 clocks depending on 2 bits prior |
| 1695 | if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) { //2 clocks and wave size is 1 1/2 |
| 1696 | if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave |
| 1697 | if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit |
| 1698 | start = i + 3; |
| 1699 | break; |
| 1700 | } |
| 1701 | } |
| 1702 | } |
| 1703 | } |
| 1704 | } |
| 1705 | // first ST not found - ERROR |
| 1706 | if (start < 0) { |
| 1707 | if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting"); |
| 1708 | return false; |
| 1709 | } else { |
| 1710 | if (g_debugMode==2) prnt("DEBUG STT: first STT found at: %d, j=%d",start, j); |
| 1711 | } |
| 1712 | if (waveLen[i+2] > clk*1+tol) |
| 1713 | phaseoff = 0; |
| 1714 | else |
| 1715 | phaseoff = clk/2; |
| 1716 | |
| 1717 | // skip over the remainder of ST |
| 1718 | skip += clk*7/2; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point |
| 1719 | |
| 1720 | // now do it again to find the end |
| 1721 | end = skip; |
| 1722 | for (i += 3; i < j - 4; ++i) { |
| 1723 | end += tmpbuff[i]; |
| 1724 | if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol && waveLen[i] < clk+tol) { //1 to 2 clocks depending on 2 bits prior |
| 1725 | if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) { //2 clocks and wave size is 1 1/2 |
| 1726 | if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave |
| 1727 | if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit |
| 1728 | complete = true; |
| 1729 | break; |
| 1730 | } |
| 1731 | } |
| 1732 | } |
| 1733 | } |
| 1734 | } |
| 1735 | end -= phaseoff; |
| 1736 | //didn't find second ST - ERROR |
| 1737 | if (!complete) { |
| 1738 | if (g_debugMode==2) prnt("DEBUG STT: second STT not found - quitting"); |
| 1739 | return false; |
| 1740 | } |
| 1741 | if (g_debugMode==2) prnt("DEBUG STT: start of data: %d end of data: %d, datalen: %d, clk: %d, bits: %d, phaseoff: %d", skip, end, end-skip, clk, (end-skip)/clk, phaseoff); |
| 1742 | //now begin to trim out ST so we can use normal demod cmds |
| 1743 | start = skip; |
| 1744 | size_t datalen = end - start; |
| 1745 | // check validity of datalen (should be even clock increments) - use a tolerance of up to 1/8th a clock |
| 1746 | if ( clk - (datalen % clk) <= clk/8) { |
| 1747 | // padd the amount off - could be problematic... but shouldn't happen often |
| 1748 | datalen += clk - (datalen % clk); |
| 1749 | } else if ( (datalen % clk) <= clk/8 ) { |
| 1750 | // padd the amount off - could be problematic... but shouldn't happen often |
| 1751 | datalen -= datalen % clk; |
| 1752 | } else { |
| 1753 | if (g_debugMode==2) prnt("DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting", datalen, clk, datalen % clk); |
| 1754 | return false; |
| 1755 | } |
| 1756 | // if datalen is less than one t55xx block - ERROR |
| 1757 | if (datalen/clk < 8*4) { |
| 1758 | if (g_debugMode==2) prnt("DEBUG STT: datalen is less than 1 full t55xx block - quitting"); |
| 1759 | return false; |
| 1760 | } |
| 1761 | size_t dataloc = start; |
| 1762 | if (buffer[dataloc-(clk*4)-(clk/8)] <= low && buffer[dataloc] <= low && buffer[dataloc-(clk*4)] >= high) { |
| 1763 | //we have low drift (and a low just before the ST and a low just after the ST) - compensate by backing up the start |
| 1764 | for ( i=0; i <= (clk/8); ++i ) { |
| 1765 | if ( buffer[dataloc - (clk*4) - i] <= low ) { |
| 1766 | dataloc -= i; |
| 1767 | break; |
| 1768 | } |
| 1769 | } |
| 1770 | } |
| 1771 | |
| 1772 | size_t newloc = 0; |
| 1773 | i=0; |
| 1774 | if (g_debugMode==2) prnt("DEBUG STT: Starting STT trim - start: %d, datalen: %d ",dataloc, datalen); |
| 1775 | |
| 1776 | // warning - overwriting buffer given with raw wave data with ST removed... |
| 1777 | while ( dataloc < bufsize-(clk/2) ) { |
| 1778 | //compensate for long high at end of ST not being high due to signal loss... (and we cut out the start of wave high part) |
| 1779 | if (buffer[dataloc]<high && buffer[dataloc]>low && buffer[dataloc+3]<high && buffer[dataloc+3]>low) { |
| 1780 | for(i=0; i < clk/2-tol; ++i) { |
| 1781 | buffer[dataloc+i] = high+5; |
| 1782 | } |
| 1783 | } |
| 1784 | for (i=0; i<datalen; ++i) { |
| 1785 | if (i+newloc < bufsize) { |
| 1786 | if (i+newloc < dataloc) |
| 1787 | buffer[i+newloc] = buffer[dataloc]; |
| 1788 | |
| 1789 | dataloc++; |
| 1790 | } |
| 1791 | } |
| 1792 | newloc += i; |
| 1793 | //skip next ST - we just assume it will be there from now on... |
| 1794 | if (g_debugMode==2) prnt("DEBUG STT: skipping STT at %d to %d", dataloc, dataloc+(clk*4)); |
| 1795 | dataloc += clk*4; |
| 1796 | } |
| 1797 | *size = newloc; |
| 1798 | return true; |
| 1799 | } |