| 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 - by marshmellow, holiman, iceman and |
| 9 | // many others who came before |
| 10 | // |
| 11 | // NOTES: |
| 12 | // LF Demod functions are placed here to allow the flexability to use client or |
| 13 | // device side. Most BUT NOT ALL of these functions are currenlty safe for |
| 14 | // device side use currently. (DetectST for example...) |
| 15 | // |
| 16 | // There are likely many improvements to the code that could be made, please |
| 17 | // make suggestions... |
| 18 | // |
| 19 | // we tried to include author comments so any questions could be directed to |
| 20 | // the source. |
| 21 | // |
| 22 | // There are 4 main sections of code below: |
| 23 | // Utilities Section: |
| 24 | // for general utilities used by multiple other functions |
| 25 | // Clock / Bitrate Detection Section: |
| 26 | // for clock detection functions for each modulation |
| 27 | // Modulation Demods &/or Decoding Section: |
| 28 | // for main general modulation demodulating and encoding decoding code. |
| 29 | // Tag format detection section: |
| 30 | // for detection of specific tag formats within demodulated data |
| 31 | // |
| 32 | // marshmellow |
| 33 | //----------------------------------------------------------------------------- |
| 34 | |
| 35 | #include <string.h> // for memset, memcmp and size_t |
| 36 | #include "lfdemod.h" |
| 37 | #include <stdint.h> // for uint_32+ |
| 38 | #include <stdbool.h> // for bool |
| 39 | #include "parity.h" // for parity test |
| 40 | |
| 41 | //********************************************************************************************** |
| 42 | //---------------------------------Utilities Section-------------------------------------------- |
| 43 | //********************************************************************************************** |
| 44 | #define LOWEST_DEFAULT_CLOCK 32 |
| 45 | #define FSK_PSK_THRESHOLD 123 |
| 46 | |
| 47 | //to allow debug print calls when used not on device |
| 48 | void dummy(char *fmt, ...){} |
| 49 | #ifndef ON_DEVICE |
| 50 | #include "ui.h" |
| 51 | #include "cmdparser.h" |
| 52 | #include "cmddata.h" |
| 53 | #define prnt PrintAndLog |
| 54 | #else |
| 55 | uint8_t g_debugMode=0; |
| 56 | #define prnt dummy |
| 57 | #endif |
| 58 | |
| 59 | uint8_t justNoise(uint8_t *BitStream, size_t size) { |
| 60 | //test samples are not just noise |
| 61 | uint8_t justNoise1 = 1; |
| 62 | for(size_t idx=0; idx < size && justNoise1 ;idx++){ |
| 63 | justNoise1 = BitStream[idx] < FSK_PSK_THRESHOLD; |
| 64 | } |
| 65 | return justNoise1; |
| 66 | } |
| 67 | |
| 68 | //by marshmellow |
| 69 | //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 |
| 70 | int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi, uint8_t fuzzLo) { |
| 71 | *high=0; |
| 72 | *low=255; |
| 73 | // get high and low thresholds |
| 74 | for (size_t i=0; i < size; i++){ |
| 75 | if (BitStream[i] > *high) *high = BitStream[i]; |
| 76 | if (BitStream[i] < *low) *low = BitStream[i]; |
| 77 | } |
| 78 | if (*high < FSK_PSK_THRESHOLD) return -1; // just noise |
| 79 | *high = ((*high-128)*fuzzHi + 12800)/100; |
| 80 | *low = ((*low-128)*fuzzLo + 12800)/100; |
| 81 | return 1; |
| 82 | } |
| 83 | |
| 84 | // by marshmellow |
| 85 | // pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType |
| 86 | // returns 1 if passed |
| 87 | bool parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType) { |
| 88 | return oddparity32(bits) ^ pType; |
| 89 | } |
| 90 | |
| 91 | // by marshmellow |
| 92 | // takes a array of binary values, start position, length of bits per parity (includes parity bit - MAX 32), |
| 93 | // Parity Type (1 for odd; 0 for even; 2 for Always 1's; 3 for Always 0's), and binary Length (length to run) |
| 94 | size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen) { |
| 95 | uint32_t parityWd = 0; |
| 96 | size_t bitCnt = 0; |
| 97 | for (int word = 0; word < (bLen); word+=pLen) { |
| 98 | for (int bit=0; bit < pLen; bit++) { |
| 99 | if (word+bit >= bLen) break; |
| 100 | parityWd = (parityWd << 1) | BitStream[startIdx+word+bit]; |
| 101 | BitStream[bitCnt++] = (BitStream[startIdx+word+bit]); |
| 102 | } |
| 103 | if (word+pLen > bLen) break; |
| 104 | |
| 105 | bitCnt--; // overwrite parity with next data |
| 106 | // if parity fails then return 0 |
| 107 | switch (pType) { |
| 108 | case 3: if (BitStream[bitCnt]==1) {return 0;} break; //should be 0 spacer bit |
| 109 | case 2: if (BitStream[bitCnt]==0) {return 0;} break; //should be 1 spacer bit |
| 110 | default: if (parityTest(parityWd, pLen, pType) == 0) {return 0;} break; //test parity |
| 111 | } |
| 112 | parityWd = 0; |
| 113 | } |
| 114 | // if we got here then all the parities passed |
| 115 | //return size |
| 116 | return bitCnt; |
| 117 | } |
| 118 | |
| 119 | // by marshmellow |
| 120 | // takes a array of binary values, length of bits per parity (includes parity bit), |
| 121 | // Parity Type (1 for odd; 0 for even; 2 Always 1's; 3 Always 0's), and binary Length (length to run) |
| 122 | // Make sure *dest is long enough to store original sourceLen + #_of_parities_to_be_added |
| 123 | size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t pLen, uint8_t pType) { |
| 124 | uint32_t parityWd = 0; |
| 125 | size_t j = 0, bitCnt = 0; |
| 126 | for (int word = 0; word < sourceLen; word+=pLen-1) { |
| 127 | for (int bit=0; bit < pLen-1; bit++){ |
| 128 | parityWd = (parityWd << 1) | BitSource[word+bit]; |
| 129 | dest[j++] = (BitSource[word+bit]); |
| 130 | } |
| 131 | // if parity fails then return 0 |
| 132 | switch (pType) { |
| 133 | case 3: dest[j++]=0; break; // marker bit which should be a 0 |
| 134 | case 2: dest[j++]=1; break; // marker bit which should be a 1 |
| 135 | default: |
| 136 | dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1; |
| 137 | break; |
| 138 | } |
| 139 | bitCnt += pLen; |
| 140 | parityWd = 0; |
| 141 | } |
| 142 | // if we got here then all the parities passed |
| 143 | //return ID start index and size |
| 144 | return bitCnt; |
| 145 | } |
| 146 | |
| 147 | uint32_t bytebits_to_byte(uint8_t *src, size_t numbits) { |
| 148 | uint32_t num = 0; |
| 149 | for(int i = 0 ; i < numbits ; i++) |
| 150 | { |
| 151 | num = (num << 1) | (*src); |
| 152 | src++; |
| 153 | } |
| 154 | return num; |
| 155 | } |
| 156 | |
| 157 | //least significant bit first |
| 158 | uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits) { |
| 159 | uint32_t num = 0; |
| 160 | for(int i = 0 ; i < numbits ; i++) |
| 161 | { |
| 162 | num = (num << 1) | *(src + (numbits-(i+1))); |
| 163 | } |
| 164 | return num; |
| 165 | } |
| 166 | |
| 167 | // search for given preamble in given BitStream and return success=1 or fail=0 and startIndex (where it was found) and length if not fineone |
| 168 | // fineone does not look for a repeating preamble for em4x05/4x69 sends preamble once, so look for it once in the first pLen bits |
| 169 | bool preambleSearchEx(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx, bool findone) { |
| 170 | // Sanity check. If preamble length is bigger than bitstream length. |
| 171 | if ( *size <= pLen ) return false; |
| 172 | |
| 173 | uint8_t foundCnt = 0; |
| 174 | for (size_t idx = 0; idx < *size - pLen; idx++) { |
| 175 | if (memcmp(BitStream+idx, preamble, pLen) == 0) { |
| 176 | //first index found |
| 177 | foundCnt++; |
| 178 | if (foundCnt == 1) { |
| 179 | if (g_debugMode) prnt("DEBUG: preamble found at %u", idx); |
| 180 | *startIdx = idx; |
| 181 | if (findone) return true; |
| 182 | } else if (foundCnt == 2) { |
| 183 | *size = idx - *startIdx; |
| 184 | return true; |
| 185 | } |
| 186 | } |
| 187 | } |
| 188 | return false; |
| 189 | } |
| 190 | |
| 191 | //by marshmellow |
| 192 | //search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length |
| 193 | uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx) { |
| 194 | return (preambleSearchEx(BitStream, preamble, pLen, size, startIdx, false)) ? 1 : 0; |
| 195 | } |
| 196 | |
| 197 | // find start of modulating data (for fsk and psk) in case of beginning noise or slow chip startup. |
| 198 | size_t findModStart(uint8_t dest[], size_t size, uint8_t expWaveSize) { |
| 199 | size_t i = 0; |
| 200 | size_t waveSizeCnt = 0; |
| 201 | uint8_t thresholdCnt = 0; |
| 202 | bool isAboveThreshold = dest[i++] >= FSK_PSK_THRESHOLD; |
| 203 | for (; i < size-20; i++ ) { |
| 204 | if(dest[i] < FSK_PSK_THRESHOLD && isAboveThreshold) { |
| 205 | thresholdCnt++; |
| 206 | if (thresholdCnt > 2 && waveSizeCnt < expWaveSize+1) break; |
| 207 | isAboveThreshold = false; |
| 208 | waveSizeCnt = 0; |
| 209 | } else if (dest[i] >= FSK_PSK_THRESHOLD && !isAboveThreshold) { |
| 210 | thresholdCnt++; |
| 211 | if (thresholdCnt > 2 && waveSizeCnt < expWaveSize+1) break; |
| 212 | isAboveThreshold = true; |
| 213 | waveSizeCnt = 0; |
| 214 | } else { |
| 215 | waveSizeCnt++; |
| 216 | } |
| 217 | if (thresholdCnt > 10) break; |
| 218 | } |
| 219 | if (g_debugMode == 2) prnt("DEBUG: threshold Count reached at %u, count: %u",i, thresholdCnt); |
| 220 | return i; |
| 221 | } |
| 222 | |
| 223 | int getClosestClock(int testclk) { |
| 224 | uint8_t fndClk[] = {8,16,32,40,50,64,128}; |
| 225 | |
| 226 | for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) |
| 227 | if (testclk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && testclk <= fndClk[clkCnt]+1) |
| 228 | return fndClk[clkCnt]; |
| 229 | |
| 230 | return 0; |
| 231 | } |
| 232 | |
| 233 | void getNextLow(uint8_t samples[], size_t size, int low, size_t *i) { |
| 234 | while ((samples[*i] > low) && (*i < size)) |
| 235 | *i+=1; |
| 236 | } |
| 237 | |
| 238 | void getNextHigh(uint8_t samples[], size_t size, int high, size_t *i) { |
| 239 | while ((samples[*i] < high) && (*i < size)) |
| 240 | *i+=1; |
| 241 | } |
| 242 | |
| 243 | // load wave counters |
| 244 | bool loadWaveCounters(uint8_t samples[], size_t size, int lowToLowWaveLen[], int highToLowWaveLen[], int *waveCnt, int *skip, int *minClk, int *high, int *low) { |
| 245 | size_t i=0, firstLow, firstHigh; |
| 246 | size_t testsize = (size < 512) ? size : 512; |
| 247 | |
| 248 | if ( getHiLo(samples, testsize, high, low, 80, 80) == -1 ) { |
| 249 | if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting"); |
| 250 | return false; //just noise |
| 251 | } |
| 252 | |
| 253 | // get to first full low to prime loop and skip incomplete first pulse |
| 254 | getNextHigh(samples, size, *high, &i); |
| 255 | getNextLow(samples, size, *low, &i); |
| 256 | *skip = i; |
| 257 | |
| 258 | // populate tmpbuff buffer with pulse lengths |
| 259 | while (i < size) { |
| 260 | // measure from low to low |
| 261 | firstLow = i; |
| 262 | //find first high point for this wave |
| 263 | getNextHigh(samples, size, *high, &i); |
| 264 | firstHigh = i; |
| 265 | |
| 266 | getNextLow(samples, size, *low, &i); |
| 267 | |
| 268 | if (*waveCnt >= (size/LOWEST_DEFAULT_CLOCK)) |
| 269 | break; |
| 270 | |
| 271 | highToLowWaveLen[*waveCnt] = i - firstHigh; //first high to first low |
| 272 | lowToLowWaveLen[*waveCnt] = i - firstLow; |
| 273 | *waveCnt += 1; |
| 274 | if (i-firstLow < *minClk && i < size) { |
| 275 | *minClk = i - firstLow; |
| 276 | } |
| 277 | } |
| 278 | return true; |
| 279 | } |
| 280 | |
| 281 | size_t pskFindFirstPhaseShift(uint8_t samples[], size_t size, uint8_t *curPhase, size_t waveStart, uint16_t fc, uint16_t *fullWaveLen) { |
| 282 | uint16_t loopCnt = (size+3 < 4096) ? size : 4096; //don't need to loop through entire array... |
| 283 | |
| 284 | uint16_t avgWaveVal=0, lastAvgWaveVal=0; |
| 285 | size_t i = waveStart, waveEnd, waveLenCnt, firstFullWave; |
| 286 | for (; i<loopCnt; i++) { |
| 287 | // find peak // was "samples[i] + fc" but why? must have been used to weed out some wave error... removed.. |
| 288 | if (samples[i] < samples[i+1] && samples[i+1] >= samples[i+2]){ |
| 289 | waveEnd = i+1; |
| 290 | if (g_debugMode == 2) prnt("DEBUG PSK: waveEnd: %u, waveStart: %u", waveEnd, waveStart); |
| 291 | waveLenCnt = waveEnd-waveStart; |
| 292 | if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+8)){ //not first peak and is a large wave but not out of whack |
| 293 | lastAvgWaveVal = avgWaveVal/(waveLenCnt); |
| 294 | firstFullWave = waveStart; |
| 295 | *fullWaveLen = waveLenCnt; |
| 296 | //if average wave value is > graph 0 then it is an up wave or a 1 (could cause inverting) |
| 297 | if (lastAvgWaveVal > FSK_PSK_THRESHOLD) *curPhase ^= 1; |
| 298 | return firstFullWave; |
| 299 | } |
| 300 | waveStart = i+1; |
| 301 | avgWaveVal = 0; |
| 302 | } |
| 303 | avgWaveVal += samples[i+2]; |
| 304 | } |
| 305 | return 0; |
| 306 | } |
| 307 | |
| 308 | //by marshmellow |
| 309 | //amplify based on ask edge detection - not accurate enough to use all the time |
| 310 | void askAmp(uint8_t *BitStream, size_t size) { |
| 311 | uint8_t Last = 128; |
| 312 | for(size_t i = 1; i<size; i++){ |
| 313 | if (BitStream[i]-BitStream[i-1]>=30) //large jump up |
| 314 | Last = 255; |
| 315 | else if(BitStream[i-1]-BitStream[i]>=20) //large jump down |
| 316 | Last = 0; |
| 317 | |
| 318 | BitStream[i-1] = Last; |
| 319 | } |
| 320 | return; |
| 321 | } |
| 322 | |
| 323 | uint32_t manchesterEncode2Bytes(uint16_t datain) { |
| 324 | uint32_t output = 0; |
| 325 | uint8_t curBit = 0; |
| 326 | for (uint8_t i=0; i<16; i++) { |
| 327 | curBit = (datain >> (15-i) & 1); |
| 328 | output |= (1<<(((15-i)*2)+curBit)); |
| 329 | } |
| 330 | return output; |
| 331 | } |
| 332 | |
| 333 | //by marshmellow |
| 334 | //encode binary data into binary manchester |
| 335 | //NOTE: BitStream must have triple the size of "size" available in memory to do the swap |
| 336 | int ManchesterEncode(uint8_t *BitStream, size_t size) { |
| 337 | //allow up to 4K out (means BitStream must be at least 2048+4096 to handle the swap) |
| 338 | size = (size>2048) ? 2048 : size; |
| 339 | size_t modIdx = size; |
| 340 | size_t i; |
| 341 | for (size_t idx=0; idx < size; idx++){ |
| 342 | BitStream[idx+modIdx++] = BitStream[idx]; |
| 343 | BitStream[idx+modIdx++] = BitStream[idx]^1; |
| 344 | } |
| 345 | for (i=0; i<(size*2); i++){ |
| 346 | BitStream[i] = BitStream[i+size]; |
| 347 | } |
| 348 | return i; |
| 349 | } |
| 350 | |
| 351 | // by marshmellow |
| 352 | // to detect a wave that has heavily clipped (clean) samples |
| 353 | uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low) { |
| 354 | bool allArePeaks = true; |
| 355 | uint16_t cntPeaks=0; |
| 356 | size_t loopEnd = 512+160; |
| 357 | if (loopEnd > size) loopEnd = size; |
| 358 | for (size_t i=160; i<loopEnd; i++){ |
| 359 | if (dest[i]>low && dest[i]<high) |
| 360 | allArePeaks = false; |
| 361 | else |
| 362 | cntPeaks++; |
| 363 | } |
| 364 | if (!allArePeaks){ |
| 365 | if (cntPeaks > 300) return true; |
| 366 | } |
| 367 | return allArePeaks; |
| 368 | } |
| 369 | |
| 370 | //********************************************************************************************** |
| 371 | //-------------------Clock / Bitrate Detection Section------------------------------------------ |
| 372 | //********************************************************************************************** |
| 373 | |
| 374 | // by marshmellow |
| 375 | // to help detect clocks on heavily clipped samples |
| 376 | // based on count of low to low |
| 377 | int DetectStrongAskClock(uint8_t dest[], size_t size, int high, int low, int *clock) { |
| 378 | size_t startwave; |
| 379 | size_t i = 100; |
| 380 | size_t minClk = 255; |
| 381 | int shortestWaveIdx = 0; |
| 382 | // get to first full low to prime loop and skip incomplete first pulse |
| 383 | getNextHigh(dest, size, high, &i); |
| 384 | getNextLow(dest, size, low, &i); |
| 385 | |
| 386 | // loop through all samples |
| 387 | while (i < size) { |
| 388 | // measure from low to low |
| 389 | startwave = i; |
| 390 | |
| 391 | getNextHigh(dest, size, high, &i); |
| 392 | getNextLow(dest, size, low, &i); |
| 393 | //get minimum measured distance |
| 394 | if (i-startwave < minClk && i < size) { |
| 395 | minClk = i - startwave; |
| 396 | shortestWaveIdx = startwave; |
| 397 | } |
| 398 | } |
| 399 | // set clock |
| 400 | if (g_debugMode==2) prnt("DEBUG ASK: DetectStrongAskClock smallest wave: %d",minClk); |
| 401 | *clock = getClosestClock(minClk); |
| 402 | if (*clock == 0) |
| 403 | return 0; |
| 404 | |
| 405 | return shortestWaveIdx; |
| 406 | } |
| 407 | |
| 408 | // by marshmellow |
| 409 | // not perfect especially with lower clocks or VERY good antennas (heavy wave clipping) |
| 410 | // maybe somehow adjust peak trimming value based on samples to fix? |
| 411 | // return start index of best starting position for that clock and return clock (by reference) |
| 412 | int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr) { |
| 413 | size_t i=1; |
| 414 | uint8_t clk[] = {255,8,16,32,40,50,64,100,128,255}; |
| 415 | uint8_t clkEnd = 9; |
| 416 | uint8_t loopCnt = 255; //don't need to loop through entire array... |
| 417 | if (size <= loopCnt+60) return -1; //not enough samples |
| 418 | size -= 60; //sometimes there is a strange end wave - filter out this.... |
| 419 | //if we already have a valid clock |
| 420 | uint8_t clockFnd=0; |
| 421 | for (;i<clkEnd;++i) |
| 422 | if (clk[i] == *clock) clockFnd = i; |
| 423 | //clock found but continue to find best startpos |
| 424 | |
| 425 | //get high and low peak |
| 426 | int peak, low; |
| 427 | if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return -1; |
| 428 | |
| 429 | //test for large clean peaks |
| 430 | if (!clockFnd){ |
| 431 | if (DetectCleanAskWave(dest, size, peak, low)==1){ |
| 432 | int ans = DetectStrongAskClock(dest, size, peak, low, clock); |
| 433 | if (g_debugMode==2) prnt("DEBUG ASK: detectaskclk Clean Ask Wave Detected: clk %i, ShortestWave: %i",clock, ans); |
| 434 | if (ans > 0) { |
| 435 | return ans; //return shortest wave start position |
| 436 | } |
| 437 | } |
| 438 | } |
| 439 | uint8_t ii; |
| 440 | uint8_t clkCnt, tol = 0; |
| 441 | uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000}; |
| 442 | uint8_t bestStart[]={0,0,0,0,0,0,0,0,0}; |
| 443 | size_t errCnt = 0; |
| 444 | size_t arrLoc, loopEnd; |
| 445 | |
| 446 | if (clockFnd>0) { |
| 447 | clkCnt = clockFnd; |
| 448 | clkEnd = clockFnd+1; |
| 449 | } |
| 450 | else clkCnt=1; |
| 451 | |
| 452 | //test each valid clock from smallest to greatest to see which lines up |
| 453 | for(; clkCnt < clkEnd; clkCnt++){ |
| 454 | if (clk[clkCnt] <= 32){ |
| 455 | tol=1; |
| 456 | }else{ |
| 457 | tol=0; |
| 458 | } |
| 459 | //if no errors allowed - keep start within the first clock |
| 460 | if (!maxErr && size > clk[clkCnt]*2 + tol && clk[clkCnt]<128) loopCnt=clk[clkCnt]*2; |
| 461 | bestErr[clkCnt]=1000; |
| 462 | //try lining up the peaks by moving starting point (try first few clocks) |
| 463 | for (ii=0; ii < loopCnt; ii++){ |
| 464 | if (dest[ii] < peak && dest[ii] > low) continue; |
| 465 | |
| 466 | errCnt=0; |
| 467 | // now that we have the first one lined up test rest of wave array |
| 468 | loopEnd = ((size-ii-tol) / clk[clkCnt]) - 1; |
| 469 | for (i=0; i < loopEnd; ++i){ |
| 470 | arrLoc = ii + (i * clk[clkCnt]); |
| 471 | if (dest[arrLoc] >= peak || dest[arrLoc] <= low){ |
| 472 | }else if (dest[arrLoc-tol] >= peak || dest[arrLoc-tol] <= low){ |
| 473 | }else if (dest[arrLoc+tol] >= peak || dest[arrLoc+tol] <= low){ |
| 474 | }else{ //error no peak detected |
| 475 | errCnt++; |
| 476 | } |
| 477 | } |
| 478 | //if we found no errors then we can stop here and a low clock (common clocks) |
| 479 | // this is correct one - return this clock |
| 480 | if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, err %d, startpos %d, endpos %d",clk[clkCnt],errCnt,ii,i); |
| 481 | if(errCnt==0 && clkCnt<7) { |
| 482 | if (!clockFnd) *clock = clk[clkCnt]; |
| 483 | return ii; |
| 484 | } |
| 485 | //if we found errors see if it is lowest so far and save it as best run |
| 486 | if(errCnt<bestErr[clkCnt]){ |
| 487 | bestErr[clkCnt]=errCnt; |
| 488 | bestStart[clkCnt]=ii; |
| 489 | } |
| 490 | } |
| 491 | } |
| 492 | uint8_t iii; |
| 493 | uint8_t best=0; |
| 494 | for (iii=1; iii<clkEnd; ++iii){ |
| 495 | if (bestErr[iii] < bestErr[best]){ |
| 496 | if (bestErr[iii] == 0) bestErr[iii]=1; |
| 497 | // current best bit to error ratio vs new bit to error ratio |
| 498 | if ( (size/clk[best])/bestErr[best] < (size/clk[iii])/bestErr[iii] ){ |
| 499 | best = iii; |
| 500 | } |
| 501 | } |
| 502 | 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]); |
| 503 | } |
| 504 | if (!clockFnd) *clock = clk[best]; |
| 505 | return bestStart[best]; |
| 506 | } |
| 507 | |
| 508 | int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low, bool *strong) { |
| 509 | //find shortest transition from high to low |
| 510 | *strong = false; |
| 511 | size_t i = 0; |
| 512 | size_t transition1 = 0; |
| 513 | int lowestTransition = 255; |
| 514 | bool lastWasHigh = false; |
| 515 | size_t transitionSampleCount = 0; |
| 516 | //find first valid beginning of a high or low wave |
| 517 | while ((dest[i] >= peak || dest[i] <= low) && (i < size)) |
| 518 | ++i; |
| 519 | while ((dest[i] < peak && dest[i] > low) && (i < size)) |
| 520 | ++i; |
| 521 | lastWasHigh = (dest[i] >= peak); |
| 522 | |
| 523 | if (i==size) return 0; |
| 524 | transition1 = i; |
| 525 | |
| 526 | for (;i < size; i++) { |
| 527 | if ((dest[i] >= peak && !lastWasHigh) || (dest[i] <= low && lastWasHigh)) { |
| 528 | lastWasHigh = (dest[i] >= peak); |
| 529 | if (i-transition1 < lowestTransition) lowestTransition = i-transition1; |
| 530 | transition1 = i; |
| 531 | } else if (dest[i] < peak && dest[i] > low) { |
| 532 | transitionSampleCount++; |
| 533 | } |
| 534 | } |
| 535 | if (lowestTransition == 255) lowestTransition = 0; |
| 536 | if (g_debugMode==2) prnt("DEBUG NRZ: detectstrongNRZclk smallest wave: %d",lowestTransition); |
| 537 | // if less than 10% of the samples were not peaks (or 90% were peaks) then we have a strong wave |
| 538 | if (transitionSampleCount / size < 10) { |
| 539 | *strong = true; |
| 540 | lowestTransition = getClosestClock(lowestTransition); |
| 541 | } |
| 542 | return lowestTransition; |
| 543 | } |
| 544 | |
| 545 | //by marshmellow |
| 546 | //detect nrz clock by reading #peaks vs no peaks(or errors) |
| 547 | int DetectNRZClock(uint8_t dest[], size_t size, int clock, size_t *clockStartIdx) { |
| 548 | size_t i=0; |
| 549 | uint8_t clk[]={8,16,32,40,50,64,100,128,255}; |
| 550 | size_t loopCnt = 4096; //don't need to loop through entire array... |
| 551 | if (size == 0) return 0; |
| 552 | if (size<loopCnt) loopCnt = size-20; |
| 553 | //if we already have a valid clock quit |
| 554 | for (; i < 8; ++i) |
| 555 | if (clk[i] == clock) return clock; |
| 556 | |
| 557 | //get high and low peak |
| 558 | int peak, low; |
| 559 | if (getHiLo(dest, loopCnt, &peak, &low, 90, 90) < 1) return 0; |
| 560 | |
| 561 | bool strong = false; |
| 562 | int lowestTransition = DetectStrongNRZClk(dest, size-20, peak, low, &strong); |
| 563 | if (strong) return lowestTransition; |
| 564 | size_t ii; |
| 565 | uint8_t clkCnt; |
| 566 | uint8_t tol = 0; |
| 567 | uint16_t smplCnt = 0; |
| 568 | int16_t peakcnt = 0; |
| 569 | int16_t peaksdet[] = {0,0,0,0,0,0,0,0}; |
| 570 | uint16_t minPeak = 255; |
| 571 | bool firstpeak = true; |
| 572 | //test for large clipped waves - ignore first peak |
| 573 | for (i=0; i<loopCnt; i++) { |
| 574 | if (dest[i] >= peak || dest[i] <= low) { |
| 575 | if (firstpeak) continue; |
| 576 | smplCnt++; |
| 577 | } else { |
| 578 | firstpeak = false; |
| 579 | if (smplCnt > 0) { |
| 580 | if (minPeak > smplCnt && smplCnt > 7) minPeak = smplCnt; |
| 581 | peakcnt++; |
| 582 | if (g_debugMode == 2) prnt("DEBUG NRZ: minPeak: %d, smplCnt: %d, peakcnt: %d",minPeak,smplCnt,peakcnt); |
| 583 | smplCnt = 0; |
| 584 | } |
| 585 | } |
| 586 | } |
| 587 | if (minPeak < 8) return 0; |
| 588 | bool errBitHigh = 0; |
| 589 | bool bitHigh = 0; |
| 590 | uint8_t ignoreCnt = 0; |
| 591 | uint8_t ignoreWindow = 4; |
| 592 | bool lastPeakHigh = 0; |
| 593 | int lastBit = 0; |
| 594 | size_t bestStart[]={0,0,0,0,0,0,0,0,0}; |
| 595 | peakcnt=0; |
| 596 | //test each valid clock from smallest to greatest to see which lines up |
| 597 | for(clkCnt=0; clkCnt < 8; ++clkCnt) { |
| 598 | //ignore clocks smaller than smallest peak |
| 599 | if (clk[clkCnt] < minPeak - (clk[clkCnt]/4)) continue; |
| 600 | //try lining up the peaks by moving starting point (try first 256) |
| 601 | for (ii=20; ii < loopCnt; ++ii) { |
| 602 | if ((dest[ii] >= peak) || (dest[ii] <= low)) { |
| 603 | peakcnt = 0; |
| 604 | bitHigh = false; |
| 605 | ignoreCnt = 0; |
| 606 | lastBit = ii-clk[clkCnt]; |
| 607 | //loop through to see if this start location works |
| 608 | for (i = ii; i < size-20; ++i) { |
| 609 | //if we are at a clock bit |
| 610 | if ((i >= lastBit + clk[clkCnt] - tol) && (i <= lastBit + clk[clkCnt] + tol)) { |
| 611 | //test high/low |
| 612 | if (dest[i] >= peak || dest[i] <= low) { |
| 613 | //if same peak don't count it |
| 614 | if ((dest[i] >= peak && !lastPeakHigh) || (dest[i] <= low && lastPeakHigh)) { |
| 615 | peakcnt++; |
| 616 | } |
| 617 | lastPeakHigh = (dest[i] >= peak); |
| 618 | bitHigh = true; |
| 619 | errBitHigh = false; |
| 620 | ignoreCnt = ignoreWindow; |
| 621 | lastBit += clk[clkCnt]; |
| 622 | } else if (i == lastBit + clk[clkCnt] + tol) { |
| 623 | lastBit += clk[clkCnt]; |
| 624 | } |
| 625 | //else if not a clock bit and no peaks |
| 626 | } else if (dest[i] < peak && dest[i] > low) { |
| 627 | if (ignoreCnt==0) { |
| 628 | bitHigh=false; |
| 629 | if (errBitHigh==true) peakcnt--; |
| 630 | errBitHigh=false; |
| 631 | } else { |
| 632 | ignoreCnt--; |
| 633 | } |
| 634 | // else if not a clock bit but we have a peak |
| 635 | } else if ((dest[i]>=peak || dest[i]<=low) && (!bitHigh)) { |
| 636 | //error bar found no clock... |
| 637 | errBitHigh=true; |
| 638 | } |
| 639 | } |
| 640 | if(peakcnt>peaksdet[clkCnt]) { |
| 641 | bestStart[clkCnt]=ii; |
| 642 | peaksdet[clkCnt]=peakcnt; |
| 643 | } |
| 644 | } |
| 645 | } |
| 646 | } |
| 647 | int iii=7; |
| 648 | uint8_t best=0; |
| 649 | for (iii=7; iii > 0; iii--) { |
| 650 | if ((peaksdet[iii] >= (peaksdet[best]-1)) && (peaksdet[iii] <= peaksdet[best]+1) && lowestTransition) { |
| 651 | if (clk[iii] > (lowestTransition - (clk[iii]/8)) && clk[iii] < (lowestTransition + (clk[iii]/8))) { |
| 652 | best = iii; |
| 653 | } |
| 654 | } else if (peaksdet[iii] > peaksdet[best]) { |
| 655 | best = iii; |
| 656 | } |
| 657 | if (g_debugMode==2) prnt("DEBUG NRZ: Clk: %d, peaks: %d, minPeak: %d, bestClk: %d, lowestTrs: %d",clk[iii],peaksdet[iii],minPeak, clk[best], lowestTransition); |
| 658 | } |
| 659 | *clockStartIdx = bestStart[best]; |
| 660 | return clk[best]; |
| 661 | } |
| 662 | |
| 663 | //by marshmellow |
| 664 | //countFC is to detect the field clock lengths. |
| 665 | //counts and returns the 2 most common wave lengths |
| 666 | //mainly used for FSK field clock detection |
| 667 | uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj) { |
| 668 | uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; |
| 669 | uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; |
| 670 | uint8_t fcLensFnd = 0; |
| 671 | uint8_t lastFCcnt = 0; |
| 672 | uint8_t fcCounter = 0; |
| 673 | size_t i; |
| 674 | if (size < 180) return 0; |
| 675 | |
| 676 | // prime i to first up transition |
| 677 | for (i = 160; i < size-20; i++) |
| 678 | if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]) |
| 679 | break; |
| 680 | |
| 681 | for (; i < size-20; i++){ |
| 682 | if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){ |
| 683 | // new up transition |
| 684 | fcCounter++; |
| 685 | if (fskAdj){ |
| 686 | //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8) |
| 687 | if (lastFCcnt==5 && fcCounter==9) fcCounter--; |
| 688 | //if fc=9 or 4 add one (for when we get a fc 9 instead of 10 or a 4 instead of a 5) |
| 689 | if ((fcCounter==9) || fcCounter==4) fcCounter++; |
| 690 | // save last field clock count (fc/xx) |
| 691 | lastFCcnt = fcCounter; |
| 692 | } |
| 693 | // find which fcLens to save it to: |
| 694 | for (int ii=0; ii<15; ii++){ |
| 695 | if (fcLens[ii]==fcCounter){ |
| 696 | fcCnts[ii]++; |
| 697 | fcCounter=0; |
| 698 | break; |
| 699 | } |
| 700 | } |
| 701 | if (fcCounter>0 && fcLensFnd<15){ |
| 702 | //add new fc length |
| 703 | fcCnts[fcLensFnd]++; |
| 704 | fcLens[fcLensFnd++]=fcCounter; |
| 705 | } |
| 706 | fcCounter=0; |
| 707 | } else { |
| 708 | // count sample |
| 709 | fcCounter++; |
| 710 | } |
| 711 | } |
| 712 | |
| 713 | uint8_t best1=14, best2=14, best3=14; |
| 714 | uint16_t maxCnt1=0; |
| 715 | // go through fclens and find which ones are bigest 2 |
| 716 | for (i=0; i<15; i++){ |
| 717 | // get the 3 best FC values |
| 718 | if (fcCnts[i]>maxCnt1) { |
| 719 | best3=best2; |
| 720 | best2=best1; |
| 721 | maxCnt1=fcCnts[i]; |
| 722 | best1=i; |
| 723 | } else if(fcCnts[i]>fcCnts[best2]){ |
| 724 | best3=best2; |
| 725 | best2=i; |
| 726 | } else if(fcCnts[i]>fcCnts[best3]){ |
| 727 | best3=i; |
| 728 | } |
| 729 | 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]); |
| 730 | if (fcLens[i]==0) break; |
| 731 | } |
| 732 | if (fcLens[best1]==0) return 0; |
| 733 | uint8_t fcH=0, fcL=0; |
| 734 | if (fcLens[best1]>fcLens[best2]){ |
| 735 | fcH=fcLens[best1]; |
| 736 | fcL=fcLens[best2]; |
| 737 | } else{ |
| 738 | fcH=fcLens[best2]; |
| 739 | fcL=fcLens[best1]; |
| 740 | } |
| 741 | if ((size-180)/fcH/3 > fcCnts[best1]+fcCnts[best2]) { |
| 742 | 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]); |
| 743 | return 0; //lots of waves not psk or fsk |
| 744 | } |
| 745 | // TODO: take top 3 answers and compare to known Field clocks to get top 2 |
| 746 | |
| 747 | uint16_t fcs = (((uint16_t)fcH)<<8) | fcL; |
| 748 | if (fskAdj) return fcs; |
| 749 | return (uint16_t)fcLens[best2] << 8 | fcLens[best1]; |
| 750 | } |
| 751 | |
| 752 | //by marshmellow |
| 753 | //detect psk clock by reading each phase shift |
| 754 | // a phase shift is determined by measuring the sample length of each wave |
| 755 | int DetectPSKClock(uint8_t dest[], size_t size, int clock, size_t *firstPhaseShift, uint8_t *curPhase, uint8_t *fc) { |
| 756 | uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock |
| 757 | uint16_t loopCnt = 4096; //don't need to loop through entire array... |
| 758 | if (size == 0) return 0; |
| 759 | if (size+3<loopCnt) loopCnt = size-20; |
| 760 | |
| 761 | uint16_t fcs = countFC(dest, size, 0); |
| 762 | *fc = fcs & 0xFF; |
| 763 | if (g_debugMode==2) prnt("DEBUG PSK: FC: %d, FC2: %d",*fc, fcs>>8); |
| 764 | if ((fcs>>8) == 10 && *fc == 8) return 0; |
| 765 | if (*fc!=2 && *fc!=4 && *fc!=8) return 0; |
| 766 | |
| 767 | //if we already have a valid clock quit |
| 768 | size_t i=1; |
| 769 | for (; i < 8; ++i) |
| 770 | if (clk[i] == clock) return clock; |
| 771 | |
| 772 | size_t waveStart=0, waveEnd=0, firstFullWave=0, lastClkBit=0; |
| 773 | |
| 774 | uint8_t clkCnt, tol=1; |
| 775 | uint16_t peakcnt=0, errCnt=0, waveLenCnt=0, fullWaveLen=0; |
| 776 | uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000}; |
| 777 | uint16_t peaksdet[]={0,0,0,0,0,0,0,0,0}; |
| 778 | |
| 779 | //find start of modulating data in trace |
| 780 | i = findModStart(dest, size, *fc); |
| 781 | |
| 782 | firstFullWave = pskFindFirstPhaseShift(dest, size, curPhase, i, *fc, &fullWaveLen); |
| 783 | if (firstFullWave == 0) { |
| 784 | // no phase shift detected - could be all 1's or 0's - doesn't matter where we start |
| 785 | // so skip a little to ensure we are past any Start Signal |
| 786 | firstFullWave = 160; |
| 787 | fullWaveLen = 0; |
| 788 | } |
| 789 | |
| 790 | *firstPhaseShift = firstFullWave; |
| 791 | if (g_debugMode ==2) prnt("DEBUG PSK: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen); |
| 792 | //test each valid clock from greatest to smallest to see which lines up |
| 793 | for(clkCnt=7; clkCnt >= 1 ; clkCnt--) { |
| 794 | tol = *fc/2; |
| 795 | lastClkBit = firstFullWave; //set end of wave as clock align |
| 796 | waveStart = 0; |
| 797 | errCnt=0; |
| 798 | peakcnt=0; |
| 799 | if (g_debugMode == 2) prnt("DEBUG PSK: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit); |
| 800 | |
| 801 | for (i = firstFullWave+fullWaveLen-1; i < loopCnt-2; i++){ |
| 802 | //top edge of wave = start of new wave |
| 803 | if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){ |
| 804 | if (waveStart == 0) { |
| 805 | waveStart = i+1; |
| 806 | waveLenCnt=0; |
| 807 | } else { //waveEnd |
| 808 | waveEnd = i+1; |
| 809 | waveLenCnt = waveEnd-waveStart; |
| 810 | if (waveLenCnt > *fc){ |
| 811 | //if this wave is a phase shift |
| 812 | 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); |
| 813 | if (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit |
| 814 | peakcnt++; |
| 815 | lastClkBit+=clk[clkCnt]; |
| 816 | } else if (i<lastClkBit+8){ |
| 817 | //noise after a phase shift - ignore |
| 818 | } else { //phase shift before supposed to based on clock |
| 819 | errCnt++; |
| 820 | } |
| 821 | } else if (i+1 > lastClkBit + clk[clkCnt] + tol + *fc){ |
| 822 | lastClkBit+=clk[clkCnt]; //no phase shift but clock bit |
| 823 | } |
| 824 | waveStart=i+1; |
| 825 | } |
| 826 | } |
| 827 | } |
| 828 | if (errCnt == 0){ |
| 829 | return clk[clkCnt]; |
| 830 | } |
| 831 | if (errCnt <= bestErr[clkCnt]) bestErr[clkCnt]=errCnt; |
| 832 | if (peakcnt > peaksdet[clkCnt]) peaksdet[clkCnt]=peakcnt; |
| 833 | } |
| 834 | //all tested with errors |
| 835 | //return the highest clk with the most peaks found |
| 836 | uint8_t best=7; |
| 837 | for (i=7; i>=1; i--){ |
| 838 | if (peaksdet[i] > peaksdet[best]) { |
| 839 | best = i; |
| 840 | } |
| 841 | if (g_debugMode == 2) prnt("DEBUG PSK: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[i],peaksdet[i],bestErr[i],clk[best]); |
| 842 | } |
| 843 | return clk[best]; |
| 844 | } |
| 845 | |
| 846 | //by marshmellow |
| 847 | //detects the bit clock for FSK given the high and low Field Clocks |
| 848 | uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow, int *firstClockEdge) { |
| 849 | uint8_t clk[] = {8,16,32,40,50,64,100,128,0}; |
| 850 | uint16_t rfLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; |
| 851 | uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; |
| 852 | uint8_t rfLensFnd = 0; |
| 853 | uint8_t lastFCcnt = 0; |
| 854 | uint16_t fcCounter = 0; |
| 855 | uint16_t rfCounter = 0; |
| 856 | uint8_t firstBitFnd = 0; |
| 857 | size_t i; |
| 858 | if (size == 0) return 0; |
| 859 | |
| 860 | uint8_t fcTol = ((fcHigh*100 - fcLow*100)/2 + 50)/100; //(uint8_t)(0.5+(float)(fcHigh-fcLow)/2); |
| 861 | rfLensFnd=0; |
| 862 | fcCounter=0; |
| 863 | rfCounter=0; |
| 864 | firstBitFnd=0; |
| 865 | //PrintAndLog("DEBUG: fcTol: %d",fcTol); |
| 866 | // prime i to first peak / up transition |
| 867 | for (i = 160; i < size-20; i++) |
| 868 | if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1]) |
| 869 | break; |
| 870 | |
| 871 | for (; i < size-20; i++){ |
| 872 | fcCounter++; |
| 873 | rfCounter++; |
| 874 | |
| 875 | if (BitStream[i] <= BitStream[i-1] || BitStream[i] < BitStream[i+1]) |
| 876 | continue; |
| 877 | // else new peak |
| 878 | // if we got less than the small fc + tolerance then set it to the small fc |
| 879 | // if it is inbetween set it to the last counter |
| 880 | if (fcCounter < fcHigh && fcCounter > fcLow) |
| 881 | fcCounter = lastFCcnt; |
| 882 | else if (fcCounter < fcLow+fcTol) |
| 883 | fcCounter = fcLow; |
| 884 | else //set it to the large fc |
| 885 | fcCounter = fcHigh; |
| 886 | |
| 887 | //look for bit clock (rf/xx) |
| 888 | if ((fcCounter < lastFCcnt || fcCounter > lastFCcnt)){ |
| 889 | //not the same size as the last wave - start of new bit sequence |
| 890 | if (firstBitFnd > 1){ //skip first wave change - probably not a complete bit |
| 891 | for (int ii=0; ii<15; ii++){ |
| 892 | if (rfLens[ii] >= (rfCounter-4) && rfLens[ii] <= (rfCounter+4)){ |
| 893 | rfCnts[ii]++; |
| 894 | rfCounter = 0; |
| 895 | break; |
| 896 | } |
| 897 | } |
| 898 | if (rfCounter > 0 && rfLensFnd < 15){ |
| 899 | //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter); |
| 900 | rfCnts[rfLensFnd]++; |
| 901 | rfLens[rfLensFnd++] = rfCounter; |
| 902 | } |
| 903 | } else { |
| 904 | *firstClockEdge = i; |
| 905 | firstBitFnd++; |
| 906 | } |
| 907 | rfCounter=0; |
| 908 | lastFCcnt=fcCounter; |
| 909 | } |
| 910 | fcCounter=0; |
| 911 | } |
| 912 | uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15; |
| 913 | |
| 914 | for (i=0; i<15; i++){ |
| 915 | //get highest 2 RF values (might need to get more values to compare or compare all?) |
| 916 | if (rfCnts[i]>rfCnts[rfHighest]){ |
| 917 | rfHighest3=rfHighest2; |
| 918 | rfHighest2=rfHighest; |
| 919 | rfHighest=i; |
| 920 | } else if(rfCnts[i]>rfCnts[rfHighest2]){ |
| 921 | rfHighest3=rfHighest2; |
| 922 | rfHighest2=i; |
| 923 | } else if(rfCnts[i]>rfCnts[rfHighest3]){ |
| 924 | rfHighest3=i; |
| 925 | } |
| 926 | if (g_debugMode==2) prnt("DEBUG FSK: RF %d, cnts %d",rfLens[i], rfCnts[i]); |
| 927 | } |
| 928 | // set allowed clock remainder tolerance to be 1 large field clock length+1 |
| 929 | // we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off |
| 930 | uint8_t tol1 = fcHigh+1; |
| 931 | |
| 932 | if (g_debugMode==2) prnt("DEBUG FSK: most counted rf values: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]); |
| 933 | |
| 934 | // loop to find the highest clock that has a remainder less than the tolerance |
| 935 | // compare samples counted divided by |
| 936 | // test 128 down to 32 (shouldn't be possible to have fc/10 & fc/8 and rf/16 or less) |
| 937 | int ii=7; |
| 938 | for (; ii>=2; ii--){ |
| 939 | if (rfLens[rfHighest] % clk[ii] < tol1 || rfLens[rfHighest] % clk[ii] > clk[ii]-tol1){ |
| 940 | if (rfLens[rfHighest2] % clk[ii] < tol1 || rfLens[rfHighest2] % clk[ii] > clk[ii]-tol1){ |
| 941 | if (rfLens[rfHighest3] % clk[ii] < tol1 || rfLens[rfHighest3] % clk[ii] > clk[ii]-tol1){ |
| 942 | if (g_debugMode==2) prnt("DEBUG FSK: clk %d divides into the 3 most rf values within tolerance",clk[ii]); |
| 943 | break; |
| 944 | } |
| 945 | } |
| 946 | } |
| 947 | } |
| 948 | |
| 949 | if (ii<2) return 0; // oops we went too far |
| 950 | |
| 951 | return clk[ii]; |
| 952 | } |
| 953 | |
| 954 | //********************************************************************************************** |
| 955 | //--------------------Modulation Demods &/or Decoding Section----------------------------------- |
| 956 | //********************************************************************************************** |
| 957 | |
| 958 | // look for Sequence Terminator - should be pulses of clk*(1 or 2), clk*2, clk*(1.5 or 2), by idx we mean graph position index... |
| 959 | bool findST(int *stStopLoc, int *stStartIdx, int lowToLowWaveLen[], int highToLowWaveLen[], int clk, int tol, int buffSize, size_t *i) { |
| 960 | if (buffSize < *i+4) return false; |
| 961 | |
| 962 | for (; *i < buffSize - 4; *i+=1) { |
| 963 | *stStartIdx += lowToLowWaveLen[*i]; //caution part of this wave may be data and part may be ST.... to be accounted for in main function for now... |
| 964 | if (lowToLowWaveLen[*i] >= clk*1-tol && lowToLowWaveLen[*i] <= (clk*2)+tol && highToLowWaveLen[*i] < clk+tol) { //1 to 2 clocks depending on 2 bits prior |
| 965 | if (lowToLowWaveLen[*i+1] >= clk*2-tol && lowToLowWaveLen[*i+1] <= clk*2+tol && highToLowWaveLen[*i+1] > clk*3/2-tol) { //2 clocks and wave size is 1 1/2 |
| 966 | if (lowToLowWaveLen[*i+2] >= (clk*3)/2-tol && lowToLowWaveLen[*i+2] <= clk*2+tol && highToLowWaveLen[*i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave |
| 967 | if (lowToLowWaveLen[*i+3] >= clk*1-tol && lowToLowWaveLen[*i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit |
| 968 | *stStopLoc = *i + 3; |
| 969 | return true; |
| 970 | } |
| 971 | } |
| 972 | } |
| 973 | } |
| 974 | } |
| 975 | return false; |
| 976 | } |
| 977 | //by marshmellow |
| 978 | //attempt to identify a Sequence Terminator in ASK modulated raw wave |
| 979 | bool DetectST(uint8_t buffer[], size_t *size, int *foundclock, size_t *ststart, size_t *stend) { |
| 980 | size_t bufsize = *size; |
| 981 | //need to loop through all samples and identify our clock, look for the ST pattern |
| 982 | int clk = 0; |
| 983 | int tol = 0; |
| 984 | int j=0, high, low, skip=0, start=0, end=0, minClk=255; |
| 985 | size_t i = 0; |
| 986 | //probably should malloc... || test if memory is available ... handle device side? memory danger!!! [marshmellow] |
| 987 | int tmpbuff[bufsize / LOWEST_DEFAULT_CLOCK]; // low to low wave count //guess rf/32 clock, if click is smaller we will only have room for a fraction of the samples captured |
| 988 | int waveLen[bufsize / LOWEST_DEFAULT_CLOCK]; // high to low wave count //if clock is larger then we waste memory in array size that is not needed... |
| 989 | //size_t testsize = (bufsize < 512) ? bufsize : 512; |
| 990 | int phaseoff = 0; |
| 991 | high = low = 128; |
| 992 | memset(tmpbuff, 0, sizeof(tmpbuff)); |
| 993 | memset(waveLen, 0, sizeof(waveLen)); |
| 994 | |
| 995 | if (!loadWaveCounters(buffer, bufsize, tmpbuff, waveLen, &j, &skip, &minClk, &high, &low)) return false; |
| 996 | // set clock - might be able to get this externally and remove this work... |
| 997 | clk = getClosestClock(minClk); |
| 998 | // clock not found - ERROR |
| 999 | if (clk == 0) { |
| 1000 | if (g_debugMode==2) prnt("DEBUG STT: clock not found - quitting"); |
| 1001 | return false; |
| 1002 | } |
| 1003 | *foundclock = clk; |
| 1004 | |
| 1005 | tol = clk/8; |
| 1006 | if (!findST(&start, &skip, tmpbuff, waveLen, clk, tol, j, &i)) { |
| 1007 | // first ST not found - ERROR |
| 1008 | if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting"); |
| 1009 | return false; |
| 1010 | } else { |
| 1011 | if (g_debugMode==2) prnt("DEBUG STT: first STT found at wave: %i, skip: %i, j=%i", start, skip, j); |
| 1012 | } |
| 1013 | if (waveLen[i+2] > clk*1+tol) |
| 1014 | phaseoff = 0; |
| 1015 | else |
| 1016 | phaseoff = clk/2; |
| 1017 | |
| 1018 | // skip over the remainder of ST |
| 1019 | skip += clk*7/2; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point |
| 1020 | |
| 1021 | // now do it again to find the end |
| 1022 | int dummy1 = 0; |
| 1023 | end = skip; |
| 1024 | i+=3; |
| 1025 | if (!findST(&dummy1, &end, tmpbuff, waveLen, clk, tol, j, &i)) { |
| 1026 | //didn't find second ST - ERROR |
| 1027 | if (g_debugMode==2) prnt("DEBUG STT: second STT not found - quitting"); |
| 1028 | return false; |
| 1029 | } |
| 1030 | end -= phaseoff; |
| 1031 | 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); |
| 1032 | //now begin to trim out ST so we can use normal demod cmds |
| 1033 | start = skip; |
| 1034 | size_t datalen = end - start; |
| 1035 | // check validity of datalen (should be even clock increments) - use a tolerance of up to 1/8th a clock |
| 1036 | if ( clk - (datalen % clk) <= clk/8) { |
| 1037 | // padd the amount off - could be problematic... but shouldn't happen often |
| 1038 | datalen += clk - (datalen % clk); |
| 1039 | } else if ( (datalen % clk) <= clk/8 ) { |
| 1040 | // padd the amount off - could be problematic... but shouldn't happen often |
| 1041 | datalen -= datalen % clk; |
| 1042 | } else { |
| 1043 | if (g_debugMode==2) prnt("DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting", datalen, clk, datalen % clk); |
| 1044 | return false; |
| 1045 | } |
| 1046 | // if datalen is less than one t55xx block - ERROR |
| 1047 | if (datalen/clk < 8*4) { |
| 1048 | if (g_debugMode==2) prnt("DEBUG STT: datalen is less than 1 full t55xx block - quitting"); |
| 1049 | return false; |
| 1050 | } |
| 1051 | size_t dataloc = start; |
| 1052 | if (buffer[dataloc-(clk*4)-(clk/4)] <= low && buffer[dataloc] <= low && buffer[dataloc-(clk*4)] >= high) { |
| 1053 | //we have low drift (and a low just before the ST and a low just after the ST) - compensate by backing up the start |
| 1054 | for ( i=0; i <= (clk/4); ++i ) { |
| 1055 | if ( buffer[dataloc - (clk*4) - i] <= low ) { |
| 1056 | dataloc -= i; |
| 1057 | break; |
| 1058 | } |
| 1059 | } |
| 1060 | } |
| 1061 | |
| 1062 | size_t newloc = 0; |
| 1063 | i=0; |
| 1064 | if (g_debugMode==2) prnt("DEBUG STT: Starting STT trim - start: %d, datalen: %d ",dataloc, datalen); |
| 1065 | bool firstrun = true; |
| 1066 | // warning - overwriting buffer given with raw wave data with ST removed... |
| 1067 | while ( dataloc < bufsize-(clk/2) ) { |
| 1068 | //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) |
| 1069 | if (buffer[dataloc]<high && buffer[dataloc]>low && buffer[dataloc+clk/4]<high && buffer[dataloc+clk/4]>low) { |
| 1070 | for(i=0; i < clk/2-tol; ++i) { |
| 1071 | buffer[dataloc+i] = high+5; |
| 1072 | } |
| 1073 | } //test for small spike outlier (high between two lows) in the case of very strong waves |
| 1074 | if (buffer[dataloc] > low && buffer[dataloc+clk/4] <= low) { |
| 1075 | for(i=0; i < clk/4; ++i) { |
| 1076 | buffer[dataloc+i] = buffer[dataloc+clk/4]; |
| 1077 | } |
| 1078 | } |
| 1079 | if (firstrun) { |
| 1080 | *stend = dataloc; |
| 1081 | *ststart = dataloc-(clk*4); |
| 1082 | firstrun=false; |
| 1083 | } |
| 1084 | for (i=0; i<datalen; ++i) { |
| 1085 | if (i+newloc < bufsize) { |
| 1086 | if (i+newloc < dataloc) |
| 1087 | buffer[i+newloc] = buffer[dataloc]; |
| 1088 | |
| 1089 | dataloc++; |
| 1090 | } |
| 1091 | } |
| 1092 | newloc += i; |
| 1093 | //skip next ST - we just assume it will be there from now on... |
| 1094 | if (g_debugMode==2) prnt("DEBUG STT: skipping STT at %d to %d", dataloc, dataloc+(clk*4)); |
| 1095 | dataloc += clk*4; |
| 1096 | } |
| 1097 | *size = newloc; |
| 1098 | return true; |
| 1099 | } |
| 1100 | |
| 1101 | //by marshmellow |
| 1102 | //take 11 10 01 11 00 and make 01100 ... miller decoding |
| 1103 | //check for phase errors - should never have half a 1 or 0 by itself and should never exceed 1111 or 0000 in a row |
| 1104 | //decodes miller encoded binary |
| 1105 | //NOTE askrawdemod will NOT demod miller encoded ask unless the clock is manually set to 1/2 what it is detected as! |
| 1106 | int millerRawDecode(uint8_t *BitStream, size_t *size, int invert) { |
| 1107 | if (*size < 16) return -1; |
| 1108 | uint16_t MaxBits = 512, errCnt = 0; |
| 1109 | size_t i, bitCnt=0; |
| 1110 | uint8_t alignCnt = 0, curBit = BitStream[0], alignedIdx = 0; |
| 1111 | uint8_t halfClkErr = 0; |
| 1112 | //find alignment, needs 4 1s or 0s to properly align |
| 1113 | for (i=1; i < *size-1; i++) { |
| 1114 | alignCnt = (BitStream[i] == curBit) ? alignCnt+1 : 0; |
| 1115 | curBit = BitStream[i]; |
| 1116 | if (alignCnt == 4) break; |
| 1117 | } |
| 1118 | // for now error if alignment not found. later add option to run it with multiple offsets... |
| 1119 | if (alignCnt != 4) { |
| 1120 | if (g_debugMode) prnt("ERROR MillerDecode: alignment not found so either your bitstream is not miller or your data does not have a 101 in it"); |
| 1121 | return -1; |
| 1122 | } |
| 1123 | alignedIdx = (i-1) % 2; |
| 1124 | for (i=alignedIdx; i < *size-3; i+=2) { |
| 1125 | halfClkErr = (uint8_t)((halfClkErr << 1 | BitStream[i]) & 0xFF); |
| 1126 | if ( (halfClkErr & 0x7) == 5 || (halfClkErr & 0x7) == 2 || (i > 2 && (halfClkErr & 0x7) == 0) || (halfClkErr & 0x1F) == 0x1F) { |
| 1127 | errCnt++; |
| 1128 | BitStream[bitCnt++] = 7; |
| 1129 | continue; |
| 1130 | } |
| 1131 | BitStream[bitCnt++] = BitStream[i] ^ BitStream[i+1] ^ invert; |
| 1132 | |
| 1133 | if (bitCnt > MaxBits) break; |
| 1134 | } |
| 1135 | *size = bitCnt; |
| 1136 | return errCnt; |
| 1137 | } |
| 1138 | |
| 1139 | //by marshmellow |
| 1140 | //take 01 or 10 = 1 and 11 or 00 = 0 |
| 1141 | //check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010 |
| 1142 | //decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding |
| 1143 | int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int *offset, int invert) { |
| 1144 | uint16_t bitnum = 0; |
| 1145 | uint16_t errCnt = 0; |
| 1146 | size_t i = *offset; |
| 1147 | uint16_t MaxBits=512; |
| 1148 | //if not enough samples - error |
| 1149 | if (*size < 51) return -1; |
| 1150 | //check for phase change faults - skip one sample if faulty |
| 1151 | uint8_t offsetA = 1, offsetB = 1; |
| 1152 | for (; i<48; i+=2){ |
| 1153 | if (BitStream[i+1]==BitStream[i+2]) offsetA=0; |
| 1154 | if (BitStream[i+2]==BitStream[i+3]) offsetB=0; |
| 1155 | } |
| 1156 | if (!offsetA && offsetB) *offset+=1; |
| 1157 | for (i=*offset; i<*size-3; i+=2){ |
| 1158 | //check for phase error |
| 1159 | if (BitStream[i+1]==BitStream[i+2]) { |
| 1160 | BitStream[bitnum++]=7; |
| 1161 | errCnt++; |
| 1162 | } |
| 1163 | if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){ |
| 1164 | BitStream[bitnum++]=1^invert; |
| 1165 | } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){ |
| 1166 | BitStream[bitnum++]=invert; |
| 1167 | } else { |
| 1168 | BitStream[bitnum++]=7; |
| 1169 | errCnt++; |
| 1170 | } |
| 1171 | if(bitnum>MaxBits) break; |
| 1172 | } |
| 1173 | *size=bitnum; |
| 1174 | return errCnt; |
| 1175 | } |
| 1176 | |
| 1177 | //by marshmellow |
| 1178 | //take 10 and 01 and manchester decode |
| 1179 | //run through 2 times and take least errCnt |
| 1180 | int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert, uint8_t *alignPos) { |
| 1181 | uint16_t bitnum=0, MaxBits = 512, errCnt = 0; |
| 1182 | size_t i, ii; |
| 1183 | uint16_t bestErr = 1000, bestRun = 0; |
| 1184 | if (*size < 16) return -1; |
| 1185 | //find correct start position [alignment] |
| 1186 | for (ii=0;ii<2;++ii){ |
| 1187 | for (i=ii; i<*size-3; i+=2) |
| 1188 | if (BitStream[i]==BitStream[i+1]) |
| 1189 | errCnt++; |
| 1190 | |
| 1191 | if (bestErr>errCnt){ |
| 1192 | bestErr=errCnt; |
| 1193 | bestRun=ii; |
| 1194 | } |
| 1195 | errCnt=0; |
| 1196 | } |
| 1197 | *alignPos=bestRun; |
| 1198 | //decode |
| 1199 | for (i=bestRun; i < *size-3; i+=2){ |
| 1200 | if(BitStream[i] == 1 && (BitStream[i+1] == 0)){ |
| 1201 | BitStream[bitnum++]=invert; |
| 1202 | } else if((BitStream[i] == 0) && BitStream[i+1] == 1){ |
| 1203 | BitStream[bitnum++]=invert^1; |
| 1204 | } else { |
| 1205 | BitStream[bitnum++]=7; |
| 1206 | } |
| 1207 | if(bitnum>MaxBits) break; |
| 1208 | } |
| 1209 | *size=bitnum; |
| 1210 | return bestErr; |
| 1211 | } |
| 1212 | |
| 1213 | //by marshmellow |
| 1214 | //demodulates strong heavily clipped samples |
| 1215 | int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low, int *startIdx) |
| 1216 | { |
| 1217 | *startIdx=0; |
| 1218 | size_t bitCnt=0, smplCnt=1, errCnt=0; |
| 1219 | bool waveHigh = (BinStream[0] >= high); |
| 1220 | for (size_t i=1; i < *size; i++){ |
| 1221 | if (BinStream[i] >= high && waveHigh){ |
| 1222 | smplCnt++; |
| 1223 | } else if (BinStream[i] <= low && !waveHigh){ |
| 1224 | smplCnt++; |
| 1225 | } else { //transition |
| 1226 | if ((BinStream[i] >= high && !waveHigh) || (BinStream[i] <= low && waveHigh)){ |
| 1227 | if (smplCnt > clk-(clk/4)-1) { //full clock |
| 1228 | if (smplCnt > clk + (clk/4)+1) { //too many samples |
| 1229 | errCnt++; |
| 1230 | if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i); |
| 1231 | BinStream[bitCnt++] = 7; |
| 1232 | } else if (waveHigh) { |
| 1233 | BinStream[bitCnt++] = invert; |
| 1234 | BinStream[bitCnt++] = invert; |
| 1235 | } else if (!waveHigh) { |
| 1236 | BinStream[bitCnt++] = invert ^ 1; |
| 1237 | BinStream[bitCnt++] = invert ^ 1; |
| 1238 | } |
| 1239 | if (*startIdx==0) *startIdx = i-clk; |
| 1240 | waveHigh = !waveHigh; |
| 1241 | smplCnt = 0; |
| 1242 | } else if (smplCnt > (clk/2) - (clk/4)-1) { //half clock |
| 1243 | if (waveHigh) { |
| 1244 | BinStream[bitCnt++] = invert; |
| 1245 | } else if (!waveHigh) { |
| 1246 | BinStream[bitCnt++] = invert ^ 1; |
| 1247 | } |
| 1248 | if (*startIdx==0) *startIdx = i-(clk/2); |
| 1249 | waveHigh = !waveHigh; |
| 1250 | smplCnt = 0; |
| 1251 | } else { |
| 1252 | smplCnt++; |
| 1253 | //transition bit oops |
| 1254 | } |
| 1255 | } else { //haven't hit new high or new low yet |
| 1256 | smplCnt++; |
| 1257 | } |
| 1258 | } |
| 1259 | } |
| 1260 | *size = bitCnt; |
| 1261 | return errCnt; |
| 1262 | } |
| 1263 | |
| 1264 | //by marshmellow |
| 1265 | //attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester |
| 1266 | int askdemod_ext(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType, int *startIdx) { |
| 1267 | if (*size==0) return -1; |
| 1268 | int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default |
| 1269 | if (*clk==0 || start < 0) return -3; |
| 1270 | if (*invert != 1) *invert = 0; |
| 1271 | if (amp==1) askAmp(BinStream, *size); |
| 1272 | if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d, amp %d", *clk, start, amp); |
| 1273 | |
| 1274 | //start pos from detect ask clock is 1/2 clock offset |
| 1275 | // NOTE: can be negative (demod assumes rest of wave was there) |
| 1276 | *startIdx = start - (*clk/2); |
| 1277 | uint8_t initLoopMax = 255; |
| 1278 | if (initLoopMax > *size) initLoopMax = *size; |
| 1279 | // Detect high and lows |
| 1280 | //25% clip in case highs and lows aren't clipped [marshmellow] |
| 1281 | int high, low; |
| 1282 | if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1) |
| 1283 | return -2; //just noise |
| 1284 | |
| 1285 | size_t errCnt = 0; |
| 1286 | // if clean clipped waves detected run alternate demod |
| 1287 | if (DetectCleanAskWave(BinStream, *size, high, low)) { |
| 1288 | if (g_debugMode==2) prnt("DEBUG ASK: Clean Wave Detected - using clean wave demod"); |
| 1289 | errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low, startIdx); |
| 1290 | if (askType) { //askman |
| 1291 | uint8_t alignPos = 0; |
| 1292 | errCnt = manrawdecode(BinStream, size, 0, &alignPos); |
| 1293 | *startIdx += *clk/2 * alignPos; |
| 1294 | if (g_debugMode) prnt("DEBUG ASK CLEAN: startIdx %i, alignPos %u", *startIdx, alignPos); |
| 1295 | return errCnt; |
| 1296 | } else { //askraw |
| 1297 | return errCnt; |
| 1298 | } |
| 1299 | } |
| 1300 | if (g_debugMode) prnt("DEBUG ASK WEAK: startIdx %i", *startIdx); |
| 1301 | if (g_debugMode==2) prnt("DEBUG ASK: Weak Wave Detected - using weak wave demod"); |
| 1302 | |
| 1303 | int lastBit; //set first clock check - can go negative |
| 1304 | size_t i, bitnum = 0; //output counter |
| 1305 | uint8_t midBit = 0; |
| 1306 | 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 |
| 1307 | 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 |
| 1308 | size_t MaxBits = 3072; //max bits to collect |
| 1309 | lastBit = start - *clk; |
| 1310 | |
| 1311 | for (i = start; i < *size; ++i) { |
| 1312 | if (i-lastBit >= *clk-tol){ |
| 1313 | if (BinStream[i] >= high) { |
| 1314 | BinStream[bitnum++] = *invert; |
| 1315 | } else if (BinStream[i] <= low) { |
| 1316 | BinStream[bitnum++] = *invert ^ 1; |
| 1317 | } else if (i-lastBit >= *clk+tol) { |
| 1318 | if (bitnum > 0) { |
| 1319 | if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i); |
| 1320 | BinStream[bitnum++]=7; |
| 1321 | errCnt++; |
| 1322 | } |
| 1323 | } else { //in tolerance - looking for peak |
| 1324 | continue; |
| 1325 | } |
| 1326 | midBit = 0; |
| 1327 | lastBit += *clk; |
| 1328 | } else if (i-lastBit >= (*clk/2-tol) && !midBit && !askType){ |
| 1329 | if (BinStream[i] >= high) { |
| 1330 | BinStream[bitnum++] = *invert; |
| 1331 | } else if (BinStream[i] <= low) { |
| 1332 | BinStream[bitnum++] = *invert ^ 1; |
| 1333 | } else if (i-lastBit >= *clk/2+tol) { |
| 1334 | BinStream[bitnum] = BinStream[bitnum-1]; |
| 1335 | bitnum++; |
| 1336 | } else { //in tolerance - looking for peak |
| 1337 | continue; |
| 1338 | } |
| 1339 | midBit = 1; |
| 1340 | } |
| 1341 | if (bitnum >= MaxBits) break; |
| 1342 | } |
| 1343 | *size = bitnum; |
| 1344 | return errCnt; |
| 1345 | } |
| 1346 | |
| 1347 | int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType) { |
| 1348 | int start = 0; |
| 1349 | return askdemod_ext(BinStream, size, clk, invert, maxErr, amp, askType, &start); |
| 1350 | } |
| 1351 | |
| 1352 | // by marshmellow - demodulate NRZ wave - requires a read with strong signal |
| 1353 | // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak |
| 1354 | int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert, int *startIdx) { |
| 1355 | if (justNoise(dest, *size)) return -1; |
| 1356 | size_t clkStartIdx = 0; |
| 1357 | *clk = DetectNRZClock(dest, *size, *clk, &clkStartIdx); |
| 1358 | if (*clk==0) return -2; |
| 1359 | size_t i, gLen = 4096; |
| 1360 | if (gLen>*size) gLen = *size-20; |
| 1361 | int high, low; |
| 1362 | if (getHiLo(dest, gLen, &high, &low, 75, 75) < 1) return -3; //25% fuzz on high 25% fuzz on low |
| 1363 | |
| 1364 | uint8_t bit=0; |
| 1365 | //convert wave samples to 1's and 0's |
| 1366 | for(i=20; i < *size-20; i++){ |
| 1367 | if (dest[i] >= high) bit = 1; |
| 1368 | if (dest[i] <= low) bit = 0; |
| 1369 | dest[i] = bit; |
| 1370 | } |
| 1371 | //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit) |
| 1372 | size_t lastBit = 0; |
| 1373 | size_t numBits = 0; |
| 1374 | for(i=21; i < *size-20; i++) { |
| 1375 | //if transition detected or large number of same bits - store the passed bits |
| 1376 | if (dest[i] != dest[i-1] || (i-lastBit) == (10 * *clk)) { |
| 1377 | memset(dest+numBits, dest[i-1] ^ *invert, (i - lastBit + (*clk/4)) / *clk); |
| 1378 | numBits += (i - lastBit + (*clk/4)) / *clk; |
| 1379 | if (lastBit == 0) { |
| 1380 | *startIdx = i - (numBits * *clk); |
| 1381 | if (g_debugMode==2) prnt("DEBUG NRZ: startIdx %i", *startIdx); |
| 1382 | } |
| 1383 | lastBit = i-1; |
| 1384 | } |
| 1385 | } |
| 1386 | *size = numBits; |
| 1387 | return 0; |
| 1388 | } |
| 1389 | |
| 1390 | //translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq]) |
| 1391 | size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow, int *startIdx) { |
| 1392 | size_t last_transition = 0; |
| 1393 | size_t idx = 1; |
| 1394 | if (fchigh==0) fchigh=10; |
| 1395 | if (fclow==0) fclow=8; |
| 1396 | //set the threshold close to 0 (graph) or 128 std to avoid static |
| 1397 | size_t preLastSample = 0; |
| 1398 | size_t LastSample = 0; |
| 1399 | size_t currSample = 0; |
| 1400 | if ( size < 1024 ) return 0; // not enough samples |
| 1401 | |
| 1402 | //find start of modulating data in trace |
| 1403 | idx = findModStart(dest, size, fchigh); |
| 1404 | // Need to threshold first sample |
| 1405 | if(dest[idx] < FSK_PSK_THRESHOLD) dest[0] = 0; |
| 1406 | else dest[0] = 1; |
| 1407 | |
| 1408 | last_transition = idx; |
| 1409 | idx++; |
| 1410 | size_t numBits = 0; |
| 1411 | // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8) |
| 1412 | // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere |
| 1413 | // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10 |
| 1414 | // (could also be fc/5 && fc/7 for fsk1 = 4-9) |
| 1415 | for(; idx < size; idx++) { |
| 1416 | // threshold current value |
| 1417 | if (dest[idx] < FSK_PSK_THRESHOLD) dest[idx] = 0; |
| 1418 | else dest[idx] = 1; |
| 1419 | |
| 1420 | // Check for 0->1 transition |
| 1421 | if (dest[idx-1] < dest[idx]) { |
| 1422 | preLastSample = LastSample; |
| 1423 | LastSample = currSample; |
| 1424 | currSample = idx-last_transition; |
| 1425 | if (currSample < (fclow-2)) { //0-5 = garbage noise (or 0-3) |
| 1426 | //do nothing with extra garbage |
| 1427 | } else if (currSample < (fchigh-1)) { //6-8 = 8 sample waves (or 3-6 = 5) |
| 1428 | //correct previous 9 wave surrounded by 8 waves (or 6 surrounded by 5) |
| 1429 | if (numBits > 1 && LastSample > (fchigh-2) && (preLastSample < (fchigh-1))){ |
| 1430 | dest[numBits-1]=1; |
| 1431 | } |
| 1432 | dest[numBits++]=1; |
| 1433 | if (numBits > 0 && *startIdx==0) *startIdx = idx - fclow; |
| 1434 | } else if (currSample > (fchigh+1) && numBits < 3) { //12 + and first two bit = unusable garbage |
| 1435 | //do nothing with beginning garbage and reset.. should be rare.. |
| 1436 | numBits = 0; |
| 1437 | } 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) |
| 1438 | dest[numBits++]=1; |
| 1439 | if (numBits > 0 && *startIdx==0) *startIdx = idx - fclow; |
| 1440 | } else { //9+ = 10 sample waves (or 6+ = 7) |
| 1441 | dest[numBits++]=0; |
| 1442 | if (numBits > 0 && *startIdx==0) *startIdx = idx - fchigh; |
| 1443 | } |
| 1444 | last_transition = idx; |
| 1445 | } |
| 1446 | } |
| 1447 | return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0 |
| 1448 | } |
| 1449 | |
| 1450 | //translate 11111100000 to 10 |
| 1451 | //rfLen = clock, fchigh = larger field clock, fclow = smaller field clock |
| 1452 | size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow, int *startIdx) { |
| 1453 | uint8_t lastval=dest[0]; |
| 1454 | size_t idx=0; |
| 1455 | size_t numBits=0; |
| 1456 | uint32_t n=1; |
| 1457 | for( idx=1; idx < size; idx++) { |
| 1458 | n++; |
| 1459 | if (dest[idx]==lastval) continue; //skip until we hit a transition |
| 1460 | |
| 1461 | //find out how many bits (n) we collected (use 1/2 clk tolerance) |
| 1462 | //if lastval was 1, we have a 1->0 crossing |
| 1463 | if (dest[idx-1]==1) { |
| 1464 | n = (n * fclow + rfLen/2) / rfLen; |
| 1465 | } else {// 0->1 crossing |
| 1466 | n = (n * fchigh + rfLen/2) / rfLen; |
| 1467 | } |
| 1468 | if (n == 0) n = 1; |
| 1469 | |
| 1470 | //first transition - save startidx |
| 1471 | if (numBits == 0) { |
| 1472 | if (lastval == 1) { //high to low |
| 1473 | *startIdx += (fclow * idx) - (n*rfLen); |
| 1474 | if (g_debugMode==2) prnt("DEBUG FSK: startIdx %i, fclow*idx %i, n*rflen %u", *startIdx, fclow*(idx), n*rfLen); |
| 1475 | } else { |
| 1476 | *startIdx += (fchigh * idx) - (n*rfLen); |
| 1477 | if (g_debugMode==2) prnt("DEBUG FSK: startIdx %i, fchigh*idx %i, n*rflen %u", *startIdx, fchigh*(idx), n*rfLen); |
| 1478 | } |
| 1479 | } |
| 1480 | |
| 1481 | //add to our destination the bits we collected |
| 1482 | memset(dest+numBits, dest[idx-1]^invert , n); |
| 1483 | numBits += n; |
| 1484 | n=0; |
| 1485 | lastval=dest[idx]; |
| 1486 | }//end for |
| 1487 | // if valid extra bits at the end were all the same frequency - add them in |
| 1488 | if (n > rfLen/fchigh) { |
| 1489 | if (dest[idx-2]==1) { |
| 1490 | n = (n * fclow + rfLen/2) / rfLen; |
| 1491 | } else { |
| 1492 | n = (n * fchigh + rfLen/2) / rfLen; |
| 1493 | } |
| 1494 | memset(dest+numBits, dest[idx-1]^invert , n); |
| 1495 | numBits += n; |
| 1496 | } |
| 1497 | return numBits; |
| 1498 | } |
| 1499 | |
| 1500 | //by marshmellow (from holiman's base) |
| 1501 | // full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod) |
| 1502 | int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow, int *startIdx) { |
| 1503 | if (justNoise(dest, size)) return 0; |
| 1504 | // FSK demodulator |
| 1505 | size = fsk_wave_demod(dest, size, fchigh, fclow, startIdx); |
| 1506 | size = aggregate_bits(dest, size, rfLen, invert, fchigh, fclow, startIdx); |
| 1507 | return size; |
| 1508 | } |
| 1509 | |
| 1510 | // by marshmellow |
| 1511 | // convert psk1 demod to psk2 demod |
| 1512 | // only transition waves are 1s |
| 1513 | void psk1TOpsk2(uint8_t *BitStream, size_t size) { |
| 1514 | size_t i=1; |
| 1515 | uint8_t lastBit=BitStream[0]; |
| 1516 | for (; i<size; i++){ |
| 1517 | if (BitStream[i]==7){ |
| 1518 | //ignore errors |
| 1519 | } else if (lastBit!=BitStream[i]){ |
| 1520 | lastBit=BitStream[i]; |
| 1521 | BitStream[i]=1; |
| 1522 | } else { |
| 1523 | BitStream[i]=0; |
| 1524 | } |
| 1525 | } |
| 1526 | return; |
| 1527 | } |
| 1528 | |
| 1529 | // by marshmellow |
| 1530 | // convert psk2 demod to psk1 demod |
| 1531 | // from only transition waves are 1s to phase shifts change bit |
| 1532 | void psk2TOpsk1(uint8_t *BitStream, size_t size) { |
| 1533 | uint8_t phase=0; |
| 1534 | for (size_t i=0; i<size; i++){ |
| 1535 | if (BitStream[i]==1){ |
| 1536 | phase ^=1; |
| 1537 | } |
| 1538 | BitStream[i]=phase; |
| 1539 | } |
| 1540 | return; |
| 1541 | } |
| 1542 | |
| 1543 | //by marshmellow - demodulate PSK1 wave |
| 1544 | //uses wave lengths (# Samples) |
| 1545 | int pskRawDemod_ext(uint8_t dest[], size_t *size, int *clock, int *invert, int *startIdx) { |
| 1546 | if (*size < 170) return -1; |
| 1547 | |
| 1548 | uint8_t curPhase = *invert; |
| 1549 | uint8_t fc=0; |
| 1550 | size_t i=0, numBits=0, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0; |
| 1551 | uint16_t fullWaveLen=0, waveLenCnt=0, avgWaveVal; |
| 1552 | uint16_t errCnt=0, errCnt2=0; |
| 1553 | |
| 1554 | *clock = DetectPSKClock(dest, *size, *clock, &firstFullWave, &curPhase, &fc); |
| 1555 | if (*clock <= 0) return -1; |
| 1556 | //if clock detect found firstfullwave... |
| 1557 | uint16_t tol = fc/2; |
| 1558 | if (firstFullWave == 0) { |
| 1559 | //find start of modulating data in trace |
| 1560 | i = findModStart(dest, *size, fc); |
| 1561 | //find first phase shift |
| 1562 | firstFullWave = pskFindFirstPhaseShift(dest, *size, &curPhase, i, fc, &fullWaveLen); |
| 1563 | if (firstFullWave == 0) { |
| 1564 | // no phase shift detected - could be all 1's or 0's - doesn't matter where we start |
| 1565 | // so skip a little to ensure we are past any Start Signal |
| 1566 | firstFullWave = 160; |
| 1567 | memset(dest, curPhase, firstFullWave / *clock); |
| 1568 | } else { |
| 1569 | memset(dest, curPhase^1, firstFullWave / *clock); |
| 1570 | } |
| 1571 | } else { |
| 1572 | memset(dest, curPhase^1, firstFullWave / *clock); |
| 1573 | } |
| 1574 | //advance bits |
| 1575 | numBits += (firstFullWave / *clock); |
| 1576 | *startIdx = firstFullWave - (*clock * numBits)+2; |
| 1577 | //set start of wave as clock align |
| 1578 | lastClkBit = firstFullWave; |
| 1579 | if (g_debugMode==2) prnt("DEBUG PSK: firstFullWave: %u, waveLen: %u, startIdx %i",firstFullWave,fullWaveLen, *startIdx); |
| 1580 | if (g_debugMode==2) prnt("DEBUG PSK: clk: %d, lastClkBit: %u, fc: %u", *clock, lastClkBit,(unsigned int) fc); |
| 1581 | waveStart = 0; |
| 1582 | dest[numBits++] = curPhase; //set first read bit |
| 1583 | for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++) { |
| 1584 | //top edge of wave = start of new wave |
| 1585 | if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]) { |
| 1586 | if (waveStart == 0) { |
| 1587 | waveStart = i+1; |
| 1588 | waveLenCnt = 0; |
| 1589 | avgWaveVal = dest[i+1]; |
| 1590 | } else { //waveEnd |
| 1591 | waveEnd = i+1; |
| 1592 | waveLenCnt = waveEnd-waveStart; |
| 1593 | if (waveLenCnt > fc) { |
| 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 | } else if (waveLenCnt < fc - 1) { //wave is smaller than field clock (shouldn't happen often) |
| 1610 | errCnt2++; |
| 1611 | if(errCnt2 > 101) return errCnt2; |
| 1612 | avgWaveVal += dest[i+1]; |
| 1613 | continue; |
| 1614 | } |
| 1615 | avgWaveVal = 0; |
| 1616 | waveStart = i+1; |
| 1617 | } |
| 1618 | } |
| 1619 | avgWaveVal += dest[i+1]; |
| 1620 | } |
| 1621 | *size = numBits; |
| 1622 | return errCnt; |
| 1623 | } |
| 1624 | |
| 1625 | int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) { |
| 1626 | int startIdx = 0; |
| 1627 | return pskRawDemod_ext(dest, size, clock, invert, &startIdx); |
| 1628 | } |
| 1629 | |
| 1630 | //********************************************************************************************** |
| 1631 | //-----------------Tag format detection section------------------------------------------------- |
| 1632 | //********************************************************************************************** |
| 1633 | |
| 1634 | // by marshmellow |
| 1635 | // FSK Demod then try to locate an AWID ID |
| 1636 | int AWIDdemodFSK(uint8_t *dest, size_t *size, int *waveStartIdx) { |
| 1637 | //make sure buffer has enough data |
| 1638 | if (*size < 96*50) return -1; |
| 1639 | |
| 1640 | // FSK demodulator |
| 1641 | *size = fskdemod(dest, *size, 50, 1, 10, 8, waveStartIdx); // fsk2a RF/50 |
| 1642 | if (*size < 96) return -3; //did we get a good demod? |
| 1643 | |
| 1644 | uint8_t preamble[] = {0,0,0,0,0,0,0,1}; |
| 1645 | size_t startIdx = 0; |
| 1646 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); |
| 1647 | if (errChk == 0) return -4; //preamble not found |
| 1648 | if (*size != 96) return -5; |
| 1649 | return (int)startIdx; |
| 1650 | } |
| 1651 | |
| 1652 | //by marshmellow |
| 1653 | //takes 1s and 0s and searches for EM410x format - output EM ID |
| 1654 | uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo) |
| 1655 | { |
| 1656 | //sanity checks |
| 1657 | if (*size < 64) return 0; |
| 1658 | if (BitStream[1]>1) return 0; //allow only 1s and 0s |
| 1659 | |
| 1660 | // 111111111 bit pattern represent start of frame |
| 1661 | // include 0 in front to help get start pos |
| 1662 | uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1}; |
| 1663 | uint8_t errChk = 0; |
| 1664 | uint8_t FmtLen = 10; // sets of 4 bits = end data |
| 1665 | *startIdx = 0; |
| 1666 | errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx); |
| 1667 | if ( errChk == 0 || (*size != 64 && *size != 128) ) return 0; |
| 1668 | if (*size == 128) FmtLen = 22; // 22 sets of 4 bits |
| 1669 | |
| 1670 | //skip last 4bit parity row for simplicity |
| 1671 | *size = removeParity(BitStream, *startIdx + sizeof(preamble), 5, 0, FmtLen * 5); |
| 1672 | if (*size == 40) { // std em410x format |
| 1673 | *hi = 0; |
| 1674 | *lo = ((uint64_t)(bytebits_to_byte(BitStream, 8)) << 32) | (bytebits_to_byte(BitStream + 8, 32)); |
| 1675 | } else if (*size == 88) { // long em format |
| 1676 | *hi = (bytebits_to_byte(BitStream, 24)); |
| 1677 | *lo = ((uint64_t)(bytebits_to_byte(BitStream + 24, 32)) << 32) | (bytebits_to_byte(BitStream + 24 + 32, 32)); |
| 1678 | } else { |
| 1679 | if (g_debugMode) prnt("Error removing parity: %u", *size); |
| 1680 | return 0; |
| 1681 | } |
| 1682 | return 1; |
| 1683 | } |
| 1684 | |
| 1685 | // Ask/Biphase Demod then try to locate an ISO 11784/85 ID |
| 1686 | // BitStream must contain previously askrawdemod and biphasedemoded data |
| 1687 | int FDXBdemodBI(uint8_t *dest, size_t *size) { |
| 1688 | //make sure buffer has enough data |
| 1689 | if (*size < 128) return -1; |
| 1690 | |
| 1691 | size_t startIdx = 0; |
| 1692 | uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,1}; |
| 1693 | |
| 1694 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); |
| 1695 | if (errChk == 0) return -2; //preamble not found |
| 1696 | if (*size != 128) return -3; //wrong size for fdxb |
| 1697 | //return start position |
| 1698 | return (int)startIdx; |
| 1699 | } |
| 1700 | |
| 1701 | // by marshmellow |
| 1702 | // demod gProxIIDemod |
| 1703 | // error returns as -x |
| 1704 | // success returns start position in BitStream |
| 1705 | // BitStream must contain previously askrawdemod and biphasedemoded data |
| 1706 | int gProxII_Demod(uint8_t BitStream[], size_t *size) { |
| 1707 | size_t startIdx=0; |
| 1708 | uint8_t preamble[] = {1,1,1,1,1,0}; |
| 1709 | |
| 1710 | uint8_t errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, &startIdx); |
| 1711 | if (errChk == 0) return -3; //preamble not found |
| 1712 | if (*size != 96) return -2; //should have found 96 bits |
| 1713 | //check first 6 spacer bits to verify format |
| 1714 | if (!BitStream[startIdx+5] && !BitStream[startIdx+10] && !BitStream[startIdx+15] && !BitStream[startIdx+20] && !BitStream[startIdx+25] && !BitStream[startIdx+30]){ |
| 1715 | //confirmed proper separator bits found |
| 1716 | //return start position |
| 1717 | return (int) startIdx; |
| 1718 | } |
| 1719 | return -5; //spacer bits not found - not a valid gproxII |
| 1720 | } |
| 1721 | |
| 1722 | // loop to get raw HID waveform then FSK demodulate the TAG ID from it |
| 1723 | int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo, int *waveStartIdx) { |
| 1724 | size_t numStart=0, size2=*size, startIdx=0; |
| 1725 | // FSK demodulator fsk2a so invert and fc/10/8 |
| 1726 | *size = fskdemod(dest, size2, 50, 1, 10, 8, waveStartIdx); |
| 1727 | if (*size < 96*2) return -2; |
| 1728 | // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1 |
| 1729 | uint8_t preamble[] = {0,0,0,1,1,1,0,1}; |
| 1730 | // find bitstring in array |
| 1731 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); |
| 1732 | if (errChk == 0) return -3; //preamble not found |
| 1733 | |
| 1734 | numStart = startIdx + sizeof(preamble); |
| 1735 | // final loop, go over previously decoded FSK data and manchester decode into usable tag ID |
| 1736 | for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){ |
| 1737 | if (dest[idx] == dest[idx+1]){ |
| 1738 | return -4; //not manchester data |
| 1739 | } |
| 1740 | *hi2 = (*hi2<<1)|(*hi>>31); |
| 1741 | *hi = (*hi<<1)|(*lo>>31); |
| 1742 | //Then, shift in a 0 or one into low |
| 1743 | if (dest[idx] && !dest[idx+1]) // 1 0 |
| 1744 | *lo=(*lo<<1)|1; |
| 1745 | else // 0 1 |
| 1746 | *lo=(*lo<<1)|0; |
| 1747 | } |
| 1748 | return (int)startIdx; |
| 1749 | } |
| 1750 | |
| 1751 | int IOdemodFSK(uint8_t *dest, size_t size, int *waveStartIdx) { |
| 1752 | //make sure buffer has data |
| 1753 | if (size < 66*64) return -2; |
| 1754 | // FSK demodulator RF/64, fsk2a so invert, and fc/10/8 |
| 1755 | size = fskdemod(dest, size, 64, 1, 10, 8, waveStartIdx); |
| 1756 | if (size < 65) return -3; //did we get a good demod? |
| 1757 | //Index map |
| 1758 | //0 10 20 30 40 50 60 |
| 1759 | //| | | | | | | |
| 1760 | //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23 |
| 1761 | //----------------------------------------------------------------------------- |
| 1762 | //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11 |
| 1763 | // |
| 1764 | //XSF(version)facility:codeone+codetwo |
| 1765 | //Handle the data |
| 1766 | size_t startIdx = 0; |
| 1767 | uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,1}; |
| 1768 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), &size, &startIdx); |
| 1769 | if (errChk == 0) return -4; //preamble not found |
| 1770 | |
| 1771 | if (!dest[startIdx+8] && dest[startIdx+17]==1 && dest[startIdx+26]==1 && dest[startIdx+35]==1 && dest[startIdx+44]==1 && dest[startIdx+53]==1){ |
| 1772 | //confirmed proper separator bits found |
| 1773 | //return start position |
| 1774 | return (int) startIdx; |
| 1775 | } |
| 1776 | return -5; |
| 1777 | } |
| 1778 | |
| 1779 | // redesigned by marshmellow adjusted from existing decode functions |
| 1780 | // indala id decoding |
| 1781 | int indala64decode(uint8_t *bitStream, size_t *size, uint8_t *invert) { |
| 1782 | //standard 64 bit indala formats including 26 bit 40134 format |
| 1783 | uint8_t preamble64[] = {1,0,1,0, 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}; |
| 1784 | uint8_t preamble64_i[] = {0,1,0,1, 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}; |
| 1785 | size_t startidx = 0; |
| 1786 | size_t found_size = *size; |
| 1787 | bool found = preambleSearch(bitStream, preamble64, sizeof(preamble64), &found_size, &startidx); |
| 1788 | if (!found) { |
| 1789 | found = preambleSearch(bitStream, preamble64_i, sizeof(preamble64_i), &found_size, &startidx); |
| 1790 | if (!found) return -1; |
| 1791 | *invert ^= 1; |
| 1792 | } |
| 1793 | if (found_size != 64) return -2; |
| 1794 | if (*invert==1) |
| 1795 | for (size_t i = startidx; i < found_size + startidx; i++) |
| 1796 | bitStream[i] ^= 1; |
| 1797 | |
| 1798 | // note: don't change *size until we are sure we got it... |
| 1799 | *size = found_size; |
| 1800 | return (int) startidx; |
| 1801 | } |
| 1802 | |
| 1803 | int indala224decode(uint8_t *bitStream, size_t *size, uint8_t *invert) { |
| 1804 | //large 224 bit indala formats (different preamble too...) |
| 1805 | uint8_t preamble224[] = {1,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,1}; |
| 1806 | uint8_t preamble224_i[] = {0,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,1, 1,1,1,0}; |
| 1807 | size_t startidx = 0; |
| 1808 | size_t found_size = *size; |
| 1809 | bool found = preambleSearch(bitStream, preamble224, sizeof(preamble224), &found_size, &startidx); |
| 1810 | if (!found) { |
| 1811 | found = preambleSearch(bitStream, preamble224_i, sizeof(preamble224_i), &found_size, &startidx); |
| 1812 | if (!found) return -1; |
| 1813 | *invert ^= 1; |
| 1814 | } |
| 1815 | if (found_size != 224) return -2; |
| 1816 | if (*invert==1 && startidx > 0) |
| 1817 | for (size_t i = startidx-1; i < found_size + startidx + 2; i++) |
| 1818 | bitStream[i] ^= 1; |
| 1819 | |
| 1820 | // 224 formats are typically PSK2 (afaik 2017 Marshmellow) |
| 1821 | // note loses 1 bit at beginning of transformation... |
| 1822 | // don't need to verify array is big enough as to get here there has to be a full preamble after all of our data |
| 1823 | psk1TOpsk2(bitStream + (startidx-1), found_size+2); |
| 1824 | startidx++; |
| 1825 | |
| 1826 | *size = found_size; |
| 1827 | return (int) startidx; |
| 1828 | } |
| 1829 | |
| 1830 | // loop to get raw paradox waveform then FSK demodulate the TAG ID from it |
| 1831 | int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo, int *waveStartIdx) { |
| 1832 | size_t numStart=0, size2=*size, startIdx=0; |
| 1833 | // FSK demodulator |
| 1834 | *size = fskdemod(dest, size2,50,1,10,8,waveStartIdx); //fsk2a |
| 1835 | if (*size < 96) return -2; |
| 1836 | |
| 1837 | // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1 |
| 1838 | uint8_t preamble[] = {0,0,0,0,1,1,1,1}; |
| 1839 | |
| 1840 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); |
| 1841 | if (errChk == 0) return -3; //preamble not found |
| 1842 | |
| 1843 | numStart = startIdx + sizeof(preamble); |
| 1844 | // final loop, go over previously decoded FSK data and manchester decode into usable tag ID |
| 1845 | for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){ |
| 1846 | if (dest[idx] == dest[idx+1]) |
| 1847 | return -4; //not manchester data |
| 1848 | *hi2 = (*hi2<<1)|(*hi>>31); |
| 1849 | *hi = (*hi<<1)|(*lo>>31); |
| 1850 | //Then, shift in a 0 or one into low |
| 1851 | if (dest[idx] && !dest[idx+1]) // 1 0 |
| 1852 | *lo=(*lo<<1)|1; |
| 1853 | else // 0 1 |
| 1854 | *lo=(*lo<<1)|0; |
| 1855 | } |
| 1856 | return (int)startIdx; |
| 1857 | } |
| 1858 | |
| 1859 | // find presco preamble 0x10D in already demoded data |
| 1860 | int PrescoDemod(uint8_t *dest, size_t *size) { |
| 1861 | //make sure buffer has data |
| 1862 | if (*size < 64*2) return -2; |
| 1863 | |
| 1864 | size_t startIdx = 0; |
| 1865 | uint8_t preamble[] = {1,0,0,0,0,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0}; |
| 1866 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); |
| 1867 | if (errChk == 0) return -4; //preamble not found |
| 1868 | //return start position |
| 1869 | return (int) startIdx; |
| 1870 | } |
| 1871 | |
| 1872 | // by marshmellow |
| 1873 | // FSK Demod then try to locate a Farpointe Data (pyramid) ID |
| 1874 | int PyramiddemodFSK(uint8_t *dest, size_t *size, int *waveStartIdx) { |
| 1875 | //make sure buffer has data |
| 1876 | if (*size < 128*50) return -5; |
| 1877 | |
| 1878 | // FSK demodulator |
| 1879 | *size = fskdemod(dest, *size, 50, 1, 10, 8, waveStartIdx); // fsk2a RF/50 |
| 1880 | if (*size < 128) return -2; //did we get a good demod? |
| 1881 | |
| 1882 | uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1}; |
| 1883 | size_t startIdx = 0; |
| 1884 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); |
| 1885 | if (errChk == 0) return -4; //preamble not found |
| 1886 | if (*size != 128) return -3; |
| 1887 | return (int)startIdx; |
| 1888 | } |
| 1889 | |
| 1890 | // by marshmellow |
| 1891 | // find viking preamble 0xF200 in already demoded data |
| 1892 | int VikingDemod_AM(uint8_t *dest, size_t *size) { |
| 1893 | //make sure buffer has data |
| 1894 | if (*size < 64*2) return -2; |
| 1895 | |
| 1896 | size_t startIdx = 0; |
| 1897 | 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}; |
| 1898 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); |
| 1899 | if (errChk == 0) return -4; //preamble not found |
| 1900 | uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^ bytebits_to_byte(dest+startIdx+8,8) ^ bytebits_to_byte(dest+startIdx+16,8) |
| 1901 | ^ bytebits_to_byte(dest+startIdx+24,8) ^ bytebits_to_byte(dest+startIdx+32,8) ^ bytebits_to_byte(dest+startIdx+40,8) |
| 1902 | ^ bytebits_to_byte(dest+startIdx+48,8) ^ bytebits_to_byte(dest+startIdx+56,8); |
| 1903 | if ( checkCalc != 0xA8 ) return -5; |
| 1904 | if (*size != 64) return -6; |
| 1905 | //return start position |
| 1906 | return (int) startIdx; |
| 1907 | } |
| 1908 | |
| 1909 | // by iceman |
| 1910 | // find Visa2000 preamble in already demoded data |
| 1911 | int Visa2kDemod_AM(uint8_t *dest, size_t *size) { |
| 1912 | if (*size < 96) return -1; //make sure buffer has data |
| 1913 | size_t startIdx = 0; |
| 1914 | uint8_t preamble[] = {0,1,0,1,0,1,1,0,0,1,0,0,1,0,0,1,0,1,0,1,0,0,1,1,0,0,1,1,0,0,1,0}; |
| 1915 | if (preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx) == 0) |
| 1916 | return -2; //preamble not found |
| 1917 | if (*size != 96) return -3; //wrong demoded size |
| 1918 | //return start position |
| 1919 | return (int)startIdx; |
| 1920 | } |