fix bug in st detect +
[proxmark3-svn] / common / lfdemod.c
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){
509 //find shortest transition from high to low
510 size_t i = 0;
511 size_t transition1 = 0;
512 int lowestTransition = 255;
513 bool lastWasHigh = false;
514
515 //find first valid beginning of a high or low wave
516 while ((dest[i] >= peak || dest[i] <= low) && (i < size))
517 ++i;
518 while ((dest[i] < peak && dest[i] > low) && (i < size))
519 ++i;
520 lastWasHigh = (dest[i] >= peak);
521
522 if (i==size) return 0;
523 transition1 = i;
524
525 for (;i < size; i++) {
526 if ((dest[i] >= peak && !lastWasHigh) || (dest[i] <= low && lastWasHigh)) {
527 lastWasHigh = (dest[i] >= peak);
528 if (i-transition1 < lowestTransition) lowestTransition = i-transition1;
529 transition1 = i;
530 }
531 }
532 if (lowestTransition == 255) lowestTransition = 0;
533 if (g_debugMode==2) prnt("DEBUG NRZ: detectstrongNRZclk smallest wave: %d",lowestTransition);
534 return lowestTransition;
535 }
536
537 //by marshmellow
538 //detect nrz clock by reading #peaks vs no peaks(or errors)
539 int DetectNRZClock(uint8_t dest[], size_t size, int clock, size_t *clockStartIdx) {
540 size_t i=0;
541 uint8_t clk[]={8,16,32,40,50,64,100,128,255};
542 size_t loopCnt = 4096; //don't need to loop through entire array...
543 if (size == 0) return 0;
544 if (size<loopCnt) loopCnt = size-20;
545 //if we already have a valid clock quit
546 for (; i < 8; ++i)
547 if (clk[i] == clock) return clock;
548
549 //get high and low peak
550 int peak, low;
551 if (getHiLo(dest, loopCnt, &peak, &low, 90, 90) < 1) return 0;
552
553 int lowestTransition = DetectStrongNRZClk(dest, size-20, peak, low);
554 size_t ii;
555 uint8_t clkCnt;
556 uint8_t tol = 0;
557 uint16_t smplCnt = 0;
558 int16_t peakcnt = 0;
559 int16_t peaksdet[] = {0,0,0,0,0,0,0,0};
560 uint16_t minPeak = 255;
561 bool firstpeak = true;
562 //test for large clipped waves - ignore first peak
563 for (i=0; i<loopCnt; i++) {
564 if (dest[i] >= peak || dest[i] <= low) {
565 if (firstpeak) continue;
566 smplCnt++;
567 } else {
568 firstpeak = false;
569 if (smplCnt > 0) {
570 if (minPeak > smplCnt && smplCnt > 7) minPeak = smplCnt;
571 peakcnt++;
572 if (g_debugMode == 2) prnt("DEBUG NRZ: minPeak: %d, smplCnt: %d, peakcnt: %d",minPeak,smplCnt,peakcnt);
573 smplCnt = 0;
574 }
575 }
576 }
577 if (minPeak < 8) return 0;
578 bool errBitHigh = 0;
579 bool bitHigh = 0;
580 uint8_t ignoreCnt = 0;
581 uint8_t ignoreWindow = 4;
582 bool lastPeakHigh = 0;
583 int lastBit = 0;
584 size_t bestStart[]={0,0,0,0,0,0,0,0,0};
585 peakcnt=0;
586 //test each valid clock from smallest to greatest to see which lines up
587 for(clkCnt=0; clkCnt < 8; ++clkCnt) {
588 //ignore clocks smaller than smallest peak
589 if (clk[clkCnt] < minPeak - (clk[clkCnt]/4)) continue;
590 //try lining up the peaks by moving starting point (try first 256)
591 for (ii=20; ii < loopCnt; ++ii) {
592 if ((dest[ii] >= peak) || (dest[ii] <= low)) {
593 peakcnt = 0;
594 bitHigh = false;
595 ignoreCnt = 0;
596 lastBit = ii-clk[clkCnt];
597 //loop through to see if this start location works
598 for (i = ii; i < size-20; ++i) {
599 //if we are at a clock bit
600 if ((i >= lastBit + clk[clkCnt] - tol) && (i <= lastBit + clk[clkCnt] + tol)) {
601 //test high/low
602 if (dest[i] >= peak || dest[i] <= low) {
603 //if same peak don't count it
604 if ((dest[i] >= peak && !lastPeakHigh) || (dest[i] <= low && lastPeakHigh)) {
605 peakcnt++;
606 }
607 lastPeakHigh = (dest[i] >= peak);
608 bitHigh = true;
609 errBitHigh = false;
610 ignoreCnt = ignoreWindow;
611 lastBit += clk[clkCnt];
612 } else if (i == lastBit + clk[clkCnt] + tol) {
613 lastBit += clk[clkCnt];
614 }
615 //else if not a clock bit and no peaks
616 } else if (dest[i] < peak && dest[i] > low) {
617 if (ignoreCnt==0) {
618 bitHigh=false;
619 if (errBitHigh==true) peakcnt--;
620 errBitHigh=false;
621 } else {
622 ignoreCnt--;
623 }
624 // else if not a clock bit but we have a peak
625 } else if ((dest[i]>=peak || dest[i]<=low) && (!bitHigh)) {
626 //error bar found no clock...
627 errBitHigh=true;
628 }
629 }
630 if(peakcnt>peaksdet[clkCnt]) {
631 bestStart[clkCnt]=ii;
632 peaksdet[clkCnt]=peakcnt;
633 }
634 }
635 }
636 }
637 int iii=7;
638 uint8_t best=0;
639 for (iii=7; iii > 0; iii--) {
640 if ((peaksdet[iii] >= (peaksdet[best]-1)) && (peaksdet[iii] <= peaksdet[best]+1) && lowestTransition) {
641 if (clk[iii] > (lowestTransition - (clk[iii]/8)) && clk[iii] < (lowestTransition + (clk[iii]/8))) {
642 best = iii;
643 }
644 } else if (peaksdet[iii] > peaksdet[best]) {
645 best = iii;
646 }
647 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);
648 }
649 *clockStartIdx = bestStart[best];
650 return clk[best];
651 }
652
653 //by marshmellow
654 //countFC is to detect the field clock lengths.
655 //counts and returns the 2 most common wave lengths
656 //mainly used for FSK field clock detection
657 uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj) {
658 uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
659 uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
660 uint8_t fcLensFnd = 0;
661 uint8_t lastFCcnt = 0;
662 uint8_t fcCounter = 0;
663 size_t i;
664 if (size < 180) return 0;
665
666 // prime i to first up transition
667 for (i = 160; i < size-20; i++)
668 if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1])
669 break;
670
671 for (; i < size-20; i++){
672 if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){
673 // new up transition
674 fcCounter++;
675 if (fskAdj){
676 //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8)
677 if (lastFCcnt==5 && fcCounter==9) fcCounter--;
678 //if fc=9 or 4 add one (for when we get a fc 9 instead of 10 or a 4 instead of a 5)
679 if ((fcCounter==9) || fcCounter==4) fcCounter++;
680 // save last field clock count (fc/xx)
681 lastFCcnt = fcCounter;
682 }
683 // find which fcLens to save it to:
684 for (int ii=0; ii<15; ii++){
685 if (fcLens[ii]==fcCounter){
686 fcCnts[ii]++;
687 fcCounter=0;
688 break;
689 }
690 }
691 if (fcCounter>0 && fcLensFnd<15){
692 //add new fc length
693 fcCnts[fcLensFnd]++;
694 fcLens[fcLensFnd++]=fcCounter;
695 }
696 fcCounter=0;
697 } else {
698 // count sample
699 fcCounter++;
700 }
701 }
702
703 uint8_t best1=14, best2=14, best3=14;
704 uint16_t maxCnt1=0;
705 // go through fclens and find which ones are bigest 2
706 for (i=0; i<15; i++){
707 // get the 3 best FC values
708 if (fcCnts[i]>maxCnt1) {
709 best3=best2;
710 best2=best1;
711 maxCnt1=fcCnts[i];
712 best1=i;
713 } else if(fcCnts[i]>fcCnts[best2]){
714 best3=best2;
715 best2=i;
716 } else if(fcCnts[i]>fcCnts[best3]){
717 best3=i;
718 }
719 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]);
720 if (fcLens[i]==0) break;
721 }
722 if (fcLens[best1]==0) return 0;
723 uint8_t fcH=0, fcL=0;
724 if (fcLens[best1]>fcLens[best2]){
725 fcH=fcLens[best1];
726 fcL=fcLens[best2];
727 } else{
728 fcH=fcLens[best2];
729 fcL=fcLens[best1];
730 }
731 if ((size-180)/fcH/3 > fcCnts[best1]+fcCnts[best2]) {
732 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]);
733 return 0; //lots of waves not psk or fsk
734 }
735 // TODO: take top 3 answers and compare to known Field clocks to get top 2
736
737 uint16_t fcs = (((uint16_t)fcH)<<8) | fcL;
738 if (fskAdj) return fcs;
739 return (uint16_t)fcLens[best2] << 8 | fcLens[best1];
740 }
741
742 //by marshmellow
743 //detect psk clock by reading each phase shift
744 // a phase shift is determined by measuring the sample length of each wave
745 int DetectPSKClock(uint8_t dest[], size_t size, int clock, size_t *firstPhaseShift, uint8_t *curPhase, uint8_t *fc) {
746 uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock
747 uint16_t loopCnt = 4096; //don't need to loop through entire array...
748 if (size == 0) return 0;
749 if (size+3<loopCnt) loopCnt = size-20;
750
751 uint16_t fcs = countFC(dest, size, 0);
752 *fc = fcs & 0xFF;
753 if (g_debugMode==2) prnt("DEBUG PSK: FC: %d, FC2: %d",*fc, fcs>>8);
754 if ((fcs>>8) == 10 && *fc == 8) return -1;
755 if (*fc!=2 && *fc!=4 && *fc!=8) return -1;
756
757 //if we already have a valid clock quit
758 size_t i=1;
759 for (; i < 8; ++i)
760 if (clk[i] == clock) return clock;
761
762 size_t waveStart=0, waveEnd=0, firstFullWave=0, lastClkBit=0;
763
764 uint8_t clkCnt, tol=1;
765 uint16_t peakcnt=0, errCnt=0, waveLenCnt=0, fullWaveLen=0;
766 uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
767 uint16_t peaksdet[]={0,0,0,0,0,0,0,0,0};
768
769 //find start of modulating data in trace
770 i = findModStart(dest, size, *fc);
771
772 firstFullWave = pskFindFirstPhaseShift(dest, size, curPhase, i, *fc, &fullWaveLen);
773 if (firstFullWave == 0) {
774 // no phase shift detected - could be all 1's or 0's - doesn't matter where we start
775 // so skip a little to ensure we are past any Start Signal
776 firstFullWave = 160;
777 fullWaveLen = 0;
778 }
779
780 *firstPhaseShift = firstFullWave;
781 if (g_debugMode ==2) prnt("DEBUG PSK: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);
782 //test each valid clock from greatest to smallest to see which lines up
783 for(clkCnt=7; clkCnt >= 1 ; clkCnt--) {
784 tol = *fc/2;
785 lastClkBit = firstFullWave; //set end of wave as clock align
786 waveStart = 0;
787 errCnt=0;
788 peakcnt=0;
789 if (g_debugMode == 2) prnt("DEBUG PSK: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit);
790
791 for (i = firstFullWave+fullWaveLen-1; i < loopCnt-2; i++){
792 //top edge of wave = start of new wave
793 if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
794 if (waveStart == 0) {
795 waveStart = i+1;
796 waveLenCnt=0;
797 } else { //waveEnd
798 waveEnd = i+1;
799 waveLenCnt = waveEnd-waveStart;
800 if (waveLenCnt > *fc){
801 //if this wave is a phase shift
802 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);
803 if (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit
804 peakcnt++;
805 lastClkBit+=clk[clkCnt];
806 } else if (i<lastClkBit+8){
807 //noise after a phase shift - ignore
808 } else { //phase shift before supposed to based on clock
809 errCnt++;
810 }
811 } else if (i+1 > lastClkBit + clk[clkCnt] + tol + *fc){
812 lastClkBit+=clk[clkCnt]; //no phase shift but clock bit
813 }
814 waveStart=i+1;
815 }
816 }
817 }
818 if (errCnt == 0){
819 return clk[clkCnt];
820 }
821 if (errCnt <= bestErr[clkCnt]) bestErr[clkCnt]=errCnt;
822 if (peakcnt > peaksdet[clkCnt]) peaksdet[clkCnt]=peakcnt;
823 }
824 //all tested with errors
825 //return the highest clk with the most peaks found
826 uint8_t best=7;
827 for (i=7; i>=1; i--){
828 if (peaksdet[i] > peaksdet[best]) {
829 best = i;
830 }
831 if (g_debugMode == 2) prnt("DEBUG PSK: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[i],peaksdet[i],bestErr[i],clk[best]);
832 }
833 return clk[best];
834 }
835
836 //int DetectPSKClock(uint8_t dest[], size_t size, int clock) {
837 // size_t firstPhaseShift = 0;
838 // uint8_t curPhase = 0;
839 // return DetectPSKClock_ext(dest, size, clock, &firstPhaseShift, &curPhase);
840 //}
841
842 //by marshmellow
843 //detects the bit clock for FSK given the high and low Field Clocks
844 uint8_t detectFSKClk_ext(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow, int *firstClockEdge) {
845 uint8_t clk[] = {8,16,32,40,50,64,100,128,0};
846 uint16_t rfLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
847 uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
848 uint8_t rfLensFnd = 0;
849 uint8_t lastFCcnt = 0;
850 uint16_t fcCounter = 0;
851 uint16_t rfCounter = 0;
852 uint8_t firstBitFnd = 0;
853 size_t i;
854 if (size == 0) return 0;
855
856 uint8_t fcTol = ((fcHigh*100 - fcLow*100)/2 + 50)/100; //(uint8_t)(0.5+(float)(fcHigh-fcLow)/2);
857 rfLensFnd=0;
858 fcCounter=0;
859 rfCounter=0;
860 firstBitFnd=0;
861 //PrintAndLog("DEBUG: fcTol: %d",fcTol);
862 // prime i to first peak / up transition
863 for (i = 160; i < size-20; i++)
864 if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1])
865 break;
866
867 for (; i < size-20; i++){
868 fcCounter++;
869 rfCounter++;
870
871 if (BitStream[i] <= BitStream[i-1] || BitStream[i] < BitStream[i+1])
872 continue;
873 // else new peak
874 // if we got less than the small fc + tolerance then set it to the small fc
875 // if it is inbetween set it to the last counter
876 if (fcCounter < fcHigh && fcCounter > fcLow)
877 fcCounter = lastFCcnt;
878 else if (fcCounter < fcLow+fcTol)
879 fcCounter = fcLow;
880 else //set it to the large fc
881 fcCounter = fcHigh;
882
883 //look for bit clock (rf/xx)
884 if ((fcCounter < lastFCcnt || fcCounter > lastFCcnt)){
885 //not the same size as the last wave - start of new bit sequence
886 if (firstBitFnd > 1){ //skip first wave change - probably not a complete bit
887 for (int ii=0; ii<15; ii++){
888 if (rfLens[ii] >= (rfCounter-4) && rfLens[ii] <= (rfCounter+4)){
889 rfCnts[ii]++;
890 rfCounter = 0;
891 break;
892 }
893 }
894 if (rfCounter > 0 && rfLensFnd < 15){
895 //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
896 rfCnts[rfLensFnd]++;
897 rfLens[rfLensFnd++] = rfCounter;
898 }
899 } else {
900 *firstClockEdge = i;
901 firstBitFnd++;
902 }
903 rfCounter=0;
904 lastFCcnt=fcCounter;
905 }
906 fcCounter=0;
907 }
908 uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15;
909
910 for (i=0; i<15; i++){
911 //get highest 2 RF values (might need to get more values to compare or compare all?)
912 if (rfCnts[i]>rfCnts[rfHighest]){
913 rfHighest3=rfHighest2;
914 rfHighest2=rfHighest;
915 rfHighest=i;
916 } else if(rfCnts[i]>rfCnts[rfHighest2]){
917 rfHighest3=rfHighest2;
918 rfHighest2=i;
919 } else if(rfCnts[i]>rfCnts[rfHighest3]){
920 rfHighest3=i;
921 }
922 if (g_debugMode==2) prnt("DEBUG FSK: RF %d, cnts %d",rfLens[i], rfCnts[i]);
923 }
924 // set allowed clock remainder tolerance to be 1 large field clock length+1
925 // we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off
926 uint8_t tol1 = fcHigh+1;
927
928 if (g_debugMode==2) prnt("DEBUG FSK: most counted rf values: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]);
929
930 // loop to find the highest clock that has a remainder less than the tolerance
931 // compare samples counted divided by
932 // test 128 down to 32 (shouldn't be possible to have fc/10 & fc/8 and rf/16 or less)
933 int ii=7;
934 for (; ii>=2; ii--){
935 if (rfLens[rfHighest] % clk[ii] < tol1 || rfLens[rfHighest] % clk[ii] > clk[ii]-tol1){
936 if (rfLens[rfHighest2] % clk[ii] < tol1 || rfLens[rfHighest2] % clk[ii] > clk[ii]-tol1){
937 if (rfLens[rfHighest3] % clk[ii] < tol1 || rfLens[rfHighest3] % clk[ii] > clk[ii]-tol1){
938 if (g_debugMode==2) prnt("DEBUG FSK: clk %d divides into the 3 most rf values within tolerance",clk[ii]);
939 break;
940 }
941 }
942 }
943 }
944
945 if (ii<2) return 0; // oops we went too far
946
947 return clk[ii];
948 }
949
950 uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow) {
951 int firstClockEdge = 0;
952 return detectFSKClk_ext(BitStream, size, fcHigh, fcLow, &firstClockEdge);
953 }
954
955 //**********************************************************************************************
956 //--------------------Modulation Demods &/or Decoding Section-----------------------------------
957 //**********************************************************************************************
958
959 // 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...
960 bool findST(int *stStopLoc, int *stStartIdx, int lowToLowWaveLen[], int highToLowWaveLen[], int clk, int tol, int buffSize, size_t *i) {
961 if (buffSize < *i+4) return false;
962
963 for (; *i < buffSize - 4; *i+=1) {
964 *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...
965 if (lowToLowWaveLen[*i] >= clk*1-tol && lowToLowWaveLen[*i] <= (clk*2)+tol && highToLowWaveLen[*i] < clk+tol) { //1 to 2 clocks depending on 2 bits prior
966 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
967 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
968 if (lowToLowWaveLen[*i+3] >= clk*1-tol && lowToLowWaveLen[*i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit
969 *stStopLoc = *i + 3;
970 return true;
971 }
972 }
973 }
974 }
975 }
976 return false;
977 }
978 //by marshmellow
979 //attempt to identify a Sequence Terminator in ASK modulated raw wave
980 bool DetectST_ext(uint8_t buffer[], size_t *size, int *foundclock, size_t *ststart, size_t *stend) {
981 size_t bufsize = *size;
982 //need to loop through all samples and identify our clock, look for the ST pattern
983 int clk = 0;
984 int tol = 0;
985 int j=0, high, low, skip=0, start=0, end=0, minClk=255;
986 size_t i = 0;
987 //probably should malloc... || test if memory is available ... handle device side? memory danger!!! [marshmellow]
988 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
989 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...
990 //size_t testsize = (bufsize < 512) ? bufsize : 512;
991 int phaseoff = 0;
992 high = low = 128;
993 memset(tmpbuff, 0, sizeof(tmpbuff));
994 memset(waveLen, 0, sizeof(waveLen));
995
996 if (!loadWaveCounters(buffer, bufsize, tmpbuff, waveLen, &j, &skip, &minClk, &high, &low)) return false;
997 // set clock - might be able to get this externally and remove this work...
998 clk = getClosestClock(minClk);
999 // clock not found - ERROR
1000 if (clk == 0) {
1001 if (g_debugMode==2) prnt("DEBUG STT: clock not found - quitting");
1002 return false;
1003 }
1004 *foundclock = clk;
1005
1006 tol = clk/8;
1007 if (!findST(&start, &skip, tmpbuff, waveLen, clk, tol, j, &i)) {
1008 // first ST not found - ERROR
1009 if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting");
1010 return false;
1011 } else {
1012 if (g_debugMode==2) prnt("DEBUG STT: first STT found at wave: %i, skip: %i, j=%i", start, skip, j);
1013 }
1014 if (waveLen[i+2] > clk*1+tol)
1015 phaseoff = 0;
1016 else
1017 phaseoff = clk/2;
1018
1019 // skip over the remainder of ST
1020 skip += clk*7/2; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point
1021
1022 // now do it again to find the end
1023 int dummy1 = 0;
1024 end = skip;
1025 i+=3;
1026 if (!findST(&dummy1, &end, tmpbuff, waveLen, clk, tol, j, &i)) {
1027 //didn't find second ST - ERROR
1028 if (g_debugMode==2) prnt("DEBUG STT: second STT not found - quitting");
1029 return false;
1030 }
1031 end -= phaseoff;
1032 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);
1033 //now begin to trim out ST so we can use normal demod cmds
1034 start = skip;
1035 size_t datalen = end - start;
1036 // check validity of datalen (should be even clock increments) - use a tolerance of up to 1/8th a clock
1037 if ( clk - (datalen % clk) <= clk/8) {
1038 // padd the amount off - could be problematic... but shouldn't happen often
1039 datalen += clk - (datalen % clk);
1040 } else if ( (datalen % clk) <= clk/8 ) {
1041 // padd the amount off - could be problematic... but shouldn't happen often
1042 datalen -= datalen % clk;
1043 } else {
1044 if (g_debugMode==2) prnt("DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting", datalen, clk, datalen % clk);
1045 return false;
1046 }
1047 // if datalen is less than one t55xx block - ERROR
1048 if (datalen/clk < 8*4) {
1049 if (g_debugMode==2) prnt("DEBUG STT: datalen is less than 1 full t55xx block - quitting");
1050 return false;
1051 }
1052 size_t dataloc = start;
1053 if (buffer[dataloc-(clk*4)-(clk/4)] <= low && buffer[dataloc] <= low && buffer[dataloc-(clk*4)] >= high) {
1054 //we have low drift (and a low just before the ST and a low just after the ST) - compensate by backing up the start
1055 for ( i=0; i <= (clk/4); ++i ) {
1056 if ( buffer[dataloc - (clk*4) - i] <= low ) {
1057 dataloc -= i;
1058 break;
1059 }
1060 }
1061 }
1062
1063 size_t newloc = 0;
1064 i=0;
1065 if (g_debugMode==2) prnt("DEBUG STT: Starting STT trim - start: %d, datalen: %d ",dataloc, datalen);
1066 bool firstrun = true;
1067 // warning - overwriting buffer given with raw wave data with ST removed...
1068 while ( dataloc < bufsize-(clk/2) ) {
1069 //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)
1070 if (buffer[dataloc]<high && buffer[dataloc]>low && buffer[dataloc+clk/4]<high && buffer[dataloc+clk/4]>low) {
1071 for(i=0; i < clk/2-tol; ++i) {
1072 buffer[dataloc+i] = high+5;
1073 }
1074 } //test for small spike outlier (high between two lows) in the case of very strong waves
1075 if (buffer[dataloc] > low && buffer[dataloc+clk/4] <= low) {
1076 for(i=0; i < clk/4; ++i) {
1077 buffer[dataloc+i] = buffer[dataloc+clk/4];
1078 }
1079 }
1080 if (firstrun) {
1081 *stend = dataloc;
1082 *ststart = dataloc-(clk*4);
1083 firstrun=false;
1084 }
1085 for (i=0; i<datalen; ++i) {
1086 if (i+newloc < bufsize) {
1087 if (i+newloc < dataloc)
1088 buffer[i+newloc] = buffer[dataloc];
1089
1090 dataloc++;
1091 }
1092 }
1093 newloc += i;
1094 //skip next ST - we just assume it will be there from now on...
1095 if (g_debugMode==2) prnt("DEBUG STT: skipping STT at %d to %d", dataloc, dataloc+(clk*4));
1096 dataloc += clk*4;
1097 }
1098 *size = newloc;
1099 return true;
1100 }
1101 bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
1102 size_t ststart = 0, stend = 0;
1103 return DetectST_ext(buffer, size, foundclock, &ststart, &stend);
1104 }
1105
1106 //by marshmellow
1107 //take 11 10 01 11 00 and make 01100 ... miller decoding
1108 //check for phase errors - should never have half a 1 or 0 by itself and should never exceed 1111 or 0000 in a row
1109 //decodes miller encoded binary
1110 //NOTE askrawdemod will NOT demod miller encoded ask unless the clock is manually set to 1/2 what it is detected as!
1111 int millerRawDecode(uint8_t *BitStream, size_t *size, int invert) {
1112 if (*size < 16) return -1;
1113 uint16_t MaxBits = 512, errCnt = 0;
1114 size_t i, bitCnt=0;
1115 uint8_t alignCnt = 0, curBit = BitStream[0], alignedIdx = 0;
1116 uint8_t halfClkErr = 0;
1117 //find alignment, needs 4 1s or 0s to properly align
1118 for (i=1; i < *size-1; i++) {
1119 alignCnt = (BitStream[i] == curBit) ? alignCnt+1 : 0;
1120 curBit = BitStream[i];
1121 if (alignCnt == 4) break;
1122 }
1123 // for now error if alignment not found. later add option to run it with multiple offsets...
1124 if (alignCnt != 4) {
1125 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");
1126 return -1;
1127 }
1128 alignedIdx = (i-1) % 2;
1129 for (i=alignedIdx; i < *size-3; i+=2) {
1130 halfClkErr = (uint8_t)((halfClkErr << 1 | BitStream[i]) & 0xFF);
1131 if ( (halfClkErr & 0x7) == 5 || (halfClkErr & 0x7) == 2 || (i > 2 && (halfClkErr & 0x7) == 0) || (halfClkErr & 0x1F) == 0x1F) {
1132 errCnt++;
1133 BitStream[bitCnt++] = 7;
1134 continue;
1135 }
1136 BitStream[bitCnt++] = BitStream[i] ^ BitStream[i+1] ^ invert;
1137
1138 if (bitCnt > MaxBits) break;
1139 }
1140 *size = bitCnt;
1141 return errCnt;
1142 }
1143
1144 //by marshmellow
1145 //take 01 or 10 = 1 and 11 or 00 = 0
1146 //check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010
1147 //decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding
1148 int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert) {
1149 uint16_t bitnum = 0;
1150 uint16_t errCnt = 0;
1151 size_t i = offset;
1152 uint16_t MaxBits=512;
1153 //if not enough samples - error
1154 if (*size < 51) return -1;
1155 //check for phase change faults - skip one sample if faulty
1156 uint8_t offsetA = 1, offsetB = 1;
1157 for (; i<48; i+=2){
1158 if (BitStream[i+1]==BitStream[i+2]) offsetA=0;
1159 if (BitStream[i+2]==BitStream[i+3]) offsetB=0;
1160 }
1161 if (!offsetA && offsetB) offset++;
1162 for (i=offset; i<*size-3; i+=2){
1163 //check for phase error
1164 if (BitStream[i+1]==BitStream[i+2]) {
1165 BitStream[bitnum++]=7;
1166 errCnt++;
1167 }
1168 if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){
1169 BitStream[bitnum++]=1^invert;
1170 } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){
1171 BitStream[bitnum++]=invert;
1172 } else {
1173 BitStream[bitnum++]=7;
1174 errCnt++;
1175 }
1176 if(bitnum>MaxBits) break;
1177 }
1178 *size=bitnum;
1179 return errCnt;
1180 }
1181
1182 //by marshmellow
1183 //take 10 and 01 and manchester decode
1184 //run through 2 times and take least errCnt
1185 int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert, uint8_t *alignPos) {
1186 uint16_t bitnum=0, MaxBits = 512, errCnt = 0;
1187 size_t i, ii;
1188 uint16_t bestErr = 1000, bestRun = 0;
1189 if (*size < 16) return -1;
1190 //find correct start position [alignment]
1191 for (ii=0;ii<2;++ii){
1192 for (i=ii; i<*size-3; i+=2)
1193 if (BitStream[i]==BitStream[i+1])
1194 errCnt++;
1195
1196 if (bestErr>errCnt){
1197 bestErr=errCnt;
1198 bestRun=ii;
1199 }
1200 errCnt=0;
1201 }
1202 *alignPos=bestRun;
1203 //decode
1204 for (i=bestRun; i < *size-3; i+=2){
1205 if(BitStream[i] == 1 && (BitStream[i+1] == 0)){
1206 BitStream[bitnum++]=invert;
1207 } else if((BitStream[i] == 0) && BitStream[i+1] == 1){
1208 BitStream[bitnum++]=invert^1;
1209 } else {
1210 BitStream[bitnum++]=7;
1211 }
1212 if(bitnum>MaxBits) break;
1213 }
1214 *size=bitnum;
1215 return bestErr;
1216 }
1217
1218 //by marshmellow
1219 //demodulates strong heavily clipped samples
1220 int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low, int *startIdx)
1221 {
1222 *startIdx=0;
1223 size_t bitCnt=0, smplCnt=1, errCnt=0;
1224 bool waveHigh = (BinStream[0] >= high);
1225 for (size_t i=1; i < *size; i++){
1226 if (BinStream[i] >= high && waveHigh){
1227 smplCnt++;
1228 } else if (BinStream[i] <= low && !waveHigh){
1229 smplCnt++;
1230 } else { //transition
1231 if ((BinStream[i] >= high && !waveHigh) || (BinStream[i] <= low && waveHigh)){
1232 if (smplCnt > clk-(clk/4)-1) { //full clock
1233 if (smplCnt > clk + (clk/4)+1) { //too many samples
1234 errCnt++;
1235 if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
1236 BinStream[bitCnt++] = 7;
1237 } else if (waveHigh) {
1238 BinStream[bitCnt++] = invert;
1239 BinStream[bitCnt++] = invert;
1240 } else if (!waveHigh) {
1241 BinStream[bitCnt++] = invert ^ 1;
1242 BinStream[bitCnt++] = invert ^ 1;
1243 }
1244 if (*startIdx==0) *startIdx = i-clk;
1245 waveHigh = !waveHigh;
1246 smplCnt = 0;
1247 } else if (smplCnt > (clk/2) - (clk/4)-1) { //half clock
1248 if (waveHigh) {
1249 BinStream[bitCnt++] = invert;
1250 } else if (!waveHigh) {
1251 BinStream[bitCnt++] = invert ^ 1;
1252 }
1253 if (*startIdx==0) *startIdx = i-(clk/2);
1254 waveHigh = !waveHigh;
1255 smplCnt = 0;
1256 } else {
1257 smplCnt++;
1258 //transition bit oops
1259 }
1260 } else { //haven't hit new high or new low yet
1261 smplCnt++;
1262 }
1263 }
1264 }
1265 *size = bitCnt;
1266 return errCnt;
1267 }
1268
1269 //by marshmellow
1270 //attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester
1271 int askdemod_ext(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType, int *startIdx) {
1272 if (*size==0) return -1;
1273 int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default
1274 if (*clk==0 || start < 0) return -3;
1275 if (*invert != 1) *invert = 0;
1276 if (amp==1) askAmp(BinStream, *size);
1277 if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d, amp %d", *clk, start, amp);
1278
1279 //start pos from detect ask clock is 1/2 clock offset
1280 // NOTE: can be negative (demod assumes rest of wave was there)
1281 *startIdx = start - (*clk/2);
1282 uint8_t initLoopMax = 255;
1283 if (initLoopMax > *size) initLoopMax = *size;
1284 // Detect high and lows
1285 //25% clip in case highs and lows aren't clipped [marshmellow]
1286 int high, low;
1287 if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1)
1288 return -2; //just noise
1289
1290 size_t errCnt = 0;
1291 // if clean clipped waves detected run alternate demod
1292 if (DetectCleanAskWave(BinStream, *size, high, low)) {
1293 if (g_debugMode==2) prnt("DEBUG ASK: Clean Wave Detected - using clean wave demod");
1294 errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low, startIdx);
1295 if (askType) { //askman
1296 uint8_t alignPos = 0;
1297 errCnt = manrawdecode(BinStream, size, 0, &alignPos);
1298 *startIdx += *clk/2 * alignPos;
1299 if (g_debugMode) prnt("DEBUG ASK CLEAN: startIdx %i, alignPos %u", *startIdx, alignPos);
1300 return errCnt;
1301 } else { //askraw
1302 return errCnt;
1303 }
1304 }
1305 if (g_debugMode) prnt("DEBUG ASK WEAK: startIdx %i", *startIdx);
1306 if (g_debugMode==2) prnt("DEBUG ASK: Weak Wave Detected - using weak wave demod");
1307
1308 int lastBit; //set first clock check - can go negative
1309 size_t i, bitnum = 0; //output counter
1310 uint8_t midBit = 0;
1311 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
1312 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
1313 size_t MaxBits = 3072; //max bits to collect
1314 lastBit = start - *clk;
1315
1316 for (i = start; i < *size; ++i) {
1317 if (i-lastBit >= *clk-tol){
1318 if (BinStream[i] >= high) {
1319 BinStream[bitnum++] = *invert;
1320 } else if (BinStream[i] <= low) {
1321 BinStream[bitnum++] = *invert ^ 1;
1322 } else if (i-lastBit >= *clk+tol) {
1323 if (bitnum > 0) {
1324 if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
1325 BinStream[bitnum++]=7;
1326 errCnt++;
1327 }
1328 } else { //in tolerance - looking for peak
1329 continue;
1330 }
1331 midBit = 0;
1332 lastBit += *clk;
1333 } else if (i-lastBit >= (*clk/2-tol) && !midBit && !askType){
1334 if (BinStream[i] >= high) {
1335 BinStream[bitnum++] = *invert;
1336 } else if (BinStream[i] <= low) {
1337 BinStream[bitnum++] = *invert ^ 1;
1338 } else if (i-lastBit >= *clk/2+tol) {
1339 BinStream[bitnum] = BinStream[bitnum-1];
1340 bitnum++;
1341 } else { //in tolerance - looking for peak
1342 continue;
1343 }
1344 midBit = 1;
1345 }
1346 if (bitnum >= MaxBits) break;
1347 }
1348 *size = bitnum;
1349 return errCnt;
1350 }
1351
1352 int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType) {
1353 int start = 0;
1354 return askdemod_ext(BinStream, size, clk, invert, maxErr, amp, askType, &start);
1355 }
1356
1357 // by marshmellow - demodulate NRZ wave - requires a read with strong signal
1358 // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
1359 int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert, int *startIdx) {
1360 if (justNoise(dest, *size)) return -1;
1361 size_t clkStartIdx = 0;
1362 *clk = DetectNRZClock(dest, *size, *clk, &clkStartIdx);
1363 if (*clk==0) return -2;
1364 size_t i, gLen = 4096;
1365 if (gLen>*size) gLen = *size-20;
1366 int high, low;
1367 if (getHiLo(dest, gLen, &high, &low, 75, 75) < 1) return -3; //25% fuzz on high 25% fuzz on low
1368
1369 uint8_t bit=0;
1370 //convert wave samples to 1's and 0's
1371 for(i=20; i < *size-20; i++){
1372 if (dest[i] >= high) bit = 1;
1373 if (dest[i] <= low) bit = 0;
1374 dest[i] = bit;
1375 }
1376 //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit)
1377 size_t lastBit = 0;
1378 size_t numBits = 0;
1379 for(i=21; i < *size-20; i++) {
1380 //if transition detected or large number of same bits - store the passed bits
1381 if (dest[i] != dest[i-1] || (i-lastBit) == (10 * *clk)) {
1382 memset(dest+numBits, dest[i-1] ^ *invert, (i - lastBit + (*clk/4)) / *clk);
1383 numBits += (i - lastBit + (*clk/4)) / *clk;
1384 if (lastBit == 0) {
1385 *startIdx = i - (numBits * *clk);
1386 if (g_debugMode==2) prnt("DEBUG NRZ: startIdx %i", *startIdx);
1387 }
1388 lastBit = i-1;
1389 }
1390 }
1391 *size = numBits;
1392 return 0;
1393 }
1394
1395 //translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq])
1396 size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow, int *startIdx) {
1397 size_t last_transition = 0;
1398 size_t idx = 1;
1399 if (fchigh==0) fchigh=10;
1400 if (fclow==0) fclow=8;
1401 //set the threshold close to 0 (graph) or 128 std to avoid static
1402 size_t preLastSample = 0;
1403 size_t LastSample = 0;
1404 size_t currSample = 0;
1405 if ( size < 1024 ) return 0; // not enough samples
1406
1407 //find start of modulating data in trace
1408 idx = findModStart(dest, size, fchigh);
1409 // Need to threshold first sample
1410 if(dest[idx] < FSK_PSK_THRESHOLD) dest[0] = 0;
1411 else dest[0] = 1;
1412
1413 last_transition = idx;
1414 idx++;
1415 size_t numBits = 0;
1416 // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
1417 // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere
1418 // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
1419 // (could also be fc/5 && fc/7 for fsk1 = 4-9)
1420 for(; idx < size; idx++) {
1421 // threshold current value
1422 if (dest[idx] < FSK_PSK_THRESHOLD) dest[idx] = 0;
1423 else dest[idx] = 1;
1424
1425 // Check for 0->1 transition
1426 if (dest[idx-1] < dest[idx]) {
1427 preLastSample = LastSample;
1428 LastSample = currSample;
1429 currSample = idx-last_transition;
1430 if (currSample < (fclow-2)) { //0-5 = garbage noise (or 0-3)
1431 //do nothing with extra garbage
1432 } else if (currSample < (fchigh-1)) { //6-8 = 8 sample waves (or 3-6 = 5)
1433 //correct previous 9 wave surrounded by 8 waves (or 6 surrounded by 5)
1434 if (numBits > 1 && LastSample > (fchigh-2) && (preLastSample < (fchigh-1))){
1435 dest[numBits-1]=1;
1436 }
1437 dest[numBits++]=1;
1438 if (numBits > 0 && *startIdx==0) *startIdx = idx - fclow;
1439 } else if (currSample > (fchigh+1) && numBits < 3) { //12 + and first two bit = unusable garbage
1440 //do nothing with beginning garbage and reset.. should be rare..
1441 numBits = 0;
1442 } 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)
1443 dest[numBits++]=1;
1444 if (numBits > 0 && *startIdx==0) *startIdx = idx - fclow;
1445 } else { //9+ = 10 sample waves (or 6+ = 7)
1446 dest[numBits++]=0;
1447 if (numBits > 0 && *startIdx==0) *startIdx = idx - fchigh;
1448 }
1449 last_transition = idx;
1450 }
1451 }
1452 return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
1453 }
1454
1455 //translate 11111100000 to 10
1456 //rfLen = clock, fchigh = larger field clock, fclow = smaller field clock
1457 size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow, int *startIdx) {
1458 uint8_t lastval=dest[0];
1459 size_t idx=0;
1460 size_t numBits=0;
1461 uint32_t n=1;
1462 for( idx=1; idx < size; idx++) {
1463 n++;
1464 if (dest[idx]==lastval) continue; //skip until we hit a transition
1465
1466 //find out how many bits (n) we collected (use 1/2 clk tolerance)
1467 //if lastval was 1, we have a 1->0 crossing
1468 if (dest[idx-1]==1) {
1469 n = (n * fclow + rfLen/2) / rfLen;
1470 } else {// 0->1 crossing
1471 n = (n * fchigh + rfLen/2) / rfLen;
1472 }
1473 if (n == 0) n = 1;
1474
1475 //first transition - save startidx
1476 if (numBits == 0) {
1477 if (lastval == 1) { //high to low
1478 *startIdx += (fclow * idx) - (n*rfLen);
1479 if (g_debugMode==2) prnt("DEBUG FSK: startIdx %i, fclow*idx %i, n*rflen %u", *startIdx, fclow*(idx), n*rfLen);
1480 } else {
1481 *startIdx += (fchigh * idx) - (n*rfLen);
1482 if (g_debugMode==2) prnt("DEBUG FSK: startIdx %i, fchigh*idx %i, n*rflen %u", *startIdx, fchigh*(idx), n*rfLen);
1483 }
1484 }
1485
1486 //add to our destination the bits we collected
1487 memset(dest+numBits, dest[idx-1]^invert , n);
1488 numBits += n;
1489 n=0;
1490 lastval=dest[idx];
1491 }//end for
1492 // if valid extra bits at the end were all the same frequency - add them in
1493 if (n > rfLen/fchigh) {
1494 if (dest[idx-2]==1) {
1495 n = (n * fclow + rfLen/2) / rfLen;
1496 } else {
1497 n = (n * fchigh + rfLen/2) / rfLen;
1498 }
1499 memset(dest+numBits, dest[idx-1]^invert , n);
1500 numBits += n;
1501 }
1502 return numBits;
1503 }
1504
1505 //by marshmellow (from holiman's base)
1506 // full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod)
1507 int fskdemod_ext(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow, int *startIdx) {
1508 // FSK demodulator
1509 size = fsk_wave_demod(dest, size, fchigh, fclow, startIdx);
1510 size = aggregate_bits(dest, size, rfLen, invert, fchigh, fclow, startIdx);
1511 return size;
1512 }
1513
1514 int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow) {
1515 int startIdx=0;
1516 return fskdemod_ext(dest, size, rfLen, invert, fchigh, fclow, &startIdx);
1517 }
1518
1519 // by marshmellow
1520 // convert psk1 demod to psk2 demod
1521 // only transition waves are 1s
1522 void psk1TOpsk2(uint8_t *BitStream, size_t size) {
1523 size_t i=1;
1524 uint8_t lastBit=BitStream[0];
1525 for (; i<size; i++){
1526 if (BitStream[i]==7){
1527 //ignore errors
1528 } else if (lastBit!=BitStream[i]){
1529 lastBit=BitStream[i];
1530 BitStream[i]=1;
1531 } else {
1532 BitStream[i]=0;
1533 }
1534 }
1535 return;
1536 }
1537
1538 // by marshmellow
1539 // convert psk2 demod to psk1 demod
1540 // from only transition waves are 1s to phase shifts change bit
1541 void psk2TOpsk1(uint8_t *BitStream, size_t size) {
1542 uint8_t phase=0;
1543 for (size_t i=0; i<size; i++){
1544 if (BitStream[i]==1){
1545 phase ^=1;
1546 }
1547 BitStream[i]=phase;
1548 }
1549 return;
1550 }
1551
1552 //by marshmellow - demodulate PSK1 wave
1553 //uses wave lengths (# Samples)
1554 int pskRawDemod_ext(uint8_t dest[], size_t *size, int *clock, int *invert, int *startIdx) {
1555 if (*size < 170) return -1;
1556
1557 uint8_t curPhase = *invert;
1558 uint8_t fc=0;
1559 size_t i=0, numBits=0, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0;
1560 uint16_t fullWaveLen=0, waveLenCnt=0, avgWaveVal;
1561 uint16_t errCnt=0, errCnt2=0;
1562
1563 *clock = DetectPSKClock(dest, *size, *clock, &firstFullWave, &curPhase, &fc);
1564 if (*clock == 0) return -1;
1565 //if clock detect found firstfullwave...
1566 uint16_t tol = fc/2;
1567 if (firstFullWave == 0) {
1568 //find start of modulating data in trace
1569 i = findModStart(dest, *size, fc);
1570 //find first phase shift
1571 firstFullWave = pskFindFirstPhaseShift(dest, *size, &curPhase, i, fc, &fullWaveLen);
1572 if (firstFullWave == 0) {
1573 // no phase shift detected - could be all 1's or 0's - doesn't matter where we start
1574 // so skip a little to ensure we are past any Start Signal
1575 firstFullWave = 160;
1576 memset(dest, curPhase, firstFullWave / *clock);
1577 } else {
1578 memset(dest, curPhase^1, firstFullWave / *clock);
1579 }
1580 } else {
1581 memset(dest, curPhase^1, firstFullWave / *clock);
1582 }
1583 //advance bits
1584 numBits += (firstFullWave / *clock);
1585 *startIdx = firstFullWave - (*clock * numBits)+2;
1586 //set start of wave as clock align
1587 lastClkBit = firstFullWave;
1588 if (g_debugMode==2) prnt("DEBUG PSK: firstFullWave: %u, waveLen: %u, startIdx %i",firstFullWave,fullWaveLen, *startIdx);
1589 if (g_debugMode==2) prnt("DEBUG PSK: clk: %d, lastClkBit: %u, fc: %u", *clock, lastClkBit,(unsigned int) fc);
1590 waveStart = 0;
1591 dest[numBits++] = curPhase; //set first read bit
1592 for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++) {
1593 //top edge of wave = start of new wave
1594 if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]) {
1595 if (waveStart == 0) {
1596 waveStart = i+1;
1597 waveLenCnt = 0;
1598 avgWaveVal = dest[i+1];
1599 } else { //waveEnd
1600 waveEnd = i+1;
1601 waveLenCnt = waveEnd-waveStart;
1602 if (waveLenCnt > fc) {
1603 //this wave is a phase shift
1604 //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc);
1605 if (i+1 >= lastClkBit + *clock - tol) { //should be a clock bit
1606 curPhase ^= 1;
1607 dest[numBits++] = curPhase;
1608 lastClkBit += *clock;
1609 } else if (i < lastClkBit+10+fc) {
1610 //noise after a phase shift - ignore
1611 } else { //phase shift before supposed to based on clock
1612 errCnt++;
1613 dest[numBits++] = 7;
1614 }
1615 } else if (i+1 > lastClkBit + *clock + tol + fc) {
1616 lastClkBit += *clock; //no phase shift but clock bit
1617 dest[numBits++] = curPhase;
1618 } else if (waveLenCnt < fc - 1) { //wave is smaller than field clock (shouldn't happen often)
1619 errCnt2++;
1620 if(errCnt2 > 101) return errCnt2;
1621 avgWaveVal += dest[i+1];
1622 continue;
1623 }
1624 avgWaveVal = 0;
1625 waveStart = i+1;
1626 }
1627 }
1628 avgWaveVal += dest[i+1];
1629 }
1630 *size = numBits;
1631 return errCnt;
1632 }
1633
1634 int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) {
1635 int startIdx = 0;
1636 return pskRawDemod_ext(dest, size, clock, invert, &startIdx);
1637 }
1638
1639 //**********************************************************************************************
1640 //-----------------Tag format detection section-------------------------------------------------
1641 //**********************************************************************************************
1642
1643 // by marshmellow
1644 // FSK Demod then try to locate an AWID ID
1645 int AWIDdemodFSK(uint8_t *dest, size_t *size) {
1646 //make sure buffer has enough data
1647 if (*size < 96*50) return -1;
1648
1649 if (justNoise(dest, *size)) return -2;
1650
1651 // FSK demodulator
1652 *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50
1653 if (*size < 96) return -3; //did we get a good demod?
1654
1655 uint8_t preamble[] = {0,0,0,0,0,0,0,1};
1656 size_t startIdx = 0;
1657 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
1658 if (errChk == 0) return -4; //preamble not found
1659 if (*size != 96) return -5;
1660 return (int)startIdx;
1661 }
1662
1663 //by marshmellow
1664 //takes 1s and 0s and searches for EM410x format - output EM ID
1665 uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo)
1666 {
1667 //sanity checks
1668 if (*size < 64) return 0;
1669 if (BitStream[1]>1) return 0; //allow only 1s and 0s
1670
1671 // 111111111 bit pattern represent start of frame
1672 // include 0 in front to help get start pos
1673 uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1};
1674 uint8_t errChk = 0;
1675 uint8_t FmtLen = 10; // sets of 4 bits = end data
1676 *startIdx = 0;
1677 errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx);
1678 if ( errChk == 0 || (*size != 64 && *size != 128) ) return 0;
1679 if (*size == 128) FmtLen = 22; // 22 sets of 4 bits
1680
1681 //skip last 4bit parity row for simplicity
1682 *size = removeParity(BitStream, *startIdx + sizeof(preamble), 5, 0, FmtLen * 5);
1683 if (*size == 40) { // std em410x format
1684 *hi = 0;
1685 *lo = ((uint64_t)(bytebits_to_byte(BitStream, 8)) << 32) | (bytebits_to_byte(BitStream + 8, 32));
1686 } else if (*size == 88) { // long em format
1687 *hi = (bytebits_to_byte(BitStream, 24));
1688 *lo = ((uint64_t)(bytebits_to_byte(BitStream + 24, 32)) << 32) | (bytebits_to_byte(BitStream + 24 + 32, 32));
1689 } else {
1690 if (g_debugMode) prnt("Error removing parity: %u", *size);
1691 return 0;
1692 }
1693 return 1;
1694 }
1695
1696 // Ask/Biphase Demod then try to locate an ISO 11784/85 ID
1697 // BitStream must contain previously askrawdemod and biphasedemoded data
1698 int FDXBdemodBI(uint8_t *dest, size_t *size) {
1699 //make sure buffer has enough data
1700 if (*size < 128) return -1;
1701
1702 size_t startIdx = 0;
1703 uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,1};
1704
1705 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
1706 if (errChk == 0) return -2; //preamble not found
1707 if (*size != 128) return -3; //wrong size for fdxb
1708 //return start position
1709 return (int)startIdx;
1710 }
1711
1712 // by marshmellow
1713 // demod gProxIIDemod
1714 // error returns as -x
1715 // success returns start position in BitStream
1716 // BitStream must contain previously askrawdemod and biphasedemoded data
1717 int gProxII_Demod(uint8_t BitStream[], size_t *size) {
1718 size_t startIdx=0;
1719 uint8_t preamble[] = {1,1,1,1,1,0};
1720
1721 uint8_t errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, &startIdx);
1722 if (errChk == 0) return -3; //preamble not found
1723 if (*size != 96) return -2; //should have found 96 bits
1724 //check first 6 spacer bits to verify format
1725 if (!BitStream[startIdx+5] && !BitStream[startIdx+10] && !BitStream[startIdx+15] && !BitStream[startIdx+20] && !BitStream[startIdx+25] && !BitStream[startIdx+30]){
1726 //confirmed proper separator bits found
1727 //return start position
1728 return (int) startIdx;
1729 }
1730 return -5; //spacer bits not found - not a valid gproxII
1731 }
1732
1733 // loop to get raw HID waveform then FSK demodulate the TAG ID from it
1734 int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo) {
1735 if (justNoise(dest, *size)) return -1;
1736
1737 size_t numStart=0, size2=*size, startIdx=0;
1738 // FSK demodulator
1739 *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
1740 if (*size < 96*2) return -2;
1741 // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
1742 uint8_t preamble[] = {0,0,0,1,1,1,0,1};
1743 // find bitstring in array
1744 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
1745 if (errChk == 0) return -3; //preamble not found
1746
1747 numStart = startIdx + sizeof(preamble);
1748 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
1749 for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
1750 if (dest[idx] == dest[idx+1]){
1751 return -4; //not manchester data
1752 }
1753 *hi2 = (*hi2<<1)|(*hi>>31);
1754 *hi = (*hi<<1)|(*lo>>31);
1755 //Then, shift in a 0 or one into low
1756 if (dest[idx] && !dest[idx+1]) // 1 0
1757 *lo=(*lo<<1)|1;
1758 else // 0 1
1759 *lo=(*lo<<1)|0;
1760 }
1761 return (int)startIdx;
1762 }
1763
1764 int IOdemodFSK(uint8_t *dest, size_t size) {
1765 if (justNoise(dest, size)) return -1;
1766 //make sure buffer has data
1767 if (size < 66*64) return -2;
1768 // FSK demodulator
1769 size = fskdemod(dest, size, 64, 1, 10, 8); // FSK2a RF/64
1770 if (size < 65) return -3; //did we get a good demod?
1771 //Index map
1772 //0 10 20 30 40 50 60
1773 //| | | | | | |
1774 //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
1775 //-----------------------------------------------------------------------------
1776 //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
1777 //
1778 //XSF(version)facility:codeone+codetwo
1779 //Handle the data
1780 size_t startIdx = 0;
1781 uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,1};
1782 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), &size, &startIdx);
1783 if (errChk == 0) return -4; //preamble not found
1784
1785 if (!dest[startIdx+8] && dest[startIdx+17]==1 && dest[startIdx+26]==1 && dest[startIdx+35]==1 && dest[startIdx+44]==1 && dest[startIdx+53]==1){
1786 //confirmed proper separator bits found
1787 //return start position
1788 return (int) startIdx;
1789 }
1790 return -5;
1791 }
1792
1793 // redesigned by marshmellow adjusted from existing decode functions
1794 // indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
1795 int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert) {
1796 //26 bit 40134 format (don't know other formats)
1797 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};
1798 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};
1799 size_t startidx = 0;
1800 if (!preambleSearch(bitStream, preamble, sizeof(preamble), size, &startidx)){
1801 // if didn't find preamble try again inverting
1802 if (!preambleSearch(bitStream, preamble_i, sizeof(preamble_i), size, &startidx)) return -1;
1803 *invert ^= 1;
1804 }
1805 if (*size != 64 && *size != 224) return -2;
1806 if (*invert==1)
1807 for (size_t i = startidx; i < *size + startidx; i++)
1808 bitStream[i] ^= 1;
1809
1810 return (int) startidx;
1811 }
1812
1813 // loop to get raw paradox waveform then FSK demodulate the TAG ID from it
1814 int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo) {
1815 if (justNoise(dest, *size)) return -1;
1816
1817 size_t numStart=0, size2=*size, startIdx=0;
1818 // FSK demodulator
1819 *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
1820 if (*size < 96) return -2;
1821
1822 // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
1823 uint8_t preamble[] = {0,0,0,0,1,1,1,1};
1824
1825 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
1826 if (errChk == 0) return -3; //preamble not found
1827
1828 numStart = startIdx + sizeof(preamble);
1829 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
1830 for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
1831 if (dest[idx] == dest[idx+1])
1832 return -4; //not manchester data
1833 *hi2 = (*hi2<<1)|(*hi>>31);
1834 *hi = (*hi<<1)|(*lo>>31);
1835 //Then, shift in a 0 or one into low
1836 if (dest[idx] && !dest[idx+1]) // 1 0
1837 *lo=(*lo<<1)|1;
1838 else // 0 1
1839 *lo=(*lo<<1)|0;
1840 }
1841 return (int)startIdx;
1842 }
1843
1844 // find presco preamble 0x10D in already demoded data
1845 int PrescoDemod(uint8_t *dest, size_t *size) {
1846 //make sure buffer has data
1847 if (*size < 64*2) return -2;
1848
1849 size_t startIdx = 0;
1850 uint8_t preamble[] = {1,0,0,0,0,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0};
1851 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
1852 if (errChk == 0) return -4; //preamble not found
1853 //return start position
1854 return (int) startIdx;
1855 }
1856
1857 // by marshmellow
1858 // FSK Demod then try to locate a Farpointe Data (pyramid) ID
1859 int PyramiddemodFSK(uint8_t *dest, size_t *size) {
1860 //make sure buffer has data
1861 if (*size < 128*50) return -5;
1862
1863 //test samples are not just noise
1864 if (justNoise(dest, *size)) return -1;
1865
1866 // FSK demodulator
1867 *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50
1868 if (*size < 128) return -2; //did we get a good demod?
1869
1870 uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
1871 size_t startIdx = 0;
1872 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
1873 if (errChk == 0) return -4; //preamble not found
1874 if (*size != 128) return -3;
1875 return (int)startIdx;
1876 }
1877
1878 // by marshmellow
1879 // find viking preamble 0xF200 in already demoded data
1880 int VikingDemod_AM(uint8_t *dest, size_t *size) {
1881 //make sure buffer has data
1882 if (*size < 64*2) return -2;
1883
1884 size_t startIdx = 0;
1885 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};
1886 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
1887 if (errChk == 0) return -4; //preamble not found
1888 uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^ bytebits_to_byte(dest+startIdx+8,8) ^ bytebits_to_byte(dest+startIdx+16,8)
1889 ^ bytebits_to_byte(dest+startIdx+24,8) ^ bytebits_to_byte(dest+startIdx+32,8) ^ bytebits_to_byte(dest+startIdx+40,8)
1890 ^ bytebits_to_byte(dest+startIdx+48,8) ^ bytebits_to_byte(dest+startIdx+56,8);
1891 if ( checkCalc != 0xA8 ) return -5;
1892 if (*size != 64) return -6;
1893 //return start position
1894 return (int) startIdx;
1895 }
1896
1897 // by iceman
1898 // find Visa2000 preamble in already demoded data
1899 int Visa2kDemod_AM(uint8_t *dest, size_t *size) {
1900 if (*size < 96) return -1; //make sure buffer has data
1901 size_t startIdx = 0;
1902 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};
1903 if (preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx) == 0)
1904 return -2; //preamble not found
1905 if (*size != 96) return -3; //wrong demoded size
1906 //return start position
1907 return (int)startIdx;
1908 }
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