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CHG: 'lf em4x' - the em4x50 demod didn't calc ASKDemod_ext with a refenence bool.
[proxmark3-svn] / common / lfdemod.c
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eb191de6 1//-----------------------------------------------------------------------------
ba1a299c 2// Copyright (C) 2014
eb191de6 3//
4// This code is licensed to you under the terms of the GNU GPL, version 2 or,
5// at your option, any later version. See the LICENSE.txt file for the text of
6// the license.
7//-----------------------------------------------------------------------------
1e090a61 8// Low frequency demod/decode commands
eb191de6 9//-----------------------------------------------------------------------------
eb191de6 10#include "lfdemod.h"
6426f6ba 11
a126332a 12//un_comment to allow debug print calls when used not on device
6426f6ba 13void dummy(char *fmt, ...){}
14
e977fb0d 15
6426f6ba 16#ifndef ON_DEVICE
e977fb0d 17# include "ui.h"
18# include "cmdparser.h"
19# include "cmddata.h"
20# define prnt PrintAndLog
6426f6ba 21#else
a126332a 22 uint8_t g_debugMode=0;
e977fb0d 23# define prnt dummy
6426f6ba 24#endif
6426f6ba 25
2dcf60f3 26//test samples are not just noise
27uint8_t justNoise(uint8_t *bits, size_t size) {
28 #define THRESHOLD 123
29 uint8_t val = 1;
30 for(size_t idx=0; idx < size && val ;idx++)
31 val = bits[idx] < THRESHOLD;
32 return val;
a1d17964 33}
34
1e090a61 35//by marshmellow
872e3d4d 36//get high and low values of a wave with passed in fuzz factor. also return noise test = 1 for passed or 0 for only noise
1e090a61 37int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi, uint8_t fuzzLo)
38{
39 *high=0;
40 *low=255;
41 // get high and low thresholds
2eec55c8 42 for (size_t i=0; i < size; i++){
1e090a61 43 if (BitStream[i] > *high) *high = BitStream[i];
44 if (BitStream[i] < *low) *low = BitStream[i];
45 }
46 if (*high < 123) return -1; // just noise
75cbbe9a 47 *high = ((*high-128)*fuzzHi + 12800)/100;
48 *low = ((*low-128)*fuzzLo + 12800)/100;
1e090a61 49 return 1;
50}
51
a1d17964 52// by marshmellow
53// pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType
54// returns 1 if passed
55uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType)
56{
57 uint8_t ans = 0;
58 for (uint8_t i = 0; i < bitLen; i++){
59 ans ^= ((bits >> i) & 1);
60 }
a38f5a07 61 //prnt("DEBUG: ans: %d, ptype: %d",ans,pType);
a1d17964 62 return (ans == pType);
63}
64
a126332a 65//by marshmellow
66// takes a array of binary values, start position, length of bits per parity (includes parity bit),
c728b2b4 67// Parity Type (1 for odd; 0 for even; 2 for Always 1's; 3 for Always 0's), and binary Length (length to run)
a126332a 68size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen)
69{
70 uint32_t parityWd = 0;
71 size_t j = 0, bitCnt = 0;
c08c796e 72 for (int word = 0; word < (bLen); word += pLen){
a126332a 73 for (int bit=0; bit < pLen; bit++){
74 parityWd = (parityWd << 1) | BitStream[startIdx+word+bit];
75 BitStream[j++] = (BitStream[startIdx+word+bit]);
76 }
77 j--; // overwrite parity with next data
78 // if parity fails then return 0
c728b2b4 79 switch (pType) {
11dee3d5 80 case 3: if (BitStream[j]==1) { return 0; } break; //should be 0 spacer bit
81 case 2: if (BitStream[j]==0) { return 0; } break; //should be 1 spacer bit
3c654208 82 default: if (parityTest(parityWd, pLen, pType) == 0) { return 0; } break; //test parity
a126332a 83 }
c08c796e 84 bitCnt += (pLen-1);
a126332a 85 parityWd = 0;
86 }
87 // if we got here then all the parities passed
88 //return ID start index and size
89 return bitCnt;
90}
91
92// by marshmellow
93// takes a array of binary values, length of bits per parity (includes parity bit),
0d2c5909 94// Parity Type (1 for odd; 0 for even; 2 Always 1's; 3 Always 0's), and binary Length (length to run)
c728b2b4 95// Make sure *dest is long enough to store original sourceLen + #_of_parities_to_be_added
a126332a 96size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t pLen, uint8_t pType)
97{
98 uint32_t parityWd = 0;
99 size_t j = 0, bitCnt = 0;
100 for (int word = 0; word < sourceLen; word+=pLen-1) {
101 for (int bit=0; bit < pLen-1; bit++){
102 parityWd = (parityWd << 1) | BitSource[word+bit];
103 dest[j++] = (BitSource[word+bit]);
104 }
0d2c5909 105
a126332a 106 // if parity fails then return 0
0d2c5909 107 switch (pType) {
108 case 3: dest[j++]=0; break; // marker bit which should be a 0
109 case 2: dest[j++]=1; break; // marker bit which should be a 1
110 default:
111 dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1;
112 break;
a126332a 113 }
114 bitCnt += pLen;
115 parityWd = 0;
116 }
117 // if we got here then all the parities passed
118 //return ID start index and size
119 return bitCnt;
120}
121
122uint32_t bytebits_to_byte(uint8_t *src, size_t numbits)
123{
124 uint32_t num = 0;
0d2c5909 125 for(int i = 0 ; i < numbits ; i++) {
a126332a 126 num = (num << 1) | (*src);
127 src++;
128 }
129 return num;
130}
131
132//least significant bit first
133uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits)
134{
135 uint32_t num = 0;
6b6815bc 136 for(int i = 0 ; i < numbits ; i++) {
a126332a 137 num = (num << 1) | *(src + (numbits-(i+1)));
138 }
139 return num;
140}
141
a1d17964 142//by marshmellow
2147c307 143//search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length
a1d17964 144uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx)
145{
5735cfa5 146 // Sanity check. If preamble length is bigger than bitstream length.
147 if ( *size <= pLen ) return 0;
148
56d0fb8e 149 uint8_t foundCnt = 0;
150 for (int idx = 0; idx < *size - pLen; idx++){
e0165dcf 151 if (memcmp(BitStream+idx, preamble, pLen) == 0){
152 //first index found
153 foundCnt++;
154 if (foundCnt == 1){
155 *startIdx = idx;
156 }
157 if (foundCnt == 2){
158 *size = idx - *startIdx;
159 return 1;
160 }
161 }
162 }
163 return 0;
a1d17964 164}
165
2147c307 166//by marshmellow
167//takes 1s and 0s and searches for EM410x format - output EM ID
da1f16d6 168int Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo)
2147c307 169{
e0165dcf 170 //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
171 // otherwise could be a void with no arguments
172 //set defaults
173 uint32_t i = 0;
da1f16d6 174 if (BitStream[1]>1) return -1; //allow only 1s and 0s
2767fc02 175
e0165dcf 176 // 111111111 bit pattern represent start of frame
177 // include 0 in front to help get start pos
178 uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1};
179 uint32_t idx = 0;
180 uint32_t parityBits = 0;
181 uint8_t errChk = 0;
182 uint8_t FmtLen = 10;
183 *startIdx = 0;
184 errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx);
da1f16d6 185 if (errChk == 0 ) return -4;
186 if (*size < 64) return -3;
e0165dcf 187 if (*size > 64) FmtLen = 22;
188 *startIdx += 1; //get rid of 0 from preamble
189 idx = *startIdx + 9;
190 for (i=0; i<FmtLen; i++){ //loop through 10 or 22 sets of 5 bits (50-10p = 40 bits or 88 bits)
191 parityBits = bytebits_to_byte(BitStream+(i*5)+idx,5);
2eec55c8 192 //check even parity - quit if failed
da1f16d6 193 if (parityTest(parityBits, 5, 0) == 0) return -5;
e0165dcf 194 //set uint64 with ID from BitStream
195 for (uint8_t ii=0; ii<4; ii++){
196 *hi = (*hi << 1) | (*lo >> 63);
197 *lo = (*lo << 1) | (BitStream[(i*5)+ii+idx]);
198 }
199 }
200 if (errChk != 0) return 1;
201 //skip last 5 bit parity test for simplicity.
202 // *size = 64 | 128;
203 return 0;
2147c307 204}
205
fef74fdc 206//by marshmellow
207//demodulates strong heavily clipped samples
23f0a7d8 208int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low)
209{
210 size_t bitCnt=0, smplCnt=0, errCnt=0;
211 uint8_t waveHigh = 0;
23f0a7d8 212 for (size_t i=0; i < *size; i++){
213 if (BinStream[i] >= high && waveHigh){
214 smplCnt++;
215 } else if (BinStream[i] <= low && !waveHigh){
216 smplCnt++;
217 } else { //transition
218 if ((BinStream[i] >= high && !waveHigh) || (BinStream[i] <= low && waveHigh)){
81e82dfe 219
23f0a7d8 220 if (smplCnt > clk-(clk/4)-1) { //full clock
a38f5a07 221 if (smplCnt > clk + (clk/4)+1) { //too many samples
23f0a7d8 222 errCnt++;
05164399 223 if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
81e82dfe 224 BinStream[bitCnt++] = 7;
23f0a7d8 225 } else if (waveHigh) {
226 BinStream[bitCnt++] = invert;
227 BinStream[bitCnt++] = invert;
228 } else if (!waveHigh) {
229 BinStream[bitCnt++] = invert ^ 1;
230 BinStream[bitCnt++] = invert ^ 1;
231 }
232 waveHigh ^= 1;
233 smplCnt = 0;
234 } else if (smplCnt > (clk/2) - (clk/4)-1) {
235 if (waveHigh) {
236 BinStream[bitCnt++] = invert;
237 } else if (!waveHigh) {
238 BinStream[bitCnt++] = invert ^ 1;
239 }
240 waveHigh ^= 1;
241 smplCnt = 0;
242 } else if (!bitCnt) {
243 //first bit
244 waveHigh = (BinStream[i] >= high);
245 smplCnt = 1;
246 } else {
247 smplCnt++;
248 //transition bit oops
249 }
250 } else { //haven't hit new high or new low yet
251 smplCnt++;
252 }
253 }
254 }
255 *size = bitCnt;
256 return errCnt;
257}
258
eb191de6 259//by marshmellow
fef74fdc 260void askAmp(uint8_t *BitStream, size_t size)
261{
9686a8d4 262 uint8_t last = 128;
263 for(size_t i = 1; i < size; ++i){
264 if (BitStream[i]-BitStream[i-1] >= 30) //large jump up
265 last = 255;
266 else if(BitStream[i-1] - BitStream[i] >= 20) //large jump down
267 last = 0;
268
269 BitStream[i] = last;
fef74fdc 270 }
fef74fdc 271}
272
273//by marshmellow
274//attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester
275int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType)
eb191de6 276{
fef74fdc 277 if (*size==0) return -1;
6e984446 278 int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default
bd09006a 279
2eec55c8 280 if (*clk==0 || start < 0) return -3;
fef74fdc 281 if (*invert != 1) *invert = 0;
282 if (amp==1) askAmp(BinStream, *size);
a38f5a07 283 if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d, amp %d", *clk, start, amp);
fef74fdc 284
2eec55c8 285 uint8_t initLoopMax = 255;
286 if (initLoopMax > *size) initLoopMax = *size;
ba1a299c 287 // Detect high and lows
fef74fdc 288 //25% clip in case highs and lows aren't clipped [marshmellow]
2eec55c8 289 int high, low;
fef74fdc 290 if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1)
291 return -2; //just noise
ba1a299c 292
fef74fdc 293 size_t errCnt = 0;
23f0a7d8 294 // if clean clipped waves detected run alternate demod
295 if (DetectCleanAskWave(BinStream, *size, high, low)) {
05164399 296 if (g_debugMode==2) prnt("DEBUG ASK: Clean Wave Detected - using clean wave demod");
fef74fdc 297 errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
298 if (askType) //askman
299 return manrawdecode(BinStream, size, 0);
81e82dfe 300 //askraw
301 return errCnt;
23f0a7d8 302 }
05164399 303 if (g_debugMode==2) prnt("DEBUG ASK: Weak Wave Detected - using weak wave demod");
23f0a7d8 304
fef74fdc 305 int lastBit; //set first clock check - can go negative
306 size_t i, bitnum = 0; //output counter
307 uint8_t midBit = 0;
2eec55c8 308 uint8_t tol = 0; //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave
fef74fdc 309 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
05164399 310 size_t MaxBits = 3072; //max bits to collect
6e984446 311 lastBit = start - *clk;
fef74fdc 312
6e984446 313 for (i = start; i < *size; ++i) {
fef74fdc 314 if (i-lastBit >= *clk-tol){
315 if (BinStream[i] >= high) {
316 BinStream[bitnum++] = *invert;
317 } else if (BinStream[i] <= low) {
318 BinStream[bitnum++] = *invert ^ 1;
319 } else if (i-lastBit >= *clk+tol) {
320 if (bitnum > 0) {
05164399 321 if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
fef74fdc 322 BinStream[bitnum++]=7;
323 errCnt++;
324 }
325 } else { //in tolerance - looking for peak
326 continue;
327 }
328 midBit = 0;
2eec55c8 329 lastBit += *clk;
fef74fdc 330 } else if (i-lastBit >= (*clk/2-tol) && !midBit && !askType){
331 if (BinStream[i] >= high) {
332 BinStream[bitnum++] = *invert;
333 } else if (BinStream[i] <= low) {
334 BinStream[bitnum++] = *invert ^ 1;
335 } else if (i-lastBit >= *clk/2+tol) {
336 BinStream[bitnum] = BinStream[bitnum-1];
337 bitnum++;
338 } else { //in tolerance - looking for peak
339 continue;
340 }
341 midBit = 1;
2eec55c8 342 }
343 if (bitnum >= MaxBits) break;
ba1a299c 344 }
2eec55c8 345 *size = bitnum;
6e984446 346 return errCnt;
eb191de6 347}
eb191de6 348//by marshmellow
349//take 10 and 01 and manchester decode
350//run through 2 times and take least errCnt
81e82dfe 351int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert){
5f5b83b7 352 int errCnt = 0, bestErr = 1000;
353 uint16_t bitnum = 0, MaxBits = 512, bestRun = 0;
81e82dfe 354 size_t i, k;
fef74fdc 355 if (*size < 16) return -1;
2767fc02 356 //find correct start position [alignment]
81e82dfe 357 for (k=0; k < 2; ++k){
358 for (i=k; i<*size-3; i += 2)
359 if (BitStream[i] == BitStream[i+1])
ba1a299c 360 errCnt++;
2eec55c8 361
81e82dfe 362 if (bestErr > errCnt){
363 bestErr = errCnt;
364 bestRun = k;
ba1a299c 365 }
366 errCnt=0;
367 }
2767fc02 368 //decode
81e82dfe 369 for (i=bestRun; i < *size-3; i += 2){
370 if (BitStream[i] == 1 && (BitStream[i+1] == 0)){
371 BitStream[bitnum++] = invert;
372 } else if ((BitStream[i] == 0) && BitStream[i+1] == 1){
373 BitStream[bitnum++] = invert^1;
23f0a7d8 374 } else {
81e82dfe 375 BitStream[bitnum++] = 7;
ba1a299c 376 }
81e82dfe 377 if (bitnum>MaxBits) break;
ba1a299c 378 }
23f0a7d8 379 *size=bitnum;
2eec55c8 380 return bestErr;
f822a063 381}
382
1d0ccbe0 383uint32_t manchesterEncode2Bytes(uint16_t datain) {
384 uint32_t output = 0;
385 uint8_t curBit = 0;
386 for (uint8_t i=0; i<16; i++) {
387 curBit = (datain >> (15-i) & 1);
388 output |= (1<<(((15-i)*2)+curBit));
389 }
390 return output;
391}
392
fef74fdc 393//by marshmellow
394//encode binary data into binary manchester
395int ManchesterEncode(uint8_t *BitStream, size_t size)
396{
397 size_t modIdx=20000, i=0;
398 if (size>modIdx) return -1;
399 for (size_t idx=0; idx < size; idx++){
400 BitStream[idx+modIdx++] = BitStream[idx];
401 BitStream[idx+modIdx++] = BitStream[idx]^1;
402 }
403 for (; i<(size*2); i++){
404 BitStream[i] = BitStream[i+20000];
405 }
406 return i;
407}
408
f822a063 409//by marshmellow
2147c307 410//take 01 or 10 = 1 and 11 or 00 = 0
411//check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010
13d77ef9 412//decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding
1e090a61 413int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert)
f822a063 414{
2eec55c8 415 uint16_t bitnum = 0;
416 uint16_t errCnt = 0;
417 size_t i = offset;
2147c307 418 uint16_t MaxBits=512;
419 //if not enough samples - error
420 if (*size < 51) return -1;
421 //check for phase change faults - skip one sample if faulty
422 uint8_t offsetA = 1, offsetB = 1;
423 for (; i<48; i+=2){
424 if (BitStream[i+1]==BitStream[i+2]) offsetA=0;
425 if (BitStream[i+2]==BitStream[i+3]) offsetB=0;
426 }
427 if (!offsetA && offsetB) offset++;
428 for (i=offset; i<*size-3; i+=2){
429 //check for phase error
13d77ef9 430 if (BitStream[i+1]==BitStream[i+2]) {
2767fc02 431 BitStream[bitnum++]=7;
2147c307 432 errCnt++;
433 }
ba1a299c 434 if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){
1e090a61 435 BitStream[bitnum++]=1^invert;
ba1a299c 436 } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){
1e090a61 437 BitStream[bitnum++]=invert;
ba1a299c 438 } else {
2767fc02 439 BitStream[bitnum++]=7;
ba1a299c 440 errCnt++;
441 }
6de43508 442 if(bitnum>MaxBits) break;
ba1a299c 443 }
444 *size=bitnum;
445 return errCnt;
eb191de6 446}
447
fef74fdc 448// by marshmellow
11081e04 449// demod gProxIIDemod
450// error returns as -x
451// success returns start position in BitStream
452// BitStream must contain previously askrawdemod and biphasedemoded data
453int gProxII_Demod(uint8_t BitStream[], size_t *size)
454{
455 size_t startIdx=0;
456 uint8_t preamble[] = {1,1,1,1,1,0};
457
458 uint8_t errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, &startIdx);
459 if (errChk == 0) return -3; //preamble not found
460 if (*size != 96) return -2; //should have found 96 bits
461 //check first 6 spacer bits to verify format
462 if (!BitStream[startIdx+5] && !BitStream[startIdx+10] && !BitStream[startIdx+15] && !BitStream[startIdx+20] && !BitStream[startIdx+25] && !BitStream[startIdx+30]){
463 //confirmed proper separator bits found
464 //return start position
465 return (int) startIdx;
466 }
7fa7e812 467 return -5; //spacer bits not found - not a valid gproxII
11081e04 468}
469
7fa7e812 470//translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq])
f822a063 471size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow)
eb191de6 472{
2eec55c8 473 size_t last_transition = 0;
474 size_t idx = 1;
ac3ba7ee 475 //uint32_t maxVal=0;
ba1a299c 476 if (fchigh==0) fchigh=10;
477 if (fclow==0) fclow=8;
84871873 478 //set the threshold close to 0 (graph) or 128 std to avoid static
479 uint8_t threshold_value = 123;
ac2df346 480 size_t preLastSample = 0;
481 size_t LastSample = 0;
482 size_t currSample = 0;
ba1a299c 483 // sync to first lo-hi transition, and threshold
484
485 // Need to threshold first sample
6426f6ba 486 // skip 160 samples to allow antenna/samples to settle
487 if(dest[160] < threshold_value) dest[0] = 0;
ba1a299c 488 else dest[0] = 1;
489
490 size_t numBits = 0;
491 // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
cd0bed3c 492 // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere
ba1a299c 493 // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
7fa7e812 494 // (could also be fc/5 && fc/7 for fsk1 = 4-9)
6426f6ba 495 for(idx = 161; idx < size-20; idx++) {
ba1a299c 496 // threshold current value
497
498 if (dest[idx] < threshold_value) dest[idx] = 0;
499 else dest[idx] = 1;
500
501 // Check for 0->1 transition
7fa7e812 502 if (dest[idx-1] < dest[idx]) {
ac2df346 503 preLastSample = LastSample;
504 LastSample = currSample;
505 currSample = idx-last_transition;
6426f6ba 506 if (currSample < (fclow-2)){ //0-5 = garbage noise (or 0-3)
ba1a299c 507 //do nothing with extra garbage
7fa7e812 508 } else if (currSample < (fchigh-1)) { //6-8 = 8 sample waves (or 3-6 = 5)
509 //correct previous 9 wave surrounded by 8 waves (or 6 surrounded by 5)
6426f6ba 510 if (LastSample > (fchigh-2) && (preLastSample < (fchigh-1) || preLastSample == 0 )){
7fa7e812 511 dest[numBits-1]=1;
ac2df346 512 }
2eec55c8 513 dest[numBits++]=1;
ac2df346 514
7fa7e812 515 } else if (currSample > (fchigh) && !numBits) { //12 + and first bit = unusable garbage
13d77ef9 516 //do nothing with beginning garbage
7fa7e812 517 } 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)
ac2df346 518 dest[numBits++]=1;
7fa7e812 519 } else { //9+ = 10 sample waves (or 6+ = 7)
2eec55c8 520 dest[numBits++]=0;
ba1a299c 521 }
522 last_transition = idx;
ba1a299c 523 }
524 }
525 return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
eb191de6 526}
527
ba1a299c 528//translate 11111100000 to 10
7fa7e812 529//rfLen = clock, fchigh = larger field clock, fclow = smaller field clock
2eec55c8 530size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen,
e0165dcf 531 uint8_t invert, uint8_t fchigh, uint8_t fclow)
eb191de6 532{
ba1a299c 533 uint8_t lastval=dest[0];
2eec55c8 534 size_t idx=0;
ba1a299c 535 size_t numBits=0;
536 uint32_t n=1;
ba1a299c 537 for( idx=1; idx < size; idx++) {
13d77ef9 538 n++;
a38f5a07 539 if (dest[idx]==lastval) continue; //skip until we hit a transition
2eec55c8 540
7fa7e812 541 //find out how many bits (n) we collected
ba1a299c 542 //if lastval was 1, we have a 1->0 crossing
13d77ef9 543 if (dest[idx-1]==1) {
75cbbe9a 544 n = (n * fclow + rfLen/2) / rfLen;
13d77ef9 545 } else {// 0->1 crossing
75cbbe9a 546 n = (n * fchigh + rfLen/2) / rfLen;
ba1a299c 547 }
548 if (n == 0) n = 1;
549
7fa7e812 550 //add to our destination the bits we collected
2eec55c8 551 memset(dest+numBits, dest[idx-1]^invert , n);
552 numBits += n;
ba1a299c 553 n=0;
554 lastval=dest[idx];
555 }//end for
13d77ef9 556 // if valid extra bits at the end were all the same frequency - add them in
75cbbe9a 557 if (n > rfLen/fchigh) {
13d77ef9 558 if (dest[idx-2]==1) {
75cbbe9a 559 n = (n * fclow + rfLen/2) / rfLen;
13d77ef9 560 } else {
75cbbe9a 561 n = (n * fchigh + rfLen/2) / rfLen;
13d77ef9 562 }
2eec55c8 563 memset(dest+numBits, dest[idx-1]^invert , n);
13d77ef9 564 numBits += n;
565 }
ba1a299c 566 return numBits;
eb191de6 567}
6426f6ba 568
eb191de6 569//by marshmellow (from holiman's base)
570// full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod)
f822a063 571int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow)
eb191de6 572{
ba1a299c 573 // FSK demodulator
574 size = fsk_wave_demod(dest, size, fchigh, fclow);
2eec55c8 575 size = aggregate_bits(dest, size, rfLen, invert, fchigh, fclow);
ba1a299c 576 return size;
eb191de6 577}
a1d17964 578
eb191de6 579// loop to get raw HID waveform then FSK demodulate the TAG ID from it
ec75f5c1 580int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo)
eb191de6 581{
e0165dcf 582 if (justNoise(dest, *size)) return -1;
583
337f7036 584 size_t numStart=0, size2 = *size, startIdx=0;
e0165dcf 585 // FSK demodulator
586 *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
2eec55c8 587 if (*size < 96*2) return -2;
e0165dcf 588 // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
589 uint8_t preamble[] = {0,0,0,1,1,1,0,1};
590 // find bitstring in array
591 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
592 if (errChk == 0) return -3; //preamble not found
593
594 numStart = startIdx + sizeof(preamble);
595 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
596 for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
597 if (dest[idx] == dest[idx+1]){
598 return -4; //not manchester data
599 }
600 *hi2 = (*hi2<<1)|(*hi>>31);
601 *hi = (*hi<<1)|(*lo>>31);
602 //Then, shift in a 0 or one into low
81b7e894 603 *lo <<= 1;
e0165dcf 604 if (dest[idx] && !dest[idx+1]) // 1 0
81b7e894 605 *lo |= 1;
e0165dcf 606 else // 0 1
81b7e894 607 *lo |= 0;
e0165dcf 608 }
609 return (int)startIdx;
eb191de6 610}
611
ec75f5c1 612// loop to get raw paradox waveform then FSK demodulate the TAG ID from it
a1d17964 613int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo)
ec75f5c1 614{
a1d17964 615 if (justNoise(dest, *size)) return -1;
616
337f7036 617 size_t numStart=0, size2 = *size, startIdx=0;
ec75f5c1 618 // FSK demodulator
a1d17964 619 *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
620 if (*size < 96) return -2;
ec75f5c1 621
a1d17964 622 // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
623 uint8_t preamble[] = {0,0,0,0,1,1,1,1};
624
625 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
626 if (errChk == 0) return -3; //preamble not found
627
628 numStart = startIdx + sizeof(preamble);
629 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
630 for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
631 if (dest[idx] == dest[idx+1])
632 return -4; //not manchester data
633 *hi2 = (*hi2<<1)|(*hi>>31);
634 *hi = (*hi<<1)|(*lo>>31);
635 //Then, shift in a 0 or one into low
636 if (dest[idx] && !dest[idx+1]) // 1 0
637 *lo=(*lo<<1)|1;
638 else // 0 1
639 *lo=(*lo<<1)|0;
ec75f5c1 640 }
a1d17964 641 return (int)startIdx;
ec75f5c1 642}
643
eb191de6 644int IOdemodFSK(uint8_t *dest, size_t size)
645{
a1d17964 646 if (justNoise(dest, size)) return -1;
ba1a299c 647 //make sure buffer has data
a1d17964 648 if (size < 66*64) return -2;
ba1a299c 649 // FSK demodulator
a1d17964 650 size = fskdemod(dest, size, 64, 1, 10, 8); // FSK2a RF/64
651 if (size < 65) return -3; //did we get a good demod?
ba1a299c 652 //Index map
653 //0 10 20 30 40 50 60
654 //| | | | | | |
655 //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
656 //-----------------------------------------------------------------------------
657 //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
658 //
659 //XSF(version)facility:codeone+codetwo
660 //Handle the data
a1d17964 661 size_t startIdx = 0;
662 uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,1};
663 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), &size, &startIdx);
664 if (errChk == 0) return -4; //preamble not found
eb191de6 665
a1d17964 666 if (!dest[startIdx+8] && dest[startIdx+17]==1 && dest[startIdx+26]==1 && dest[startIdx+35]==1 && dest[startIdx+44]==1 && dest[startIdx+53]==1){
667 //confirmed proper separator bits found
668 //return start position
669 return (int) startIdx;
1e090a61 670 }
a1d17964 671 return -5;
1e090a61 672}
673
70459879 674// by marshmellow
675// find viking preamble 0xF200 in already demoded data
676int VikingDemod_AM(uint8_t *dest, size_t *size) {
70459879 677 //make sure buffer has data
678 if (*size < 64*2) return -2;
70459879 679 size_t startIdx = 0;
680 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};
681 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
682 if (errChk == 0) return -4; //preamble not found
c0afa86f 683 uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^
684 bytebits_to_byte(dest+startIdx+8,8) ^
685 bytebits_to_byte(dest+startIdx+16,8) ^
686 bytebits_to_byte(dest+startIdx+24,8) ^
687 bytebits_to_byte(dest+startIdx+32,8) ^
688 bytebits_to_byte(dest+startIdx+40,8) ^
689 bytebits_to_byte(dest+startIdx+48,8) ^
690 bytebits_to_byte(dest+startIdx+56,8);
691 if ( checkCalc != 0xA8 ) return -5;
57c7b44b 692 if (*size != 64) return -6;
70459879 693 //return start position
deba67ab 694 return (int)startIdx;
70459879 695}
696
5daad826 697// by iceman
698// find Visa2000 preamble in already demoded data
699int Visa2kDemod_AM(uint8_t *dest, size_t *size) {
371a40bf 700 if (*size < 96) return -1; //make sure buffer has data
5daad826 701 size_t startIdx = 0;
702 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};
703 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
704 if (errChk == 0) return -2; //preamble not found
705 if (*size != 96) return -3; //wrong demoded size
706 //return start position
deba67ab 707 return (int)startIdx;
5daad826 708}
207fc33a 709// by iceman
710// find Noralsy preamble in already demoded data
711int NoralsyDemod_AM(uint8_t *dest, size_t *size) {
7d269265 712 if (*size < 96) return -1; //make sure buffer has data
207fc33a 713 size_t startIdx = 0;
714 uint8_t preamble[] = {1,0,1,1,1,0,1,1,0,0,0,0};
715 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
716 if (errChk == 0) return -2; //preamble not found
717 if (*size != 96) return -3; //wrong demoded size
718 //return start position
deba67ab 719 return (int)startIdx;
207fc33a 720}
4469412e 721// find presco preamble 0x10D in already demoded data
722int PrescoDemod(uint8_t *dest, size_t *size) {
d48175d4 723 if (*size < 128*2) return -1; //make sure buffer has data
4469412e 724 size_t startIdx = 0;
d48175d4 725 uint8_t preamble[] = {0,0,0,1,0,0,0,0,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0};
4469412e 726 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
d48175d4 727 if (errChk == 0) return -2; //preamble not found
728 if (*size != 128) return -3; //wrong demoded size
4469412e 729 //return start position
deba67ab 730 return (int)startIdx;
4469412e 731}
732
615f21dd 733// Ask/Biphase Demod then try to locate an ISO 11784/85 ID
0df669a2 734// BitStream must contain previously askrawdemod and biphasedemoded data
deba67ab 735int FDXBdemodBI(uint8_t *dest, size_t *size) {
736 if (*size < 128*2) return -1; //make sure buffer has enough data
615f21dd 737 size_t startIdx = 0;
0df669a2 738 uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,1};
615f21dd 739 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
0df669a2 740 if (errChk == 0) return -2; //preamble not found
deba67ab 741 if (*size != 128) return -3; //wrong demoded size
742 //return start position
615f21dd 743 return (int)startIdx;
744}
1e090a61 745
6c283951 746// ASK/Diphase fc/64 (inverted Biphase)
747// Note: this i s not a demod, this is only a detection
748// the parameter *dest needs to be demoded before call
deba67ab 749// 0xFFFF preamble, 64bits
6c283951 750int JablotronDemod(uint8_t *dest, size_t *size){
deba67ab 751 if (*size < 64*2) return -1; //make sure buffer has enough data
6c283951 752 size_t startIdx = 0;
deba67ab 753 uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0};
6c283951 754 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
deba67ab 755 if (errChk == 0) return -2; //preamble not found
756 if (*size != 64) return -3; // wrong demoded size
6c283951 757
29ce214c 758 uint8_t checkchksum = 0;
6c283951 759 for (int i=16; i < 56; i += 8) {
29ce214c 760 checkchksum += bytebits_to_byte(dest+startIdx+i,8);
6c283951 761 }
29ce214c 762 checkchksum ^= 0x3A;
29ce214c 763 uint8_t crc = bytebits_to_byte(dest+startIdx+56, 8);
deba67ab 764 if ( checkchksum != crc ) return -5;
6c283951 765 return (int)startIdx;
766}
767
1e090a61 768// by marshmellow
769// FSK Demod then try to locate an AWID ID
a1d17964 770int AWIDdemodFSK(uint8_t *dest, size_t *size)
1e090a61 771{
a1d17964 772 //make sure buffer has enough data
773 if (*size < 96*50) return -1;
774
775 if (justNoise(dest, *size)) return -2;
1e090a61 776
777 // FSK demodulator
a1d17964 778 *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50
779 if (*size < 96) return -3; //did we get a good demod?
780
781 uint8_t preamble[] = {0,0,0,0,0,0,0,1};
782 size_t startIdx = 0;
783 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
784 if (errChk == 0) return -4; //preamble not found
785 if (*size != 96) return -5;
786 return (int)startIdx;
1e090a61 787}
788
789// by marshmellow
6426f6ba 790// FSK Demod then try to locate a Farpointe Data (pyramid) ID
a1d17964 791int PyramiddemodFSK(uint8_t *dest, size_t *size)
1e090a61 792{
f3bf15e4 793 //make sure buffer has data
794 if (*size < 128*50) return -5;
a1d17964 795
f3bf15e4 796 //test samples are not just noise
797 if (justNoise(dest, *size)) return -1;
1e090a61 798
f3bf15e4 799 // FSK demodulator
800 *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50
801 if (*size < 128) return -2; //did we get a good demod?
a1d17964 802
c08c796e 803 uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1};
a1d17964 804 size_t startIdx = 0;
805 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
806 if (errChk == 0) return -4; //preamble not found
807 if (*size != 128) return -3;
808 return (int)startIdx;
1e090a61 809}
810
0cbe0cb8 811// find nedap preamble in already demoded data
56bbb25a 812int NedapDemod(uint8_t *dest, size_t *size) {
813 //make sure buffer has data
814 if (*size < 128) return -3;
96faed21 815
56bbb25a 816 size_t startIdx = 0;
15d49e82 817 //uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,0,0,0,1};
818 uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,0};
56bbb25a 819 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
820 if (errChk == 0) return -4; //preamble not found
56bbb25a 821 return (int) startIdx;
822}
823
3acac886 824// Find IDTEC PSK1, RF Preamble == 0x4944544B, Demodsize 64bits
825// by iceman
826int IdteckDemodPSK(uint8_t *dest, size_t *size) {
827 //make sure buffer has data
828 if (*size < 64*2) return -1;
829 size_t startIdx = 0;
830 uint8_t preamble[] = {0,1,0,0,1,0,0,1,0,1,0,0,0,1,0,0,0,1,0,1,0,1,0,0,0,1,0,0,1,0,1,1};
831 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
832 if (errChk == 0) return -2; //preamble not found
833 if (*size != 64) return -3; // wrong demoded size
834 return (int) startIdx;
835}
836
fef74fdc 837// by marshmellow
838// to detect a wave that has heavily clipped (clean) samples
cc15a118 839uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low)
6de43508 840{
6426f6ba 841 bool allArePeaks = true;
6de43508 842 uint16_t cntPeaks=0;
6426f6ba 843 size_t loopEnd = 512+160;
1fbf8956 844 if (loopEnd > size) loopEnd = size;
6426f6ba 845 for (size_t i=160; i<loopEnd; i++){
6de43508 846 if (dest[i]>low && dest[i]<high)
6426f6ba 847 allArePeaks = false;
6de43508 848 else
849 cntPeaks++;
850 }
6426f6ba 851 if (!allArePeaks){
852 if (cntPeaks > 300) return true;
6de43508 853 }
6426f6ba 854 return allArePeaks;
6de43508 855}
2eec55c8 856// by marshmellow
857// to help detect clocks on heavily clipped samples
cc15a118 858// based on count of low to low
859int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low)
13d77ef9 860{
cc15a118 861 uint8_t fndClk[] = {8,16,32,40,50,64,128};
862 size_t startwave;
6426f6ba 863 size_t i = 100;
cc15a118 864 size_t minClk = 255;
865 // get to first full low to prime loop and skip incomplete first pulse
866 while ((dest[i] < high) && (i < size))
867 ++i;
868 while ((dest[i] > low) && (i < size))
869 ++i;
870
871 // loop through all samples
872 while (i < size) {
873 // measure from low to low
874 while ((dest[i] > low) && (i < size))
875 ++i;
876 startwave= i;
877 while ((dest[i] < high) && (i < size))
878 ++i;
879 while ((dest[i] > low) && (i < size))
880 ++i;
881 //get minimum measured distance
882 if (i-startwave < minClk && i < size)
883 minClk = i - startwave;
13d77ef9 884 }
cc15a118 885 // set clock
a126332a 886 if (g_debugMode==2) prnt("DEBUG ASK: detectstrongASKclk smallest wave: %d",minClk);
cc15a118 887 for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
888 if (minClk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1)
889 return fndClk[clkCnt];
13d77ef9 890 }
cc15a118 891 return 0;
13d77ef9 892}
893
eb191de6 894// by marshmellow
895// not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)
896// maybe somehow adjust peak trimming value based on samples to fix?
6de43508 897// return start index of best starting position for that clock and return clock (by reference)
898int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
eb191de6 899{
6e984446 900 size_t i=1;
cc15a118 901 uint8_t clk[] = {255,8,16,32,40,50,64,100,128,255};
902 uint8_t clkEnd = 9;
2eec55c8 903 uint8_t loopCnt = 255; //don't need to loop through entire array...
6426f6ba 904 if (size <= loopCnt+60) return -1; //not enough samples
905 size -= 60; //sometimes there is a strange end wave - filter out this....
6e984446 906 //if we already have a valid clock
907 uint8_t clockFnd=0;
cc15a118 908 for (;i<clkEnd;++i)
909 if (clk[i] == *clock) clockFnd = i;
6e984446 910 //clock found but continue to find best startpos
e0165dcf 911
912 //get high and low peak
913 int peak, low;
2eec55c8 914 if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return -1;
e0165dcf 915
916 //test for large clean peaks
cc15a118 917 if (!clockFnd){
918 if (DetectCleanAskWave(dest, size, peak, low)==1){
919 int ans = DetectStrongAskClock(dest, size, peak, low);
a126332a 920 if (g_debugMode==2) prnt("DEBUG ASK: detectaskclk Clean Ask Wave Detected: clk %d",ans);
cc15a118 921 for (i=clkEnd-1; i>0; i--){
922 if (clk[i] == ans) {
923 *clock = ans;
924 //clockFnd = i;
925 return 0; // for strong waves i don't use the 'best start position' yet...
926 //break; //clock found but continue to find best startpos [not yet]
927 }
e0165dcf 928 }
929 }
930 }
2eec55c8 931 uint8_t ii;
932 uint8_t clkCnt, tol = 0;
933 uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
934 uint8_t bestStart[]={0,0,0,0,0,0,0,0,0};
935 size_t errCnt = 0;
936 size_t arrLoc, loopEnd;
6e984446 937
cc15a118 938 if (clockFnd>0) {
939 clkCnt = clockFnd;
940 clkEnd = clockFnd+1;
81e82dfe 941 } else {
942 clkCnt=1;
cc15a118 943 }
cc15a118 944
945 //test each valid clock from smallest to greatest to see which lines up
81e82dfe 946 for(; clkCnt < clkEnd; clkCnt++) {
947 if (clk[clkCnt] <= 32) {
e0165dcf 948 tol=1;
81e82dfe 949 } else {
e0165dcf 950 tol=0;
951 }
2767fc02 952 //if no errors allowed - keep start within the first clock
81e82dfe 953 if (!maxErr && size > clk[clkCnt]*2 + tol && clk[clkCnt]<128)
954 loopCnt = clk[clkCnt] * 2;
955
956 bestErr[clkCnt] = 1000;
957
6e984446 958 //try lining up the peaks by moving starting point (try first few clocks)
cc15a118 959 for (ii=0; ii < loopCnt; ii++){
2eec55c8 960 if (dest[ii] < peak && dest[ii] > low) continue;
961
81e82dfe 962 errCnt = 0;
2eec55c8 963 // now that we have the first one lined up test rest of wave array
964 loopEnd = ((size-ii-tol) / clk[clkCnt]) - 1;
965 for (i=0; i < loopEnd; ++i){
966 arrLoc = ii + (i * clk[clkCnt]);
967 if (dest[arrLoc] >= peak || dest[arrLoc] <= low){
968 }else if (dest[arrLoc-tol] >= peak || dest[arrLoc-tol] <= low){
969 }else if (dest[arrLoc+tol] >= peak || dest[arrLoc+tol] <= low){
970 }else{ //error no peak detected
971 errCnt++;
e0165dcf 972 }
973 }
cc15a118 974 //if we found no errors then we can stop here and a low clock (common clocks)
2eec55c8 975 // this is correct one - return this clock
81e82dfe 976 if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, err %d, startpos %d, endpos %d", clk[clkCnt], errCnt, ii, i);
977 if (errCnt==0 && clkCnt<7) {
cc15a118 978 if (!clockFnd) *clock = clk[clkCnt];
2eec55c8 979 return ii;
980 }
981 //if we found errors see if it is lowest so far and save it as best run
81e82dfe 982 if (errCnt < bestErr[clkCnt]) {
983 bestErr[clkCnt] = errCnt;
984 bestStart[clkCnt] = ii;
2eec55c8 985 }
e0165dcf 986 }
987 }
81e82dfe 988 uint8_t k;
989 uint8_t best = 0;
990 for (k=1; k < clkEnd; ++k){
991 if (bestErr[k] < bestErr[best]){
992 if (bestErr[k] == 0) bestErr[k]=1;
e0165dcf 993 // current best bit to error ratio vs new bit to error ratio
81e82dfe 994 if ( (size/clk[best])/bestErr[best] < (size/clk[k])/bestErr[k] ){
995 best = k;
e0165dcf 996 }
997 }
81e82dfe 998 if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, # Errors %d, Current Best Clk %d, bestStart %d", clk[k], bestErr[k], clk[best], bestStart[best]);
e0165dcf 999 }
cc15a118 1000 if (!clockFnd) *clock = clk[best];
e0165dcf 1001 return bestStart[best];
eb191de6 1002}
ba1a299c 1003
1004//by marshmellow
6de43508 1005//detect psk clock by reading each phase shift
1006// a phase shift is determined by measuring the sample length of each wave
1007int DetectPSKClock(uint8_t dest[], size_t size, int clock)
ba1a299c 1008{
e0165dcf 1009 uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock
1010 uint16_t loopCnt = 4096; //don't need to loop through entire array...
1011 if (size == 0) return 0;
6426f6ba 1012 if (size<loopCnt) loopCnt = size-20;
e0165dcf 1013
1014 //if we already have a valid clock quit
1015 size_t i=1;
1016 for (; i < 8; ++i)
1017 if (clk[i] == clock) return clock;
1018
1019 size_t waveStart=0, waveEnd=0, firstFullWave=0, lastClkBit=0;
1020 uint8_t clkCnt, fc=0, fullWaveLen=0, tol=1;
1021 uint16_t peakcnt=0, errCnt=0, waveLenCnt=0;
1022 uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
1023 uint16_t peaksdet[]={0,0,0,0,0,0,0,0,0};
2eec55c8 1024 fc = countFC(dest, size, 0);
1025 if (fc!=2 && fc!=4 && fc!=8) return -1;
a126332a 1026 if (g_debugMode==2) prnt("DEBUG PSK: FC: %d",fc);
e0165dcf 1027
1028 //find first full wave
6426f6ba 1029 for (i=160; i<loopCnt; i++){
e0165dcf 1030 if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
1031 if (waveStart == 0) {
1032 waveStart = i+1;
6426f6ba 1033 //prnt("DEBUG: waveStart: %d",waveStart);
e0165dcf 1034 } else {
1035 waveEnd = i+1;
6426f6ba 1036 //prnt("DEBUG: waveEnd: %d",waveEnd);
e0165dcf 1037 waveLenCnt = waveEnd-waveStart;
1038 if (waveLenCnt > fc){
1039 firstFullWave = waveStart;
1040 fullWaveLen=waveLenCnt;
1041 break;
1042 }
1043 waveStart=0;
1044 }
1045 }
1046 }
a126332a 1047 if (g_debugMode ==2) prnt("DEBUG PSK: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);
e0165dcf 1048
1049 //test each valid clock from greatest to smallest to see which lines up
1050 for(clkCnt=7; clkCnt >= 1 ; clkCnt--){
1051 lastClkBit = firstFullWave; //set end of wave as clock align
1052 waveStart = 0;
1053 errCnt=0;
1054 peakcnt=0;
a126332a 1055 if (g_debugMode == 2) prnt("DEBUG PSK: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit);
e0165dcf 1056
1057 for (i = firstFullWave+fullWaveLen-1; i < loopCnt-2; i++){
1058 //top edge of wave = start of new wave
1059 if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
1060 if (waveStart == 0) {
1061 waveStart = i+1;
1062 waveLenCnt=0;
1063 } else { //waveEnd
1064 waveEnd = i+1;
1065 waveLenCnt = waveEnd-waveStart;
1066 if (waveLenCnt > fc){
1067 //if this wave is a phase shift
a126332a 1068 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);
e0165dcf 1069 if (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit
1070 peakcnt++;
1071 lastClkBit+=clk[clkCnt];
1072 } else if (i<lastClkBit+8){
1073 //noise after a phase shift - ignore
1074 } else { //phase shift before supposed to based on clock
1075 errCnt++;
1076 }
1077 } else if (i+1 > lastClkBit + clk[clkCnt] + tol + fc){
1078 lastClkBit+=clk[clkCnt]; //no phase shift but clock bit
1079 }
1080 waveStart=i+1;
1081 }
1082 }
1083 }
1084 if (errCnt == 0){
1085 return clk[clkCnt];
1086 }
1087 if (errCnt <= bestErr[clkCnt]) bestErr[clkCnt]=errCnt;
1088 if (peakcnt > peaksdet[clkCnt]) peaksdet[clkCnt]=peakcnt;
1089 }
1090 //all tested with errors
1091 //return the highest clk with the most peaks found
1092 uint8_t best=7;
1093 for (i=7; i>=1; i--){
1094 if (peaksdet[i] > peaksdet[best]) {
1095 best = i;
1096 }
a126332a 1097 if (g_debugMode == 2) prnt("DEBUG PSK: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[i],peaksdet[i],bestErr[i],clk[best]);
e0165dcf 1098 }
1099 return clk[best];
ba1a299c 1100}
1101
6426f6ba 1102int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low){
1103 //find shortest transition from high to low
1104 size_t i = 0;
1105 size_t transition1 = 0;
1106 int lowestTransition = 255;
1107 bool lastWasHigh = false;
1108
1109 //find first valid beginning of a high or low wave
1110 while ((dest[i] >= peak || dest[i] <= low) && (i < size))
1111 ++i;
1112 while ((dest[i] < peak && dest[i] > low) && (i < size))
1113 ++i;
1114 lastWasHigh = (dest[i] >= peak);
1115
1116 if (i==size) return 0;
1117 transition1 = i;
1118
1119 for (;i < size; i++) {
1120 if ((dest[i] >= peak && !lastWasHigh) || (dest[i] <= low && lastWasHigh)) {
1121 lastWasHigh = (dest[i] >= peak);
1122 if (i-transition1 < lowestTransition) lowestTransition = i-transition1;
1123 transition1 = i;
1124 }
1125 }
6426f6ba 1126 if (lowestTransition == 255) lowestTransition = 0;
a126332a 1127 if (g_debugMode==2) prnt("DEBUG NRZ: detectstrongNRZclk smallest wave: %d",lowestTransition);
6426f6ba 1128 return lowestTransition;
1129}
1130
6de43508 1131//by marshmellow
1132//detect nrz clock by reading #peaks vs no peaks(or errors)
1133int DetectNRZClock(uint8_t dest[], size_t size, int clock)
ba1a299c 1134{
2eec55c8 1135 size_t i=0;
1136 uint8_t clk[]={8,16,32,40,50,64,100,128,255};
1137 size_t loopCnt = 4096; //don't need to loop through entire array...
e0165dcf 1138 if (size == 0) return 0;
6426f6ba 1139 if (size<loopCnt) loopCnt = size-20;
e0165dcf 1140 //if we already have a valid clock quit
1141 for (; i < 8; ++i)
1142 if (clk[i] == clock) return clock;
1143
1144 //get high and low peak
1145 int peak, low;
2eec55c8 1146 if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return 0;
e0165dcf 1147
6426f6ba 1148 int lowestTransition = DetectStrongNRZClk(dest, size-20, peak, low);
2eec55c8 1149 size_t ii;
e0165dcf 1150 uint8_t clkCnt;
1151 uint8_t tol = 0;
6426f6ba 1152 uint16_t smplCnt = 0;
1153 int16_t peakcnt = 0;
1154 int16_t peaksdet[] = {0,0,0,0,0,0,0,0};
1155 uint16_t maxPeak = 255;
1156 bool firstpeak = false;
e0165dcf 1157 //test for large clipped waves
1158 for (i=0; i<loopCnt; i++){
1159 if (dest[i] >= peak || dest[i] <= low){
6426f6ba 1160 if (!firstpeak) continue;
1161 smplCnt++;
e0165dcf 1162 } else {
6426f6ba 1163 firstpeak=true;
1164 if (smplCnt > 6 ){
1165 if (maxPeak > smplCnt){
1166 maxPeak = smplCnt;
1167 //prnt("maxPk: %d",maxPeak);
1168 }
1169 peakcnt++;
1170 //prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt);
1171 smplCnt=0;
e0165dcf 1172 }
e0165dcf 1173 }
1174 }
6426f6ba 1175 bool errBitHigh = 0;
1176 bool bitHigh = 0;
1177 uint8_t ignoreCnt = 0;
1178 uint8_t ignoreWindow = 4;
1179 bool lastPeakHigh = 0;
1180 int lastBit = 0;
e0165dcf 1181 peakcnt=0;
1182 //test each valid clock from smallest to greatest to see which lines up
1183 for(clkCnt=0; clkCnt < 8; ++clkCnt){
6426f6ba 1184 //ignore clocks smaller than smallest peak
1185 if (clk[clkCnt] < maxPeak - (clk[clkCnt]/4)) continue;
e0165dcf 1186 //try lining up the peaks by moving starting point (try first 256)
6426f6ba 1187 for (ii=20; ii < loopCnt; ++ii){
e0165dcf 1188 if ((dest[ii] >= peak) || (dest[ii] <= low)){
1189 peakcnt=0;
6426f6ba 1190 bitHigh = false;
1191 ignoreCnt = 0;
1192 lastBit = ii-clk[clkCnt];
1193 //loop through to see if this start location works
1194 for (i = ii; i < size-20; ++i) {
1195 //if we are at a clock bit
1196 if ((i >= lastBit + clk[clkCnt] - tol) && (i <= lastBit + clk[clkCnt] + tol)) {
1197 //test high/low
1198 if (dest[i] >= peak || dest[i] <= low) {
1199 //if same peak don't count it
1200 if ((dest[i] >= peak && !lastPeakHigh) || (dest[i] <= low && lastPeakHigh)) {
e0165dcf 1201 peakcnt++;
6426f6ba 1202 }
1203 lastPeakHigh = (dest[i] >= peak);
1204 bitHigh = true;
1205 errBitHigh = false;
1206 ignoreCnt = ignoreWindow;
1207 lastBit += clk[clkCnt];
1208 } else if (i == lastBit + clk[clkCnt] + tol) {
1209 lastBit += clk[clkCnt];
1210 }
1211 //else if not a clock bit and no peaks
1212 } else if (dest[i] < peak && dest[i] > low){
1213 if (ignoreCnt==0){
1214 bitHigh=false;
1215 if (errBitHigh==true) peakcnt--;
1216 errBitHigh=false;
1217 } else {
1218 ignoreCnt--;
1219 }
1220 // else if not a clock bit but we have a peak
1221 } else if ((dest[i]>=peak || dest[i]<=low) && (!bitHigh)) {
1222 //error bar found no clock...
1223 errBitHigh=true;
e0165dcf 1224 }
1225 }
1226 if(peakcnt>peaksdet[clkCnt]) {
1227 peaksdet[clkCnt]=peakcnt;
1228 }
1229 }
1230 }
1231 }
1232 int iii=7;
2eec55c8 1233 uint8_t best=0;
e0165dcf 1234 for (iii=7; iii > 0; iii--){
6426f6ba 1235 if ((peaksdet[iii] >= (peaksdet[best]-1)) && (peaksdet[iii] <= peaksdet[best]+1) && lowestTransition) {
1236 if (clk[iii] > (lowestTransition - (clk[iii]/8)) && clk[iii] < (lowestTransition + (clk[iii]/8))) {
1237 best = iii;
1238 }
1239 } else if (peaksdet[iii] > peaksdet[best]){
e0165dcf 1240 best = iii;
1241 }
a126332a 1242 if (g_debugMode==2) prnt("DEBUG NRZ: Clk: %d, peaks: %d, maxPeak: %d, bestClk: %d, lowestTrs: %d",clk[iii],peaksdet[iii],maxPeak, clk[best], lowestTransition);
e0165dcf 1243 }
6426f6ba 1244
e0165dcf 1245 return clk[best];
ba1a299c 1246}
1247
04d2721b 1248// by marshmellow
1249// convert psk1 demod to psk2 demod
1250// only transition waves are 1s
1251void psk1TOpsk2(uint8_t *BitStream, size_t size)
1252{
1253 size_t i=1;
1254 uint8_t lastBit=BitStream[0];
1255 for (; i<size; i++){
2767fc02 1256 if (BitStream[i]==7){
7a8a982b 1257 //ignore errors
1258 } else if (lastBit!=BitStream[i]){
04d2721b 1259 lastBit=BitStream[i];
1260 BitStream[i]=1;
1261 } else {
1262 BitStream[i]=0;
1263 }
1264 }
1265 return;
1266}
ba1a299c 1267
3bc66a96 1268// by marshmellow
1269// convert psk2 demod to psk1 demod
1270// from only transition waves are 1s to phase shifts change bit
1271void psk2TOpsk1(uint8_t *BitStream, size_t size)
1272{
712ebfa6 1273 uint8_t phase=0;
1274 for (size_t i=0; i<size; i++){
1275 if (BitStream[i]==1){
3bc66a96 1276 phase ^=1;
1277 }
1278 BitStream[i]=phase;
1279 }
1280 return;
1281}
1282
04d2721b 1283// redesigned by marshmellow adjusted from existing decode functions
1284// indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
ba1a299c 1285int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert)
1286{
1287 //26 bit 40134 format (don't know other formats)
57c7b44b 1288 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};
1289 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};
1290 size_t startidx = 0;
1291 if (!preambleSearch(bitStream, preamble, sizeof(preamble), size, &startidx)){
1292 // if didn't find preamble try again inverting
1293 if (!preambleSearch(bitStream, preamble_i, sizeof(preamble_i), size, &startidx)) return -1;
1294 *invert ^= 1;
1295 }
1296 if (*size != 64 && *size != 224) return -2;
1297 if (*invert==1)
1298 for (size_t i = startidx; i < *size; i++)
1299 bitStream[i] ^= 1;
ba1a299c 1300
57c7b44b 1301 return (int) startidx;
ba1a299c 1302}
1303
05164399 1304// by marshmellow - demodulate NRZ wave - requires a read with strong signal
04d2721b 1305// peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
6426f6ba 1306int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert){
e0165dcf 1307 if (justNoise(dest, *size)) return -1;
1308 *clk = DetectNRZClock(dest, *size, *clk);
1309 if (*clk==0) return -2;
2eec55c8 1310 size_t i, gLen = 4096;
6426f6ba 1311 if (gLen>*size) gLen = *size-20;
e0165dcf 1312 int high, low;
1313 if (getHiLo(dest, gLen, &high, &low, 75, 75) < 1) return -3; //25% fuzz on high 25% fuzz on low
6426f6ba 1314
1315 uint8_t bit=0;
1316 //convert wave samples to 1's and 0's
1317 for(i=20; i < *size-20; i++){
1318 if (dest[i] >= high) bit = 1;
1319 if (dest[i] <= low) bit = 0;
1320 dest[i] = bit;
e0165dcf 1321 }
6426f6ba 1322 //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit)
1323 size_t lastBit = 0;
1324 size_t numBits = 0;
1325 for(i=21; i < *size-20; i++) {
1326 //if transition detected or large number of same bits - store the passed bits
1327 if (dest[i] != dest[i-1] || (i-lastBit) == (10 * *clk)) {
1328 memset(dest+numBits, dest[i-1] ^ *invert, (i - lastBit + (*clk/4)) / *clk);
1329 numBits += (i - lastBit + (*clk/4)) / *clk;
1330 lastBit = i-1;
e0165dcf 1331 }
e0165dcf 1332 }
6426f6ba 1333 *size = numBits;
1334 return 0;
ba1a299c 1335}
1336
1e090a61 1337//by marshmellow
03e6bb4a 1338//detects the bit clock for FSK given the high and low Field Clocks
1339uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow)
1e090a61 1340{
e0165dcf 1341 uint8_t clk[] = {8,16,32,40,50,64,100,128,0};
1342 uint16_t rfLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
1343 uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
1344 uint8_t rfLensFnd = 0;
2eec55c8 1345 uint8_t lastFCcnt = 0;
1346 uint16_t fcCounter = 0;
e0165dcf 1347 uint16_t rfCounter = 0;
1348 uint8_t firstBitFnd = 0;
1349 size_t i;
1350 if (size == 0) return 0;
1351
6426f6ba 1352 uint8_t fcTol = ((fcHigh*100 - fcLow*100)/2 + 50)/100; //(uint8_t)(0.5+(float)(fcHigh-fcLow)/2);
e0165dcf 1353 rfLensFnd=0;
1354 fcCounter=0;
1355 rfCounter=0;
1356 firstBitFnd=0;
a38f5a07 1357 //prnt("DEBUG: fcTol: %d",fcTol);
6426f6ba 1358 // prime i to first peak / up transition
1359 for (i = 160; i < size-20; i++)
e0165dcf 1360 if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1])
1361 break;
1362
6426f6ba 1363 for (; i < size-20; i++){
2eec55c8 1364 fcCounter++;
1365 rfCounter++;
1366
1367 if (BitStream[i] <= BitStream[i-1] || BitStream[i] < BitStream[i+1])
1368 continue;
1369 // else new peak
1370 // if we got less than the small fc + tolerance then set it to the small fc
1371 if (fcCounter < fcLow+fcTol)
1372 fcCounter = fcLow;
1373 else //set it to the large fc
1374 fcCounter = fcHigh;
1375
1376 //look for bit clock (rf/xx)
1377 if ((fcCounter < lastFCcnt || fcCounter > lastFCcnt)){
1378 //not the same size as the last wave - start of new bit sequence
1379 if (firstBitFnd > 1){ //skip first wave change - probably not a complete bit
1380 for (int ii=0; ii<15; ii++){
6426f6ba 1381 if (rfLens[ii] >= (rfCounter-4) && rfLens[ii] <= (rfCounter+4)){
2eec55c8 1382 rfCnts[ii]++;
1383 rfCounter = 0;
1384 break;
e0165dcf 1385 }
e0165dcf 1386 }
2eec55c8 1387 if (rfCounter > 0 && rfLensFnd < 15){
a38f5a07 1388 //prnt("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
2eec55c8 1389 rfCnts[rfLensFnd]++;
1390 rfLens[rfLensFnd++] = rfCounter;
1391 }
1392 } else {
1393 firstBitFnd++;
e0165dcf 1394 }
2eec55c8 1395 rfCounter=0;
1396 lastFCcnt=fcCounter;
e0165dcf 1397 }
2eec55c8 1398 fcCounter=0;
e0165dcf 1399 }
1400 uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15;
1401
1402 for (i=0; i<15; i++){
e0165dcf 1403 //get highest 2 RF values (might need to get more values to compare or compare all?)
1404 if (rfCnts[i]>rfCnts[rfHighest]){
1405 rfHighest3=rfHighest2;
1406 rfHighest2=rfHighest;
1407 rfHighest=i;
1408 } else if(rfCnts[i]>rfCnts[rfHighest2]){
1409 rfHighest3=rfHighest2;
1410 rfHighest2=i;
1411 } else if(rfCnts[i]>rfCnts[rfHighest3]){
1412 rfHighest3=i;
1413 }
a126332a 1414 if (g_debugMode==2) prnt("DEBUG FSK: RF %d, cnts %d",rfLens[i], rfCnts[i]);
e0165dcf 1415 }
1416 // set allowed clock remainder tolerance to be 1 large field clock length+1
1417 // we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off
1418 uint8_t tol1 = fcHigh+1;
1419
a126332a 1420 if (g_debugMode==2) prnt("DEBUG FSK: most counted rf values: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]);
e0165dcf 1421
1422 // loop to find the highest clock that has a remainder less than the tolerance
1423 // compare samples counted divided by
6426f6ba 1424 // test 128 down to 32 (shouldn't be possible to have fc/10 & fc/8 and rf/16 or less)
e0165dcf 1425 int ii=7;
6426f6ba 1426 for (; ii>=2; ii--){
e0165dcf 1427 if (rfLens[rfHighest] % clk[ii] < tol1 || rfLens[rfHighest] % clk[ii] > clk[ii]-tol1){
1428 if (rfLens[rfHighest2] % clk[ii] < tol1 || rfLens[rfHighest2] % clk[ii] > clk[ii]-tol1){
1429 if (rfLens[rfHighest3] % clk[ii] < tol1 || rfLens[rfHighest3] % clk[ii] > clk[ii]-tol1){
a126332a 1430 if (g_debugMode==2) prnt("DEBUG FSK: clk %d divides into the 3 most rf values within tolerance",clk[ii]);
e0165dcf 1431 break;
1432 }
1433 }
1434 }
1435 }
1436
1437 if (ii<0) return 0; // oops we went too far
1438
1439 return clk[ii];
03e6bb4a 1440}
1e090a61 1441
03e6bb4a 1442//by marshmellow
1443//countFC is to detect the field clock lengths.
1444//counts and returns the 2 most common wave lengths
6de43508 1445//mainly used for FSK field clock detection
2eec55c8 1446uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj)
03e6bb4a 1447{
6426f6ba 1448 uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
1449 uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
e0165dcf 1450 uint8_t fcLensFnd = 0;
1451 uint8_t lastFCcnt=0;
2eec55c8 1452 uint8_t fcCounter = 0;
e0165dcf 1453 size_t i;
1454 if (size == 0) return 0;
1455
1456 // prime i to first up transition
6426f6ba 1457 for (i = 160; i < size-20; i++)
e0165dcf 1458 if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1])
1459 break;
1460
6426f6ba 1461 for (; i < size-20; i++){
e0165dcf 1462 if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){
1463 // new up transition
1464 fcCounter++;
2eec55c8 1465 if (fskAdj){
1466 //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8)
1467 if (lastFCcnt==5 && fcCounter==9) fcCounter--;
1468 //if fc=9 or 4 add one (for when we get a fc 9 instead of 10 or a 4 instead of a 5)
1469 if ((fcCounter==9) || fcCounter==4) fcCounter++;
e0165dcf 1470 // save last field clock count (fc/xx)
2eec55c8 1471 lastFCcnt = fcCounter;
1472 }
e0165dcf 1473 // find which fcLens to save it to:
6426f6ba 1474 for (int ii=0; ii<15; ii++){
e0165dcf 1475 if (fcLens[ii]==fcCounter){
1476 fcCnts[ii]++;
1477 fcCounter=0;
1478 break;
1479 }
1480 }
6426f6ba 1481 if (fcCounter>0 && fcLensFnd<15){
e0165dcf 1482 //add new fc length
1483 fcCnts[fcLensFnd]++;
1484 fcLens[fcLensFnd++]=fcCounter;
1485 }
1486 fcCounter=0;
1487 } else {
1488 // count sample
1489 fcCounter++;
1490 }
1491 }
1492
6426f6ba 1493 uint8_t best1=14, best2=14, best3=14;
e0165dcf 1494 uint16_t maxCnt1=0;
1495 // go through fclens and find which ones are bigest 2
6426f6ba 1496 for (i=0; i<15; i++){
e0165dcf 1497 // get the 3 best FC values
1498 if (fcCnts[i]>maxCnt1) {
1499 best3=best2;
1500 best2=best1;
1501 maxCnt1=fcCnts[i];
1502 best1=i;
1503 } else if(fcCnts[i]>fcCnts[best2]){
1504 best3=best2;
1505 best2=i;
1506 } else if(fcCnts[i]>fcCnts[best3]){
1507 best3=i;
1508 }
a126332a 1509 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]);
e0165dcf 1510 }
6426f6ba 1511 if (fcLens[best1]==0) return 0;
e0165dcf 1512 uint8_t fcH=0, fcL=0;
1513 if (fcLens[best1]>fcLens[best2]){
1514 fcH=fcLens[best1];
1515 fcL=fcLens[best2];
1516 } else{
1517 fcH=fcLens[best2];
1518 fcL=fcLens[best1];
1519 }
a126332a 1520 if ((size-180)/fcH/3 > fcCnts[best1]+fcCnts[best2]) {
1521 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]);
1522 return 0; //lots of waves not psk or fsk
1523 }
e0165dcf 1524 // TODO: take top 3 answers and compare to known Field clocks to get top 2
1525
1526 uint16_t fcs = (((uint16_t)fcH)<<8) | fcL;
2eec55c8 1527 if (fskAdj) return fcs;
1528 return fcLens[best1];
6de43508 1529}
1530
1531//by marshmellow - demodulate PSK1 wave
1532//uses wave lengths (# Samples)
1533int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
1534{
e0165dcf 1535 if (size == 0) return -1;
2eec55c8 1536 uint16_t loopCnt = 4096; //don't need to loop through entire array...
e0165dcf 1537 if (*size<loopCnt) loopCnt = *size;
1538
6426f6ba 1539 size_t numBits=0;
e0165dcf 1540 uint8_t curPhase = *invert;
1541 size_t i, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0;
1542 uint8_t fc=0, fullWaveLen=0, tol=1;
1543 uint16_t errCnt=0, waveLenCnt=0;
2eec55c8 1544 fc = countFC(dest, *size, 0);
e0165dcf 1545 if (fc!=2 && fc!=4 && fc!=8) return -1;
a38f5a07 1546 //prnt("DEBUG: FC: %d",fc);
e0165dcf 1547 *clock = DetectPSKClock(dest, *size, *clock);
2eec55c8 1548 if (*clock == 0) return -1;
e0165dcf 1549 int avgWaveVal=0, lastAvgWaveVal=0;
1550 //find first phase shift
1551 for (i=0; i<loopCnt; i++){
1552 if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
1553 waveEnd = i+1;
a38f5a07 1554 //prnt("DEBUG: waveEnd: %d",waveEnd);
e0165dcf 1555 waveLenCnt = waveEnd-waveStart;
6426f6ba 1556 if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+2)){ //not first peak and is a large wave but not out of whack
e0165dcf 1557 lastAvgWaveVal = avgWaveVal/(waveLenCnt);
1558 firstFullWave = waveStart;
1559 fullWaveLen=waveLenCnt;
1560 //if average wave value is > graph 0 then it is an up wave or a 1
2eec55c8 1561 if (lastAvgWaveVal > 123) curPhase ^= 1; //fudge graph 0 a little 123 vs 128
e0165dcf 1562 break;
1563 }
1564 waveStart = i+1;
1565 avgWaveVal = 0;
1566 }
2eec55c8 1567 avgWaveVal += dest[i+2];
e0165dcf 1568 }
6426f6ba 1569 if (firstFullWave == 0) {
1570 // no phase shift detected - could be all 1's or 0's - doesn't matter where we start
1571 // so skip a little to ensure we are past any Start Signal
1572 firstFullWave = 160;
1573 memset(dest, curPhase, firstFullWave / *clock);
1574 } else {
1575 memset(dest, curPhase^1, firstFullWave / *clock);
1576 }
1577 //advance bits
1578 numBits += (firstFullWave / *clock);
1579 //set start of wave as clock align
1580 lastClkBit = firstFullWave;
7fa7e812 1581 if (g_debugMode==2) prnt("DEBUG PSK: firstFullWave: %u, waveLen: %u",firstFullWave,fullWaveLen);
1582 if (g_debugMode==2) prnt("DEBUG: clk: %d, lastClkBit: %u, fc: %u", *clock, lastClkBit,(unsigned int) fc);
e0165dcf 1583 waveStart = 0;
e0165dcf 1584 dest[numBits++] = curPhase; //set first read bit
2eec55c8 1585 for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){
e0165dcf 1586 //top edge of wave = start of new wave
1587 if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
1588 if (waveStart == 0) {
1589 waveStart = i+1;
2eec55c8 1590 waveLenCnt = 0;
e0165dcf 1591 avgWaveVal = dest[i+1];
1592 } else { //waveEnd
1593 waveEnd = i+1;
1594 waveLenCnt = waveEnd-waveStart;
1595 lastAvgWaveVal = avgWaveVal/waveLenCnt;
1596 if (waveLenCnt > fc){
a38f5a07 1597 //prnt("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);
2eec55c8 1598 //this wave is a phase shift
a38f5a07 1599 //prnt("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc);
e0165dcf 1600 if (i+1 >= lastClkBit + *clock - tol){ //should be a clock bit
2eec55c8 1601 curPhase ^= 1;
e0165dcf 1602 dest[numBits++] = curPhase;
1603 lastClkBit += *clock;
2eec55c8 1604 } else if (i < lastClkBit+10+fc){
e0165dcf 1605 //noise after a phase shift - ignore
1606 } else { //phase shift before supposed to based on clock
1607 errCnt++;
2767fc02 1608 dest[numBits++] = 7;
e0165dcf 1609 }
1610 } else if (i+1 > lastClkBit + *clock + tol + fc){
1611 lastClkBit += *clock; //no phase shift but clock bit
1612 dest[numBits++] = curPhase;
1613 }
2eec55c8 1614 avgWaveVal = 0;
1615 waveStart = i+1;
e0165dcf 1616 }
1617 }
2eec55c8 1618 avgWaveVal += dest[i+1];
e0165dcf 1619 }
1620 *size = numBits;
1621 return errCnt;
6de43508 1622}
05164399 1623
1624//by marshmellow
1625//attempt to identify a Sequence Terminator in ASK modulated raw wave
1626bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
1627 size_t bufsize = *size;
1628 //need to loop through all samples and identify our clock, look for the ST pattern
1629 uint8_t fndClk[] = {8,16,32,40,50,64,128};
1630 int clk = 0;
1631 int tol = 0;
1632 int i, j, skip, start, end, low, high, minClk, waveStart;
1633 bool complete = false;
a38f5a07 1634 int tmpbuff[bufsize / 32]; //guess rf/32 clock, if click is smaller we will only have room for a fraction of the samples captured
1635 int waveLen[bufsize / 32]; // if clock is larger then we waste memory in array size that is not needed...
05164399 1636 size_t testsize = (bufsize < 512) ? bufsize : 512;
1637 int phaseoff = 0;
1638 high = low = 128;
1639 memset(tmpbuff, 0, sizeof(tmpbuff));
a38f5a07 1640 memset(waveLen, 0, sizeof(waveLen));
05164399 1641
a38f5a07 1642
05164399 1643 if ( getHiLo(buffer, testsize, &high, &low, 80, 80) == -1 ) {
1644 if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting");
1645 return false; //just noise
1646 }
1647 i = 0;
1648 j = 0;
1649 minClk = 255;
1650 // get to first full low to prime loop and skip incomplete first pulse
1651 while ((buffer[i] < high) && (i < bufsize))
1652 ++i;
1653 while ((buffer[i] > low) && (i < bufsize))
1654 ++i;
1655 skip = i;
1656
1657 // populate tmpbuff buffer with pulse lengths
1658 while (i < bufsize) {
1659 // measure from low to low
1660 while ((buffer[i] > low) && (i < bufsize))
1661 ++i;
1662 start= i;
1663 while ((buffer[i] < high) && (i < bufsize))
1664 ++i;
1665 //first high point for this wave
1666 waveStart = i;
1667 while ((buffer[i] > low) && (i < bufsize))
1668 ++i;
a38f5a07 1669 if (j >= (bufsize/32)) {
05164399 1670 break;
1671 }
1672 waveLen[j] = i - waveStart; //first high to first low
1673 tmpbuff[j++] = i - start;
1674 if (i-start < minClk && i < bufsize) {
1675 minClk = i - start;
1676 }
1677 }
1678 // set clock - might be able to get this externally and remove this work...
1679 if (!clk) {
1680 for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
1681 tol = fndClk[clkCnt]/8;
1682 if (minClk >= fndClk[clkCnt]-tol && minClk <= fndClk[clkCnt]+1) {
1683 clk=fndClk[clkCnt];
1684 break;
1685 }
1686 }
1687 // clock not found - ERROR
1688 if (!clk) {
1689 if (g_debugMode==2) prnt("DEBUG STT: clock not found - quitting");
1690 return false;
1691 }
1692 } else tol = clk/8;
1693
1694 *foundclock = clk;
1695
1696 // look for Sequence Terminator - should be pulses of clk*(1 or 1.5), clk*2, clk*(1.5 or 2)
1697 start = -1;
1698 for (i = 0; i < j - 4; ++i) {
1699 skip += tmpbuff[i];
1700 if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol && waveLen[i] < clk+tol) { //1 to 2 clocks depending on 2 bits prior
1701 if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) { //2 clocks and wave size is 1 1/2
1702 if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave
1703 if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit
1704 start = i + 3;
1705 break;
1706 }
1707 }
1708 }
1709 }
1710 }
1711 // first ST not found - ERROR
1712 if (start < 0) {
1713 if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting");
1714 return false;
a38f5a07 1715 } else {
1716 if (g_debugMode==2) prnt("DEBUG STT: first STT found at: %d, j=%d",start, j);
05164399 1717 }
1718 if (waveLen[i+2] > clk*1+tol)
1719 phaseoff = 0;
1720 else
1721 phaseoff = clk/2;
1722
1723 // skip over the remainder of ST
1724 skip += clk*7/2; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point
1725
1726 // now do it again to find the end
1727 end = skip;
1728 for (i += 3; i < j - 4; ++i) {
1729 end += tmpbuff[i];
a38f5a07 1730 if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol && waveLen[i] < clk+tol) { //1 to 2 clocks depending on 2 bits prior
05164399 1731 if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) { //2 clocks and wave size is 1 1/2
1732 if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave
1733 if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit
1734 complete = true;
1735 break;
1736 }
1737 }
1738 }
1739 }
1740 }
1741 end -= phaseoff;
1742 //didn't find second ST - ERROR
1743 if (!complete) {
1744 if (g_debugMode==2) prnt("DEBUG STT: second STT not found - quitting");
1745 return false;
1746 }
1747 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);
1748 //now begin to trim out ST so we can use normal demod cmds
1749 start = skip;
1750 size_t datalen = end - start;
1751 // check validity of datalen (should be even clock increments) - use a tolerance of up to 1/8th a clock
a38f5a07 1752 if ( clk - (datalen % clk) <= clk/8) {
1753 // padd the amount off - could be problematic... but shouldn't happen often
1754 datalen += clk - (datalen % clk);
1755 } else if ( (datalen % clk) <= clk/8 ) {
1756 // padd the amount off - could be problematic... but shouldn't happen often
1757 datalen -= datalen % clk;
1758 } else {
05164399 1759 if (g_debugMode==2) prnt("DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting", datalen, clk, datalen % clk);
1760 return false;
05164399 1761 }
1762 // if datalen is less than one t55xx block - ERROR
1763 if (datalen/clk < 8*4) {
1764 if (g_debugMode==2) prnt("DEBUG STT: datalen is less than 1 full t55xx block - quitting");
1765 return false;
1766 }
1767 size_t dataloc = start;
a38f5a07 1768 if (buffer[dataloc-(clk*4)-(clk/8)] <= low && buffer[dataloc] <= low && buffer[dataloc-(clk*4)] >= high) {
1769 //we have low drift (and a low just before the ST and a low just after the ST) - compensate by backing up the start
1770 for ( i=0; i <= (clk/8); ++i ) {
1771 if ( buffer[dataloc - (clk*4) - i] <= low ) {
1772 dataloc -= i;
1773 break;
1774 }
1775 }
1776 }
1777
05164399 1778 size_t newloc = 0;
1779 i=0;
a38f5a07 1780 if (g_debugMode==2) prnt("DEBUG STT: Starting STT trim - start: %d, datalen: %d ",dataloc, datalen);
1781
05164399 1782 // warning - overwriting buffer given with raw wave data with ST removed...
1783 while ( dataloc < bufsize-(clk/2) ) {
7fa7e812 1784 //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)
05164399 1785 if (buffer[dataloc]<high && buffer[dataloc]>low && buffer[dataloc+3]<high && buffer[dataloc+3]>low) {
1786 for(i=0; i < clk/2-tol; ++i) {
1787 buffer[dataloc+i] = high+5;
1788 }
1789 }
1790 for (i=0; i<datalen; ++i) {
1791 if (i+newloc < bufsize) {
1792 if (i+newloc < dataloc)
1793 buffer[i+newloc] = buffer[dataloc];
1794
1795 dataloc++;
1796 }
1797 }
1798 newloc += i;
7fa7e812 1799 //skip next ST - we just assume it will be there from now on...
a38f5a07 1800 if (g_debugMode==2) prnt("DEBUG STT: skipping STT at %d to %d", dataloc, dataloc+(clk*4));
05164399 1801 dataloc += clk*4;
1802 }
1803 *size = newloc;
1804 return true;
1805}
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