]> git.zerfleddert.de Git - proxmark3-svn/blame - common/lfdemod.c
CHG: adding the HID wiegand calcs again. Still need to set the bit37 indicator...
[proxmark3-svn] / common / lfdemod.c
CommitLineData
eb191de6 1//-----------------------------------------------------------------------------
ba1a299c 2// Copyright (C) 2014
eb191de6 3//
4// This code is licensed to you under the terms of the GNU GPL, version 2 or,
5// at your option, any later version. See the LICENSE.txt file for the text of
6// the license.
7//-----------------------------------------------------------------------------
1e090a61 8// Low frequency demod/decode commands
eb191de6 9//-----------------------------------------------------------------------------
10
eb191de6 11#include <stdlib.h>
eb191de6 12#include "lfdemod.h"
05164399 13#include <string.h>
6426f6ba 14
a126332a 15//un_comment to allow debug print calls when used not on device
6426f6ba 16void dummy(char *fmt, ...){}
17
18#ifndef ON_DEVICE
19#include "ui.h"
a126332a 20#include "cmdparser.h"
21#include "cmddata.h"
6426f6ba 22#define prnt PrintAndLog
23#else
a126332a 24 uint8_t g_debugMode=0;
6426f6ba 25#define prnt dummy
26#endif
6426f6ba 27
2dcf60f3 28//test samples are not just noise
29uint8_t justNoise(uint8_t *bits, size_t size) {
30 #define THRESHOLD 123
31 uint8_t val = 1;
32 for(size_t idx=0; idx < size && val ;idx++)
33 val = bits[idx] < THRESHOLD;
34 return val;
a1d17964 35}
36
1e090a61 37//by marshmellow
872e3d4d 38//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 39int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi, uint8_t fuzzLo)
40{
41 *high=0;
42 *low=255;
43 // get high and low thresholds
2eec55c8 44 for (size_t i=0; i < size; i++){
1e090a61 45 if (BitStream[i] > *high) *high = BitStream[i];
46 if (BitStream[i] < *low) *low = BitStream[i];
47 }
48 if (*high < 123) return -1; // just noise
75cbbe9a 49 *high = ((*high-128)*fuzzHi + 12800)/100;
50 *low = ((*low-128)*fuzzLo + 12800)/100;
1e090a61 51 return 1;
52}
53
a1d17964 54// by marshmellow
55// pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType
56// returns 1 if passed
57uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType)
58{
59 uint8_t ans = 0;
60 for (uint8_t i = 0; i < bitLen; i++){
61 ans ^= ((bits >> i) & 1);
62 }
f3bf15e4 63 //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType);
a1d17964 64 return (ans == pType);
65}
66
a126332a 67//by marshmellow
68// takes a array of binary values, start position, length of bits per parity (includes parity bit),
c728b2b4 69// 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 70size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen)
71{
72 uint32_t parityWd = 0;
73 size_t j = 0, bitCnt = 0;
c08c796e 74 for (int word = 0; word < (bLen); word += pLen){
a126332a 75 for (int bit=0; bit < pLen; bit++){
76 parityWd = (parityWd << 1) | BitStream[startIdx+word+bit];
77 BitStream[j++] = (BitStream[startIdx+word+bit]);
78 }
79 j--; // overwrite parity with next data
80 // if parity fails then return 0
c728b2b4 81 switch (pType) {
11dee3d5 82 case 3: if (BitStream[j]==1) { return 0; } break; //should be 0 spacer bit
83 case 2: if (BitStream[j]==0) { return 0; } break; //should be 1 spacer bit
3c654208 84 default: if (parityTest(parityWd, pLen, pType) == 0) { return 0; } break; //test parity
a126332a 85 }
c08c796e 86 bitCnt += (pLen-1);
a126332a 87 parityWd = 0;
88 }
89 // if we got here then all the parities passed
90 //return ID start index and size
91 return bitCnt;
92}
93
94// by marshmellow
95// takes a array of binary values, length of bits per parity (includes parity bit),
0d2c5909 96// Parity Type (1 for odd; 0 for even; 2 Always 1's; 3 Always 0's), and binary Length (length to run)
c728b2b4 97// Make sure *dest is long enough to store original sourceLen + #_of_parities_to_be_added
a126332a 98size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t pLen, uint8_t pType)
99{
100 uint32_t parityWd = 0;
101 size_t j = 0, bitCnt = 0;
102 for (int word = 0; word < sourceLen; word+=pLen-1) {
103 for (int bit=0; bit < pLen-1; bit++){
104 parityWd = (parityWd << 1) | BitSource[word+bit];
105 dest[j++] = (BitSource[word+bit]);
106 }
0d2c5909 107
a126332a 108 // if parity fails then return 0
0d2c5909 109 switch (pType) {
110 case 3: dest[j++]=0; break; // marker bit which should be a 0
111 case 2: dest[j++]=1; break; // marker bit which should be a 1
112 default:
113 dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1;
114 break;
a126332a 115 }
116 bitCnt += pLen;
117 parityWd = 0;
118 }
119 // if we got here then all the parities passed
120 //return ID start index and size
121 return bitCnt;
122}
123
124uint32_t bytebits_to_byte(uint8_t *src, size_t numbits)
125{
126 uint32_t num = 0;
0d2c5909 127 for(int i = 0 ; i < numbits ; i++) {
a126332a 128 num = (num << 1) | (*src);
129 src++;
130 }
131 return num;
132}
133
134//least significant bit first
135uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits)
136{
137 uint32_t num = 0;
6b6815bc 138 for(int i = 0 ; i < numbits ; i++) {
a126332a 139 num = (num << 1) | *(src + (numbits-(i+1)));
140 }
141 return num;
142}
143
a1d17964 144//by marshmellow
2147c307 145//search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length
a1d17964 146uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx)
147{
5735cfa5 148 // Sanity check. If preamble length is bigger than bitstream length.
149 if ( *size <= pLen ) return 0;
150
56d0fb8e 151 uint8_t foundCnt = 0;
152 for (int idx = 0; idx < *size - pLen; idx++){
e0165dcf 153 if (memcmp(BitStream+idx, preamble, pLen) == 0){
154 //first index found
155 foundCnt++;
156 if (foundCnt == 1){
157 *startIdx = idx;
158 }
159 if (foundCnt == 2){
160 *size = idx - *startIdx;
161 return 1;
162 }
163 }
164 }
165 return 0;
a1d17964 166}
167
2147c307 168//by marshmellow
169//takes 1s and 0s and searches for EM410x format - output EM ID
da1f16d6 170int Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo)
2147c307 171{
e0165dcf 172 //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
173 // otherwise could be a void with no arguments
174 //set defaults
175 uint32_t i = 0;
da1f16d6 176 if (BitStream[1]>1) return -1; //allow only 1s and 0s
2767fc02 177
e0165dcf 178 // 111111111 bit pattern represent start of frame
179 // include 0 in front to help get start pos
180 uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1};
181 uint32_t idx = 0;
182 uint32_t parityBits = 0;
183 uint8_t errChk = 0;
184 uint8_t FmtLen = 10;
185 *startIdx = 0;
186 errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx);
da1f16d6 187 if (errChk == 0 ) return -4;
188 if (*size < 64) return -3;
e0165dcf 189 if (*size > 64) FmtLen = 22;
190 *startIdx += 1; //get rid of 0 from preamble
191 idx = *startIdx + 9;
192 for (i=0; i<FmtLen; i++){ //loop through 10 or 22 sets of 5 bits (50-10p = 40 bits or 88 bits)
193 parityBits = bytebits_to_byte(BitStream+(i*5)+idx,5);
2eec55c8 194 //check even parity - quit if failed
da1f16d6 195 if (parityTest(parityBits, 5, 0) == 0) return -5;
e0165dcf 196 //set uint64 with ID from BitStream
197 for (uint8_t ii=0; ii<4; ii++){
198 *hi = (*hi << 1) | (*lo >> 63);
199 *lo = (*lo << 1) | (BitStream[(i*5)+ii+idx]);
200 }
201 }
202 if (errChk != 0) return 1;
203 //skip last 5 bit parity test for simplicity.
204 // *size = 64 | 128;
205 return 0;
2147c307 206}
207
fef74fdc 208//by marshmellow
209//demodulates strong heavily clipped samples
23f0a7d8 210int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low)
211{
212 size_t bitCnt=0, smplCnt=0, errCnt=0;
213 uint8_t waveHigh = 0;
23f0a7d8 214 for (size_t i=0; i < *size; i++){
215 if (BinStream[i] >= high && waveHigh){
216 smplCnt++;
217 } else if (BinStream[i] <= low && !waveHigh){
218 smplCnt++;
219 } else { //transition
220 if ((BinStream[i] >= high && !waveHigh) || (BinStream[i] <= low && waveHigh)){
221 if (smplCnt > clk-(clk/4)-1) { //full clock
222 if (smplCnt > clk + (clk/4)+1) { //too many samples
223 errCnt++;
05164399 224 if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
2767fc02 225 BinStream[bitCnt++]=7;
23f0a7d8 226 } else if (waveHigh) {
227 BinStream[bitCnt++] = invert;
228 BinStream[bitCnt++] = invert;
229 } else if (!waveHigh) {
230 BinStream[bitCnt++] = invert ^ 1;
231 BinStream[bitCnt++] = invert ^ 1;
232 }
233 waveHigh ^= 1;
234 smplCnt = 0;
235 } else if (smplCnt > (clk/2) - (clk/4)-1) {
236 if (waveHigh) {
237 BinStream[bitCnt++] = invert;
238 } else if (!waveHigh) {
239 BinStream[bitCnt++] = invert ^ 1;
240 }
241 waveHigh ^= 1;
242 smplCnt = 0;
243 } else if (!bitCnt) {
244 //first bit
245 waveHigh = (BinStream[i] >= high);
246 smplCnt = 1;
247 } else {
248 smplCnt++;
249 //transition bit oops
250 }
251 } else { //haven't hit new high or new low yet
252 smplCnt++;
253 }
254 }
255 }
256 *size = bitCnt;
257 return errCnt;
258}
259
eb191de6 260//by marshmellow
fef74fdc 261void askAmp(uint8_t *BitStream, size_t size)
262{
9686a8d4 263 uint8_t last = 128;
264 for(size_t i = 1; i < size; ++i){
265 if (BitStream[i]-BitStream[i-1] >= 30) //large jump up
266 last = 255;
267 else if(BitStream[i-1] - BitStream[i] >= 20) //large jump down
268 last = 0;
269
270 BitStream[i] = last;
fef74fdc 271 }
fef74fdc 272}
273
274//by marshmellow
275//attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester
276int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType)
eb191de6 277{
fef74fdc 278 if (*size==0) return -1;
6e984446 279 int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default
2eec55c8 280 if (*clk==0 || start < 0) return -3;
fef74fdc 281 if (*invert != 1) *invert = 0;
282 if (amp==1) askAmp(BinStream, *size);
05164399 283 if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d", *clk, start);
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);
300 else //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}
348
349//by marshmellow
350//take 10 and 01 and manchester decode
351//run through 2 times and take least errCnt
fef74fdc 352int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert)
eb191de6 353{
13d77ef9 354 uint16_t bitnum=0, MaxBits = 512, errCnt = 0;
355 size_t i, ii;
356 uint16_t bestErr = 1000, bestRun = 0;
fef74fdc 357 if (*size < 16) return -1;
2767fc02 358 //find correct start position [alignment]
13d77ef9 359 for (ii=0;ii<2;++ii){
fef74fdc 360 for (i=ii; i<*size-3; i+=2)
2eec55c8 361 if (BitStream[i]==BitStream[i+1])
ba1a299c 362 errCnt++;
2eec55c8 363
ba1a299c 364 if (bestErr>errCnt){
365 bestErr=errCnt;
366 bestRun=ii;
367 }
368 errCnt=0;
369 }
2767fc02 370 //decode
fef74fdc 371 for (i=bestRun; i < *size-3; i+=2){
23f0a7d8 372 if(BitStream[i] == 1 && (BitStream[i+1] == 0)){
fef74fdc 373 BitStream[bitnum++]=invert;
23f0a7d8 374 } else if((BitStream[i] == 0) && BitStream[i+1] == 1){
fef74fdc 375 BitStream[bitnum++]=invert^1;
23f0a7d8 376 } else {
2767fc02 377 BitStream[bitnum++]=7;
ba1a299c 378 }
23f0a7d8 379 if(bitnum>MaxBits) break;
ba1a299c 380 }
23f0a7d8 381 *size=bitnum;
2eec55c8 382 return bestErr;
f822a063 383}
384
1d0ccbe0 385uint32_t manchesterEncode2Bytes(uint16_t datain) {
386 uint32_t output = 0;
387 uint8_t curBit = 0;
388 for (uint8_t i=0; i<16; i++) {
389 curBit = (datain >> (15-i) & 1);
390 output |= (1<<(((15-i)*2)+curBit));
391 }
392 return output;
393}
394
fef74fdc 395//by marshmellow
396//encode binary data into binary manchester
397int ManchesterEncode(uint8_t *BitStream, size_t size)
398{
399 size_t modIdx=20000, i=0;
400 if (size>modIdx) return -1;
401 for (size_t idx=0; idx < size; idx++){
402 BitStream[idx+modIdx++] = BitStream[idx];
403 BitStream[idx+modIdx++] = BitStream[idx]^1;
404 }
405 for (; i<(size*2); i++){
406 BitStream[i] = BitStream[i+20000];
407 }
408 return i;
409}
410
f822a063 411//by marshmellow
2147c307 412//take 01 or 10 = 1 and 11 or 00 = 0
413//check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010
13d77ef9 414//decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding
1e090a61 415int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert)
f822a063 416{
2eec55c8 417 uint16_t bitnum = 0;
418 uint16_t errCnt = 0;
419 size_t i = offset;
2147c307 420 uint16_t MaxBits=512;
421 //if not enough samples - error
422 if (*size < 51) return -1;
423 //check for phase change faults - skip one sample if faulty
424 uint8_t offsetA = 1, offsetB = 1;
425 for (; i<48; i+=2){
426 if (BitStream[i+1]==BitStream[i+2]) offsetA=0;
427 if (BitStream[i+2]==BitStream[i+3]) offsetB=0;
428 }
429 if (!offsetA && offsetB) offset++;
430 for (i=offset; i<*size-3; i+=2){
431 //check for phase error
13d77ef9 432 if (BitStream[i+1]==BitStream[i+2]) {
2767fc02 433 BitStream[bitnum++]=7;
2147c307 434 errCnt++;
435 }
ba1a299c 436 if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){
1e090a61 437 BitStream[bitnum++]=1^invert;
ba1a299c 438 } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){
1e090a61 439 BitStream[bitnum++]=invert;
ba1a299c 440 } else {
2767fc02 441 BitStream[bitnum++]=7;
ba1a299c 442 errCnt++;
443 }
6de43508 444 if(bitnum>MaxBits) break;
ba1a299c 445 }
446 *size=bitnum;
447 return errCnt;
eb191de6 448}
449
fef74fdc 450// by marshmellow
11081e04 451// demod gProxIIDemod
452// error returns as -x
453// success returns start position in BitStream
454// BitStream must contain previously askrawdemod and biphasedemoded data
455int gProxII_Demod(uint8_t BitStream[], size_t *size)
456{
457 size_t startIdx=0;
458 uint8_t preamble[] = {1,1,1,1,1,0};
459
460 uint8_t errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, &startIdx);
461 if (errChk == 0) return -3; //preamble not found
462 if (*size != 96) return -2; //should have found 96 bits
463 //check first 6 spacer bits to verify format
464 if (!BitStream[startIdx+5] && !BitStream[startIdx+10] && !BitStream[startIdx+15] && !BitStream[startIdx+20] && !BitStream[startIdx+25] && !BitStream[startIdx+30]){
465 //confirmed proper separator bits found
466 //return start position
467 return (int) startIdx;
468 }
7fa7e812 469 return -5; //spacer bits not found - not a valid gproxII
11081e04 470}
471
7fa7e812 472//translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq])
f822a063 473size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow)
eb191de6 474{
2eec55c8 475 size_t last_transition = 0;
476 size_t idx = 1;
ac3ba7ee 477 //uint32_t maxVal=0;
ba1a299c 478 if (fchigh==0) fchigh=10;
479 if (fclow==0) fclow=8;
84871873 480 //set the threshold close to 0 (graph) or 128 std to avoid static
481 uint8_t threshold_value = 123;
ac2df346 482 size_t preLastSample = 0;
483 size_t LastSample = 0;
484 size_t currSample = 0;
ba1a299c 485 // sync to first lo-hi transition, and threshold
486
487 // Need to threshold first sample
6426f6ba 488 // skip 160 samples to allow antenna/samples to settle
489 if(dest[160] < threshold_value) dest[0] = 0;
ba1a299c 490 else dest[0] = 1;
491
492 size_t numBits = 0;
493 // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
cd0bed3c 494 // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere
ba1a299c 495 // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
7fa7e812 496 // (could also be fc/5 && fc/7 for fsk1 = 4-9)
6426f6ba 497 for(idx = 161; idx < size-20; idx++) {
ba1a299c 498 // threshold current value
499
500 if (dest[idx] < threshold_value) dest[idx] = 0;
501 else dest[idx] = 1;
502
503 // Check for 0->1 transition
7fa7e812 504 if (dest[idx-1] < dest[idx]) {
ac2df346 505 preLastSample = LastSample;
506 LastSample = currSample;
507 currSample = idx-last_transition;
6426f6ba 508 if (currSample < (fclow-2)){ //0-5 = garbage noise (or 0-3)
ba1a299c 509 //do nothing with extra garbage
7fa7e812 510 } else if (currSample < (fchigh-1)) { //6-8 = 8 sample waves (or 3-6 = 5)
511 //correct previous 9 wave surrounded by 8 waves (or 6 surrounded by 5)
6426f6ba 512 if (LastSample > (fchigh-2) && (preLastSample < (fchigh-1) || preLastSample == 0 )){
7fa7e812 513 dest[numBits-1]=1;
ac2df346 514 }
2eec55c8 515 dest[numBits++]=1;
ac2df346 516
7fa7e812 517 } else if (currSample > (fchigh) && !numBits) { //12 + and first bit = unusable garbage
13d77ef9 518 //do nothing with beginning garbage
7fa7e812 519 } 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 520 dest[numBits++]=1;
7fa7e812 521 } else { //9+ = 10 sample waves (or 6+ = 7)
2eec55c8 522 dest[numBits++]=0;
ba1a299c 523 }
524 last_transition = idx;
ba1a299c 525 }
526 }
527 return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
eb191de6 528}
529
ba1a299c 530//translate 11111100000 to 10
7fa7e812 531//rfLen = clock, fchigh = larger field clock, fclow = smaller field clock
2eec55c8 532size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen,
e0165dcf 533 uint8_t invert, uint8_t fchigh, uint8_t fclow)
eb191de6 534{
ba1a299c 535 uint8_t lastval=dest[0];
2eec55c8 536 size_t idx=0;
ba1a299c 537 size_t numBits=0;
538 uint32_t n=1;
ba1a299c 539 for( idx=1; idx < size; idx++) {
13d77ef9 540 n++;
2eec55c8 541 if (dest[idx]==lastval) continue;
542
7fa7e812 543 //find out how many bits (n) we collected
ba1a299c 544 //if lastval was 1, we have a 1->0 crossing
13d77ef9 545 if (dest[idx-1]==1) {
75cbbe9a 546 n = (n * fclow + rfLen/2) / rfLen;
13d77ef9 547 } else {// 0->1 crossing
75cbbe9a 548 n = (n * fchigh + rfLen/2) / rfLen;
ba1a299c 549 }
550 if (n == 0) n = 1;
551
7fa7e812 552 //add to our destination the bits we collected
2eec55c8 553 memset(dest+numBits, dest[idx-1]^invert , n);
554 numBits += n;
ba1a299c 555 n=0;
556 lastval=dest[idx];
557 }//end for
13d77ef9 558 // if valid extra bits at the end were all the same frequency - add them in
75cbbe9a 559 if (n > rfLen/fchigh) {
13d77ef9 560 if (dest[idx-2]==1) {
75cbbe9a 561 n = (n * fclow + rfLen/2) / rfLen;
13d77ef9 562 } else {
75cbbe9a 563 n = (n * fchigh + rfLen/2) / rfLen;
13d77ef9 564 }
2eec55c8 565 memset(dest+numBits, dest[idx-1]^invert , n);
13d77ef9 566 numBits += n;
567 }
ba1a299c 568 return numBits;
eb191de6 569}
6426f6ba 570
eb191de6 571//by marshmellow (from holiman's base)
572// full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod)
f822a063 573int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow)
eb191de6 574{
ba1a299c 575 // FSK demodulator
576 size = fsk_wave_demod(dest, size, fchigh, fclow);
2eec55c8 577 size = aggregate_bits(dest, size, rfLen, invert, fchigh, fclow);
ba1a299c 578 return size;
eb191de6 579}
a1d17964 580
eb191de6 581// loop to get raw HID waveform then FSK demodulate the TAG ID from it
ec75f5c1 582int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo)
eb191de6 583{
e0165dcf 584 if (justNoise(dest, *size)) return -1;
585
337f7036 586 size_t numStart=0, size2 = *size, startIdx=0;
e0165dcf 587 // FSK demodulator
588 *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
2eec55c8 589 if (*size < 96*2) return -2;
e0165dcf 590 // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
591 uint8_t preamble[] = {0,0,0,1,1,1,0,1};
592 // find bitstring in array
593 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
594 if (errChk == 0) return -3; //preamble not found
595
596 numStart = startIdx + sizeof(preamble);
597 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
598 for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
599 if (dest[idx] == dest[idx+1]){
600 return -4; //not manchester data
601 }
602 *hi2 = (*hi2<<1)|(*hi>>31);
603 *hi = (*hi<<1)|(*lo>>31);
604 //Then, shift in a 0 or one into low
605 if (dest[idx] && !dest[idx+1]) // 1 0
606 *lo=(*lo<<1)|1;
607 else // 0 1
608 *lo=(*lo<<1)|0;
609 }
610 return (int)startIdx;
eb191de6 611}
612
ec75f5c1 613// loop to get raw paradox waveform then FSK demodulate the TAG ID from it
a1d17964 614int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo)
ec75f5c1 615{
a1d17964 616 if (justNoise(dest, *size)) return -1;
617
337f7036 618 size_t numStart=0, size2 = *size, startIdx=0;
ec75f5c1 619 // FSK demodulator
a1d17964 620 *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
621 if (*size < 96) return -2;
ec75f5c1 622
a1d17964 623 // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
624 uint8_t preamble[] = {0,0,0,0,1,1,1,1};
625
626 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
627 if (errChk == 0) return -3; //preamble not found
628
629 numStart = startIdx + sizeof(preamble);
630 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
631 for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
632 if (dest[idx] == dest[idx+1])
633 return -4; //not manchester data
634 *hi2 = (*hi2<<1)|(*hi>>31);
635 *hi = (*hi<<1)|(*lo>>31);
636 //Then, shift in a 0 or one into low
637 if (dest[idx] && !dest[idx+1]) // 1 0
638 *lo=(*lo<<1)|1;
639 else // 0 1
640 *lo=(*lo<<1)|0;
ec75f5c1 641 }
a1d17964 642 return (int)startIdx;
ec75f5c1 643}
644
eb191de6 645int IOdemodFSK(uint8_t *dest, size_t size)
646{
a1d17964 647 if (justNoise(dest, size)) return -1;
ba1a299c 648 //make sure buffer has data
a1d17964 649 if (size < 66*64) return -2;
ba1a299c 650 // FSK demodulator
a1d17964 651 size = fskdemod(dest, size, 64, 1, 10, 8); // FSK2a RF/64
652 if (size < 65) return -3; //did we get a good demod?
ba1a299c 653 //Index map
654 //0 10 20 30 40 50 60
655 //| | | | | | |
656 //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
657 //-----------------------------------------------------------------------------
658 //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
659 //
660 //XSF(version)facility:codeone+codetwo
661 //Handle the data
a1d17964 662 size_t startIdx = 0;
663 uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,1};
664 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), &size, &startIdx);
665 if (errChk == 0) return -4; //preamble not found
eb191de6 666
a1d17964 667 if (!dest[startIdx+8] && dest[startIdx+17]==1 && dest[startIdx+26]==1 && dest[startIdx+35]==1 && dest[startIdx+44]==1 && dest[startIdx+53]==1){
668 //confirmed proper separator bits found
669 //return start position
670 return (int) startIdx;
1e090a61 671 }
a1d17964 672 return -5;
1e090a61 673}
674
70459879 675// by marshmellow
676// find viking preamble 0xF200 in already demoded data
677int VikingDemod_AM(uint8_t *dest, size_t *size) {
70459879 678 //make sure buffer has data
679 if (*size < 64*2) return -2;
70459879 680 size_t startIdx = 0;
681 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};
682 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
683 if (errChk == 0) return -4; //preamble not found
c0afa86f 684 uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^
685 bytebits_to_byte(dest+startIdx+8,8) ^
686 bytebits_to_byte(dest+startIdx+16,8) ^
687 bytebits_to_byte(dest+startIdx+24,8) ^
688 bytebits_to_byte(dest+startIdx+32,8) ^
689 bytebits_to_byte(dest+startIdx+40,8) ^
690 bytebits_to_byte(dest+startIdx+48,8) ^
691 bytebits_to_byte(dest+startIdx+56,8);
692 if ( checkCalc != 0xA8 ) return -5;
57c7b44b 693 if (*size != 64) return -6;
70459879 694 //return start position
deba67ab 695 return (int)startIdx;
70459879 696}
697
5daad826 698// by iceman
699// find Visa2000 preamble in already demoded data
700int Visa2kDemod_AM(uint8_t *dest, size_t *size) {
701 if (*size < 96*2) return -1; //make sure buffer has data
702 size_t startIdx = 0;
703 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};
704 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
705 if (errChk == 0) return -2; //preamble not found
706 if (*size != 96) return -3; //wrong demoded size
707 //return start position
deba67ab 708 return (int)startIdx;
5daad826 709}
207fc33a 710// by iceman
711// find Noralsy preamble in already demoded data
712int NoralsyDemod_AM(uint8_t *dest, size_t *size) {
713 if (*size < 96*2) return -1; //make sure buffer has data
714 size_t startIdx = 0;
715 uint8_t preamble[] = {1,0,1,1,1,0,1,1,0,0,0,0};
716 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
717 if (errChk == 0) return -2; //preamble not found
718 if (*size != 96) return -3; //wrong demoded size
719 //return start position
deba67ab 720 return (int)startIdx;
207fc33a 721}
4469412e 722// find presco preamble 0x10D in already demoded data
723int PrescoDemod(uint8_t *dest, size_t *size) {
d48175d4 724 if (*size < 128*2) return -1; //make sure buffer has data
4469412e 725 size_t startIdx = 0;
d48175d4 726 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 727 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
d48175d4 728 if (errChk == 0) return -2; //preamble not found
729 if (*size != 128) return -3; //wrong demoded size
4469412e 730 //return start position
deba67ab 731 return (int)startIdx;
4469412e 732}
733
615f21dd 734// Ask/Biphase Demod then try to locate an ISO 11784/85 ID
0df669a2 735// BitStream must contain previously askrawdemod and biphasedemoded data
deba67ab 736int FDXBdemodBI(uint8_t *dest, size_t *size) {
737 if (*size < 128*2) return -1; //make sure buffer has enough data
615f21dd 738 size_t startIdx = 0;
0df669a2 739 uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,1};
615f21dd 740 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
0df669a2 741 if (errChk == 0) return -2; //preamble not found
deba67ab 742 if (*size != 128) return -3; //wrong demoded size
743 //return start position
615f21dd 744 return (int)startIdx;
745}
1e090a61 746
6c283951 747// ASK/Diphase fc/64 (inverted Biphase)
748// Note: this i s not a demod, this is only a detection
749// the parameter *dest needs to be demoded before call
deba67ab 750// 0xFFFF preamble, 64bits
6c283951 751int JablotronDemod(uint8_t *dest, size_t *size){
deba67ab 752 if (*size < 64*2) return -1; //make sure buffer has enough data
6c283951 753 size_t startIdx = 0;
deba67ab 754 uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0};
6c283951 755 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
deba67ab 756 if (errChk == 0) return -2; //preamble not found
757 if (*size != 64) return -3; // wrong demoded size
6c283951 758
29ce214c 759 uint8_t checkchksum = 0;
6c283951 760 for (int i=16; i < 56; i += 8) {
29ce214c 761 checkchksum += bytebits_to_byte(dest+startIdx+i,8);
6c283951 762 }
29ce214c 763 checkchksum ^= 0x3A;
29ce214c 764 uint8_t crc = bytebits_to_byte(dest+startIdx+56, 8);
deba67ab 765 if ( checkchksum != crc ) return -5;
6c283951 766 return (int)startIdx;
767}
768
1e090a61 769// by marshmellow
770// FSK Demod then try to locate an AWID ID
a1d17964 771int AWIDdemodFSK(uint8_t *dest, size_t *size)
1e090a61 772{
a1d17964 773 //make sure buffer has enough data
774 if (*size < 96*50) return -1;
775
776 if (justNoise(dest, *size)) return -2;
1e090a61 777
778 // FSK demodulator
a1d17964 779 *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50
780 if (*size < 96) return -3; //did we get a good demod?
781
782 uint8_t preamble[] = {0,0,0,0,0,0,0,1};
783 size_t startIdx = 0;
784 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
785 if (errChk == 0) return -4; //preamble not found
786 if (*size != 96) return -5;
787 return (int)startIdx;
1e090a61 788}
789
790// by marshmellow
6426f6ba 791// FSK Demod then try to locate a Farpointe Data (pyramid) ID
a1d17964 792int PyramiddemodFSK(uint8_t *dest, size_t *size)
1e090a61 793{
f3bf15e4 794 //make sure buffer has data
795 if (*size < 128*50) return -5;
a1d17964 796
f3bf15e4 797 //test samples are not just noise
798 if (justNoise(dest, *size)) return -1;
1e090a61 799
f3bf15e4 800 // FSK demodulator
801 *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50
802 if (*size < 128) return -2; //did we get a good demod?
a1d17964 803
c08c796e 804 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 805 size_t startIdx = 0;
806 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
807 if (errChk == 0) return -4; //preamble not found
808 if (*size != 128) return -3;
809 return (int)startIdx;
1e090a61 810}
811
0cbe0cb8 812// find nedap preamble in already demoded data
56bbb25a 813int NedapDemod(uint8_t *dest, size_t *size) {
814 //make sure buffer has data
815 if (*size < 128) return -3;
96faed21 816
56bbb25a 817 size_t startIdx = 0;
15d49e82 818 //uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,0,0,0,1};
819 uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,0};
56bbb25a 820 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
821 if (errChk == 0) return -4; //preamble not found
56bbb25a 822 return (int) startIdx;
823}
824
fef74fdc 825// by marshmellow
826// to detect a wave that has heavily clipped (clean) samples
cc15a118 827uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low)
6de43508 828{
6426f6ba 829 bool allArePeaks = true;
6de43508 830 uint16_t cntPeaks=0;
6426f6ba 831 size_t loopEnd = 512+160;
1fbf8956 832 if (loopEnd > size) loopEnd = size;
6426f6ba 833 for (size_t i=160; i<loopEnd; i++){
6de43508 834 if (dest[i]>low && dest[i]<high)
6426f6ba 835 allArePeaks = false;
6de43508 836 else
837 cntPeaks++;
838 }
6426f6ba 839 if (!allArePeaks){
840 if (cntPeaks > 300) return true;
6de43508 841 }
6426f6ba 842 return allArePeaks;
6de43508 843}
2eec55c8 844// by marshmellow
845// to help detect clocks on heavily clipped samples
cc15a118 846// based on count of low to low
847int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low)
13d77ef9 848{
cc15a118 849 uint8_t fndClk[] = {8,16,32,40,50,64,128};
850 size_t startwave;
6426f6ba 851 size_t i = 100;
cc15a118 852 size_t minClk = 255;
853 // get to first full low to prime loop and skip incomplete first pulse
854 while ((dest[i] < high) && (i < size))
855 ++i;
856 while ((dest[i] > low) && (i < size))
857 ++i;
858
859 // loop through all samples
860 while (i < size) {
861 // measure from low to low
862 while ((dest[i] > low) && (i < size))
863 ++i;
864 startwave= i;
865 while ((dest[i] < high) && (i < size))
866 ++i;
867 while ((dest[i] > low) && (i < size))
868 ++i;
869 //get minimum measured distance
870 if (i-startwave < minClk && i < size)
871 minClk = i - startwave;
13d77ef9 872 }
cc15a118 873 // set clock
a126332a 874 if (g_debugMode==2) prnt("DEBUG ASK: detectstrongASKclk smallest wave: %d",minClk);
cc15a118 875 for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
876 if (minClk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1)
877 return fndClk[clkCnt];
13d77ef9 878 }
cc15a118 879 return 0;
13d77ef9 880}
881
eb191de6 882// by marshmellow
883// not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)
884// maybe somehow adjust peak trimming value based on samples to fix?
6de43508 885// return start index of best starting position for that clock and return clock (by reference)
886int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
eb191de6 887{
6e984446 888 size_t i=1;
cc15a118 889 uint8_t clk[] = {255,8,16,32,40,50,64,100,128,255};
890 uint8_t clkEnd = 9;
2eec55c8 891 uint8_t loopCnt = 255; //don't need to loop through entire array...
6426f6ba 892 if (size <= loopCnt+60) return -1; //not enough samples
893 size -= 60; //sometimes there is a strange end wave - filter out this....
6e984446 894 //if we already have a valid clock
895 uint8_t clockFnd=0;
cc15a118 896 for (;i<clkEnd;++i)
897 if (clk[i] == *clock) clockFnd = i;
6e984446 898 //clock found but continue to find best startpos
e0165dcf 899
900 //get high and low peak
901 int peak, low;
2eec55c8 902 if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return -1;
e0165dcf 903
904 //test for large clean peaks
cc15a118 905 if (!clockFnd){
906 if (DetectCleanAskWave(dest, size, peak, low)==1){
907 int ans = DetectStrongAskClock(dest, size, peak, low);
a126332a 908 if (g_debugMode==2) prnt("DEBUG ASK: detectaskclk Clean Ask Wave Detected: clk %d",ans);
cc15a118 909 for (i=clkEnd-1; i>0; i--){
910 if (clk[i] == ans) {
911 *clock = ans;
912 //clockFnd = i;
913 return 0; // for strong waves i don't use the 'best start position' yet...
914 //break; //clock found but continue to find best startpos [not yet]
915 }
e0165dcf 916 }
917 }
918 }
2eec55c8 919 uint8_t ii;
920 uint8_t clkCnt, tol = 0;
921 uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
922 uint8_t bestStart[]={0,0,0,0,0,0,0,0,0};
923 size_t errCnt = 0;
924 size_t arrLoc, loopEnd;
6e984446 925
cc15a118 926 if (clockFnd>0) {
927 clkCnt = clockFnd;
928 clkEnd = clockFnd+1;
929 }
930 else clkCnt=1;
931
932 //test each valid clock from smallest to greatest to see which lines up
933 for(; clkCnt < clkEnd; clkCnt++){
fef74fdc 934 if (clk[clkCnt] <= 32){
e0165dcf 935 tol=1;
936 }else{
937 tol=0;
938 }
2767fc02 939 //if no errors allowed - keep start within the first clock
cc15a118 940 if (!maxErr && size > clk[clkCnt]*2 + tol && clk[clkCnt]<128) loopCnt=clk[clkCnt]*2;
e0165dcf 941 bestErr[clkCnt]=1000;
6e984446 942 //try lining up the peaks by moving starting point (try first few clocks)
cc15a118 943 for (ii=0; ii < loopCnt; ii++){
2eec55c8 944 if (dest[ii] < peak && dest[ii] > low) continue;
945
946 errCnt=0;
947 // now that we have the first one lined up test rest of wave array
948 loopEnd = ((size-ii-tol) / clk[clkCnt]) - 1;
949 for (i=0; i < loopEnd; ++i){
950 arrLoc = ii + (i * clk[clkCnt]);
951 if (dest[arrLoc] >= peak || dest[arrLoc] <= low){
952 }else if (dest[arrLoc-tol] >= peak || dest[arrLoc-tol] <= low){
953 }else if (dest[arrLoc+tol] >= peak || dest[arrLoc+tol] <= low){
954 }else{ //error no peak detected
955 errCnt++;
e0165dcf 956 }
957 }
cc15a118 958 //if we found no errors then we can stop here and a low clock (common clocks)
2eec55c8 959 // this is correct one - return this clock
a126332a 960 if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, err %d, startpos %d, endpos %d",clk[clkCnt],errCnt,ii,i);
cc15a118 961 if(errCnt==0 && clkCnt<7) {
962 if (!clockFnd) *clock = clk[clkCnt];
2eec55c8 963 return ii;
964 }
965 //if we found errors see if it is lowest so far and save it as best run
966 if(errCnt<bestErr[clkCnt]){
967 bestErr[clkCnt]=errCnt;
968 bestStart[clkCnt]=ii;
969 }
e0165dcf 970 }
971 }
cc15a118 972 uint8_t iii;
e0165dcf 973 uint8_t best=0;
cc15a118 974 for (iii=1; iii<clkEnd; ++iii){
2eec55c8 975 if (bestErr[iii] < bestErr[best]){
976 if (bestErr[iii] == 0) bestErr[iii]=1;
e0165dcf 977 // current best bit to error ratio vs new bit to error ratio
2eec55c8 978 if ( (size/clk[best])/bestErr[best] < (size/clk[iii])/bestErr[iii] ){
e0165dcf 979 best = iii;
980 }
981 }
a126332a 982 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]);
e0165dcf 983 }
cc15a118 984 if (!clockFnd) *clock = clk[best];
e0165dcf 985 return bestStart[best];
eb191de6 986}
ba1a299c 987
988//by marshmellow
6de43508 989//detect psk clock by reading each phase shift
990// a phase shift is determined by measuring the sample length of each wave
991int DetectPSKClock(uint8_t dest[], size_t size, int clock)
ba1a299c 992{
e0165dcf 993 uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock
994 uint16_t loopCnt = 4096; //don't need to loop through entire array...
995 if (size == 0) return 0;
6426f6ba 996 if (size<loopCnt) loopCnt = size-20;
e0165dcf 997
998 //if we already have a valid clock quit
999 size_t i=1;
1000 for (; i < 8; ++i)
1001 if (clk[i] == clock) return clock;
1002
1003 size_t waveStart=0, waveEnd=0, firstFullWave=0, lastClkBit=0;
1004 uint8_t clkCnt, fc=0, fullWaveLen=0, tol=1;
1005 uint16_t peakcnt=0, errCnt=0, waveLenCnt=0;
1006 uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
1007 uint16_t peaksdet[]={0,0,0,0,0,0,0,0,0};
2eec55c8 1008 fc = countFC(dest, size, 0);
1009 if (fc!=2 && fc!=4 && fc!=8) return -1;
a126332a 1010 if (g_debugMode==2) prnt("DEBUG PSK: FC: %d",fc);
e0165dcf 1011
1012 //find first full wave
6426f6ba 1013 for (i=160; i<loopCnt; i++){
e0165dcf 1014 if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
1015 if (waveStart == 0) {
1016 waveStart = i+1;
6426f6ba 1017 //prnt("DEBUG: waveStart: %d",waveStart);
e0165dcf 1018 } else {
1019 waveEnd = i+1;
6426f6ba 1020 //prnt("DEBUG: waveEnd: %d",waveEnd);
e0165dcf 1021 waveLenCnt = waveEnd-waveStart;
1022 if (waveLenCnt > fc){
1023 firstFullWave = waveStart;
1024 fullWaveLen=waveLenCnt;
1025 break;
1026 }
1027 waveStart=0;
1028 }
1029 }
1030 }
a126332a 1031 if (g_debugMode ==2) prnt("DEBUG PSK: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);
e0165dcf 1032
1033 //test each valid clock from greatest to smallest to see which lines up
1034 for(clkCnt=7; clkCnt >= 1 ; clkCnt--){
1035 lastClkBit = firstFullWave; //set end of wave as clock align
1036 waveStart = 0;
1037 errCnt=0;
1038 peakcnt=0;
a126332a 1039 if (g_debugMode == 2) prnt("DEBUG PSK: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit);
e0165dcf 1040
1041 for (i = firstFullWave+fullWaveLen-1; i < loopCnt-2; i++){
1042 //top edge of wave = start of new wave
1043 if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
1044 if (waveStart == 0) {
1045 waveStart = i+1;
1046 waveLenCnt=0;
1047 } else { //waveEnd
1048 waveEnd = i+1;
1049 waveLenCnt = waveEnd-waveStart;
1050 if (waveLenCnt > fc){
1051 //if this wave is a phase shift
a126332a 1052 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 1053 if (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit
1054 peakcnt++;
1055 lastClkBit+=clk[clkCnt];
1056 } else if (i<lastClkBit+8){
1057 //noise after a phase shift - ignore
1058 } else { //phase shift before supposed to based on clock
1059 errCnt++;
1060 }
1061 } else if (i+1 > lastClkBit + clk[clkCnt] + tol + fc){
1062 lastClkBit+=clk[clkCnt]; //no phase shift but clock bit
1063 }
1064 waveStart=i+1;
1065 }
1066 }
1067 }
1068 if (errCnt == 0){
1069 return clk[clkCnt];
1070 }
1071 if (errCnt <= bestErr[clkCnt]) bestErr[clkCnt]=errCnt;
1072 if (peakcnt > peaksdet[clkCnt]) peaksdet[clkCnt]=peakcnt;
1073 }
1074 //all tested with errors
1075 //return the highest clk with the most peaks found
1076 uint8_t best=7;
1077 for (i=7; i>=1; i--){
1078 if (peaksdet[i] > peaksdet[best]) {
1079 best = i;
1080 }
a126332a 1081 if (g_debugMode == 2) prnt("DEBUG PSK: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[i],peaksdet[i],bestErr[i],clk[best]);
e0165dcf 1082 }
1083 return clk[best];
ba1a299c 1084}
1085
6426f6ba 1086int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low){
1087 //find shortest transition from high to low
1088 size_t i = 0;
1089 size_t transition1 = 0;
1090 int lowestTransition = 255;
1091 bool lastWasHigh = false;
1092
1093 //find first valid beginning of a high or low wave
1094 while ((dest[i] >= peak || dest[i] <= low) && (i < size))
1095 ++i;
1096 while ((dest[i] < peak && dest[i] > low) && (i < size))
1097 ++i;
1098 lastWasHigh = (dest[i] >= peak);
1099
1100 if (i==size) return 0;
1101 transition1 = i;
1102
1103 for (;i < size; i++) {
1104 if ((dest[i] >= peak && !lastWasHigh) || (dest[i] <= low && lastWasHigh)) {
1105 lastWasHigh = (dest[i] >= peak);
1106 if (i-transition1 < lowestTransition) lowestTransition = i-transition1;
1107 transition1 = i;
1108 }
1109 }
6426f6ba 1110 if (lowestTransition == 255) lowestTransition = 0;
a126332a 1111 if (g_debugMode==2) prnt("DEBUG NRZ: detectstrongNRZclk smallest wave: %d",lowestTransition);
6426f6ba 1112 return lowestTransition;
1113}
1114
6de43508 1115//by marshmellow
1116//detect nrz clock by reading #peaks vs no peaks(or errors)
1117int DetectNRZClock(uint8_t dest[], size_t size, int clock)
ba1a299c 1118{
2eec55c8 1119 size_t i=0;
1120 uint8_t clk[]={8,16,32,40,50,64,100,128,255};
1121 size_t loopCnt = 4096; //don't need to loop through entire array...
e0165dcf 1122 if (size == 0) return 0;
6426f6ba 1123 if (size<loopCnt) loopCnt = size-20;
e0165dcf 1124 //if we already have a valid clock quit
1125 for (; i < 8; ++i)
1126 if (clk[i] == clock) return clock;
1127
1128 //get high and low peak
1129 int peak, low;
2eec55c8 1130 if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return 0;
e0165dcf 1131
6426f6ba 1132 int lowestTransition = DetectStrongNRZClk(dest, size-20, peak, low);
2eec55c8 1133 size_t ii;
e0165dcf 1134 uint8_t clkCnt;
1135 uint8_t tol = 0;
6426f6ba 1136 uint16_t smplCnt = 0;
1137 int16_t peakcnt = 0;
1138 int16_t peaksdet[] = {0,0,0,0,0,0,0,0};
1139 uint16_t maxPeak = 255;
1140 bool firstpeak = false;
e0165dcf 1141 //test for large clipped waves
1142 for (i=0; i<loopCnt; i++){
1143 if (dest[i] >= peak || dest[i] <= low){
6426f6ba 1144 if (!firstpeak) continue;
1145 smplCnt++;
e0165dcf 1146 } else {
6426f6ba 1147 firstpeak=true;
1148 if (smplCnt > 6 ){
1149 if (maxPeak > smplCnt){
1150 maxPeak = smplCnt;
1151 //prnt("maxPk: %d",maxPeak);
1152 }
1153 peakcnt++;
1154 //prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt);
1155 smplCnt=0;
e0165dcf 1156 }
e0165dcf 1157 }
1158 }
6426f6ba 1159 bool errBitHigh = 0;
1160 bool bitHigh = 0;
1161 uint8_t ignoreCnt = 0;
1162 uint8_t ignoreWindow = 4;
1163 bool lastPeakHigh = 0;
1164 int lastBit = 0;
e0165dcf 1165 peakcnt=0;
1166 //test each valid clock from smallest to greatest to see which lines up
1167 for(clkCnt=0; clkCnt < 8; ++clkCnt){
6426f6ba 1168 //ignore clocks smaller than smallest peak
1169 if (clk[clkCnt] < maxPeak - (clk[clkCnt]/4)) continue;
e0165dcf 1170 //try lining up the peaks by moving starting point (try first 256)
6426f6ba 1171 for (ii=20; ii < loopCnt; ++ii){
e0165dcf 1172 if ((dest[ii] >= peak) || (dest[ii] <= low)){
1173 peakcnt=0;
6426f6ba 1174 bitHigh = false;
1175 ignoreCnt = 0;
1176 lastBit = ii-clk[clkCnt];
1177 //loop through to see if this start location works
1178 for (i = ii; i < size-20; ++i) {
1179 //if we are at a clock bit
1180 if ((i >= lastBit + clk[clkCnt] - tol) && (i <= lastBit + clk[clkCnt] + tol)) {
1181 //test high/low
1182 if (dest[i] >= peak || dest[i] <= low) {
1183 //if same peak don't count it
1184 if ((dest[i] >= peak && !lastPeakHigh) || (dest[i] <= low && lastPeakHigh)) {
e0165dcf 1185 peakcnt++;
6426f6ba 1186 }
1187 lastPeakHigh = (dest[i] >= peak);
1188 bitHigh = true;
1189 errBitHigh = false;
1190 ignoreCnt = ignoreWindow;
1191 lastBit += clk[clkCnt];
1192 } else if (i == lastBit + clk[clkCnt] + tol) {
1193 lastBit += clk[clkCnt];
1194 }
1195 //else if not a clock bit and no peaks
1196 } else if (dest[i] < peak && dest[i] > low){
1197 if (ignoreCnt==0){
1198 bitHigh=false;
1199 if (errBitHigh==true) peakcnt--;
1200 errBitHigh=false;
1201 } else {
1202 ignoreCnt--;
1203 }
1204 // else if not a clock bit but we have a peak
1205 } else if ((dest[i]>=peak || dest[i]<=low) && (!bitHigh)) {
1206 //error bar found no clock...
1207 errBitHigh=true;
e0165dcf 1208 }
1209 }
1210 if(peakcnt>peaksdet[clkCnt]) {
1211 peaksdet[clkCnt]=peakcnt;
1212 }
1213 }
1214 }
1215 }
1216 int iii=7;
2eec55c8 1217 uint8_t best=0;
e0165dcf 1218 for (iii=7; iii > 0; iii--){
6426f6ba 1219 if ((peaksdet[iii] >= (peaksdet[best]-1)) && (peaksdet[iii] <= peaksdet[best]+1) && lowestTransition) {
1220 if (clk[iii] > (lowestTransition - (clk[iii]/8)) && clk[iii] < (lowestTransition + (clk[iii]/8))) {
1221 best = iii;
1222 }
1223 } else if (peaksdet[iii] > peaksdet[best]){
e0165dcf 1224 best = iii;
1225 }
a126332a 1226 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 1227 }
6426f6ba 1228
e0165dcf 1229 return clk[best];
ba1a299c 1230}
1231
04d2721b 1232// by marshmellow
1233// convert psk1 demod to psk2 demod
1234// only transition waves are 1s
1235void psk1TOpsk2(uint8_t *BitStream, size_t size)
1236{
1237 size_t i=1;
1238 uint8_t lastBit=BitStream[0];
1239 for (; i<size; i++){
2767fc02 1240 if (BitStream[i]==7){
7a8a982b 1241 //ignore errors
1242 } else if (lastBit!=BitStream[i]){
04d2721b 1243 lastBit=BitStream[i];
1244 BitStream[i]=1;
1245 } else {
1246 BitStream[i]=0;
1247 }
1248 }
1249 return;
1250}
ba1a299c 1251
3bc66a96 1252// by marshmellow
1253// convert psk2 demod to psk1 demod
1254// from only transition waves are 1s to phase shifts change bit
1255void psk2TOpsk1(uint8_t *BitStream, size_t size)
1256{
712ebfa6 1257 uint8_t phase=0;
1258 for (size_t i=0; i<size; i++){
1259 if (BitStream[i]==1){
3bc66a96 1260 phase ^=1;
1261 }
1262 BitStream[i]=phase;
1263 }
1264 return;
1265}
1266
04d2721b 1267// redesigned by marshmellow adjusted from existing decode functions
1268// indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
ba1a299c 1269int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert)
1270{
1271 //26 bit 40134 format (don't know other formats)
57c7b44b 1272 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};
1273 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};
1274 size_t startidx = 0;
1275 if (!preambleSearch(bitStream, preamble, sizeof(preamble), size, &startidx)){
1276 // if didn't find preamble try again inverting
1277 if (!preambleSearch(bitStream, preamble_i, sizeof(preamble_i), size, &startidx)) return -1;
1278 *invert ^= 1;
1279 }
1280 if (*size != 64 && *size != 224) return -2;
1281 if (*invert==1)
1282 for (size_t i = startidx; i < *size; i++)
1283 bitStream[i] ^= 1;
ba1a299c 1284
57c7b44b 1285 return (int) startidx;
ba1a299c 1286}
1287
05164399 1288// by marshmellow - demodulate NRZ wave - requires a read with strong signal
04d2721b 1289// peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
6426f6ba 1290int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert){
e0165dcf 1291 if (justNoise(dest, *size)) return -1;
1292 *clk = DetectNRZClock(dest, *size, *clk);
1293 if (*clk==0) return -2;
2eec55c8 1294 size_t i, gLen = 4096;
6426f6ba 1295 if (gLen>*size) gLen = *size-20;
e0165dcf 1296 int high, low;
1297 if (getHiLo(dest, gLen, &high, &low, 75, 75) < 1) return -3; //25% fuzz on high 25% fuzz on low
6426f6ba 1298
1299 uint8_t bit=0;
1300 //convert wave samples to 1's and 0's
1301 for(i=20; i < *size-20; i++){
1302 if (dest[i] >= high) bit = 1;
1303 if (dest[i] <= low) bit = 0;
1304 dest[i] = bit;
e0165dcf 1305 }
6426f6ba 1306 //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit)
1307 size_t lastBit = 0;
1308 size_t numBits = 0;
1309 for(i=21; i < *size-20; i++) {
1310 //if transition detected or large number of same bits - store the passed bits
1311 if (dest[i] != dest[i-1] || (i-lastBit) == (10 * *clk)) {
1312 memset(dest+numBits, dest[i-1] ^ *invert, (i - lastBit + (*clk/4)) / *clk);
1313 numBits += (i - lastBit + (*clk/4)) / *clk;
1314 lastBit = i-1;
e0165dcf 1315 }
e0165dcf 1316 }
6426f6ba 1317 *size = numBits;
1318 return 0;
ba1a299c 1319}
1320
1e090a61 1321//by marshmellow
03e6bb4a 1322//detects the bit clock for FSK given the high and low Field Clocks
1323uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow)
1e090a61 1324{
e0165dcf 1325 uint8_t clk[] = {8,16,32,40,50,64,100,128,0};
1326 uint16_t rfLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
1327 uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
1328 uint8_t rfLensFnd = 0;
2eec55c8 1329 uint8_t lastFCcnt = 0;
1330 uint16_t fcCounter = 0;
e0165dcf 1331 uint16_t rfCounter = 0;
1332 uint8_t firstBitFnd = 0;
1333 size_t i;
1334 if (size == 0) return 0;
1335
6426f6ba 1336 uint8_t fcTol = ((fcHigh*100 - fcLow*100)/2 + 50)/100; //(uint8_t)(0.5+(float)(fcHigh-fcLow)/2);
e0165dcf 1337 rfLensFnd=0;
1338 fcCounter=0;
1339 rfCounter=0;
1340 firstBitFnd=0;
1341 //PrintAndLog("DEBUG: fcTol: %d",fcTol);
6426f6ba 1342 // prime i to first peak / up transition
1343 for (i = 160; i < size-20; i++)
e0165dcf 1344 if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1])
1345 break;
1346
6426f6ba 1347 for (; i < size-20; i++){
2eec55c8 1348 fcCounter++;
1349 rfCounter++;
1350
1351 if (BitStream[i] <= BitStream[i-1] || BitStream[i] < BitStream[i+1])
1352 continue;
1353 // else new peak
1354 // if we got less than the small fc + tolerance then set it to the small fc
1355 if (fcCounter < fcLow+fcTol)
1356 fcCounter = fcLow;
1357 else //set it to the large fc
1358 fcCounter = fcHigh;
1359
1360 //look for bit clock (rf/xx)
1361 if ((fcCounter < lastFCcnt || fcCounter > lastFCcnt)){
1362 //not the same size as the last wave - start of new bit sequence
1363 if (firstBitFnd > 1){ //skip first wave change - probably not a complete bit
1364 for (int ii=0; ii<15; ii++){
6426f6ba 1365 if (rfLens[ii] >= (rfCounter-4) && rfLens[ii] <= (rfCounter+4)){
2eec55c8 1366 rfCnts[ii]++;
1367 rfCounter = 0;
1368 break;
e0165dcf 1369 }
e0165dcf 1370 }
2eec55c8 1371 if (rfCounter > 0 && rfLensFnd < 15){
1372 //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
1373 rfCnts[rfLensFnd]++;
1374 rfLens[rfLensFnd++] = rfCounter;
1375 }
1376 } else {
1377 firstBitFnd++;
e0165dcf 1378 }
2eec55c8 1379 rfCounter=0;
1380 lastFCcnt=fcCounter;
e0165dcf 1381 }
2eec55c8 1382 fcCounter=0;
e0165dcf 1383 }
1384 uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15;
1385
1386 for (i=0; i<15; i++){
e0165dcf 1387 //get highest 2 RF values (might need to get more values to compare or compare all?)
1388 if (rfCnts[i]>rfCnts[rfHighest]){
1389 rfHighest3=rfHighest2;
1390 rfHighest2=rfHighest;
1391 rfHighest=i;
1392 } else if(rfCnts[i]>rfCnts[rfHighest2]){
1393 rfHighest3=rfHighest2;
1394 rfHighest2=i;
1395 } else if(rfCnts[i]>rfCnts[rfHighest3]){
1396 rfHighest3=i;
1397 }
a126332a 1398 if (g_debugMode==2) prnt("DEBUG FSK: RF %d, cnts %d",rfLens[i], rfCnts[i]);
e0165dcf 1399 }
1400 // set allowed clock remainder tolerance to be 1 large field clock length+1
1401 // we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off
1402 uint8_t tol1 = fcHigh+1;
1403
a126332a 1404 if (g_debugMode==2) prnt("DEBUG FSK: most counted rf values: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]);
e0165dcf 1405
1406 // loop to find the highest clock that has a remainder less than the tolerance
1407 // compare samples counted divided by
6426f6ba 1408 // test 128 down to 32 (shouldn't be possible to have fc/10 & fc/8 and rf/16 or less)
e0165dcf 1409 int ii=7;
6426f6ba 1410 for (; ii>=2; ii--){
e0165dcf 1411 if (rfLens[rfHighest] % clk[ii] < tol1 || rfLens[rfHighest] % clk[ii] > clk[ii]-tol1){
1412 if (rfLens[rfHighest2] % clk[ii] < tol1 || rfLens[rfHighest2] % clk[ii] > clk[ii]-tol1){
1413 if (rfLens[rfHighest3] % clk[ii] < tol1 || rfLens[rfHighest3] % clk[ii] > clk[ii]-tol1){
a126332a 1414 if (g_debugMode==2) prnt("DEBUG FSK: clk %d divides into the 3 most rf values within tolerance",clk[ii]);
e0165dcf 1415 break;
1416 }
1417 }
1418 }
1419 }
1420
1421 if (ii<0) return 0; // oops we went too far
1422
1423 return clk[ii];
03e6bb4a 1424}
1e090a61 1425
03e6bb4a 1426//by marshmellow
1427//countFC is to detect the field clock lengths.
1428//counts and returns the 2 most common wave lengths
6de43508 1429//mainly used for FSK field clock detection
2eec55c8 1430uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj)
03e6bb4a 1431{
6426f6ba 1432 uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
1433 uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
e0165dcf 1434 uint8_t fcLensFnd = 0;
1435 uint8_t lastFCcnt=0;
2eec55c8 1436 uint8_t fcCounter = 0;
e0165dcf 1437 size_t i;
1438 if (size == 0) return 0;
1439
1440 // prime i to first up transition
6426f6ba 1441 for (i = 160; i < size-20; i++)
e0165dcf 1442 if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1])
1443 break;
1444
6426f6ba 1445 for (; i < size-20; i++){
e0165dcf 1446 if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){
1447 // new up transition
1448 fcCounter++;
2eec55c8 1449 if (fskAdj){
1450 //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8)
1451 if (lastFCcnt==5 && fcCounter==9) fcCounter--;
1452 //if fc=9 or 4 add one (for when we get a fc 9 instead of 10 or a 4 instead of a 5)
1453 if ((fcCounter==9) || fcCounter==4) fcCounter++;
e0165dcf 1454 // save last field clock count (fc/xx)
2eec55c8 1455 lastFCcnt = fcCounter;
1456 }
e0165dcf 1457 // find which fcLens to save it to:
6426f6ba 1458 for (int ii=0; ii<15; ii++){
e0165dcf 1459 if (fcLens[ii]==fcCounter){
1460 fcCnts[ii]++;
1461 fcCounter=0;
1462 break;
1463 }
1464 }
6426f6ba 1465 if (fcCounter>0 && fcLensFnd<15){
e0165dcf 1466 //add new fc length
1467 fcCnts[fcLensFnd]++;
1468 fcLens[fcLensFnd++]=fcCounter;
1469 }
1470 fcCounter=0;
1471 } else {
1472 // count sample
1473 fcCounter++;
1474 }
1475 }
1476
6426f6ba 1477 uint8_t best1=14, best2=14, best3=14;
e0165dcf 1478 uint16_t maxCnt1=0;
1479 // go through fclens and find which ones are bigest 2
6426f6ba 1480 for (i=0; i<15; i++){
e0165dcf 1481 // get the 3 best FC values
1482 if (fcCnts[i]>maxCnt1) {
1483 best3=best2;
1484 best2=best1;
1485 maxCnt1=fcCnts[i];
1486 best1=i;
1487 } else if(fcCnts[i]>fcCnts[best2]){
1488 best3=best2;
1489 best2=i;
1490 } else if(fcCnts[i]>fcCnts[best3]){
1491 best3=i;
1492 }
a126332a 1493 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 1494 }
6426f6ba 1495 if (fcLens[best1]==0) return 0;
e0165dcf 1496 uint8_t fcH=0, fcL=0;
1497 if (fcLens[best1]>fcLens[best2]){
1498 fcH=fcLens[best1];
1499 fcL=fcLens[best2];
1500 } else{
1501 fcH=fcLens[best2];
1502 fcL=fcLens[best1];
1503 }
a126332a 1504 if ((size-180)/fcH/3 > fcCnts[best1]+fcCnts[best2]) {
1505 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]);
1506 return 0; //lots of waves not psk or fsk
1507 }
e0165dcf 1508 // TODO: take top 3 answers and compare to known Field clocks to get top 2
1509
1510 uint16_t fcs = (((uint16_t)fcH)<<8) | fcL;
2eec55c8 1511 if (fskAdj) return fcs;
1512 return fcLens[best1];
6de43508 1513}
1514
1515//by marshmellow - demodulate PSK1 wave
1516//uses wave lengths (# Samples)
1517int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
1518{
e0165dcf 1519 if (size == 0) return -1;
2eec55c8 1520 uint16_t loopCnt = 4096; //don't need to loop through entire array...
e0165dcf 1521 if (*size<loopCnt) loopCnt = *size;
1522
6426f6ba 1523 size_t numBits=0;
e0165dcf 1524 uint8_t curPhase = *invert;
1525 size_t i, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0;
1526 uint8_t fc=0, fullWaveLen=0, tol=1;
1527 uint16_t errCnt=0, waveLenCnt=0;
2eec55c8 1528 fc = countFC(dest, *size, 0);
e0165dcf 1529 if (fc!=2 && fc!=4 && fc!=8) return -1;
1530 //PrintAndLog("DEBUG: FC: %d",fc);
1531 *clock = DetectPSKClock(dest, *size, *clock);
2eec55c8 1532 if (*clock == 0) return -1;
e0165dcf 1533 int avgWaveVal=0, lastAvgWaveVal=0;
1534 //find first phase shift
1535 for (i=0; i<loopCnt; i++){
1536 if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
1537 waveEnd = i+1;
1538 //PrintAndLog("DEBUG: waveEnd: %d",waveEnd);
1539 waveLenCnt = waveEnd-waveStart;
6426f6ba 1540 if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+2)){ //not first peak and is a large wave but not out of whack
e0165dcf 1541 lastAvgWaveVal = avgWaveVal/(waveLenCnt);
1542 firstFullWave = waveStart;
1543 fullWaveLen=waveLenCnt;
1544 //if average wave value is > graph 0 then it is an up wave or a 1
2eec55c8 1545 if (lastAvgWaveVal > 123) curPhase ^= 1; //fudge graph 0 a little 123 vs 128
e0165dcf 1546 break;
1547 }
1548 waveStart = i+1;
1549 avgWaveVal = 0;
1550 }
2eec55c8 1551 avgWaveVal += dest[i+2];
e0165dcf 1552 }
6426f6ba 1553 if (firstFullWave == 0) {
1554 // no phase shift detected - could be all 1's or 0's - doesn't matter where we start
1555 // so skip a little to ensure we are past any Start Signal
1556 firstFullWave = 160;
1557 memset(dest, curPhase, firstFullWave / *clock);
1558 } else {
1559 memset(dest, curPhase^1, firstFullWave / *clock);
1560 }
1561 //advance bits
1562 numBits += (firstFullWave / *clock);
1563 //set start of wave as clock align
1564 lastClkBit = firstFullWave;
7fa7e812 1565 if (g_debugMode==2) prnt("DEBUG PSK: firstFullWave: %u, waveLen: %u",firstFullWave,fullWaveLen);
1566 if (g_debugMode==2) prnt("DEBUG: clk: %d, lastClkBit: %u, fc: %u", *clock, lastClkBit,(unsigned int) fc);
e0165dcf 1567 waveStart = 0;
e0165dcf 1568 dest[numBits++] = curPhase; //set first read bit
2eec55c8 1569 for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){
e0165dcf 1570 //top edge of wave = start of new wave
1571 if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
1572 if (waveStart == 0) {
1573 waveStart = i+1;
2eec55c8 1574 waveLenCnt = 0;
e0165dcf 1575 avgWaveVal = dest[i+1];
1576 } else { //waveEnd
1577 waveEnd = i+1;
1578 waveLenCnt = waveEnd-waveStart;
1579 lastAvgWaveVal = avgWaveVal/waveLenCnt;
1580 if (waveLenCnt > fc){
1581 //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);
2eec55c8 1582 //this wave is a phase shift
e0165dcf 1583 //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc);
1584 if (i+1 >= lastClkBit + *clock - tol){ //should be a clock bit
2eec55c8 1585 curPhase ^= 1;
e0165dcf 1586 dest[numBits++] = curPhase;
1587 lastClkBit += *clock;
2eec55c8 1588 } else if (i < lastClkBit+10+fc){
e0165dcf 1589 //noise after a phase shift - ignore
1590 } else { //phase shift before supposed to based on clock
1591 errCnt++;
2767fc02 1592 dest[numBits++] = 7;
e0165dcf 1593 }
1594 } else if (i+1 > lastClkBit + *clock + tol + fc){
1595 lastClkBit += *clock; //no phase shift but clock bit
1596 dest[numBits++] = curPhase;
1597 }
2eec55c8 1598 avgWaveVal = 0;
1599 waveStart = i+1;
e0165dcf 1600 }
1601 }
2eec55c8 1602 avgWaveVal += dest[i+1];
e0165dcf 1603 }
1604 *size = numBits;
1605 return errCnt;
6de43508 1606}
05164399 1607
1608//by marshmellow
1609//attempt to identify a Sequence Terminator in ASK modulated raw wave
1610bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
1611 size_t bufsize = *size;
1612 //need to loop through all samples and identify our clock, look for the ST pattern
1613 uint8_t fndClk[] = {8,16,32,40,50,64,128};
1614 int clk = 0;
1615 int tol = 0;
1616 int i, j, skip, start, end, low, high, minClk, waveStart;
1617 bool complete = false;
1618 int tmpbuff[bufsize / 64];
1619 int waveLen[bufsize / 64];
1620 size_t testsize = (bufsize < 512) ? bufsize : 512;
1621 int phaseoff = 0;
1622 high = low = 128;
1623 memset(tmpbuff, 0, sizeof(tmpbuff));
1624
1625 if ( getHiLo(buffer, testsize, &high, &low, 80, 80) == -1 ) {
1626 if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting");
1627 return false; //just noise
1628 }
1629 i = 0;
1630 j = 0;
1631 minClk = 255;
1632 // get to first full low to prime loop and skip incomplete first pulse
1633 while ((buffer[i] < high) && (i < bufsize))
1634 ++i;
1635 while ((buffer[i] > low) && (i < bufsize))
1636 ++i;
1637 skip = i;
1638
1639 // populate tmpbuff buffer with pulse lengths
1640 while (i < bufsize) {
1641 // measure from low to low
1642 while ((buffer[i] > low) && (i < bufsize))
1643 ++i;
1644 start= i;
1645 while ((buffer[i] < high) && (i < bufsize))
1646 ++i;
1647 //first high point for this wave
1648 waveStart = i;
1649 while ((buffer[i] > low) && (i < bufsize))
1650 ++i;
1651 if (j >= (bufsize/64)) {
1652 break;
1653 }
1654 waveLen[j] = i - waveStart; //first high to first low
1655 tmpbuff[j++] = i - start;
1656 if (i-start < minClk && i < bufsize) {
1657 minClk = i - start;
1658 }
1659 }
1660 // set clock - might be able to get this externally and remove this work...
1661 if (!clk) {
1662 for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
1663 tol = fndClk[clkCnt]/8;
1664 if (minClk >= fndClk[clkCnt]-tol && minClk <= fndClk[clkCnt]+1) {
1665 clk=fndClk[clkCnt];
1666 break;
1667 }
1668 }
1669 // clock not found - ERROR
1670 if (!clk) {
1671 if (g_debugMode==2) prnt("DEBUG STT: clock not found - quitting");
1672 return false;
1673 }
1674 } else tol = clk/8;
1675
1676 *foundclock = clk;
1677
1678 // look for Sequence Terminator - should be pulses of clk*(1 or 1.5), clk*2, clk*(1.5 or 2)
1679 start = -1;
1680 for (i = 0; i < j - 4; ++i) {
1681 skip += tmpbuff[i];
1682 if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol && waveLen[i] < clk+tol) { //1 to 2 clocks depending on 2 bits prior
1683 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
1684 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
1685 if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit
1686 start = i + 3;
1687 break;
1688 }
1689 }
1690 }
1691 }
1692 }
1693 // first ST not found - ERROR
1694 if (start < 0) {
1695 if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting");
1696 return false;
1697 }
1698 if (waveLen[i+2] > clk*1+tol)
1699 phaseoff = 0;
1700 else
1701 phaseoff = clk/2;
1702
1703 // skip over the remainder of ST
1704 skip += clk*7/2; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point
1705
1706 // now do it again to find the end
1707 end = skip;
1708 for (i += 3; i < j - 4; ++i) {
1709 end += tmpbuff[i];
1710 if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol) { //1 to 2 clocks depending on 2 bits prior
1711 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
1712 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
1713 if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit
1714 complete = true;
1715 break;
1716 }
1717 }
1718 }
1719 }
1720 }
1721 end -= phaseoff;
1722 //didn't find second ST - ERROR
1723 if (!complete) {
1724 if (g_debugMode==2) prnt("DEBUG STT: second STT not found - quitting");
1725 return false;
1726 }
1727 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);
1728 //now begin to trim out ST so we can use normal demod cmds
1729 start = skip;
1730 size_t datalen = end - start;
1731 // check validity of datalen (should be even clock increments) - use a tolerance of up to 1/8th a clock
1732 if (datalen % clk > clk/8) {
1733 if (g_debugMode==2) prnt("DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting", datalen, clk, datalen % clk);
1734 return false;
1735 } else {
1736 // padd the amount off - could be problematic... but shouldn't happen often
1737 datalen += datalen % clk;
1738 }
1739 // if datalen is less than one t55xx block - ERROR
1740 if (datalen/clk < 8*4) {
1741 if (g_debugMode==2) prnt("DEBUG STT: datalen is less than 1 full t55xx block - quitting");
1742 return false;
1743 }
1744 size_t dataloc = start;
1745 size_t newloc = 0;
1746 i=0;
1747 // warning - overwriting buffer given with raw wave data with ST removed...
1748 while ( dataloc < bufsize-(clk/2) ) {
7fa7e812 1749 //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 1750 if (buffer[dataloc]<high && buffer[dataloc]>low && buffer[dataloc+3]<high && buffer[dataloc+3]>low) {
1751 for(i=0; i < clk/2-tol; ++i) {
1752 buffer[dataloc+i] = high+5;
1753 }
1754 }
1755 for (i=0; i<datalen; ++i) {
1756 if (i+newloc < bufsize) {
1757 if (i+newloc < dataloc)
1758 buffer[i+newloc] = buffer[dataloc];
1759
1760 dataloc++;
1761 }
1762 }
1763 newloc += i;
7fa7e812 1764 //skip next ST - we just assume it will be there from now on...
05164399 1765 dataloc += clk*4;
1766 }
1767 *size = newloc;
1768 return true;
1769}
Impressum, Datenschutz