refactor detectST a little...
[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//-----------------------------------------------------------------------------
bf74114d 8// Low frequency demod/decode commands - by marshmellow, holiman, iceman and
9// many others who came before
4d3c1796 10//
11// NOTES:
12// LF Demod functions are placed here to allow the flexability to use client or
13// device side. Most BUT NOT ALL of these functions are currenlty safe for
14// device side use currently. (DetectST for example...)
15//
16// There are likely many improvements to the code that could be made, please
17// make suggestions...
18//
bf74114d 19// we tried to include author comments so any questions could be directed to
20// the source.
21//
4d3c1796 22// There are 4 main sections of code below:
23// Utilities Section:
24// for general utilities used by multiple other functions
25// Modulation Demods &/or Decoding Section:
26// for main general modulation demodulating and encoding decoding code.
27// Clock / Bitrate Detection Section:
28// for clock detection functions for each modulation
29// Tag format detection section:
30// for detection of specific tag formats within demodulated data
31//
32// marshmellow
eb191de6 33//-----------------------------------------------------------------------------
34
eb191de6 35#include <stdlib.h>
eb191de6 36#include "lfdemod.h"
d1869c33 37#include <string.h>
6fe5c94b 38
bf74114d 39//---------------------------------Utilities Section--------------------------------------------------
40
d1869c33 41//to allow debug print calls when used not on device
6fe5c94b 42void dummy(char *fmt, ...){}
6fe5c94b 43#ifndef ON_DEVICE
44#include "ui.h"
709665b5 45#include "cmdparser.h"
46#include "cmddata.h"
6fe5c94b 47#define prnt PrintAndLog
48#else
709665b5 49 uint8_t g_debugMode=0;
6fe5c94b 50#define prnt dummy
51#endif
6fe5c94b 52
bf74114d 53uint8_t justNoise(uint8_t *BitStream, size_t size) {
a1d17964 54 static const uint8_t THRESHOLD = 123;
55 //test samples are not just noise
56 uint8_t justNoise1 = 1;
57 for(size_t idx=0; idx < size && justNoise1 ;idx++){
58 justNoise1 = BitStream[idx] < THRESHOLD;
59 }
60 return justNoise1;
61}
62
1e090a61 63//by marshmellow
872e3d4d 64//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
bf74114d 65int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi, uint8_t fuzzLo) {
1e090a61 66 *high=0;
67 *low=255;
68 // get high and low thresholds
2eec55c8 69 for (size_t i=0; i < size; i++){
1e090a61 70 if (BitStream[i] > *high) *high = BitStream[i];
71 if (BitStream[i] < *low) *low = BitStream[i];
72 }
73 if (*high < 123) return -1; // just noise
75cbbe9a 74 *high = ((*high-128)*fuzzHi + 12800)/100;
75 *low = ((*low-128)*fuzzLo + 12800)/100;
1e090a61 76 return 1;
77}
78
a1d17964 79// by marshmellow
80// pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType
81// returns 1 if passed
bf74114d 82uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType) {
a1d17964 83 uint8_t ans = 0;
84 for (uint8_t i = 0; i < bitLen; i++){
85 ans ^= ((bits >> i) & 1);
86 }
e39a92bb 87 if (g_debugMode) prnt("DEBUG: ans: %d, ptype: %d, bits: %08X",ans,pType,bits);
a1d17964 88 return (ans == pType);
89}
90
709665b5 91// by marshmellow
92// takes a array of binary values, start position, length of bits per parity (includes parity bit),
88e85bde 93// Parity Type (1 for odd; 0 for even; 2 for Always 1's; 3 for Always 0's), and binary Length (length to run)
bf74114d 94size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen) {
709665b5 95 uint32_t parityWd = 0;
96 size_t j = 0, bitCnt = 0;
e39a92bb 97 for (int word = 0; word < (bLen); word+=pLen) {
98 for (int bit=0; bit < pLen; bit++) {
709665b5 99 parityWd = (parityWd << 1) | BitStream[startIdx+word+bit];
100 BitStream[j++] = (BitStream[startIdx+word+bit]);
101 }
e88096ba 102 if (word+pLen > bLen) break;
e39a92bb 103
709665b5 104 j--; // overwrite parity with next data
105 // if parity fails then return 0
88e85bde 106 switch (pType) {
29435274 107 case 3: if (BitStream[j]==1) {return 0;} break; //should be 0 spacer bit
108 case 2: if (BitStream[j]==0) {return 0;} break; //should be 1 spacer bit
109 default: if (parityTest(parityWd, pLen, pType) == 0) {return 0;} break; //test parity
709665b5 110 }
111 bitCnt+=(pLen-1);
112 parityWd = 0;
113 }
114 // if we got here then all the parities passed
115 //return ID start index and size
116 return bitCnt;
117}
118
119// by marshmellow
120// takes a array of binary values, length of bits per parity (includes parity bit),
88e85bde 121// Parity Type (1 for odd; 0 for even; 2 Always 1's; 3 Always 0's), and binary Length (length to run)
122// Make sure *dest is long enough to store original sourceLen + #_of_parities_to_be_added
bf74114d 123size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t pLen, uint8_t pType) {
709665b5 124 uint32_t parityWd = 0;
125 size_t j = 0, bitCnt = 0;
126 for (int word = 0; word < sourceLen; word+=pLen-1) {
127 for (int bit=0; bit < pLen-1; bit++){
128 parityWd = (parityWd << 1) | BitSource[word+bit];
129 dest[j++] = (BitSource[word+bit]);
130 }
131 // if parity fails then return 0
88e85bde 132 switch (pType) {
133 case 3: dest[j++]=0; break; // marker bit which should be a 0
134 case 2: dest[j++]=1; break; // marker bit which should be a 1
135 default:
136 dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1;
137 break;
709665b5 138 }
139 bitCnt += pLen;
140 parityWd = 0;
141 }
142 // if we got here then all the parities passed
143 //return ID start index and size
144 return bitCnt;
145}
146
bf74114d 147uint32_t bytebits_to_byte(uint8_t *src, size_t numbits) {
709665b5 148 uint32_t num = 0;
149 for(int i = 0 ; i < numbits ; i++)
150 {
151 num = (num << 1) | (*src);
152 src++;
153 }
154 return num;
155}
156
157//least significant bit first
bf74114d 158uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits) {
709665b5 159 uint32_t num = 0;
160 for(int i = 0 ; i < numbits ; i++)
161 {
162 num = (num << 1) | *(src + (numbits-(i+1)));
163 }
164 return num;
165}
166
e88096ba 167// search for given preamble in given BitStream and return success=1 or fail=0 and startIndex (where it was found) and length if not fineone
168// fineone does not look for a repeating preamble for em4x05/4x69 sends preamble once, so look for it once in the first pLen bits
169bool preambleSearchEx(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx, bool findone) {
59f726c9 170 // Sanity check. If preamble length is bigger than bitstream length.
e88096ba 171 if ( *size <= pLen ) return false;
59f726c9 172
e88096ba 173 uint8_t foundCnt = 0;
174 for (size_t idx = 0; idx < *size - pLen; idx++) {
175 if (memcmp(BitStream+idx, preamble, pLen) == 0) {
e0165dcf 176 //first index found
177 foundCnt++;
e88096ba 178 if (foundCnt == 1) {
179 if (g_debugMode) prnt("DEBUG: preamble found at %u", idx);
e0165dcf 180 *startIdx = idx;
e88096ba 181 if (findone) return true;
182 } else if (foundCnt == 2) {
e0165dcf 183 *size = idx - *startIdx;
e88096ba 184 return true;
e0165dcf 185 }
186 }
187 }
4c6ccc2b 188 return false;
189}
190
bf74114d 191//by marshmellow
192//search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length
193uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx) {
194 return (preambleSearchEx(BitStream, preamble, pLen, size, startIdx, false)) ? 1 : 0;
195}
196
34ff8985 197// find start of modulating data (for fsk and psk) in case of beginning noise or slow chip startup.
198size_t findModStart(uint8_t dest[], size_t size, uint8_t threshold_value, uint8_t expWaveSize) {
199 size_t i = 0;
200 size_t waveSizeCnt = 0;
201 uint8_t thresholdCnt = 0;
202 bool isAboveThreshold = dest[i++] >= threshold_value;
203 for (; i < size-20; i++ ) {
204 if(dest[i] < threshold_value && isAboveThreshold) {
205 thresholdCnt++;
206 if (thresholdCnt > 2 && waveSizeCnt < expWaveSize+1) break;
207 isAboveThreshold = false;
208 waveSizeCnt = 0;
209 } else if (dest[i] >= threshold_value && !isAboveThreshold) {
210 thresholdCnt++;
211 if (thresholdCnt > 2 && waveSizeCnt < expWaveSize+1) break;
212 isAboveThreshold = true;
213 waveSizeCnt = 0;
214 } else {
215 waveSizeCnt++;
216 }
217 if (thresholdCnt > 10) break;
218 }
219 if (g_debugMode == 2) prnt("DEBUG: threshold Count reached at %u, count: %u",i, thresholdCnt);
220 return i;
221}
222
2147c307 223//by marshmellow
4d3c1796 224//amplify based on ask edge detection - not accurate enough to use all the time
225void askAmp(uint8_t *BitStream, size_t size) {
16ea2b8c 226 uint8_t Last = 128;
fef74fdc 227 for(size_t i = 1; i<size; i++){
228 if (BitStream[i]-BitStream[i-1]>=30) //large jump up
16ea2b8c 229 Last = 255;
230 else if(BitStream[i-1]-BitStream[i]>=20) //large jump down
231 Last = 0;
232
233 BitStream[i-1] = Last;
fef74fdc 234 }
235 return;
236}
f822a063 237
3606ac0a 238uint32_t manchesterEncode2Bytes(uint16_t datain) {
239 uint32_t output = 0;
240 uint8_t curBit = 0;
241 for (uint8_t i=0; i<16; i++) {
242 curBit = (datain >> (15-i) & 1);
243 output |= (1<<(((15-i)*2)+curBit));
244 }
245 return output;
246}
247
fef74fdc 248//by marshmellow
249//encode binary data into binary manchester
4d3c1796 250//NOTE: BitStream must have double the size available in memory to do the swap
251int ManchesterEncode(uint8_t *BitStream, size_t size) {
252 size_t modIdx=size, i=0;
fef74fdc 253 if (size>modIdx) return -1;
254 for (size_t idx=0; idx < size; idx++){
255 BitStream[idx+modIdx++] = BitStream[idx];
256 BitStream[idx+modIdx++] = BitStream[idx]^1;
257 }
258 for (; i<(size*2); i++){
4d3c1796 259 BitStream[i] = BitStream[i+size];
fef74fdc 260 }
261 return i;
262}
263
4d3c1796 264//------------------------------Modulation Demods &/or Decoding Section------------------------------------------------------
265
bf74114d 266// look for Sequence Terminator - should be pulses of clk*(1 or 2), clk*2, clk*(1.5 or 2), by idx we mean graph position index...
267bool findST(int *stStopLoc, int *stStartIdx, int lowToLowWaveLen[], int highToLowWaveLen[], int clk, int tol, int buffSize, int i) {
268 for (; i < buffSize - 4; ++i) {
269 *stStartIdx += lowToLowWaveLen[i]; //caution part of this wave may be data and part may be ST.... to be accounted for in main function for now...
270 if (lowToLowWaveLen[i] >= clk*1-tol && lowToLowWaveLen[i] <= (clk*2)+tol && highToLowWaveLen[i] < clk+tol) { //1 to 2 clocks depending on 2 bits prior
271 if (lowToLowWaveLen[i+1] >= clk*2-tol && lowToLowWaveLen[i+1] <= clk*2+tol && highToLowWaveLen[i+1] > clk*3/2-tol) { //2 clocks and wave size is 1 1/2
272 if (lowToLowWaveLen[i+2] >= (clk*3)/2-tol && lowToLowWaveLen[i+2] <= clk*2+tol && highToLowWaveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave
273 if (lowToLowWaveLen[i+3] >= clk*1-tol && lowToLowWaveLen[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit
274 *stStopLoc = i + 3;
275 return true;
276 }
277 }
278 }
279 }
280 }
281 return false;
282}
f822a063 283//by marshmellow
4d3c1796 284//attempt to identify a Sequence Terminator in ASK modulated raw wave
285bool DetectST_ext(uint8_t buffer[], size_t *size, int *foundclock, size_t *ststart, size_t *stend) {
286 size_t bufsize = *size;
287 //need to loop through all samples and identify our clock, look for the ST pattern
288 uint8_t fndClk[] = {8,16,32,40,50,64,128};
289 int clk = 0;
290 int tol = 0;
291 int i, j, skip, start, end, low, high, minClk, waveStart;
bf74114d 292 //probably should malloc... || test if memory is available ... handle device side? memory danger!!! [marshmellow]
293 int tmpbuff[bufsize / 32]; // low to low wave count //guess rf/32 clock, if click is smaller we will only have room for a fraction of the samples captured
294 int waveLen[bufsize / 32]; // high to low wave count //if clock is larger then we waste memory in array size that is not needed...
4d3c1796 295 size_t testsize = (bufsize < 512) ? bufsize : 512;
296 int phaseoff = 0;
297 high = low = 128;
298 memset(tmpbuff, 0, sizeof(tmpbuff));
299
300 if ( getHiLo(buffer, testsize, &high, &low, 80, 80) == -1 ) {
301 if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting");
302 return false; //just noise
2147c307 303 }
4d3c1796 304 i = 0;
305 j = 0;
306 minClk = 255;
307 // get to first full low to prime loop and skip incomplete first pulse
308 while ((buffer[i] < high) && (i < bufsize))
309 ++i;
310 while ((buffer[i] > low) && (i < bufsize))
311 ++i;
312 skip = i;
313
314 // populate tmpbuff buffer with pulse lengths
315 while (i < bufsize) {
316 // measure from low to low
317 while ((buffer[i] > low) && (i < bufsize))
318 ++i;
319 start= i;
320 while ((buffer[i] < high) && (i < bufsize))
321 ++i;
322 //first high point for this wave
323 waveStart = i;
324 while ((buffer[i] > low) && (i < bufsize))
325 ++i;
326 if (j >= (bufsize/32)) {
327 break;
328 }
329 waveLen[j] = i - waveStart; //first high to first low
330 tmpbuff[j++] = i - start;
331 if (i-start < minClk && i < bufsize) {
332 minClk = i - start;
333 }
334 }
335 // set clock - might be able to get this externally and remove this work...
336 if (!clk) {
337 for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
338 tol = fndClk[clkCnt]/8;
339 if (minClk >= fndClk[clkCnt]-tol && minClk <= fndClk[clkCnt]+1) {
340 clk=fndClk[clkCnt];
341 break;
342 }
343 }
344 // clock not found - ERROR
345 if (!clk) {
346 if (g_debugMode==2) prnt("DEBUG STT: clock not found - quitting");
347 return false;
348 }
349 } else tol = clk/8;
350
351 *foundclock = clk;
bf74114d 352 i=0;
353 if (!findST(&start, &skip, tmpbuff, waveLen, clk, tol, j, i)) {
354 // first ST not found - ERROR
4d3c1796 355 if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting");
356 return false;
357 } else {
358 if (g_debugMode==2) prnt("DEBUG STT: first STT found at: %d, j=%d",start, j);
359 }
360 if (waveLen[i+2] > clk*1+tol)
361 phaseoff = 0;
362 else
363 phaseoff = clk/2;
364
365 // skip over the remainder of ST
366 skip += clk*7/2; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point
367
368 // now do it again to find the end
bf74114d 369 int dummy1 = 0;
4d3c1796 370 end = skip;
bf74114d 371 if (!findST(&dummy1, &end, tmpbuff, waveLen, clk, tol, j, i+3)) {
372 //didn't find second ST - ERROR
4d3c1796 373 if (g_debugMode==2) prnt("DEBUG STT: second STT not found - quitting");
374 return false;
375 }
bf74114d 376 end -= phaseoff;
4d3c1796 377 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);
378 //now begin to trim out ST so we can use normal demod cmds
379 start = skip;
380 size_t datalen = end - start;
381 // check validity of datalen (should be even clock increments) - use a tolerance of up to 1/8th a clock
382 if ( clk - (datalen % clk) <= clk/8) {
383 // padd the amount off - could be problematic... but shouldn't happen often
384 datalen += clk - (datalen % clk);
385 } else if ( (datalen % clk) <= clk/8 ) {
386 // padd the amount off - could be problematic... but shouldn't happen often
387 datalen -= datalen % clk;
388 } else {
389 if (g_debugMode==2) prnt("DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting", datalen, clk, datalen % clk);
390 return false;
391 }
392 // if datalen is less than one t55xx block - ERROR
393 if (datalen/clk < 8*4) {
394 if (g_debugMode==2) prnt("DEBUG STT: datalen is less than 1 full t55xx block - quitting");
395 return false;
396 }
397 size_t dataloc = start;
398 if (buffer[dataloc-(clk*4)-(clk/8)] <= low && buffer[dataloc] <= low && buffer[dataloc-(clk*4)] >= high) {
399 //we have low drift (and a low just before the ST and a low just after the ST) - compensate by backing up the start
400 for ( i=0; i <= (clk/8); ++i ) {
401 if ( buffer[dataloc - (clk*4) - i] <= low ) {
402 dataloc -= i;
403 break;
404 }
405 }
406 }
407
408 size_t newloc = 0;
409 i=0;
410 if (g_debugMode==2) prnt("DEBUG STT: Starting STT trim - start: %d, datalen: %d ",dataloc, datalen);
411 bool firstrun = true;
412 // warning - overwriting buffer given with raw wave data with ST removed...
413 while ( dataloc < bufsize-(clk/2) ) {
414 //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)
415 if (buffer[dataloc]<high && buffer[dataloc]>low && buffer[dataloc+3]<high && buffer[dataloc+3]>low) {
416 for(i=0; i < clk/2-tol; ++i) {
417 buffer[dataloc+i] = high+5;
418 }
419 } //test for single sample outlier (high between two lows) in the case of very strong waves
420 if (buffer[dataloc] >= high && buffer[dataloc+2] <= low) {
421 buffer[dataloc] = buffer[dataloc+2];
422 buffer[dataloc+1] = buffer[dataloc+2];
423 }
424 if (firstrun) {
425 *stend = dataloc;
426 *ststart = dataloc-(clk*4);
427 firstrun=false;
428 }
429 for (i=0; i<datalen; ++i) {
430 if (i+newloc < bufsize) {
431 if (i+newloc < dataloc)
432 buffer[i+newloc] = buffer[dataloc];
433
434 dataloc++;
435 }
436 }
437 newloc += i;
438 //skip next ST - we just assume it will be there from now on...
439 if (g_debugMode==2) prnt("DEBUG STT: skipping STT at %d to %d", dataloc, dataloc+(clk*4));
440 dataloc += clk*4;
441 }
442 *size = newloc;
443 return true;
444}
445bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
446 size_t ststart = 0, stend = 0;
447 return DetectST_ext(buffer, size, foundclock, &ststart, &stend);
448}
449
450//by marshmellow
451//take 01 or 10 = 1 and 11 or 00 = 0
452//check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010
453//decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding
454int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert) {
455 uint16_t bitnum = 0;
456 uint16_t errCnt = 0;
457 size_t i = offset;
458 uint16_t MaxBits=512;
459 //if not enough samples - error
460 if (*size < 51) return -1;
461 //check for phase change faults - skip one sample if faulty
462 uint8_t offsetA = 1, offsetB = 1;
463 for (; i<48; i+=2){
464 if (BitStream[i+1]==BitStream[i+2]) offsetA=0;
465 if (BitStream[i+2]==BitStream[i+3]) offsetB=0;
466 }
467 if (!offsetA && offsetB) offset++;
468 for (i=offset; i<*size-3; i+=2){
469 //check for phase error
470 if (BitStream[i+1]==BitStream[i+2]) {
471 BitStream[bitnum++]=7;
472 errCnt++;
473 }
474 if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){
475 BitStream[bitnum++]=1^invert;
ba1a299c 476 } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){
1e090a61 477 BitStream[bitnum++]=invert;
ba1a299c 478 } else {
2767fc02 479 BitStream[bitnum++]=7;
ba1a299c 480 errCnt++;
481 }
6de43508 482 if(bitnum>MaxBits) break;
ba1a299c 483 }
484 *size=bitnum;
485 return errCnt;
eb191de6 486}
487
4d3c1796 488//by marshmellow
489//take 10 and 01 and manchester decode
490//run through 2 times and take least errCnt
491int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert, uint8_t *alignPos) {
492 uint16_t bitnum=0, MaxBits = 512, errCnt = 0;
493 size_t i, ii;
494 uint16_t bestErr = 1000, bestRun = 0;
495 if (*size < 16) return -1;
496 //find correct start position [alignment]
497 for (ii=0;ii<2;++ii){
498 for (i=ii; i<*size-3; i+=2)
499 if (BitStream[i]==BitStream[i+1])
500 errCnt++;
11081e04 501
4d3c1796 502 if (bestErr>errCnt){
503 bestErr=errCnt;
504 bestRun=ii;
505 }
506 errCnt=0;
11081e04 507 }
4d3c1796 508 *alignPos=bestRun;
509 //decode
510 for (i=bestRun; i < *size-3; i+=2){
511 if(BitStream[i] == 1 && (BitStream[i+1] == 0)){
512 BitStream[bitnum++]=invert;
513 } else if((BitStream[i] == 0) && BitStream[i+1] == 1){
514 BitStream[bitnum++]=invert^1;
515 } else {
516 BitStream[bitnum++]=7;
517 }
518 if(bitnum>MaxBits) break;
519 }
520 *size=bitnum;
521 return bestErr;
11081e04 522}
523
4d3c1796 524// by marshmellow
525// to detect a wave that has heavily clipped (clean) samples
526uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low) {
527 bool allArePeaks = true;
528 uint16_t cntPeaks=0;
529 size_t loopEnd = 512+160;
530 if (loopEnd > size) loopEnd = size;
531 for (size_t i=160; i<loopEnd; i++){
532 if (dest[i]>low && dest[i]<high)
533 allArePeaks = false;
534 else
535 cntPeaks++;
536 }
537 if (!allArePeaks){
538 if (cntPeaks > 300) return true;
539 }
540 return allArePeaks;
541}
542
543//by marshmellow
544//demodulates strong heavily clipped samples
545int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low, int *startIdx)
546{
547 *startIdx=0;
548 size_t bitCnt=0, smplCnt=1, errCnt=0;
549 bool waveHigh = (BinStream[0] >= high);
550 for (size_t i=1; i < *size; i++){
551 if (BinStream[i] >= high && waveHigh){
552 smplCnt++;
553 } else if (BinStream[i] <= low && !waveHigh){
554 smplCnt++;
555 } else { //transition
556 if ((BinStream[i] >= high && !waveHigh) || (BinStream[i] <= low && waveHigh)){
557 if (smplCnt > clk-(clk/4)-1) { //full clock
558 if (smplCnt > clk + (clk/4)+1) { //too many samples
559 errCnt++;
560 if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
561 BinStream[bitCnt++] = 7;
562 } else if (waveHigh) {
563 BinStream[bitCnt++] = invert;
564 BinStream[bitCnt++] = invert;
565 } else if (!waveHigh) {
566 BinStream[bitCnt++] = invert ^ 1;
567 BinStream[bitCnt++] = invert ^ 1;
568 }
569 if (*startIdx==0) *startIdx = i-clk;
570 waveHigh = !waveHigh;
571 smplCnt = 0;
572 } else if (smplCnt > (clk/2) - (clk/4)-1) { //half clock
573 if (waveHigh) {
574 BinStream[bitCnt++] = invert;
575 } else if (!waveHigh) {
576 BinStream[bitCnt++] = invert ^ 1;
577 }
578 if (*startIdx==0) *startIdx = i-(clk/2);
579 waveHigh = !waveHigh;
580 smplCnt = 0;
581 } else {
582 smplCnt++;
583 //transition bit oops
584 }
585 } else { //haven't hit new high or new low yet
586 smplCnt++;
587 }
588 }
589 }
590 *size = bitCnt;
591 return errCnt;
592}
593
594//by marshmellow
595//attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester
596int askdemod_ext(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType, int *startIdx) {
597 if (*size==0) return -1;
598 int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default
599 if (*clk==0 || start < 0) return -3;
600 if (*invert != 1) *invert = 0;
601 if (amp==1) askAmp(BinStream, *size);
602 if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d, amp %d", *clk, start, amp);
603
604 //start pos from detect ask clock is 1/2 clock offset
605 // NOTE: can be negative (demod assumes rest of wave was there)
606 *startIdx = start - (*clk/2);
607 uint8_t initLoopMax = 255;
608 if (initLoopMax > *size) initLoopMax = *size;
609 // Detect high and lows
610 //25% clip in case highs and lows aren't clipped [marshmellow]
611 int high, low;
612 if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1)
613 return -2; //just noise
614
615 size_t errCnt = 0;
616 // if clean clipped waves detected run alternate demod
617 if (DetectCleanAskWave(BinStream, *size, high, low)) {
618 if (g_debugMode==2) prnt("DEBUG ASK: Clean Wave Detected - using clean wave demod");
619 errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low, startIdx);
620 if (askType) { //askman
621 uint8_t alignPos = 0;
622 errCnt = manrawdecode(BinStream, size, 0, &alignPos);
623 *startIdx += *clk/2 * alignPos;
624 if (g_debugMode) prnt("DEBUG ASK CLEAN: startIdx %i, alignPos %u", *startIdx, alignPos);
625 return errCnt;
626 } else { //askraw
627 return errCnt;
628 }
629 }
630 if (g_debugMode) prnt("DEBUG ASK WEAK: startIdx %i", *startIdx);
631 if (g_debugMode==2) prnt("DEBUG ASK: Weak Wave Detected - using weak wave demod");
632
633 int lastBit; //set first clock check - can go negative
634 size_t i, bitnum = 0; //output counter
635 uint8_t midBit = 0;
636 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
637 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
638 size_t MaxBits = 3072; //max bits to collect
639 lastBit = start - *clk;
640
641 for (i = start; i < *size; ++i) {
642 if (i-lastBit >= *clk-tol){
643 if (BinStream[i] >= high) {
644 BinStream[bitnum++] = *invert;
645 } else if (BinStream[i] <= low) {
646 BinStream[bitnum++] = *invert ^ 1;
647 } else if (i-lastBit >= *clk+tol) {
648 if (bitnum > 0) {
649 if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
650 BinStream[bitnum++]=7;
651 errCnt++;
652 }
653 } else { //in tolerance - looking for peak
654 continue;
655 }
656 midBit = 0;
657 lastBit += *clk;
658 } else if (i-lastBit >= (*clk/2-tol) && !midBit && !askType){
659 if (BinStream[i] >= high) {
660 BinStream[bitnum++] = *invert;
661 } else if (BinStream[i] <= low) {
662 BinStream[bitnum++] = *invert ^ 1;
663 } else if (i-lastBit >= *clk/2+tol) {
664 BinStream[bitnum] = BinStream[bitnum-1];
665 bitnum++;
666 } else { //in tolerance - looking for peak
667 continue;
668 }
669 midBit = 1;
670 }
671 if (bitnum >= MaxBits) break;
672 }
673 *size = bitnum;
674 return errCnt;
675}
676
677int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType) {
678 int start = 0;
679 return askdemod_ext(BinStream, size, clk, invert, maxErr, amp, askType, &start);
680}
681
682// by marshmellow - demodulate NRZ wave - requires a read with strong signal
683// peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
684int nrzRawDemod_ext(uint8_t *dest, size_t *size, int *clk, int *invert, int *startIdx) {
685 if (justNoise(dest, *size)) return -1;
686 *clk = DetectNRZClock(dest, *size, *clk);
687 if (*clk==0) return -2;
688 size_t i, gLen = 4096;
689 if (gLen>*size) gLen = *size-20;
690 int high, low;
691 if (getHiLo(dest, gLen, &high, &low, 75, 75) < 1) return -3; //25% fuzz on high 25% fuzz on low
692
693 uint8_t bit=0;
694 //convert wave samples to 1's and 0's
695 for(i=20; i < *size-20; i++){
696 if (dest[i] >= high) bit = 1;
697 if (dest[i] <= low) bit = 0;
698 dest[i] = bit;
699 }
700 //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit)
701 size_t lastBit = 0;
702 size_t numBits = 0;
703 for(i=21; i < *size-20; i++) {
704 //if transition detected or large number of same bits - store the passed bits
705 if (dest[i] != dest[i-1] || (i-lastBit) == (10 * *clk)) {
706 memset(dest+numBits, dest[i-1] ^ *invert, (i - lastBit + (*clk/4)) / *clk);
707 numBits += (i - lastBit + (*clk/4)) / *clk;
708 if (lastBit == 0) {
709 *startIdx = i - (numBits * *clk);
710 if (g_debugMode==2) prnt("DEBUG NRZ: startIdx %i", *startIdx);
711 }
712 lastBit = i-1;
713 }
714 }
715 *size = numBits;
716 return 0;
717}
718int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert) {
719 int startIdx = 0;
720 return nrzRawDemod_ext(dest, size, clk, invert, &startIdx);
721}
722
723//translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq])
724size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow, int *startIdx) {
725 size_t last_transition = 0;
726 size_t idx = 1;
727 if (fchigh==0) fchigh=10;
728 if (fclow==0) fclow=8;
729 //set the threshold close to 0 (graph) or 128 std to avoid static
730 uint8_t threshold_value = 123;
731 size_t preLastSample = 0;
732 size_t LastSample = 0;
f4eadf8a 733 size_t currSample = 0;
c85858f5 734 if ( size < 1024 ) return 0; // not enough samples
735
34ff8985 736 //find start of modulating data in trace
737 idx = findModStart(dest, size, threshold_value, fchigh);
ba1a299c 738 // Need to threshold first sample
c85858f5 739 if(dest[idx] < threshold_value) dest[0] = 0;
ba1a299c 740 else dest[0] = 1;
c85858f5 741
669959bc 742 last_transition = idx;
743 idx++;
ba1a299c 744 size_t numBits = 0;
745 // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
63744b56 746 // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere
ba1a299c 747 // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
cf194819 748 // (could also be fc/5 && fc/7 for fsk1 = 4-9)
669959bc 749 for(; idx < size; idx++) {
ba1a299c 750 // threshold current value
ba1a299c 751 if (dest[idx] < threshold_value) dest[idx] = 0;
752 else dest[idx] = 1;
753
754 // Check for 0->1 transition
cf194819 755 if (dest[idx-1] < dest[idx]) {
f4eadf8a 756 preLastSample = LastSample;
757 LastSample = currSample;
758 currSample = idx-last_transition;
cf194819 759 if (currSample < (fclow-2)) { //0-5 = garbage noise (or 0-3)
ba1a299c 760 //do nothing with extra garbage
cf194819 761 } else if (currSample < (fchigh-1)) { //6-8 = 8 sample waves (or 3-6 = 5)
762 //correct previous 9 wave surrounded by 8 waves (or 6 surrounded by 5)
669959bc 763 if (numBits > 1 && LastSample > (fchigh-2) && (preLastSample < (fchigh-1))){
cf194819 764 dest[numBits-1]=1;
f4eadf8a 765 }
2eec55c8 766 dest[numBits++]=1;
669959bc 767 if (numBits > 0 && *startIdx==0) *startIdx = idx - fclow;
c85858f5 768 } else if (currSample > (fchigh+1) && numBits < 3) { //12 + and first two bit = unusable garbage
769 //do nothing with beginning garbage and reset.. should be rare..
770 numBits = 0;
cf194819 771 } 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)
f4eadf8a 772 dest[numBits++]=1;
669959bc 773 if (numBits > 0 && *startIdx==0) *startIdx = idx - fclow;
cf194819 774 } else { //9+ = 10 sample waves (or 6+ = 7)
2eec55c8 775 dest[numBits++]=0;
669959bc 776 if (numBits > 0 && *startIdx==0) *startIdx = idx - fchigh;
ba1a299c 777 }
778 last_transition = idx;
ba1a299c 779 }
780 }
781 return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
eb191de6 782}
783
ba1a299c 784//translate 11111100000 to 10
cf194819 785//rfLen = clock, fchigh = larger field clock, fclow = smaller field clock
4d3c1796 786size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow, int *startIdx) {
ba1a299c 787 uint8_t lastval=dest[0];
2eec55c8 788 size_t idx=0;
ba1a299c 789 size_t numBits=0;
790 uint32_t n=1;
ba1a299c 791 for( idx=1; idx < size; idx++) {
13d77ef9 792 n++;
cf194819 793 if (dest[idx]==lastval) continue; //skip until we hit a transition
2eec55c8 794
669959bc 795 //find out how many bits (n) we collected (use 1/2 clk tolerance)
ba1a299c 796 //if lastval was 1, we have a 1->0 crossing
13d77ef9 797 if (dest[idx-1]==1) {
6fe5c94b 798 n = (n * fclow + rfLen/2) / rfLen;
13d77ef9 799 } else {// 0->1 crossing
75cbbe9a 800 n = (n * fchigh + rfLen/2) / rfLen;
ba1a299c 801 }
802 if (n == 0) n = 1;
669959bc 803
804 //first transition - save startidx
805 if (numBits == 0) {
806 if (lastval == 1) { //high to low
807 *startIdx += (fclow * idx) - (n*rfLen);
808 if (g_debugMode==2) prnt("DEBUG FSK: startIdx %i, fclow*idx %i, n*rflen %u", *startIdx, fclow*(idx), n*rfLen);
809 } else {
810 *startIdx += (fchigh * idx) - (n*rfLen);
811 if (g_debugMode==2) prnt("DEBUG FSK: startIdx %i, fchigh*idx %i, n*rflen %u", *startIdx, fchigh*(idx), n*rfLen);
812 }
813 }
ba1a299c 814
cf194819 815 //add to our destination the bits we collected
2eec55c8 816 memset(dest+numBits, dest[idx-1]^invert , n);
817 numBits += n;
ba1a299c 818 n=0;
819 lastval=dest[idx];
820 }//end for
13d77ef9 821 // if valid extra bits at the end were all the same frequency - add them in
75cbbe9a 822 if (n > rfLen/fchigh) {
13d77ef9 823 if (dest[idx-2]==1) {
75cbbe9a 824 n = (n * fclow + rfLen/2) / rfLen;
13d77ef9 825 } else {
75cbbe9a 826 n = (n * fchigh + rfLen/2) / rfLen;
13d77ef9 827 }
2eec55c8 828 memset(dest+numBits, dest[idx-1]^invert , n);
13d77ef9 829 numBits += n;
830 }
ba1a299c 831 return numBits;
eb191de6 832}
6fe5c94b 833
eb191de6 834//by marshmellow (from holiman's base)
835// full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod)
669959bc 836int fskdemod_ext(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow, int *startIdx) {
ba1a299c 837 // FSK demodulator
669959bc 838 size = fsk_wave_demod(dest, size, fchigh, fclow, startIdx);
839 size = aggregate_bits(dest, size, rfLen, invert, fchigh, fclow, startIdx);
ba1a299c 840 return size;
eb191de6 841}
a1d17964 842
669959bc 843int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow) {
844 int startIdx=0;
845 return fskdemod_ext(dest, size, rfLen, invert, fchigh, fclow, &startIdx);
846}
847
4d3c1796 848// by marshmellow
849// convert psk1 demod to psk2 demod
850// only transition waves are 1s
851void psk1TOpsk2(uint8_t *BitStream, size_t size) {
852 size_t i=1;
853 uint8_t lastBit=BitStream[0];
854 for (; i<size; i++){
855 if (BitStream[i]==7){
856 //ignore errors
857 } else if (lastBit!=BitStream[i]){
858 lastBit=BitStream[i];
859 BitStream[i]=1;
860 } else {
861 BitStream[i]=0;
e0165dcf 862 }
e0165dcf 863 }
4d3c1796 864 return;
eb191de6 865}
866
4d3c1796 867// by marshmellow
868// convert psk2 demod to psk1 demod
869// from only transition waves are 1s to phase shifts change bit
870void psk2TOpsk1(uint8_t *BitStream, size_t size) {
871 uint8_t phase=0;
872 for (size_t i=0; i<size; i++){
873 if (BitStream[i]==1){
874 phase ^=1;
875 }
876 BitStream[i]=phase;
ec75f5c1 877 }
4d3c1796 878 return;
ec75f5c1 879}
880
4d3c1796 881//by marshmellow - demodulate PSK1 wave
882//uses wave lengths (# Samples)
883int pskRawDemod_ext(uint8_t dest[], size_t *size, int *clock, int *invert, int *startIdx) {
884 if (size == 0) return -1;
885 uint16_t loopCnt = 4096; //don't need to loop through entire array...
886 if (*size<loopCnt) loopCnt = *size;
eb191de6 887
4d3c1796 888 size_t numBits=0;
889 uint8_t curPhase = *invert;
890 size_t i=0, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0;
891 uint16_t fc=0, fullWaveLen=0, tol=1;
892 uint16_t errCnt=0, waveLenCnt=0, errCnt2=0;
893 fc = countFC(dest, *size, 1);
894 uint8_t fc2 = fc >> 8;
895 if (fc2 == 10) return -1; //fsk found - quit
896 fc = fc & 0xFF;
897 if (fc!=2 && fc!=4 && fc!=8) return -1;
898 //PrintAndLog("DEBUG: FC: %d",fc);
899 *clock = DetectPSKClock(dest, *size, *clock);
900 if (*clock == 0) return -1;
415274a7 901
4d3c1796 902 //find start of modulating data in trace
903 uint8_t threshold_value = 123; //-5
904 i = findModStart(dest, *size, threshold_value, fc);
415274a7 905
4d3c1796 906 //find first phase shift
907 int avgWaveVal=0, lastAvgWaveVal=0;
908 waveStart = i;
909 for (; i<loopCnt; i++) {
910 // find peak
911 if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
912 waveEnd = i+1;
913 if (g_debugMode == 2) prnt("DEBUG PSK: waveEnd: %u, waveStart: %u",waveEnd, waveStart);
914 waveLenCnt = waveEnd-waveStart;
915 if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+3)){ //not first peak and is a large wave but not out of whack
916 lastAvgWaveVal = avgWaveVal/(waveLenCnt);
917 firstFullWave = waveStart;
918 fullWaveLen=waveLenCnt;
919 //if average wave value is > graph 0 then it is an up wave or a 1 (could cause inverting)
920 if (lastAvgWaveVal > threshold_value) curPhase ^= 1;
921 break;
922 }
1e090a61 923
4d3c1796 924 waveStart = i+1;
925 avgWaveVal = 0;
926 }
927 avgWaveVal += dest[i+2];
928 }
929 if (firstFullWave == 0) {
930 // no phase shift detected - could be all 1's or 0's - doesn't matter where we start
931 // so skip a little to ensure we are past any Start Signal
932 firstFullWave = 160;
933 memset(dest, curPhase, firstFullWave / *clock);
934 } else {
935 memset(dest, curPhase^1, firstFullWave / *clock);
936 }
937 //advance bits
938 numBits += (firstFullWave / *clock);
939 *startIdx = firstFullWave - (*clock * numBits)+2;
940 //set start of wave as clock align
941 lastClkBit = firstFullWave;
942 if (g_debugMode==2) prnt("DEBUG PSK: firstFullWave: %u, waveLen: %u, startIdx %i",firstFullWave,fullWaveLen, *startIdx);
943 if (g_debugMode==2) prnt("DEBUG PSK: clk: %d, lastClkBit: %u, fc: %u", *clock, lastClkBit,(unsigned int) fc);
944 waveStart = 0;
945 dest[numBits++] = curPhase; //set first read bit
946 for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){
947 //top edge of wave = start of new wave
948 if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
949 if (waveStart == 0) {
950 waveStart = i+1;
951 waveLenCnt = 0;
952 avgWaveVal = dest[i+1];
953 } else { //waveEnd
954 waveEnd = i+1;
955 waveLenCnt = waveEnd-waveStart;
956 lastAvgWaveVal = avgWaveVal/waveLenCnt;
957 if (waveLenCnt > fc){
958 //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);
959 //this wave is a phase shift
960 //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc);
961 if (i+1 >= lastClkBit + *clock - tol){ //should be a clock bit
962 curPhase ^= 1;
963 dest[numBits++] = curPhase;
964 lastClkBit += *clock;
965 } else if (i < lastClkBit+10+fc){
966 //noise after a phase shift - ignore
967 } else { //phase shift before supposed to based on clock
968 errCnt++;
969 dest[numBits++] = 7;
970 }
971 } else if (i+1 > lastClkBit + *clock + tol + fc){
972 lastClkBit += *clock; //no phase shift but clock bit
973 dest[numBits++] = curPhase;
974 } else if (waveLenCnt < fc - 1) { //wave is smaller than field clock (shouldn't happen often)
975 errCnt2++;
976 if(errCnt2 > 101) return errCnt2;
977 }
978 avgWaveVal = 0;
979 waveStart = i+1;
980 }
981 }
982 avgWaveVal += dest[i+1];
983 }
984 *size = numBits;
985 return errCnt;
986}
6923d3f1 987
4d3c1796 988int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) {
989 int startIdx = 0;
990 return pskRawDemod_ext(dest, size, clock, invert, &startIdx);
6923d3f1 991}
992
4d3c1796 993//-------------------Clock / Bitrate Detection Section------------------------------------------------------------------------------------
04bb0567 994
4d3c1796 995// by marshmellow
996// to help detect clocks on heavily clipped samples
997// based on count of low to low
998int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low, int *clock) {
999 uint8_t fndClk[] = {8,16,32,40,50,64,128};
1000 size_t startwave;
1001 size_t i = 100;
1002 size_t minClk = 255;
1003 int shortestWaveIdx = 0;
1004 // get to first full low to prime loop and skip incomplete first pulse
1005 while ((dest[i] < high) && (i < size))
1006 ++i;
1007 while ((dest[i] > low) && (i < size))
1008 ++i;
04bb0567 1009
4d3c1796 1010 // loop through all samples
1011 while (i < size) {
1012 // measure from low to low
1013 while ((dest[i] > low) && (i < size))
1014 ++i;
1015 startwave = i;
1016 while ((dest[i] < high) && (i < size))
1017 ++i;
1018 while ((dest[i] > low) && (i < size))
1019 ++i;
1020 //get minimum measured distance
1021 if (i-startwave < minClk && i < size) {
1022 minClk = i - startwave;
1023 shortestWaveIdx = startwave;
1024 }
1025 }
1026 // set clock
1027 if (g_debugMode==2) prnt("DEBUG ASK: detectstrongASKclk smallest wave: %d",minClk);
1028 for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
1029 if (minClk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1) {
1030 *clock = fndClk[clkCnt];
1031 return shortestWaveIdx;
1032 }
1033 }
1034 return 0;
13d77ef9 1035}
1036
eb191de6 1037// by marshmellow
1038// not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)
1039// maybe somehow adjust peak trimming value based on samples to fix?
6de43508 1040// return start index of best starting position for that clock and return clock (by reference)
4d3c1796 1041int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr) {
6e984446 1042 size_t i=1;
cc15a118 1043 uint8_t clk[] = {255,8,16,32,40,50,64,100,128,255};
1044 uint8_t clkEnd = 9;
2eec55c8 1045 uint8_t loopCnt = 255; //don't need to loop through entire array...
db829602 1046 if (size <= loopCnt+60) return -1; //not enough samples
1047 size -= 60; //sometimes there is a strange end wave - filter out this....
6e984446 1048 //if we already have a valid clock
1049 uint8_t clockFnd=0;
cc15a118 1050 for (;i<clkEnd;++i)
1051 if (clk[i] == *clock) clockFnd = i;
6e984446 1052 //clock found but continue to find best startpos
e0165dcf 1053
1054 //get high and low peak
1055 int peak, low;
2eec55c8 1056 if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return -1;
e0165dcf 1057
1058 //test for large clean peaks
cc15a118 1059 if (!clockFnd){
1060 if (DetectCleanAskWave(dest, size, peak, low)==1){
8b6abef5 1061 int ans = DetectStrongAskClock(dest, size, peak, low, clock);
1062 if (g_debugMode==2) prnt("DEBUG ASK: detectaskclk Clean Ask Wave Detected: clk %i, ShortestWave: %i",clock, ans);
1063 if (ans > 0) {
1064 return ans; //return shortest wave start position
e0165dcf 1065 }
1066 }
1067 }
2eec55c8 1068 uint8_t ii;
1069 uint8_t clkCnt, tol = 0;
1070 uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
1071 uint8_t bestStart[]={0,0,0,0,0,0,0,0,0};
1072 size_t errCnt = 0;
1073 size_t arrLoc, loopEnd;
6e984446 1074
cc15a118 1075 if (clockFnd>0) {
1076 clkCnt = clockFnd;
1077 clkEnd = clockFnd+1;
1078 }
1079 else clkCnt=1;
1080
1081 //test each valid clock from smallest to greatest to see which lines up
1082 for(; clkCnt < clkEnd; clkCnt++){
fef74fdc 1083 if (clk[clkCnt] <= 32){
e0165dcf 1084 tol=1;
1085 }else{
1086 tol=0;
1087 }
2767fc02 1088 //if no errors allowed - keep start within the first clock
cc15a118 1089 if (!maxErr && size > clk[clkCnt]*2 + tol && clk[clkCnt]<128) loopCnt=clk[clkCnt]*2;
e0165dcf 1090 bestErr[clkCnt]=1000;
6e984446 1091 //try lining up the peaks by moving starting point (try first few clocks)
cc15a118 1092 for (ii=0; ii < loopCnt; ii++){
2eec55c8 1093 if (dest[ii] < peak && dest[ii] > low) continue;
1094
1095 errCnt=0;
1096 // now that we have the first one lined up test rest of wave array
1097 loopEnd = ((size-ii-tol) / clk[clkCnt]) - 1;
1098 for (i=0; i < loopEnd; ++i){
1099 arrLoc = ii + (i * clk[clkCnt]);
1100 if (dest[arrLoc] >= peak || dest[arrLoc] <= low){
1101 }else if (dest[arrLoc-tol] >= peak || dest[arrLoc-tol] <= low){
1102 }else if (dest[arrLoc+tol] >= peak || dest[arrLoc+tol] <= low){
1103 }else{ //error no peak detected
1104 errCnt++;
e0165dcf 1105 }
1106 }
cc15a118 1107 //if we found no errors then we can stop here and a low clock (common clocks)
2eec55c8 1108 // this is correct one - return this clock
709665b5 1109 if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, err %d, startpos %d, endpos %d",clk[clkCnt],errCnt,ii,i);
cc15a118 1110 if(errCnt==0 && clkCnt<7) {
1111 if (!clockFnd) *clock = clk[clkCnt];
2eec55c8 1112 return ii;
1113 }
1114 //if we found errors see if it is lowest so far and save it as best run
1115 if(errCnt<bestErr[clkCnt]){
1116 bestErr[clkCnt]=errCnt;
1117 bestStart[clkCnt]=ii;
1118 }
e0165dcf 1119 }
1120 }
cc15a118 1121 uint8_t iii;
e0165dcf 1122 uint8_t best=0;
cc15a118 1123 for (iii=1; iii<clkEnd; ++iii){
2eec55c8 1124 if (bestErr[iii] < bestErr[best]){
1125 if (bestErr[iii] == 0) bestErr[iii]=1;
e0165dcf 1126 // current best bit to error ratio vs new bit to error ratio
2eec55c8 1127 if ( (size/clk[best])/bestErr[best] < (size/clk[iii])/bestErr[iii] ){
e0165dcf 1128 best = iii;
1129 }
1130 }
709665b5 1131 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 1132 }
cc15a118 1133 if (!clockFnd) *clock = clk[best];
e0165dcf 1134 return bestStart[best];
eb191de6 1135}
ba1a299c 1136
db829602 1137int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low){
1138 //find shortest transition from high to low
1139 size_t i = 0;
1140 size_t transition1 = 0;
1141 int lowestTransition = 255;
6fe5c94b 1142 bool lastWasHigh = false;
1143
1144 //find first valid beginning of a high or low wave
1145 while ((dest[i] >= peak || dest[i] <= low) && (i < size))
1146 ++i;
1147 while ((dest[i] < peak && dest[i] > low) && (i < size))
1148 ++i;
1149 lastWasHigh = (dest[i] >= peak);
1150
db829602 1151 if (i==size) return 0;
1152 transition1 = i;
1153
1154 for (;i < size; i++) {
1155 if ((dest[i] >= peak && !lastWasHigh) || (dest[i] <= low && lastWasHigh)) {
1156 lastWasHigh = (dest[i] >= peak);
1157 if (i-transition1 < lowestTransition) lowestTransition = i-transition1;
1158 transition1 = i;
1159 }
1160 }
1161 if (lowestTransition == 255) lowestTransition = 0;
709665b5 1162 if (g_debugMode==2) prnt("DEBUG NRZ: detectstrongNRZclk smallest wave: %d",lowestTransition);
db829602 1163 return lowestTransition;
1164}
1165
6de43508 1166//by marshmellow
1167//detect nrz clock by reading #peaks vs no peaks(or errors)
8b6abef5 1168int DetectNRZClock_ext(uint8_t dest[], size_t size, int clock, size_t *clockStartIdx) {
2eec55c8 1169 size_t i=0;
1170 uint8_t clk[]={8,16,32,40,50,64,100,128,255};
1171 size_t loopCnt = 4096; //don't need to loop through entire array...
e0165dcf 1172 if (size == 0) return 0;
db829602 1173 if (size<loopCnt) loopCnt = size-20;
e0165dcf 1174 //if we already have a valid clock quit
1175 for (; i < 8; ++i)
1176 if (clk[i] == clock) return clock;
1177
1178 //get high and low peak
1179 int peak, low;
2eec55c8 1180 if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return 0;
e0165dcf 1181
db829602 1182 int lowestTransition = DetectStrongNRZClk(dest, size-20, peak, low);
2eec55c8 1183 size_t ii;
e0165dcf 1184 uint8_t clkCnt;
1185 uint8_t tol = 0;
db829602 1186 uint16_t smplCnt = 0;
1187 int16_t peakcnt = 0;
1188 int16_t peaksdet[] = {0,0,0,0,0,0,0,0};
1189 uint16_t maxPeak = 255;
6fe5c94b 1190 bool firstpeak = false;
e0165dcf 1191 //test for large clipped waves
1192 for (i=0; i<loopCnt; i++){
1193 if (dest[i] >= peak || dest[i] <= low){
db829602 1194 if (!firstpeak) continue;
1195 smplCnt++;
e0165dcf 1196 } else {
6fe5c94b 1197 firstpeak=true;
db829602 1198 if (smplCnt > 6 ){
1199 if (maxPeak > smplCnt){
1200 maxPeak = smplCnt;
1201 //prnt("maxPk: %d",maxPeak);
1202 }
1203 peakcnt++;
1204 //prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt);
1205 smplCnt=0;
e0165dcf 1206 }
e0165dcf 1207 }
1208 }
6fe5c94b 1209 bool errBitHigh = 0;
1210 bool bitHigh = 0;
1211 uint8_t ignoreCnt = 0;
1212 uint8_t ignoreWindow = 4;
1213 bool lastPeakHigh = 0;
1214 int lastBit = 0;
8b6abef5 1215 size_t bestStart[]={0,0,0,0,0,0,0,0,0};
e0165dcf 1216 peakcnt=0;
1217 //test each valid clock from smallest to greatest to see which lines up
1218 for(clkCnt=0; clkCnt < 8; ++clkCnt){
db829602 1219 //ignore clocks smaller than smallest peak
1220 if (clk[clkCnt] < maxPeak - (clk[clkCnt]/4)) continue;
e0165dcf 1221 //try lining up the peaks by moving starting point (try first 256)
db829602 1222 for (ii=20; ii < loopCnt; ++ii){
e0165dcf 1223 if ((dest[ii] >= peak) || (dest[ii] <= low)){
6fe5c94b 1224 peakcnt = 0;
1225 bitHigh = false;
1226 ignoreCnt = 0;
1227 lastBit = ii-clk[clkCnt];
db829602 1228 //loop through to see if this start location works
1229 for (i = ii; i < size-20; ++i) {
6fe5c94b 1230 //if we are at a clock bit
db829602 1231 if ((i >= lastBit + clk[clkCnt] - tol) && (i <= lastBit + clk[clkCnt] + tol)) {
1232 //test high/low
1233 if (dest[i] >= peak || dest[i] <= low) {
6fe5c94b 1234 //if same peak don't count it
1235 if ((dest[i] >= peak && !lastPeakHigh) || (dest[i] <= low && lastPeakHigh)) {
1236 peakcnt++;
1237 }
1238 lastPeakHigh = (dest[i] >= peak);
1239 bitHigh = true;
1240 errBitHigh = false;
db829602 1241 ignoreCnt = ignoreWindow;
1242 lastBit += clk[clkCnt];
db829602 1243 } else if (i == lastBit + clk[clkCnt] + tol) {
1244 lastBit += clk[clkCnt];
db829602 1245 }
1246 //else if not a clock bit and no peaks
1247 } else if (dest[i] < peak && dest[i] > low){
db829602 1248 if (ignoreCnt==0){
6fe5c94b 1249 bitHigh=false;
1250 if (errBitHigh==true) peakcnt--;
1251 errBitHigh=false;
db829602 1252 } else {
1253 ignoreCnt--;
1254 }
1255 // else if not a clock bit but we have a peak
6fe5c94b 1256 } else if ((dest[i]>=peak || dest[i]<=low) && (!bitHigh)) {
db829602 1257 //error bar found no clock...
6fe5c94b 1258 errBitHigh=true;
e0165dcf 1259 }
1260 }
1261 if(peakcnt>peaksdet[clkCnt]) {
8b6abef5 1262 bestStart[clkCnt]=ii;
e0165dcf 1263 peaksdet[clkCnt]=peakcnt;
1264 }
1265 }
1266 }
1267 }
1268 int iii=7;
2eec55c8 1269 uint8_t best=0;
e0165dcf 1270 for (iii=7; iii > 0; iii--){
6fe5c94b 1271 if ((peaksdet[iii] >= (peaksdet[best]-1)) && (peaksdet[iii] <= peaksdet[best]+1) && lowestTransition) {
1272 if (clk[iii] > (lowestTransition - (clk[iii]/8)) && clk[iii] < (lowestTransition + (clk[iii]/8))) {
db829602 1273 best = iii;
1274 }
6fe5c94b 1275 } else if (peaksdet[iii] > peaksdet[best]){
1276 best = iii;
e0165dcf 1277 }
709665b5 1278 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 1279 }
8b6abef5 1280 *clockStartIdx = bestStart[best];
e0165dcf 1281 return clk[best];
ba1a299c 1282}
1283
669959bc 1284int DetectNRZClock(uint8_t dest[], size_t size, int clock) {
1285 size_t bestStart=0;
1286 return DetectNRZClock_ext(dest, size, clock, &bestStart);
1287}
1288
4d3c1796 1289//by marshmellow
1290//countFC is to detect the field clock lengths.
1291//counts and returns the 2 most common wave lengths
1292//mainly used for FSK field clock detection
1293uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj) {
1294 uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
1295 uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
1296 uint8_t fcLensFnd = 0;
1297 uint8_t lastFCcnt = 0;
1298 uint8_t fcCounter = 0;
1299 size_t i;
1300 if (size < 180) return 0;
1301
1302 // prime i to first up transition
1303 for (i = 160; i < size-20; i++)
1304 if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1])
1305 break;
1306
1307 for (; i < size-20; i++){
1308 if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){
1309 // new up transition
1310 fcCounter++;
1311 if (fskAdj){
1312 //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8)
1313 if (lastFCcnt==5 && fcCounter==9) fcCounter--;
1314 //if fc=9 or 4 add one (for when we get a fc 9 instead of 10 or a 4 instead of a 5)
1315 if ((fcCounter==9) || fcCounter==4) fcCounter++;
1316 // save last field clock count (fc/xx)
1317 lastFCcnt = fcCounter;
1318 }
1319 // find which fcLens to save it to:
1320 for (int ii=0; ii<15; ii++){
1321 if (fcLens[ii]==fcCounter){
1322 fcCnts[ii]++;
1323 fcCounter=0;
1324 break;
1325 }
1326 }
1327 if (fcCounter>0 && fcLensFnd<15){
1328 //add new fc length
1329 fcCnts[fcLensFnd]++;
1330 fcLens[fcLensFnd++]=fcCounter;
1331 }
1332 fcCounter=0;
04d2721b 1333 } else {
4d3c1796 1334 // count sample
1335 fcCounter++;
04d2721b 1336 }
1337 }
4d3c1796 1338
1339 uint8_t best1=14, best2=14, best3=14;
1340 uint16_t maxCnt1=0;
1341 // go through fclens and find which ones are bigest 2
1342 for (i=0; i<15; i++){
1343 // get the 3 best FC values
1344 if (fcCnts[i]>maxCnt1) {
1345 best3=best2;
1346 best2=best1;
1347 maxCnt1=fcCnts[i];
1348 best1=i;
1349 } else if(fcCnts[i]>fcCnts[best2]){
1350 best3=best2;
1351 best2=i;
1352 } else if(fcCnts[i]>fcCnts[best3]){
1353 best3=i;
3bc66a96 1354 }
4d3c1796 1355 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]);
3bc66a96 1356 }
4d3c1796 1357 if (fcLens[best1]==0) return 0;
1358 uint8_t fcH=0, fcL=0;
1359 if (fcLens[best1]>fcLens[best2]){
1360 fcH=fcLens[best1];
1361 fcL=fcLens[best2];
1362 } else{
1363 fcH=fcLens[best2];
1364 fcL=fcLens[best1];
1365 }
1366 if ((size-180)/fcH/3 > fcCnts[best1]+fcCnts[best2]) {
1367 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]);
1368 return 0; //lots of waves not psk or fsk
1369 }
1370 // TODO: take top 3 answers and compare to known Field clocks to get top 2
1371
1372 uint16_t fcs = (((uint16_t)fcH)<<8) | fcL;
1373 if (fskAdj) return fcs;
1374 return fcLens[best1];
3bc66a96 1375}
1376
4d3c1796 1377//by marshmellow
1378//detect psk clock by reading each phase shift
1379// a phase shift is determined by measuring the sample length of each wave
1380int DetectPSKClock_ext(uint8_t dest[], size_t size, int clock, int *firstPhaseShift) {
1381 uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock
1382 uint16_t loopCnt = 4096; //don't need to loop through entire array...
1383 if (size == 0) return 0;
1384 if (size<loopCnt) loopCnt = size-20;
ba1a299c 1385
4d3c1796 1386 //if we already have a valid clock quit
1387 size_t i=1;
1388 for (; i < 8; ++i)
1389 if (clk[i] == clock) return clock;
ba1a299c 1390
4d3c1796 1391 size_t waveStart=0, waveEnd=0, firstFullWave=0, lastClkBit=0;
1392 uint8_t clkCnt, fc=0, fullWaveLen=0, tol=1;
1393 uint16_t peakcnt=0, errCnt=0, waveLenCnt=0;
1394 uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
1395 uint16_t peaksdet[]={0,0,0,0,0,0,0,0,0};
1396 fc = countFC(dest, size, 0);
1397 if (fc!=2 && fc!=4 && fc!=8) return -1;
1398 if (g_debugMode==2) prnt("DEBUG PSK: FC: %d",fc);
1399
1400 //find first full wave
1401 for (i=160; i<loopCnt; i++){
1402 if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
1403 if (waveStart == 0) {
1404 waveStart = i+1;
1405 //prnt("DEBUG: waveStart: %d",waveStart);
1406 } else {
1407 waveEnd = i+1;
1408 //prnt("DEBUG: waveEnd: %d",waveEnd);
1409 waveLenCnt = waveEnd-waveStart;
1410 if (waveLenCnt > fc){
1411 firstFullWave = waveStart;
1412 fullWaveLen=waveLenCnt;
1413 break;
1414 }
1415 waveStart=0;
1416 }
1417 }
e0165dcf 1418 }
4d3c1796 1419 *firstPhaseShift = firstFullWave;
1420 if (g_debugMode ==2) prnt("DEBUG PSK: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);
1421 //test each valid clock from greatest to smallest to see which lines up
1422 for(clkCnt=7; clkCnt >= 1 ; clkCnt--){
1423 lastClkBit = firstFullWave; //set end of wave as clock align
1424 waveStart = 0;
1425 errCnt=0;
1426 peakcnt=0;
1427 if (g_debugMode == 2) prnt("DEBUG PSK: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit);
1428
1429 for (i = firstFullWave+fullWaveLen-1; i < loopCnt-2; i++){
1430 //top edge of wave = start of new wave
1431 if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
1432 if (waveStart == 0) {
1433 waveStart = i+1;
1434 waveLenCnt=0;
1435 } else { //waveEnd
1436 waveEnd = i+1;
1437 waveLenCnt = waveEnd-waveStart;
1438 if (waveLenCnt > fc){
1439 //if this wave is a phase shift
1440 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);
1441 if (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit
1442 peakcnt++;
1443 lastClkBit+=clk[clkCnt];
1444 } else if (i<lastClkBit+8){
1445 //noise after a phase shift - ignore
1446 } else { //phase shift before supposed to based on clock
1447 errCnt++;
1448 }
1449 } else if (i+1 > lastClkBit + clk[clkCnt] + tol + fc){
1450 lastClkBit+=clk[clkCnt]; //no phase shift but clock bit
1451 }
1452 waveStart=i+1;
1453 }
669959bc 1454 }
e0165dcf 1455 }
4d3c1796 1456 if (errCnt == 0){
1457 return clk[clkCnt];
1458 }
1459 if (errCnt <= bestErr[clkCnt]) bestErr[clkCnt]=errCnt;
1460 if (peakcnt > peaksdet[clkCnt]) peaksdet[clkCnt]=peakcnt;
1461 }
1462 //all tested with errors
1463 //return the highest clk with the most peaks found
1464 uint8_t best=7;
1465 for (i=7; i>=1; i--){
1466 if (peaksdet[i] > peaksdet[best]) {
1467 best = i;
1468 }
1469 if (g_debugMode == 2) prnt("DEBUG PSK: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[i],peaksdet[i],bestErr[i],clk[best]);
e0165dcf 1470 }
4d3c1796 1471 return clk[best];
ba1a299c 1472}
4d3c1796 1473
1474int DetectPSKClock(uint8_t dest[], size_t size, int clock) {
1475 int firstPhaseShift = 0;
1476 return DetectPSKClock_ext(dest, size, clock, &firstPhaseShift);
8b6abef5 1477}
1478
1e090a61 1479//by marshmellow
03e6bb4a 1480//detects the bit clock for FSK given the high and low Field Clocks
8b6abef5 1481uint8_t detectFSKClk_ext(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow, int *firstClockEdge) {
e0165dcf 1482 uint8_t clk[] = {8,16,32,40,50,64,100,128,0};
1483 uint16_t rfLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
1484 uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
1485 uint8_t rfLensFnd = 0;
2eec55c8 1486 uint8_t lastFCcnt = 0;
1487 uint16_t fcCounter = 0;
e0165dcf 1488 uint16_t rfCounter = 0;
1489 uint8_t firstBitFnd = 0;
1490 size_t i;
1491 if (size == 0) return 0;
1492
6fe5c94b 1493 uint8_t fcTol = ((fcHigh*100 - fcLow*100)/2 + 50)/100; //(uint8_t)(0.5+(float)(fcHigh-fcLow)/2);
e0165dcf 1494 rfLensFnd=0;
1495 fcCounter=0;
1496 rfCounter=0;
1497 firstBitFnd=0;
1498 //PrintAndLog("DEBUG: fcTol: %d",fcTol);
6fe5c94b 1499 // prime i to first peak / up transition
1500 for (i = 160; i < size-20; i++)
e0165dcf 1501 if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1])
1502 break;
1503
6fe5c94b 1504 for (; i < size-20; i++){
2eec55c8 1505 fcCounter++;
1506 rfCounter++;
1507
1508 if (BitStream[i] <= BitStream[i-1] || BitStream[i] < BitStream[i+1])
1509 continue;
1510 // else new peak
1511 // if we got less than the small fc + tolerance then set it to the small fc
33a1fe96 1512 // if it is inbetween set it to the last counter
1513 if (fcCounter < fcHigh && fcCounter > fcLow)
1514 fcCounter = lastFCcnt;
1515 else if (fcCounter < fcLow+fcTol)
2eec55c8 1516 fcCounter = fcLow;
1517 else //set it to the large fc
1518 fcCounter = fcHigh;
1519
1520 //look for bit clock (rf/xx)
1521 if ((fcCounter < lastFCcnt || fcCounter > lastFCcnt)){
1522 //not the same size as the last wave - start of new bit sequence
1523 if (firstBitFnd > 1){ //skip first wave change - probably not a complete bit
1524 for (int ii=0; ii<15; ii++){
6fe5c94b 1525 if (rfLens[ii] >= (rfCounter-4) && rfLens[ii] <= (rfCounter+4)){
2eec55c8 1526 rfCnts[ii]++;
1527 rfCounter = 0;
1528 break;
e0165dcf 1529 }
e0165dcf 1530 }
2eec55c8 1531 if (rfCounter > 0 && rfLensFnd < 15){
1532 //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
1533 rfCnts[rfLensFnd]++;
1534 rfLens[rfLensFnd++] = rfCounter;
1535 }
1536 } else {
8b6abef5 1537 *firstClockEdge = i;
2eec55c8 1538 firstBitFnd++;
e0165dcf 1539 }
2eec55c8 1540 rfCounter=0;
1541 lastFCcnt=fcCounter;
e0165dcf 1542 }
2eec55c8 1543 fcCounter=0;
e0165dcf 1544 }
1545 uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15;
1546
1547 for (i=0; i<15; i++){
e0165dcf 1548 //get highest 2 RF values (might need to get more values to compare or compare all?)
1549 if (rfCnts[i]>rfCnts[rfHighest]){
1550 rfHighest3=rfHighest2;
1551 rfHighest2=rfHighest;
1552 rfHighest=i;
1553 } else if(rfCnts[i]>rfCnts[rfHighest2]){
1554 rfHighest3=rfHighest2;
1555 rfHighest2=i;
1556 } else if(rfCnts[i]>rfCnts[rfHighest3]){
1557 rfHighest3=i;
1558 }
709665b5 1559 if (g_debugMode==2) prnt("DEBUG FSK: RF %d, cnts %d",rfLens[i], rfCnts[i]);
e0165dcf 1560 }
1561 // set allowed clock remainder tolerance to be 1 large field clock length+1
1562 // we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off
1563 uint8_t tol1 = fcHigh+1;
1564
709665b5 1565 if (g_debugMode==2) prnt("DEBUG FSK: most counted rf values: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]);
e0165dcf 1566
1567 // loop to find the highest clock that has a remainder less than the tolerance
1568 // compare samples counted divided by
6fe5c94b 1569 // test 128 down to 32 (shouldn't be possible to have fc/10 & fc/8 and rf/16 or less)
e0165dcf 1570 int ii=7;
6fe5c94b 1571 for (; ii>=2; ii--){
e0165dcf 1572 if (rfLens[rfHighest] % clk[ii] < tol1 || rfLens[rfHighest] % clk[ii] > clk[ii]-tol1){
1573 if (rfLens[rfHighest2] % clk[ii] < tol1 || rfLens[rfHighest2] % clk[ii] > clk[ii]-tol1){
1574 if (rfLens[rfHighest3] % clk[ii] < tol1 || rfLens[rfHighest3] % clk[ii] > clk[ii]-tol1){
709665b5 1575 if (g_debugMode==2) prnt("DEBUG FSK: clk %d divides into the 3 most rf values within tolerance",clk[ii]);
e0165dcf 1576 break;
1577 }
1578 }
1579 }
1580 }
1581
33a1fe96 1582 if (ii<2) return 0; // oops we went too far
e0165dcf 1583
1584 return clk[ii];
03e6bb4a 1585}
1e090a61 1586
669959bc 1587uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow) {
1588 int firstClockEdge = 0;
1589 return detectFSKClk_ext(BitStream, size, fcHigh, fcLow, &firstClockEdge);
1590}
1591
4d3c1796 1592//-----------------Tag format detection section--------------------------------------------------------------
1593
1594// by marshmellow
1595// FSK Demod then try to locate an AWID ID
1596int AWIDdemodFSK(uint8_t *dest, size_t *size) {
1597 //make sure buffer has enough data
1598 if (*size < 96*50) return -1;
1599
1600 if (justNoise(dest, *size)) return -2;
1601
1602 // FSK demodulator
1603 *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50
1604 if (*size < 96) return -3; //did we get a good demod?
1605
1606 uint8_t preamble[] = {0,0,0,0,0,0,0,1};
1607 size_t startIdx = 0;
1608 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
1609 if (errChk == 0) return -4; //preamble not found
1610 if (*size != 96) return -5;
1611 return (int)startIdx;
1612}
1613
03e6bb4a 1614//by marshmellow
4d3c1796 1615//takes 1s and 0s and searches for EM410x format - output EM ID
1616uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo)
03e6bb4a 1617{
4d3c1796 1618 //sanity checks
1619 if (*size < 64) return 0;
1620 if (BitStream[1]>1) return 0; //allow only 1s and 0s
e0165dcf 1621
4d3c1796 1622 // 111111111 bit pattern represent start of frame
1623 // include 0 in front to help get start pos
1624 uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1};
1625 uint8_t errChk = 0;
1626 uint8_t FmtLen = 10; // sets of 4 bits = end data
1627 *startIdx = 0;
1628 errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx);
1629 if ( errChk == 0 || (*size != 64 && *size != 128) ) return 0;
1630 if (*size == 128) FmtLen = 22; // 22 sets of 4 bits
e0165dcf 1631
4d3c1796 1632 //skip last 4bit parity row for simplicity
1633 *size = removeParity(BitStream, *startIdx + sizeof(preamble), 5, 0, FmtLen * 5);
1634 if (*size == 40) { // std em410x format
1635 *hi = 0;
1636 *lo = ((uint64_t)(bytebits_to_byte(BitStream, 8)) << 32) | (bytebits_to_byte(BitStream + 8, 32));
1637 } else if (*size == 88) { // long em format
1638 *hi = (bytebits_to_byte(BitStream, 24));
1639 *lo = ((uint64_t)(bytebits_to_byte(BitStream + 24, 32)) << 32) | (bytebits_to_byte(BitStream + 24 + 32, 32));
1640 } else {
1641 return 0;
709665b5 1642 }
4d3c1796 1643 return 1;
6de43508 1644}
1645
4d3c1796 1646// Ask/Biphase Demod then try to locate an ISO 11784/85 ID
1647// BitStream must contain previously askrawdemod and biphasedemoded data
1648int FDXBdemodBI(uint8_t *dest, size_t *size) {
1649 //make sure buffer has enough data
1650 if (*size < 128) return -1;
e0165dcf 1651
4d3c1796 1652 size_t startIdx = 0;
1653 uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,1};
6980d66b 1654
4d3c1796 1655 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
1656 if (errChk == 0) return -2; //preamble not found
1657 return (int)startIdx;
1658}
6980d66b 1659
4d3c1796 1660// by marshmellow
1661// demod gProxIIDemod
1662// error returns as -x
1663// success returns start position in BitStream
1664// BitStream must contain previously askrawdemod and biphasedemoded data
1665int gProxII_Demod(uint8_t BitStream[], size_t *size) {
1666 size_t startIdx=0;
1667 uint8_t preamble[] = {1,1,1,1,1,0};
669959bc 1668
4d3c1796 1669 uint8_t errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, &startIdx);
1670 if (errChk == 0) return -3; //preamble not found
1671 if (*size != 96) return -2; //should have found 96 bits
1672 //check first 6 spacer bits to verify format
1673 if (!BitStream[startIdx+5] && !BitStream[startIdx+10] && !BitStream[startIdx+15] && !BitStream[startIdx+20] && !BitStream[startIdx+25] && !BitStream[startIdx+30]){
1674 //confirmed proper separator bits found
1675 //return start position
1676 return (int) startIdx;
e0165dcf 1677 }
4d3c1796 1678 return -5; //spacer bits not found - not a valid gproxII
ab812dfa 1679}
1680
4d3c1796 1681// loop to get raw HID waveform then FSK demodulate the TAG ID from it
1682int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo) {
1683 if (justNoise(dest, *size)) return -1;
d1869c33 1684
4d3c1796 1685 size_t numStart=0, size2=*size, startIdx=0;
1686 // FSK demodulator
1687 *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
1688 if (*size < 96*2) return -2;
1689 // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
1690 uint8_t preamble[] = {0,0,0,1,1,1,0,1};
1691 // find bitstring in array
1692 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
1693 if (errChk == 0) return -3; //preamble not found
d1869c33 1694
4d3c1796 1695 numStart = startIdx + sizeof(preamble);
1696 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
1697 for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
1698 if (dest[idx] == dest[idx+1]){
1699 return -4; //not manchester data
d1869c33 1700 }
4d3c1796 1701 *hi2 = (*hi2<<1)|(*hi>>31);
1702 *hi = (*hi<<1)|(*lo>>31);
1703 //Then, shift in a 0 or one into low
1704 if (dest[idx] && !dest[idx+1]) // 1 0
1705 *lo=(*lo<<1)|1;
1706 else // 0 1
1707 *lo=(*lo<<1)|0;
d1869c33 1708 }
4d3c1796 1709 return (int)startIdx;
1710}
d1869c33 1711
4d3c1796 1712int IOdemodFSK(uint8_t *dest, size_t size) {
1713 if (justNoise(dest, size)) return -1;
1714 //make sure buffer has data
1715 if (size < 66*64) return -2;
1716 // FSK demodulator
1717 size = fskdemod(dest, size, 64, 1, 10, 8); // FSK2a RF/64
1718 if (size < 65) return -3; //did we get a good demod?
1719 //Index map
1720 //0 10 20 30 40 50 60
1721 //| | | | | | |
1722 //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
1723 //-----------------------------------------------------------------------------
1724 //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
1725 //
1726 //XSF(version)facility:codeone+codetwo
1727 //Handle the data
1728 size_t startIdx = 0;
1729 uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,1};
1730 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), &size, &startIdx);
1731 if (errChk == 0) return -4; //preamble not found
d1869c33 1732
4d3c1796 1733 if (!dest[startIdx+8] && dest[startIdx+17]==1 && dest[startIdx+26]==1 && dest[startIdx+35]==1 && dest[startIdx+44]==1 && dest[startIdx+53]==1){
1734 //confirmed proper separator bits found
1735 //return start position
1736 return (int) startIdx;
d1869c33 1737 }
4d3c1796 1738 return -5;
1739}
d1869c33 1740
4d3c1796 1741// redesigned by marshmellow adjusted from existing decode functions
1742// indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
1743int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert) {
1744 //26 bit 40134 format (don't know other formats)
1745 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};
1746 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};
1747 size_t startidx = 0;
1748 if (!preambleSearch(bitStream, preamble, sizeof(preamble), size, &startidx)){
1749 // if didn't find preamble try again inverting
1750 if (!preambleSearch(bitStream, preamble_i, sizeof(preamble_i), size, &startidx)) return -1;
1751 *invert ^= 1;
1752 }
1753 if (*size != 64 && *size != 224) return -2;
1754 if (*invert==1)
1755 for (size_t i = startidx; i < *size; i++)
1756 bitStream[i] ^= 1;
1757
1758 return (int) startidx;
1759}
1760
1761// loop to get raw paradox waveform then FSK demodulate the TAG ID from it
1762int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo) {
1763 if (justNoise(dest, *size)) return -1;
01d0f8ae 1764
4d3c1796 1765 size_t numStart=0, size2=*size, startIdx=0;
1766 // FSK demodulator
1767 *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
1768 if (*size < 96) return -2;
d1869c33 1769
4d3c1796 1770 // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
1771 uint8_t preamble[] = {0,0,0,0,1,1,1,1};
1772
1773 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
1774 if (errChk == 0) return -3; //preamble not found
1775
1776 numStart = startIdx + sizeof(preamble);
1777 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
1778 for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
1779 if (dest[idx] == dest[idx+1])
1780 return -4; //not manchester data
1781 *hi2 = (*hi2<<1)|(*hi>>31);
1782 *hi = (*hi<<1)|(*lo>>31);
1783 //Then, shift in a 0 or one into low
1784 if (dest[idx] && !dest[idx+1]) // 1 0
1785 *lo=(*lo<<1)|1;
1786 else // 0 1
1787 *lo=(*lo<<1)|0;
d1869c33 1788 }
4d3c1796 1789 return (int)startIdx;
d1869c33 1790}
8b6abef5 1791
4d3c1796 1792// find presco preamble 0x10D in already demoded data
1793int PrescoDemod(uint8_t *dest, size_t *size) {
1794 //make sure buffer has data
1795 if (*size < 64*2) return -2;
1796
1797 size_t startIdx = 0;
1798 uint8_t preamble[] = {1,0,0,0,0,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0};
1799 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
1800 if (errChk == 0) return -4; //preamble not found
1801 //return start position
1802 return (int) startIdx;
669959bc 1803}
1804
4d3c1796 1805// by marshmellow
1806// FSK Demod then try to locate a Farpointe Data (pyramid) ID
1807int PyramiddemodFSK(uint8_t *dest, size_t *size) {
1808 //make sure buffer has data
1809 if (*size < 128*50) return -5;
1810
1811 //test samples are not just noise
1812 if (justNoise(dest, *size)) return -1;
1813
1814 // FSK demodulator
1815 *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50
1816 if (*size < 128) return -2; //did we get a good demod?
1817
1818 uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
1819 size_t startIdx = 0;
1820 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
1821 if (errChk == 0) return -4; //preamble not found
1822 if (*size != 128) return -3;
1823 return (int)startIdx;
1824}
1825
1826// by marshmellow
1827// find viking preamble 0xF200 in already demoded data
1828int VikingDemod_AM(uint8_t *dest, size_t *size) {
1829 //make sure buffer has data
1830 if (*size < 64*2) return -2;
1831
1832 size_t startIdx = 0;
1833 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};
1834 uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
1835 if (errChk == 0) return -4; //preamble not found
1836 uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^ bytebits_to_byte(dest+startIdx+8,8) ^ bytebits_to_byte(dest+startIdx+16,8)
1837 ^ bytebits_to_byte(dest+startIdx+24,8) ^ bytebits_to_byte(dest+startIdx+32,8) ^ bytebits_to_byte(dest+startIdx+40,8)
1838 ^ bytebits_to_byte(dest+startIdx+48,8) ^ bytebits_to_byte(dest+startIdx+56,8);
1839 if ( checkCalc != 0xA8 ) return -5;
1840 if (*size != 64) return -6;
1841 //return start position
1842 return (int) startIdx;
1843}
1844
1845
8b6abef5 1846// by iceman
1847// find Visa2000 preamble in already demoded data
1848int Visa2kDemod_AM(uint8_t *dest, size_t *size) {
1849 if (*size < 96) return -1; //make sure buffer has data
1850 size_t startIdx = 0;
1851 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};
1852 if (preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx) == 0)
1853 return -2; //preamble not found
1854 if (*size != 96) return -3; //wrong demoded size
1855 //return start position
1856 return (int)startIdx;
1857}
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