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eb191de6 | 1 | //----------------------------------------------------------------------------- |
ba1a299c | 2 | // Copyright (C) 2014 |
eb191de6 | 3 | // |
4 | // This code is licensed to you under the terms of the GNU GPL, version 2 or, | |
5 | // at your option, any later version. See the LICENSE.txt file for the text of | |
6 | // the license. | |
7 | //----------------------------------------------------------------------------- | |
1e090a61 | 8 | // Low frequency demod/decode commands |
eb191de6 | 9 | //----------------------------------------------------------------------------- |
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 | 16 | void 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 | |
a1d17964 | 28 | uint8_t justNoise(uint8_t *BitStream, size_t size) |
29 | { | |
30 | static const uint8_t THRESHOLD = 123; | |
31 | //test samples are not just noise | |
32 | uint8_t justNoise1 = 1; | |
33 | for(size_t idx=0; idx < size && justNoise1 ;idx++){ | |
34 | justNoise1 = BitStream[idx] < THRESHOLD; | |
35 | } | |
36 | return justNoise1; | |
37 | } | |
38 | ||
1e090a61 | 39 | //by marshmellow |
872e3d4d | 40 | //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 | 41 | int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi, uint8_t fuzzLo) |
42 | { | |
43 | *high=0; | |
44 | *low=255; | |
45 | // get high and low thresholds | |
2eec55c8 | 46 | for (size_t i=0; i < size; i++){ |
1e090a61 | 47 | if (BitStream[i] > *high) *high = BitStream[i]; |
48 | if (BitStream[i] < *low) *low = BitStream[i]; | |
49 | } | |
50 | if (*high < 123) return -1; // just noise | |
75cbbe9a | 51 | *high = ((*high-128)*fuzzHi + 12800)/100; |
52 | *low = ((*low-128)*fuzzLo + 12800)/100; | |
1e090a61 | 53 | return 1; |
54 | } | |
55 | ||
a1d17964 | 56 | // by marshmellow |
57 | // pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType | |
58 | // returns 1 if passed | |
59 | uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType) | |
60 | { | |
61 | uint8_t ans = 0; | |
62 | for (uint8_t i = 0; i < bitLen; i++){ | |
63 | ans ^= ((bits >> i) & 1); | |
64 | } | |
f3bf15e4 | 65 | //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType); |
a1d17964 | 66 | return (ans == pType); |
67 | } | |
68 | ||
a126332a | 69 | //by marshmellow |
70 | // takes a array of binary values, start position, length of bits per parity (includes parity bit), | |
c728b2b4 | 71 | // 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 | 72 | size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen) |
73 | { | |
74 | uint32_t parityWd = 0; | |
75 | size_t j = 0, bitCnt = 0; | |
76 | for (int word = 0; word < (bLen); word+=pLen){ | |
77 | for (int bit=0; bit < pLen; bit++){ | |
78 | parityWd = (parityWd << 1) | BitStream[startIdx+word+bit]; | |
79 | BitStream[j++] = (BitStream[startIdx+word+bit]); | |
80 | } | |
81 | j--; // overwrite parity with next data | |
82 | // if parity fails then return 0 | |
c728b2b4 | 83 | switch (pType) { |
84 | case 3: if (BitStream[j]==1) return 0; break; //should be 0 spacer bit | |
85 | case 2: if (BitStream[j]==0) return 0; break; //should be 1 spacer bit | |
86 | default: //test parity | |
87 | if (parityTest(parityWd, pLen, pType) == 0) return 0; break; | |
a126332a | 88 | } |
89 | bitCnt+=(pLen-1); | |
90 | parityWd = 0; | |
91 | } | |
92 | // if we got here then all the parities passed | |
93 | //return ID start index and size | |
94 | return bitCnt; | |
95 | } | |
96 | ||
97 | // by marshmellow | |
98 | // takes a array of binary values, length of bits per parity (includes parity bit), | |
0d2c5909 | 99 | // Parity Type (1 for odd; 0 for even; 2 Always 1's; 3 Always 0's), and binary Length (length to run) |
c728b2b4 | 100 | // Make sure *dest is long enough to store original sourceLen + #_of_parities_to_be_added |
a126332a | 101 | size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t pLen, uint8_t pType) |
102 | { | |
103 | uint32_t parityWd = 0; | |
104 | size_t j = 0, bitCnt = 0; | |
105 | for (int word = 0; word < sourceLen; word+=pLen-1) { | |
106 | for (int bit=0; bit < pLen-1; bit++){ | |
107 | parityWd = (parityWd << 1) | BitSource[word+bit]; | |
108 | dest[j++] = (BitSource[word+bit]); | |
109 | } | |
0d2c5909 | 110 | |
a126332a | 111 | // if parity fails then return 0 |
0d2c5909 | 112 | switch (pType) { |
113 | case 3: dest[j++]=0; break; // marker bit which should be a 0 | |
114 | case 2: dest[j++]=1; break; // marker bit which should be a 1 | |
115 | default: | |
116 | dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1; | |
117 | break; | |
a126332a | 118 | } |
119 | bitCnt += pLen; | |
120 | parityWd = 0; | |
121 | } | |
122 | // if we got here then all the parities passed | |
123 | //return ID start index and size | |
124 | return bitCnt; | |
125 | } | |
126 | ||
127 | uint32_t bytebits_to_byte(uint8_t *src, size_t numbits) | |
128 | { | |
129 | uint32_t num = 0; | |
0d2c5909 | 130 | for(int i = 0 ; i < numbits ; i++) { |
a126332a | 131 | num = (num << 1) | (*src); |
132 | src++; | |
133 | } | |
134 | return num; | |
135 | } | |
136 | ||
137 | //least significant bit first | |
138 | uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits) | |
139 | { | |
140 | uint32_t num = 0; | |
6b6815bc | 141 | for(int i = 0 ; i < numbits ; i++) { |
a126332a | 142 | num = (num << 1) | *(src + (numbits-(i+1))); |
143 | } | |
144 | return num; | |
145 | } | |
146 | ||
a1d17964 | 147 | //by marshmellow |
2147c307 | 148 | //search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length |
a1d17964 | 149 | uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx) |
150 | { | |
e0165dcf | 151 | uint8_t foundCnt=0; |
152 | for (int idx=0; idx < *size - pLen; idx++){ | |
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 | |
170 | uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo) | |
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; | |
2767fc02 | 176 | if (BitStream[1]>1) return 0; //allow only 1s and 0s |
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); | |
187 | if (errChk == 0 || *size < 64) return 0; | |
188 | if (*size > 64) FmtLen = 22; | |
189 | *startIdx += 1; //get rid of 0 from preamble | |
190 | idx = *startIdx + 9; | |
191 | for (i=0; i<FmtLen; i++){ //loop through 10 or 22 sets of 5 bits (50-10p = 40 bits or 88 bits) | |
192 | parityBits = bytebits_to_byte(BitStream+(i*5)+idx,5); | |
2eec55c8 | 193 | //check even parity - quit if failed |
194 | if (parityTest(parityBits, 5, 0) == 0) return 0; | |
e0165dcf | 195 | //set uint64 with ID from BitStream |
196 | for (uint8_t ii=0; ii<4; ii++){ | |
197 | *hi = (*hi << 1) | (*lo >> 63); | |
198 | *lo = (*lo << 1) | (BitStream[(i*5)+ii+idx]); | |
199 | } | |
200 | } | |
201 | if (errChk != 0) return 1; | |
202 | //skip last 5 bit parity test for simplicity. | |
203 | // *size = 64 | 128; | |
204 | return 0; | |
2147c307 | 205 | } |
206 | ||
fef74fdc | 207 | //by marshmellow |
208 | //demodulates strong heavily clipped samples | |
23f0a7d8 | 209 | int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low) |
210 | { | |
211 | size_t bitCnt=0, smplCnt=0, errCnt=0; | |
212 | uint8_t waveHigh = 0; | |
23f0a7d8 | 213 | for (size_t i=0; i < *size; i++){ |
214 | if (BinStream[i] >= high && waveHigh){ | |
215 | smplCnt++; | |
216 | } else if (BinStream[i] <= low && !waveHigh){ | |
217 | smplCnt++; | |
218 | } else { //transition | |
219 | if ((BinStream[i] >= high && !waveHigh) || (BinStream[i] <= low && waveHigh)){ | |
220 | if (smplCnt > clk-(clk/4)-1) { //full clock | |
221 | if (smplCnt > clk + (clk/4)+1) { //too many samples | |
222 | errCnt++; | |
05164399 | 223 | if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i); |
2767fc02 | 224 | BinStream[bitCnt++]=7; |
23f0a7d8 | 225 | } else if (waveHigh) { |
226 | BinStream[bitCnt++] = invert; | |
227 | BinStream[bitCnt++] = invert; | |
228 | } else if (!waveHigh) { | |
229 | BinStream[bitCnt++] = invert ^ 1; | |
230 | BinStream[bitCnt++] = invert ^ 1; | |
231 | } | |
232 | waveHigh ^= 1; | |
233 | smplCnt = 0; | |
234 | } else if (smplCnt > (clk/2) - (clk/4)-1) { | |
235 | if (waveHigh) { | |
236 | BinStream[bitCnt++] = invert; | |
237 | } else if (!waveHigh) { | |
238 | BinStream[bitCnt++] = invert ^ 1; | |
239 | } | |
240 | waveHigh ^= 1; | |
241 | smplCnt = 0; | |
242 | } else if (!bitCnt) { | |
243 | //first bit | |
244 | waveHigh = (BinStream[i] >= high); | |
245 | smplCnt = 1; | |
246 | } else { | |
247 | smplCnt++; | |
248 | //transition bit oops | |
249 | } | |
250 | } else { //haven't hit new high or new low yet | |
251 | smplCnt++; | |
252 | } | |
253 | } | |
254 | } | |
255 | *size = bitCnt; | |
256 | return errCnt; | |
257 | } | |
258 | ||
eb191de6 | 259 | //by marshmellow |
fef74fdc | 260 | void askAmp(uint8_t *BitStream, size_t size) |
261 | { | |
9686a8d4 | 262 | uint8_t last = 128; |
263 | for(size_t i = 1; i < size; ++i){ | |
264 | if (BitStream[i]-BitStream[i-1] >= 30) //large jump up | |
265 | last = 255; | |
266 | else if(BitStream[i-1] - BitStream[i] >= 20) //large jump down | |
267 | last = 0; | |
268 | ||
269 | BitStream[i] = last; | |
fef74fdc | 270 | } |
fef74fdc | 271 | } |
272 | ||
273 | //by marshmellow | |
274 | //attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester | |
275 | int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType) | |
eb191de6 | 276 | { |
fef74fdc | 277 | if (*size==0) return -1; |
6e984446 | 278 | int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default |
2eec55c8 | 279 | if (*clk==0 || start < 0) return -3; |
fef74fdc | 280 | if (*invert != 1) *invert = 0; |
281 | if (amp==1) askAmp(BinStream, *size); | |
05164399 | 282 | if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d", *clk, start); |
fef74fdc | 283 | |
2eec55c8 | 284 | uint8_t initLoopMax = 255; |
285 | if (initLoopMax > *size) initLoopMax = *size; | |
ba1a299c | 286 | // Detect high and lows |
fef74fdc | 287 | //25% clip in case highs and lows aren't clipped [marshmellow] |
2eec55c8 | 288 | int high, low; |
fef74fdc | 289 | if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1) |
290 | return -2; //just noise | |
ba1a299c | 291 | |
fef74fdc | 292 | size_t errCnt = 0; |
23f0a7d8 | 293 | // if clean clipped waves detected run alternate demod |
294 | if (DetectCleanAskWave(BinStream, *size, high, low)) { | |
05164399 | 295 | if (g_debugMode==2) prnt("DEBUG ASK: Clean Wave Detected - using clean wave demod"); |
fef74fdc | 296 | errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low); |
297 | if (askType) //askman | |
298 | return manrawdecode(BinStream, size, 0); | |
299 | else //askraw | |
300 | return errCnt; | |
23f0a7d8 | 301 | } |
05164399 | 302 | if (g_debugMode==2) prnt("DEBUG ASK: Weak Wave Detected - using weak wave demod"); |
23f0a7d8 | 303 | |
fef74fdc | 304 | int lastBit; //set first clock check - can go negative |
305 | size_t i, bitnum = 0; //output counter | |
306 | uint8_t midBit = 0; | |
2eec55c8 | 307 | 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 | 308 | 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 | 309 | size_t MaxBits = 3072; //max bits to collect |
6e984446 | 310 | lastBit = start - *clk; |
fef74fdc | 311 | |
6e984446 | 312 | for (i = start; i < *size; ++i) { |
fef74fdc | 313 | if (i-lastBit >= *clk-tol){ |
314 | if (BinStream[i] >= high) { | |
315 | BinStream[bitnum++] = *invert; | |
316 | } else if (BinStream[i] <= low) { | |
317 | BinStream[bitnum++] = *invert ^ 1; | |
318 | } else if (i-lastBit >= *clk+tol) { | |
319 | if (bitnum > 0) { | |
05164399 | 320 | if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i); |
fef74fdc | 321 | BinStream[bitnum++]=7; |
322 | errCnt++; | |
323 | } | |
324 | } else { //in tolerance - looking for peak | |
325 | continue; | |
326 | } | |
327 | midBit = 0; | |
2eec55c8 | 328 | lastBit += *clk; |
fef74fdc | 329 | } else if (i-lastBit >= (*clk/2-tol) && !midBit && !askType){ |
330 | if (BinStream[i] >= high) { | |
331 | BinStream[bitnum++] = *invert; | |
332 | } else if (BinStream[i] <= low) { | |
333 | BinStream[bitnum++] = *invert ^ 1; | |
334 | } else if (i-lastBit >= *clk/2+tol) { | |
335 | BinStream[bitnum] = BinStream[bitnum-1]; | |
336 | bitnum++; | |
337 | } else { //in tolerance - looking for peak | |
338 | continue; | |
339 | } | |
340 | midBit = 1; | |
2eec55c8 | 341 | } |
342 | if (bitnum >= MaxBits) break; | |
ba1a299c | 343 | } |
2eec55c8 | 344 | *size = bitnum; |
6e984446 | 345 | return errCnt; |
eb191de6 | 346 | } |
347 | ||
348 | //by marshmellow | |
349 | //take 10 and 01 and manchester decode | |
350 | //run through 2 times and take least errCnt | |
fef74fdc | 351 | int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert) |
eb191de6 | 352 | { |
13d77ef9 | 353 | uint16_t bitnum=0, MaxBits = 512, errCnt = 0; |
354 | size_t i, ii; | |
355 | uint16_t bestErr = 1000, bestRun = 0; | |
fef74fdc | 356 | if (*size < 16) return -1; |
2767fc02 | 357 | //find correct start position [alignment] |
13d77ef9 | 358 | for (ii=0;ii<2;++ii){ |
fef74fdc | 359 | for (i=ii; i<*size-3; i+=2) |
2eec55c8 | 360 | if (BitStream[i]==BitStream[i+1]) |
ba1a299c | 361 | errCnt++; |
2eec55c8 | 362 | |
ba1a299c | 363 | if (bestErr>errCnt){ |
364 | bestErr=errCnt; | |
365 | bestRun=ii; | |
366 | } | |
367 | errCnt=0; | |
368 | } | |
2767fc02 | 369 | //decode |
fef74fdc | 370 | for (i=bestRun; i < *size-3; i+=2){ |
23f0a7d8 | 371 | if(BitStream[i] == 1 && (BitStream[i+1] == 0)){ |
fef74fdc | 372 | BitStream[bitnum++]=invert; |
23f0a7d8 | 373 | } else if((BitStream[i] == 0) && BitStream[i+1] == 1){ |
fef74fdc | 374 | BitStream[bitnum++]=invert^1; |
23f0a7d8 | 375 | } else { |
2767fc02 | 376 | BitStream[bitnum++]=7; |
ba1a299c | 377 | } |
23f0a7d8 | 378 | if(bitnum>MaxBits) break; |
ba1a299c | 379 | } |
23f0a7d8 | 380 | *size=bitnum; |
2eec55c8 | 381 | return bestErr; |
f822a063 | 382 | } |
383 | ||
1d0ccbe0 | 384 | uint32_t manchesterEncode2Bytes(uint16_t datain) { |
385 | uint32_t output = 0; | |
386 | uint8_t curBit = 0; | |
387 | for (uint8_t i=0; i<16; i++) { | |
388 | curBit = (datain >> (15-i) & 1); | |
389 | output |= (1<<(((15-i)*2)+curBit)); | |
390 | } | |
391 | return output; | |
392 | } | |
393 | ||
fef74fdc | 394 | //by marshmellow |
395 | //encode binary data into binary manchester | |
396 | int ManchesterEncode(uint8_t *BitStream, size_t size) | |
397 | { | |
398 | size_t modIdx=20000, i=0; | |
399 | if (size>modIdx) return -1; | |
400 | for (size_t idx=0; idx < size; idx++){ | |
401 | BitStream[idx+modIdx++] = BitStream[idx]; | |
402 | BitStream[idx+modIdx++] = BitStream[idx]^1; | |
403 | } | |
404 | for (; i<(size*2); i++){ | |
405 | BitStream[i] = BitStream[i+20000]; | |
406 | } | |
407 | return i; | |
408 | } | |
409 | ||
f822a063 | 410 | //by marshmellow |
2147c307 | 411 | //take 01 or 10 = 1 and 11 or 00 = 0 |
412 | //check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010 | |
13d77ef9 | 413 | //decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding |
1e090a61 | 414 | int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert) |
f822a063 | 415 | { |
2eec55c8 | 416 | uint16_t bitnum = 0; |
417 | uint16_t errCnt = 0; | |
418 | size_t i = offset; | |
2147c307 | 419 | uint16_t MaxBits=512; |
420 | //if not enough samples - error | |
421 | if (*size < 51) return -1; | |
422 | //check for phase change faults - skip one sample if faulty | |
423 | uint8_t offsetA = 1, offsetB = 1; | |
424 | for (; i<48; i+=2){ | |
425 | if (BitStream[i+1]==BitStream[i+2]) offsetA=0; | |
426 | if (BitStream[i+2]==BitStream[i+3]) offsetB=0; | |
427 | } | |
428 | if (!offsetA && offsetB) offset++; | |
429 | for (i=offset; i<*size-3; i+=2){ | |
430 | //check for phase error | |
13d77ef9 | 431 | if (BitStream[i+1]==BitStream[i+2]) { |
2767fc02 | 432 | BitStream[bitnum++]=7; |
2147c307 | 433 | errCnt++; |
434 | } | |
ba1a299c | 435 | if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){ |
1e090a61 | 436 | BitStream[bitnum++]=1^invert; |
ba1a299c | 437 | } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){ |
1e090a61 | 438 | BitStream[bitnum++]=invert; |
ba1a299c | 439 | } else { |
2767fc02 | 440 | BitStream[bitnum++]=7; |
ba1a299c | 441 | errCnt++; |
442 | } | |
6de43508 | 443 | if(bitnum>MaxBits) break; |
ba1a299c | 444 | } |
445 | *size=bitnum; | |
446 | return errCnt; | |
eb191de6 | 447 | } |
448 | ||
fef74fdc | 449 | // by marshmellow |
11081e04 | 450 | // demod gProxIIDemod |
451 | // error returns as -x | |
452 | // success returns start position in BitStream | |
453 | // BitStream must contain previously askrawdemod and biphasedemoded data | |
454 | int gProxII_Demod(uint8_t BitStream[], size_t *size) | |
455 | { | |
456 | size_t startIdx=0; | |
457 | uint8_t preamble[] = {1,1,1,1,1,0}; | |
458 | ||
459 | uint8_t errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, &startIdx); | |
460 | if (errChk == 0) return -3; //preamble not found | |
461 | if (*size != 96) return -2; //should have found 96 bits | |
462 | //check first 6 spacer bits to verify format | |
463 | if (!BitStream[startIdx+5] && !BitStream[startIdx+10] && !BitStream[startIdx+15] && !BitStream[startIdx+20] && !BitStream[startIdx+25] && !BitStream[startIdx+30]){ | |
464 | //confirmed proper separator bits found | |
465 | //return start position | |
466 | return (int) startIdx; | |
467 | } | |
7fa7e812 | 468 | return -5; //spacer bits not found - not a valid gproxII |
11081e04 | 469 | } |
470 | ||
7fa7e812 | 471 | //translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq]) |
f822a063 | 472 | size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow) |
eb191de6 | 473 | { |
2eec55c8 | 474 | size_t last_transition = 0; |
475 | size_t idx = 1; | |
ac3ba7ee | 476 | //uint32_t maxVal=0; |
ba1a299c | 477 | if (fchigh==0) fchigh=10; |
478 | if (fclow==0) fclow=8; | |
84871873 | 479 | //set the threshold close to 0 (graph) or 128 std to avoid static |
480 | uint8_t threshold_value = 123; | |
ac2df346 | 481 | size_t preLastSample = 0; |
482 | size_t LastSample = 0; | |
483 | size_t currSample = 0; | |
ba1a299c | 484 | // sync to first lo-hi transition, and threshold |
485 | ||
486 | // Need to threshold first sample | |
6426f6ba | 487 | // skip 160 samples to allow antenna/samples to settle |
488 | if(dest[160] < threshold_value) dest[0] = 0; | |
ba1a299c | 489 | else dest[0] = 1; |
490 | ||
491 | size_t numBits = 0; | |
492 | // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8) | |
cd0bed3c | 493 | // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere |
ba1a299c | 494 | // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10 |
7fa7e812 | 495 | // (could also be fc/5 && fc/7 for fsk1 = 4-9) |
6426f6ba | 496 | for(idx = 161; idx < size-20; idx++) { |
ba1a299c | 497 | // threshold current value |
498 | ||
499 | if (dest[idx] < threshold_value) dest[idx] = 0; | |
500 | else dest[idx] = 1; | |
501 | ||
502 | // Check for 0->1 transition | |
7fa7e812 | 503 | if (dest[idx-1] < dest[idx]) { |
ac2df346 | 504 | preLastSample = LastSample; |
505 | LastSample = currSample; | |
506 | currSample = idx-last_transition; | |
6426f6ba | 507 | if (currSample < (fclow-2)){ //0-5 = garbage noise (or 0-3) |
ba1a299c | 508 | //do nothing with extra garbage |
7fa7e812 | 509 | } else if (currSample < (fchigh-1)) { //6-8 = 8 sample waves (or 3-6 = 5) |
510 | //correct previous 9 wave surrounded by 8 waves (or 6 surrounded by 5) | |
6426f6ba | 511 | if (LastSample > (fchigh-2) && (preLastSample < (fchigh-1) || preLastSample == 0 )){ |
7fa7e812 | 512 | dest[numBits-1]=1; |
ac2df346 | 513 | } |
2eec55c8 | 514 | dest[numBits++]=1; |
ac2df346 | 515 | |
7fa7e812 | 516 | } else if (currSample > (fchigh) && !numBits) { //12 + and first bit = unusable garbage |
13d77ef9 | 517 | //do nothing with beginning garbage |
7fa7e812 | 518 | } 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 | 519 | dest[numBits++]=1; |
7fa7e812 | 520 | } else { //9+ = 10 sample waves (or 6+ = 7) |
2eec55c8 | 521 | dest[numBits++]=0; |
ba1a299c | 522 | } |
523 | last_transition = idx; | |
ba1a299c | 524 | } |
525 | } | |
526 | return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0 | |
eb191de6 | 527 | } |
528 | ||
ba1a299c | 529 | //translate 11111100000 to 10 |
7fa7e812 | 530 | //rfLen = clock, fchigh = larger field clock, fclow = smaller field clock |
2eec55c8 | 531 | size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, |
e0165dcf | 532 | uint8_t invert, uint8_t fchigh, uint8_t fclow) |
eb191de6 | 533 | { |
ba1a299c | 534 | uint8_t lastval=dest[0]; |
2eec55c8 | 535 | size_t idx=0; |
ba1a299c | 536 | size_t numBits=0; |
537 | uint32_t n=1; | |
ba1a299c | 538 | for( idx=1; idx < size; idx++) { |
13d77ef9 | 539 | n++; |
2eec55c8 | 540 | if (dest[idx]==lastval) continue; |
541 | ||
7fa7e812 | 542 | //find out how many bits (n) we collected |
ba1a299c | 543 | //if lastval was 1, we have a 1->0 crossing |
13d77ef9 | 544 | if (dest[idx-1]==1) { |
75cbbe9a | 545 | n = (n * fclow + rfLen/2) / rfLen; |
13d77ef9 | 546 | } else {// 0->1 crossing |
75cbbe9a | 547 | n = (n * fchigh + rfLen/2) / rfLen; |
ba1a299c | 548 | } |
549 | if (n == 0) n = 1; | |
550 | ||
7fa7e812 | 551 | //add to our destination the bits we collected |
2eec55c8 | 552 | memset(dest+numBits, dest[idx-1]^invert , n); |
553 | numBits += n; | |
ba1a299c | 554 | n=0; |
555 | lastval=dest[idx]; | |
556 | }//end for | |
13d77ef9 | 557 | // if valid extra bits at the end were all the same frequency - add them in |
75cbbe9a | 558 | if (n > rfLen/fchigh) { |
13d77ef9 | 559 | if (dest[idx-2]==1) { |
75cbbe9a | 560 | n = (n * fclow + rfLen/2) / rfLen; |
13d77ef9 | 561 | } else { |
75cbbe9a | 562 | n = (n * fchigh + rfLen/2) / rfLen; |
13d77ef9 | 563 | } |
2eec55c8 | 564 | memset(dest+numBits, dest[idx-1]^invert , n); |
13d77ef9 | 565 | numBits += n; |
566 | } | |
ba1a299c | 567 | return numBits; |
eb191de6 | 568 | } |
6426f6ba | 569 | |
eb191de6 | 570 | //by marshmellow (from holiman's base) |
571 | // full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod) | |
f822a063 | 572 | int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow) |
eb191de6 | 573 | { |
ba1a299c | 574 | // FSK demodulator |
575 | size = fsk_wave_demod(dest, size, fchigh, fclow); | |
2eec55c8 | 576 | size = aggregate_bits(dest, size, rfLen, invert, fchigh, fclow); |
ba1a299c | 577 | return size; |
eb191de6 | 578 | } |
a1d17964 | 579 | |
eb191de6 | 580 | // loop to get raw HID waveform then FSK demodulate the TAG ID from it |
ec75f5c1 | 581 | int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo) |
eb191de6 | 582 | { |
e0165dcf | 583 | if (justNoise(dest, *size)) return -1; |
584 | ||
585 | size_t numStart=0, size2=*size, startIdx=0; | |
586 | // FSK demodulator | |
587 | *size = fskdemod(dest, size2,50,1,10,8); //fsk2a | |
2eec55c8 | 588 | if (*size < 96*2) return -2; |
e0165dcf | 589 | // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1 |
590 | uint8_t preamble[] = {0,0,0,1,1,1,0,1}; | |
591 | // find bitstring in array | |
592 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); | |
593 | if (errChk == 0) return -3; //preamble not found | |
594 | ||
595 | numStart = startIdx + sizeof(preamble); | |
596 | // final loop, go over previously decoded FSK data and manchester decode into usable tag ID | |
597 | for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){ | |
598 | if (dest[idx] == dest[idx+1]){ | |
599 | return -4; //not manchester data | |
600 | } | |
601 | *hi2 = (*hi2<<1)|(*hi>>31); | |
602 | *hi = (*hi<<1)|(*lo>>31); | |
603 | //Then, shift in a 0 or one into low | |
604 | if (dest[idx] && !dest[idx+1]) // 1 0 | |
605 | *lo=(*lo<<1)|1; | |
606 | else // 0 1 | |
607 | *lo=(*lo<<1)|0; | |
608 | } | |
609 | return (int)startIdx; | |
eb191de6 | 610 | } |
611 | ||
ec75f5c1 | 612 | // loop to get raw paradox waveform then FSK demodulate the TAG ID from it |
a1d17964 | 613 | int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo) |
ec75f5c1 | 614 | { |
a1d17964 | 615 | if (justNoise(dest, *size)) return -1; |
616 | ||
617 | size_t numStart=0, size2=*size, startIdx=0; | |
ec75f5c1 | 618 | // FSK demodulator |
a1d17964 | 619 | *size = fskdemod(dest, size2,50,1,10,8); //fsk2a |
620 | if (*size < 96) return -2; | |
ec75f5c1 | 621 | |
a1d17964 | 622 | // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1 |
623 | uint8_t preamble[] = {0,0,0,0,1,1,1,1}; | |
624 | ||
625 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); | |
626 | if (errChk == 0) return -3; //preamble not found | |
627 | ||
628 | numStart = startIdx + sizeof(preamble); | |
629 | // final loop, go over previously decoded FSK data and manchester decode into usable tag ID | |
630 | for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){ | |
631 | if (dest[idx] == dest[idx+1]) | |
632 | return -4; //not manchester data | |
633 | *hi2 = (*hi2<<1)|(*hi>>31); | |
634 | *hi = (*hi<<1)|(*lo>>31); | |
635 | //Then, shift in a 0 or one into low | |
636 | if (dest[idx] && !dest[idx+1]) // 1 0 | |
637 | *lo=(*lo<<1)|1; | |
638 | else // 0 1 | |
639 | *lo=(*lo<<1)|0; | |
ec75f5c1 | 640 | } |
a1d17964 | 641 | return (int)startIdx; |
ec75f5c1 | 642 | } |
643 | ||
eb191de6 | 644 | int IOdemodFSK(uint8_t *dest, size_t size) |
645 | { | |
a1d17964 | 646 | if (justNoise(dest, size)) return -1; |
ba1a299c | 647 | //make sure buffer has data |
a1d17964 | 648 | if (size < 66*64) return -2; |
ba1a299c | 649 | // FSK demodulator |
a1d17964 | 650 | size = fskdemod(dest, size, 64, 1, 10, 8); // FSK2a RF/64 |
651 | if (size < 65) return -3; //did we get a good demod? | |
ba1a299c | 652 | //Index map |
653 | //0 10 20 30 40 50 60 | |
654 | //| | | | | | | | |
655 | //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23 | |
656 | //----------------------------------------------------------------------------- | |
657 | //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11 | |
658 | // | |
659 | //XSF(version)facility:codeone+codetwo | |
660 | //Handle the data | |
a1d17964 | 661 | size_t startIdx = 0; |
662 | uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,1}; | |
663 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), &size, &startIdx); | |
664 | if (errChk == 0) return -4; //preamble not found | |
eb191de6 | 665 | |
a1d17964 | 666 | if (!dest[startIdx+8] && dest[startIdx+17]==1 && dest[startIdx+26]==1 && dest[startIdx+35]==1 && dest[startIdx+44]==1 && dest[startIdx+53]==1){ |
667 | //confirmed proper separator bits found | |
668 | //return start position | |
669 | return (int) startIdx; | |
1e090a61 | 670 | } |
a1d17964 | 671 | return -5; |
1e090a61 | 672 | } |
673 | ||
70459879 | 674 | // by marshmellow |
675 | // find viking preamble 0xF200 in already demoded data | |
676 | int VikingDemod_AM(uint8_t *dest, size_t *size) { | |
70459879 | 677 | //make sure buffer has data |
678 | if (*size < 64*2) return -2; | |
679 | ||
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 |
695 | return (int) startIdx; | |
696 | } | |
697 | ||
4469412e | 698 | // find presco preamble 0x10D in already demoded data |
699 | int PrescoDemod(uint8_t *dest, size_t *size) { | |
700 | //make sure buffer has data | |
701 | if (*size < 64*2) return -2; | |
702 | ||
703 | size_t startIdx = 0; | |
704 | uint8_t preamble[] = {1,0,0,0,0,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0}; | |
705 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); | |
706 | if (errChk == 0) return -4; //preamble not found | |
707 | //return start position | |
708 | return (int) startIdx; | |
709 | } | |
710 | ||
615f21dd | 711 | // Ask/Biphase Demod then try to locate an ISO 11784/85 ID |
0df669a2 | 712 | // BitStream must contain previously askrawdemod and biphasedemoded data |
ad6219fc | 713 | int FDXBdemodBI(uint8_t *dest, size_t *size) |
615f21dd | 714 | { |
715 | //make sure buffer has enough data | |
0df669a2 | 716 | if (*size < 128) return -1; |
615f21dd | 717 | |
615f21dd | 718 | size_t startIdx = 0; |
0df669a2 | 719 | uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,1}; |
720 | ||
615f21dd | 721 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); |
0df669a2 | 722 | if (errChk == 0) return -2; //preamble not found |
615f21dd | 723 | return (int)startIdx; |
724 | } | |
1e090a61 | 725 | |
6c283951 | 726 | // ASK/Diphase fc/64 (inverted Biphase) |
727 | // Note: this i s not a demod, this is only a detection | |
728 | // the parameter *dest needs to be demoded before call | |
729 | int JablotronDemod(uint8_t *dest, size_t *size){ | |
730 | //make sure buffer has enough data | |
731 | if (*size < 64) return -1; | |
732 | ||
733 | size_t startIdx = 0; | |
734 | // 0xFFFF preamble, 64bits | |
735 | uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1}; | |
736 | ||
737 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); | |
738 | if (errChk == 0) return -4; //preamble not found | |
739 | ||
740 | uint8_t checkCalc = 0; | |
741 | for (int i=16; i < 56; i += 8) { | |
742 | checkCalc += bytebits_to_byte(dest+startIdx+i,8); | |
743 | } | |
744 | checkCalc ^= 0x3A; | |
745 | ||
746 | uint8_t crc = bytebits_to_byte(dest+startIdx+56,8); | |
747 | ||
748 | if ( checkCalc != crc ) return -5; | |
749 | if (*size != 64) return -6; | |
750 | return (int)startIdx; | |
751 | } | |
752 | ||
1e090a61 | 753 | // by marshmellow |
754 | // FSK Demod then try to locate an AWID ID | |
a1d17964 | 755 | int AWIDdemodFSK(uint8_t *dest, size_t *size) |
1e090a61 | 756 | { |
a1d17964 | 757 | //make sure buffer has enough data |
758 | if (*size < 96*50) return -1; | |
759 | ||
760 | if (justNoise(dest, *size)) return -2; | |
1e090a61 | 761 | |
762 | // FSK demodulator | |
a1d17964 | 763 | *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50 |
764 | if (*size < 96) return -3; //did we get a good demod? | |
765 | ||
766 | uint8_t preamble[] = {0,0,0,0,0,0,0,1}; | |
767 | size_t startIdx = 0; | |
768 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); | |
769 | if (errChk == 0) return -4; //preamble not found | |
770 | if (*size != 96) return -5; | |
771 | return (int)startIdx; | |
1e090a61 | 772 | } |
773 | ||
774 | // by marshmellow | |
6426f6ba | 775 | // FSK Demod then try to locate a Farpointe Data (pyramid) ID |
a1d17964 | 776 | int PyramiddemodFSK(uint8_t *dest, size_t *size) |
1e090a61 | 777 | { |
f3bf15e4 | 778 | //make sure buffer has data |
779 | if (*size < 128*50) return -5; | |
a1d17964 | 780 | |
f3bf15e4 | 781 | //test samples are not just noise |
782 | if (justNoise(dest, *size)) return -1; | |
1e090a61 | 783 | |
f3bf15e4 | 784 | // FSK demodulator |
785 | *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50 | |
786 | if (*size < 128) return -2; //did we get a good demod? | |
a1d17964 | 787 | |
f3bf15e4 | 788 | uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1}; |
a1d17964 | 789 | size_t startIdx = 0; |
790 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); | |
791 | if (errChk == 0) return -4; //preamble not found | |
792 | if (*size != 128) return -3; | |
793 | return (int)startIdx; | |
1e090a61 | 794 | } |
795 | ||
0cbe0cb8 | 796 | // find nedap preamble in already demoded data |
56bbb25a | 797 | int NedapDemod(uint8_t *dest, size_t *size) { |
798 | //make sure buffer has data | |
799 | if (*size < 128) return -3; | |
96faed21 | 800 | |
56bbb25a | 801 | size_t startIdx = 0; |
15d49e82 | 802 | //uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,0,0,0,1}; |
803 | uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,0}; | |
56bbb25a | 804 | uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); |
805 | if (errChk == 0) return -4; //preamble not found | |
56bbb25a | 806 | return (int) startIdx; |
807 | } | |
808 | ||
fef74fdc | 809 | // by marshmellow |
810 | // to detect a wave that has heavily clipped (clean) samples | |
cc15a118 | 811 | uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low) |
6de43508 | 812 | { |
6426f6ba | 813 | bool allArePeaks = true; |
6de43508 | 814 | uint16_t cntPeaks=0; |
6426f6ba | 815 | size_t loopEnd = 512+160; |
1fbf8956 | 816 | if (loopEnd > size) loopEnd = size; |
6426f6ba | 817 | for (size_t i=160; i<loopEnd; i++){ |
6de43508 | 818 | if (dest[i]>low && dest[i]<high) |
6426f6ba | 819 | allArePeaks = false; |
6de43508 | 820 | else |
821 | cntPeaks++; | |
822 | } | |
6426f6ba | 823 | if (!allArePeaks){ |
824 | if (cntPeaks > 300) return true; | |
6de43508 | 825 | } |
6426f6ba | 826 | return allArePeaks; |
6de43508 | 827 | } |
2eec55c8 | 828 | // by marshmellow |
829 | // to help detect clocks on heavily clipped samples | |
cc15a118 | 830 | // based on count of low to low |
831 | int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low) | |
13d77ef9 | 832 | { |
cc15a118 | 833 | uint8_t fndClk[] = {8,16,32,40,50,64,128}; |
834 | size_t startwave; | |
6426f6ba | 835 | size_t i = 100; |
cc15a118 | 836 | size_t minClk = 255; |
837 | // get to first full low to prime loop and skip incomplete first pulse | |
838 | while ((dest[i] < high) && (i < size)) | |
839 | ++i; | |
840 | while ((dest[i] > low) && (i < size)) | |
841 | ++i; | |
842 | ||
843 | // loop through all samples | |
844 | while (i < size) { | |
845 | // measure from low to low | |
846 | while ((dest[i] > low) && (i < size)) | |
847 | ++i; | |
848 | startwave= i; | |
849 | while ((dest[i] < high) && (i < size)) | |
850 | ++i; | |
851 | while ((dest[i] > low) && (i < size)) | |
852 | ++i; | |
853 | //get minimum measured distance | |
854 | if (i-startwave < minClk && i < size) | |
855 | minClk = i - startwave; | |
13d77ef9 | 856 | } |
cc15a118 | 857 | // set clock |
a126332a | 858 | if (g_debugMode==2) prnt("DEBUG ASK: detectstrongASKclk smallest wave: %d",minClk); |
cc15a118 | 859 | for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) { |
860 | if (minClk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1) | |
861 | return fndClk[clkCnt]; | |
13d77ef9 | 862 | } |
cc15a118 | 863 | return 0; |
13d77ef9 | 864 | } |
865 | ||
eb191de6 | 866 | // by marshmellow |
867 | // not perfect especially with lower clocks or VERY good antennas (heavy wave clipping) | |
868 | // maybe somehow adjust peak trimming value based on samples to fix? | |
6de43508 | 869 | // return start index of best starting position for that clock and return clock (by reference) |
870 | int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr) | |
eb191de6 | 871 | { |
6e984446 | 872 | size_t i=1; |
cc15a118 | 873 | uint8_t clk[] = {255,8,16,32,40,50,64,100,128,255}; |
874 | uint8_t clkEnd = 9; | |
2eec55c8 | 875 | uint8_t loopCnt = 255; //don't need to loop through entire array... |
6426f6ba | 876 | if (size <= loopCnt+60) return -1; //not enough samples |
877 | size -= 60; //sometimes there is a strange end wave - filter out this.... | |
6e984446 | 878 | //if we already have a valid clock |
879 | uint8_t clockFnd=0; | |
cc15a118 | 880 | for (;i<clkEnd;++i) |
881 | if (clk[i] == *clock) clockFnd = i; | |
6e984446 | 882 | //clock found but continue to find best startpos |
e0165dcf | 883 | |
884 | //get high and low peak | |
885 | int peak, low; | |
2eec55c8 | 886 | if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return -1; |
e0165dcf | 887 | |
888 | //test for large clean peaks | |
cc15a118 | 889 | if (!clockFnd){ |
890 | if (DetectCleanAskWave(dest, size, peak, low)==1){ | |
891 | int ans = DetectStrongAskClock(dest, size, peak, low); | |
a126332a | 892 | if (g_debugMode==2) prnt("DEBUG ASK: detectaskclk Clean Ask Wave Detected: clk %d",ans); |
cc15a118 | 893 | for (i=clkEnd-1; i>0; i--){ |
894 | if (clk[i] == ans) { | |
895 | *clock = ans; | |
896 | //clockFnd = i; | |
897 | return 0; // for strong waves i don't use the 'best start position' yet... | |
898 | //break; //clock found but continue to find best startpos [not yet] | |
899 | } | |
e0165dcf | 900 | } |
901 | } | |
902 | } | |
2eec55c8 | 903 | uint8_t ii; |
904 | uint8_t clkCnt, tol = 0; | |
905 | uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000}; | |
906 | uint8_t bestStart[]={0,0,0,0,0,0,0,0,0}; | |
907 | size_t errCnt = 0; | |
908 | size_t arrLoc, loopEnd; | |
6e984446 | 909 | |
cc15a118 | 910 | if (clockFnd>0) { |
911 | clkCnt = clockFnd; | |
912 | clkEnd = clockFnd+1; | |
913 | } | |
914 | else clkCnt=1; | |
915 | ||
916 | //test each valid clock from smallest to greatest to see which lines up | |
917 | for(; clkCnt < clkEnd; clkCnt++){ | |
fef74fdc | 918 | if (clk[clkCnt] <= 32){ |
e0165dcf | 919 | tol=1; |
920 | }else{ | |
921 | tol=0; | |
922 | } | |
2767fc02 | 923 | //if no errors allowed - keep start within the first clock |
cc15a118 | 924 | if (!maxErr && size > clk[clkCnt]*2 + tol && clk[clkCnt]<128) loopCnt=clk[clkCnt]*2; |
e0165dcf | 925 | bestErr[clkCnt]=1000; |
6e984446 | 926 | //try lining up the peaks by moving starting point (try first few clocks) |
cc15a118 | 927 | for (ii=0; ii < loopCnt; ii++){ |
2eec55c8 | 928 | if (dest[ii] < peak && dest[ii] > low) continue; |
929 | ||
930 | errCnt=0; | |
931 | // now that we have the first one lined up test rest of wave array | |
932 | loopEnd = ((size-ii-tol) / clk[clkCnt]) - 1; | |
933 | for (i=0; i < loopEnd; ++i){ | |
934 | arrLoc = ii + (i * clk[clkCnt]); | |
935 | if (dest[arrLoc] >= peak || dest[arrLoc] <= low){ | |
936 | }else if (dest[arrLoc-tol] >= peak || dest[arrLoc-tol] <= low){ | |
937 | }else if (dest[arrLoc+tol] >= peak || dest[arrLoc+tol] <= low){ | |
938 | }else{ //error no peak detected | |
939 | errCnt++; | |
e0165dcf | 940 | } |
941 | } | |
cc15a118 | 942 | //if we found no errors then we can stop here and a low clock (common clocks) |
2eec55c8 | 943 | // this is correct one - return this clock |
a126332a | 944 | if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, err %d, startpos %d, endpos %d",clk[clkCnt],errCnt,ii,i); |
cc15a118 | 945 | if(errCnt==0 && clkCnt<7) { |
946 | if (!clockFnd) *clock = clk[clkCnt]; | |
2eec55c8 | 947 | return ii; |
948 | } | |
949 | //if we found errors see if it is lowest so far and save it as best run | |
950 | if(errCnt<bestErr[clkCnt]){ | |
951 | bestErr[clkCnt]=errCnt; | |
952 | bestStart[clkCnt]=ii; | |
953 | } | |
e0165dcf | 954 | } |
955 | } | |
cc15a118 | 956 | uint8_t iii; |
e0165dcf | 957 | uint8_t best=0; |
cc15a118 | 958 | for (iii=1; iii<clkEnd; ++iii){ |
2eec55c8 | 959 | if (bestErr[iii] < bestErr[best]){ |
960 | if (bestErr[iii] == 0) bestErr[iii]=1; | |
e0165dcf | 961 | // current best bit to error ratio vs new bit to error ratio |
2eec55c8 | 962 | if ( (size/clk[best])/bestErr[best] < (size/clk[iii])/bestErr[iii] ){ |
e0165dcf | 963 | best = iii; |
964 | } | |
965 | } | |
a126332a | 966 | 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 | 967 | } |
cc15a118 | 968 | if (!clockFnd) *clock = clk[best]; |
e0165dcf | 969 | return bestStart[best]; |
eb191de6 | 970 | } |
ba1a299c | 971 | |
972 | //by marshmellow | |
6de43508 | 973 | //detect psk clock by reading each phase shift |
974 | // a phase shift is determined by measuring the sample length of each wave | |
975 | int DetectPSKClock(uint8_t dest[], size_t size, int clock) | |
ba1a299c | 976 | { |
e0165dcf | 977 | uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock |
978 | uint16_t loopCnt = 4096; //don't need to loop through entire array... | |
979 | if (size == 0) return 0; | |
6426f6ba | 980 | if (size<loopCnt) loopCnt = size-20; |
e0165dcf | 981 | |
982 | //if we already have a valid clock quit | |
983 | size_t i=1; | |
984 | for (; i < 8; ++i) | |
985 | if (clk[i] == clock) return clock; | |
986 | ||
987 | size_t waveStart=0, waveEnd=0, firstFullWave=0, lastClkBit=0; | |
988 | uint8_t clkCnt, fc=0, fullWaveLen=0, tol=1; | |
989 | uint16_t peakcnt=0, errCnt=0, waveLenCnt=0; | |
990 | uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000}; | |
991 | uint16_t peaksdet[]={0,0,0,0,0,0,0,0,0}; | |
2eec55c8 | 992 | fc = countFC(dest, size, 0); |
993 | if (fc!=2 && fc!=4 && fc!=8) return -1; | |
a126332a | 994 | if (g_debugMode==2) prnt("DEBUG PSK: FC: %d",fc); |
e0165dcf | 995 | |
996 | //find first full wave | |
6426f6ba | 997 | for (i=160; i<loopCnt; i++){ |
e0165dcf | 998 | if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){ |
999 | if (waveStart == 0) { | |
1000 | waveStart = i+1; | |
6426f6ba | 1001 | //prnt("DEBUG: waveStart: %d",waveStart); |
e0165dcf | 1002 | } else { |
1003 | waveEnd = i+1; | |
6426f6ba | 1004 | //prnt("DEBUG: waveEnd: %d",waveEnd); |
e0165dcf | 1005 | waveLenCnt = waveEnd-waveStart; |
1006 | if (waveLenCnt > fc){ | |
1007 | firstFullWave = waveStart; | |
1008 | fullWaveLen=waveLenCnt; | |
1009 | break; | |
1010 | } | |
1011 | waveStart=0; | |
1012 | } | |
1013 | } | |
1014 | } | |
a126332a | 1015 | if (g_debugMode ==2) prnt("DEBUG PSK: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen); |
e0165dcf | 1016 | |
1017 | //test each valid clock from greatest to smallest to see which lines up | |
1018 | for(clkCnt=7; clkCnt >= 1 ; clkCnt--){ | |
1019 | lastClkBit = firstFullWave; //set end of wave as clock align | |
1020 | waveStart = 0; | |
1021 | errCnt=0; | |
1022 | peakcnt=0; | |
a126332a | 1023 | if (g_debugMode == 2) prnt("DEBUG PSK: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit); |
e0165dcf | 1024 | |
1025 | for (i = firstFullWave+fullWaveLen-1; i < loopCnt-2; i++){ | |
1026 | //top edge of wave = start of new wave | |
1027 | if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){ | |
1028 | if (waveStart == 0) { | |
1029 | waveStart = i+1; | |
1030 | waveLenCnt=0; | |
1031 | } else { //waveEnd | |
1032 | waveEnd = i+1; | |
1033 | waveLenCnt = waveEnd-waveStart; | |
1034 | if (waveLenCnt > fc){ | |
1035 | //if this wave is a phase shift | |
a126332a | 1036 | 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 | 1037 | if (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit |
1038 | peakcnt++; | |
1039 | lastClkBit+=clk[clkCnt]; | |
1040 | } else if (i<lastClkBit+8){ | |
1041 | //noise after a phase shift - ignore | |
1042 | } else { //phase shift before supposed to based on clock | |
1043 | errCnt++; | |
1044 | } | |
1045 | } else if (i+1 > lastClkBit + clk[clkCnt] + tol + fc){ | |
1046 | lastClkBit+=clk[clkCnt]; //no phase shift but clock bit | |
1047 | } | |
1048 | waveStart=i+1; | |
1049 | } | |
1050 | } | |
1051 | } | |
1052 | if (errCnt == 0){ | |
1053 | return clk[clkCnt]; | |
1054 | } | |
1055 | if (errCnt <= bestErr[clkCnt]) bestErr[clkCnt]=errCnt; | |
1056 | if (peakcnt > peaksdet[clkCnt]) peaksdet[clkCnt]=peakcnt; | |
1057 | } | |
1058 | //all tested with errors | |
1059 | //return the highest clk with the most peaks found | |
1060 | uint8_t best=7; | |
1061 | for (i=7; i>=1; i--){ | |
1062 | if (peaksdet[i] > peaksdet[best]) { | |
1063 | best = i; | |
1064 | } | |
a126332a | 1065 | if (g_debugMode == 2) prnt("DEBUG PSK: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[i],peaksdet[i],bestErr[i],clk[best]); |
e0165dcf | 1066 | } |
1067 | return clk[best]; | |
ba1a299c | 1068 | } |
1069 | ||
6426f6ba | 1070 | int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low){ |
1071 | //find shortest transition from high to low | |
1072 | size_t i = 0; | |
1073 | size_t transition1 = 0; | |
1074 | int lowestTransition = 255; | |
1075 | bool lastWasHigh = false; | |
1076 | ||
1077 | //find first valid beginning of a high or low wave | |
1078 | while ((dest[i] >= peak || dest[i] <= low) && (i < size)) | |
1079 | ++i; | |
1080 | while ((dest[i] < peak && dest[i] > low) && (i < size)) | |
1081 | ++i; | |
1082 | lastWasHigh = (dest[i] >= peak); | |
1083 | ||
1084 | if (i==size) return 0; | |
1085 | transition1 = i; | |
1086 | ||
1087 | for (;i < size; i++) { | |
1088 | if ((dest[i] >= peak && !lastWasHigh) || (dest[i] <= low && lastWasHigh)) { | |
1089 | lastWasHigh = (dest[i] >= peak); | |
1090 | if (i-transition1 < lowestTransition) lowestTransition = i-transition1; | |
1091 | transition1 = i; | |
1092 | } | |
1093 | } | |
6426f6ba | 1094 | if (lowestTransition == 255) lowestTransition = 0; |
a126332a | 1095 | if (g_debugMode==2) prnt("DEBUG NRZ: detectstrongNRZclk smallest wave: %d",lowestTransition); |
6426f6ba | 1096 | return lowestTransition; |
1097 | } | |
1098 | ||
6de43508 | 1099 | //by marshmellow |
1100 | //detect nrz clock by reading #peaks vs no peaks(or errors) | |
1101 | int DetectNRZClock(uint8_t dest[], size_t size, int clock) | |
ba1a299c | 1102 | { |
2eec55c8 | 1103 | size_t i=0; |
1104 | uint8_t clk[]={8,16,32,40,50,64,100,128,255}; | |
1105 | size_t loopCnt = 4096; //don't need to loop through entire array... | |
e0165dcf | 1106 | if (size == 0) return 0; |
6426f6ba | 1107 | if (size<loopCnt) loopCnt = size-20; |
e0165dcf | 1108 | //if we already have a valid clock quit |
1109 | for (; i < 8; ++i) | |
1110 | if (clk[i] == clock) return clock; | |
1111 | ||
1112 | //get high and low peak | |
1113 | int peak, low; | |
2eec55c8 | 1114 | if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return 0; |
e0165dcf | 1115 | |
6426f6ba | 1116 | int lowestTransition = DetectStrongNRZClk(dest, size-20, peak, low); |
2eec55c8 | 1117 | size_t ii; |
e0165dcf | 1118 | uint8_t clkCnt; |
1119 | uint8_t tol = 0; | |
6426f6ba | 1120 | uint16_t smplCnt = 0; |
1121 | int16_t peakcnt = 0; | |
1122 | int16_t peaksdet[] = {0,0,0,0,0,0,0,0}; | |
1123 | uint16_t maxPeak = 255; | |
1124 | bool firstpeak = false; | |
e0165dcf | 1125 | //test for large clipped waves |
1126 | for (i=0; i<loopCnt; i++){ | |
1127 | if (dest[i] >= peak || dest[i] <= low){ | |
6426f6ba | 1128 | if (!firstpeak) continue; |
1129 | smplCnt++; | |
e0165dcf | 1130 | } else { |
6426f6ba | 1131 | firstpeak=true; |
1132 | if (smplCnt > 6 ){ | |
1133 | if (maxPeak > smplCnt){ | |
1134 | maxPeak = smplCnt; | |
1135 | //prnt("maxPk: %d",maxPeak); | |
1136 | } | |
1137 | peakcnt++; | |
1138 | //prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt); | |
1139 | smplCnt=0; | |
e0165dcf | 1140 | } |
e0165dcf | 1141 | } |
1142 | } | |
6426f6ba | 1143 | bool errBitHigh = 0; |
1144 | bool bitHigh = 0; | |
1145 | uint8_t ignoreCnt = 0; | |
1146 | uint8_t ignoreWindow = 4; | |
1147 | bool lastPeakHigh = 0; | |
1148 | int lastBit = 0; | |
e0165dcf | 1149 | peakcnt=0; |
1150 | //test each valid clock from smallest to greatest to see which lines up | |
1151 | for(clkCnt=0; clkCnt < 8; ++clkCnt){ | |
6426f6ba | 1152 | //ignore clocks smaller than smallest peak |
1153 | if (clk[clkCnt] < maxPeak - (clk[clkCnt]/4)) continue; | |
e0165dcf | 1154 | //try lining up the peaks by moving starting point (try first 256) |
6426f6ba | 1155 | for (ii=20; ii < loopCnt; ++ii){ |
e0165dcf | 1156 | if ((dest[ii] >= peak) || (dest[ii] <= low)){ |
1157 | peakcnt=0; | |
6426f6ba | 1158 | bitHigh = false; |
1159 | ignoreCnt = 0; | |
1160 | lastBit = ii-clk[clkCnt]; | |
1161 | //loop through to see if this start location works | |
1162 | for (i = ii; i < size-20; ++i) { | |
1163 | //if we are at a clock bit | |
1164 | if ((i >= lastBit + clk[clkCnt] - tol) && (i <= lastBit + clk[clkCnt] + tol)) { | |
1165 | //test high/low | |
1166 | if (dest[i] >= peak || dest[i] <= low) { | |
1167 | //if same peak don't count it | |
1168 | if ((dest[i] >= peak && !lastPeakHigh) || (dest[i] <= low && lastPeakHigh)) { | |
e0165dcf | 1169 | peakcnt++; |
6426f6ba | 1170 | } |
1171 | lastPeakHigh = (dest[i] >= peak); | |
1172 | bitHigh = true; | |
1173 | errBitHigh = false; | |
1174 | ignoreCnt = ignoreWindow; | |
1175 | lastBit += clk[clkCnt]; | |
1176 | } else if (i == lastBit + clk[clkCnt] + tol) { | |
1177 | lastBit += clk[clkCnt]; | |
1178 | } | |
1179 | //else if not a clock bit and no peaks | |
1180 | } else if (dest[i] < peak && dest[i] > low){ | |
1181 | if (ignoreCnt==0){ | |
1182 | bitHigh=false; | |
1183 | if (errBitHigh==true) peakcnt--; | |
1184 | errBitHigh=false; | |
1185 | } else { | |
1186 | ignoreCnt--; | |
1187 | } | |
1188 | // else if not a clock bit but we have a peak | |
1189 | } else if ((dest[i]>=peak || dest[i]<=low) && (!bitHigh)) { | |
1190 | //error bar found no clock... | |
1191 | errBitHigh=true; | |
e0165dcf | 1192 | } |
1193 | } | |
1194 | if(peakcnt>peaksdet[clkCnt]) { | |
1195 | peaksdet[clkCnt]=peakcnt; | |
1196 | } | |
1197 | } | |
1198 | } | |
1199 | } | |
1200 | int iii=7; | |
2eec55c8 | 1201 | uint8_t best=0; |
e0165dcf | 1202 | for (iii=7; iii > 0; iii--){ |
6426f6ba | 1203 | if ((peaksdet[iii] >= (peaksdet[best]-1)) && (peaksdet[iii] <= peaksdet[best]+1) && lowestTransition) { |
1204 | if (clk[iii] > (lowestTransition - (clk[iii]/8)) && clk[iii] < (lowestTransition + (clk[iii]/8))) { | |
1205 | best = iii; | |
1206 | } | |
1207 | } else if (peaksdet[iii] > peaksdet[best]){ | |
e0165dcf | 1208 | best = iii; |
1209 | } | |
a126332a | 1210 | 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 | 1211 | } |
6426f6ba | 1212 | |
e0165dcf | 1213 | return clk[best]; |
ba1a299c | 1214 | } |
1215 | ||
04d2721b | 1216 | // by marshmellow |
1217 | // convert psk1 demod to psk2 demod | |
1218 | // only transition waves are 1s | |
1219 | void psk1TOpsk2(uint8_t *BitStream, size_t size) | |
1220 | { | |
1221 | size_t i=1; | |
1222 | uint8_t lastBit=BitStream[0]; | |
1223 | for (; i<size; i++){ | |
2767fc02 | 1224 | if (BitStream[i]==7){ |
7a8a982b | 1225 | //ignore errors |
1226 | } else if (lastBit!=BitStream[i]){ | |
04d2721b | 1227 | lastBit=BitStream[i]; |
1228 | BitStream[i]=1; | |
1229 | } else { | |
1230 | BitStream[i]=0; | |
1231 | } | |
1232 | } | |
1233 | return; | |
1234 | } | |
ba1a299c | 1235 | |
3bc66a96 | 1236 | // by marshmellow |
1237 | // convert psk2 demod to psk1 demod | |
1238 | // from only transition waves are 1s to phase shifts change bit | |
1239 | void psk2TOpsk1(uint8_t *BitStream, size_t size) | |
1240 | { | |
712ebfa6 | 1241 | uint8_t phase=0; |
1242 | for (size_t i=0; i<size; i++){ | |
1243 | if (BitStream[i]==1){ | |
3bc66a96 | 1244 | phase ^=1; |
1245 | } | |
1246 | BitStream[i]=phase; | |
1247 | } | |
1248 | return; | |
1249 | } | |
1250 | ||
04d2721b | 1251 | // redesigned by marshmellow adjusted from existing decode functions |
1252 | // indala id decoding - only tested on 26 bit tags, but attempted to make it work for more | |
ba1a299c | 1253 | int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert) |
1254 | { | |
1255 | //26 bit 40134 format (don't know other formats) | |
57c7b44b | 1256 | 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}; |
1257 | 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}; | |
1258 | size_t startidx = 0; | |
1259 | if (!preambleSearch(bitStream, preamble, sizeof(preamble), size, &startidx)){ | |
1260 | // if didn't find preamble try again inverting | |
1261 | if (!preambleSearch(bitStream, preamble_i, sizeof(preamble_i), size, &startidx)) return -1; | |
1262 | *invert ^= 1; | |
1263 | } | |
1264 | if (*size != 64 && *size != 224) return -2; | |
1265 | if (*invert==1) | |
1266 | for (size_t i = startidx; i < *size; i++) | |
1267 | bitStream[i] ^= 1; | |
ba1a299c | 1268 | |
57c7b44b | 1269 | return (int) startidx; |
ba1a299c | 1270 | } |
1271 | ||
05164399 | 1272 | // by marshmellow - demodulate NRZ wave - requires a read with strong signal |
04d2721b | 1273 | // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak |
6426f6ba | 1274 | int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert){ |
e0165dcf | 1275 | if (justNoise(dest, *size)) return -1; |
1276 | *clk = DetectNRZClock(dest, *size, *clk); | |
1277 | if (*clk==0) return -2; | |
2eec55c8 | 1278 | size_t i, gLen = 4096; |
6426f6ba | 1279 | if (gLen>*size) gLen = *size-20; |
e0165dcf | 1280 | int high, low; |
1281 | if (getHiLo(dest, gLen, &high, &low, 75, 75) < 1) return -3; //25% fuzz on high 25% fuzz on low | |
6426f6ba | 1282 | |
1283 | uint8_t bit=0; | |
1284 | //convert wave samples to 1's and 0's | |
1285 | for(i=20; i < *size-20; i++){ | |
1286 | if (dest[i] >= high) bit = 1; | |
1287 | if (dest[i] <= low) bit = 0; | |
1288 | dest[i] = bit; | |
e0165dcf | 1289 | } |
6426f6ba | 1290 | //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit) |
1291 | size_t lastBit = 0; | |
1292 | size_t numBits = 0; | |
1293 | for(i=21; i < *size-20; i++) { | |
1294 | //if transition detected or large number of same bits - store the passed bits | |
1295 | if (dest[i] != dest[i-1] || (i-lastBit) == (10 * *clk)) { | |
1296 | memset(dest+numBits, dest[i-1] ^ *invert, (i - lastBit + (*clk/4)) / *clk); | |
1297 | numBits += (i - lastBit + (*clk/4)) / *clk; | |
1298 | lastBit = i-1; | |
e0165dcf | 1299 | } |
e0165dcf | 1300 | } |
6426f6ba | 1301 | *size = numBits; |
1302 | return 0; | |
ba1a299c | 1303 | } |
1304 | ||
1e090a61 | 1305 | //by marshmellow |
03e6bb4a | 1306 | //detects the bit clock for FSK given the high and low Field Clocks |
1307 | uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow) | |
1e090a61 | 1308 | { |
e0165dcf | 1309 | uint8_t clk[] = {8,16,32,40,50,64,100,128,0}; |
1310 | uint16_t rfLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; | |
1311 | uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; | |
1312 | uint8_t rfLensFnd = 0; | |
2eec55c8 | 1313 | uint8_t lastFCcnt = 0; |
1314 | uint16_t fcCounter = 0; | |
e0165dcf | 1315 | uint16_t rfCounter = 0; |
1316 | uint8_t firstBitFnd = 0; | |
1317 | size_t i; | |
1318 | if (size == 0) return 0; | |
1319 | ||
6426f6ba | 1320 | uint8_t fcTol = ((fcHigh*100 - fcLow*100)/2 + 50)/100; //(uint8_t)(0.5+(float)(fcHigh-fcLow)/2); |
e0165dcf | 1321 | rfLensFnd=0; |
1322 | fcCounter=0; | |
1323 | rfCounter=0; | |
1324 | firstBitFnd=0; | |
1325 | //PrintAndLog("DEBUG: fcTol: %d",fcTol); | |
6426f6ba | 1326 | // prime i to first peak / up transition |
1327 | for (i = 160; i < size-20; i++) | |
e0165dcf | 1328 | if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1]) |
1329 | break; | |
1330 | ||
6426f6ba | 1331 | for (; i < size-20; i++){ |
2eec55c8 | 1332 | fcCounter++; |
1333 | rfCounter++; | |
1334 | ||
1335 | if (BitStream[i] <= BitStream[i-1] || BitStream[i] < BitStream[i+1]) | |
1336 | continue; | |
1337 | // else new peak | |
1338 | // if we got less than the small fc + tolerance then set it to the small fc | |
1339 | if (fcCounter < fcLow+fcTol) | |
1340 | fcCounter = fcLow; | |
1341 | else //set it to the large fc | |
1342 | fcCounter = fcHigh; | |
1343 | ||
1344 | //look for bit clock (rf/xx) | |
1345 | if ((fcCounter < lastFCcnt || fcCounter > lastFCcnt)){ | |
1346 | //not the same size as the last wave - start of new bit sequence | |
1347 | if (firstBitFnd > 1){ //skip first wave change - probably not a complete bit | |
1348 | for (int ii=0; ii<15; ii++){ | |
6426f6ba | 1349 | if (rfLens[ii] >= (rfCounter-4) && rfLens[ii] <= (rfCounter+4)){ |
2eec55c8 | 1350 | rfCnts[ii]++; |
1351 | rfCounter = 0; | |
1352 | break; | |
e0165dcf | 1353 | } |
e0165dcf | 1354 | } |
2eec55c8 | 1355 | if (rfCounter > 0 && rfLensFnd < 15){ |
1356 | //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter); | |
1357 | rfCnts[rfLensFnd]++; | |
1358 | rfLens[rfLensFnd++] = rfCounter; | |
1359 | } | |
1360 | } else { | |
1361 | firstBitFnd++; | |
e0165dcf | 1362 | } |
2eec55c8 | 1363 | rfCounter=0; |
1364 | lastFCcnt=fcCounter; | |
e0165dcf | 1365 | } |
2eec55c8 | 1366 | fcCounter=0; |
e0165dcf | 1367 | } |
1368 | uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15; | |
1369 | ||
1370 | for (i=0; i<15; i++){ | |
e0165dcf | 1371 | //get highest 2 RF values (might need to get more values to compare or compare all?) |
1372 | if (rfCnts[i]>rfCnts[rfHighest]){ | |
1373 | rfHighest3=rfHighest2; | |
1374 | rfHighest2=rfHighest; | |
1375 | rfHighest=i; | |
1376 | } else if(rfCnts[i]>rfCnts[rfHighest2]){ | |
1377 | rfHighest3=rfHighest2; | |
1378 | rfHighest2=i; | |
1379 | } else if(rfCnts[i]>rfCnts[rfHighest3]){ | |
1380 | rfHighest3=i; | |
1381 | } | |
a126332a | 1382 | if (g_debugMode==2) prnt("DEBUG FSK: RF %d, cnts %d",rfLens[i], rfCnts[i]); |
e0165dcf | 1383 | } |
1384 | // set allowed clock remainder tolerance to be 1 large field clock length+1 | |
1385 | // we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off | |
1386 | uint8_t tol1 = fcHigh+1; | |
1387 | ||
a126332a | 1388 | if (g_debugMode==2) prnt("DEBUG FSK: most counted rf values: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]); |
e0165dcf | 1389 | |
1390 | // loop to find the highest clock that has a remainder less than the tolerance | |
1391 | // compare samples counted divided by | |
6426f6ba | 1392 | // test 128 down to 32 (shouldn't be possible to have fc/10 & fc/8 and rf/16 or less) |
e0165dcf | 1393 | int ii=7; |
6426f6ba | 1394 | for (; ii>=2; ii--){ |
e0165dcf | 1395 | if (rfLens[rfHighest] % clk[ii] < tol1 || rfLens[rfHighest] % clk[ii] > clk[ii]-tol1){ |
1396 | if (rfLens[rfHighest2] % clk[ii] < tol1 || rfLens[rfHighest2] % clk[ii] > clk[ii]-tol1){ | |
1397 | if (rfLens[rfHighest3] % clk[ii] < tol1 || rfLens[rfHighest3] % clk[ii] > clk[ii]-tol1){ | |
a126332a | 1398 | if (g_debugMode==2) prnt("DEBUG FSK: clk %d divides into the 3 most rf values within tolerance",clk[ii]); |
e0165dcf | 1399 | break; |
1400 | } | |
1401 | } | |
1402 | } | |
1403 | } | |
1404 | ||
1405 | if (ii<0) return 0; // oops we went too far | |
1406 | ||
1407 | return clk[ii]; | |
03e6bb4a | 1408 | } |
1e090a61 | 1409 | |
03e6bb4a | 1410 | //by marshmellow |
1411 | //countFC is to detect the field clock lengths. | |
1412 | //counts and returns the 2 most common wave lengths | |
6de43508 | 1413 | //mainly used for FSK field clock detection |
2eec55c8 | 1414 | uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj) |
03e6bb4a | 1415 | { |
6426f6ba | 1416 | uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; |
1417 | uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; | |
e0165dcf | 1418 | uint8_t fcLensFnd = 0; |
1419 | uint8_t lastFCcnt=0; | |
2eec55c8 | 1420 | uint8_t fcCounter = 0; |
e0165dcf | 1421 | size_t i; |
1422 | if (size == 0) return 0; | |
1423 | ||
1424 | // prime i to first up transition | |
6426f6ba | 1425 | for (i = 160; i < size-20; i++) |
e0165dcf | 1426 | if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]) |
1427 | break; | |
1428 | ||
6426f6ba | 1429 | for (; i < size-20; i++){ |
e0165dcf | 1430 | if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){ |
1431 | // new up transition | |
1432 | fcCounter++; | |
2eec55c8 | 1433 | if (fskAdj){ |
1434 | //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8) | |
1435 | if (lastFCcnt==5 && fcCounter==9) fcCounter--; | |
1436 | //if fc=9 or 4 add one (for when we get a fc 9 instead of 10 or a 4 instead of a 5) | |
1437 | if ((fcCounter==9) || fcCounter==4) fcCounter++; | |
e0165dcf | 1438 | // save last field clock count (fc/xx) |
2eec55c8 | 1439 | lastFCcnt = fcCounter; |
1440 | } | |
e0165dcf | 1441 | // find which fcLens to save it to: |
6426f6ba | 1442 | for (int ii=0; ii<15; ii++){ |
e0165dcf | 1443 | if (fcLens[ii]==fcCounter){ |
1444 | fcCnts[ii]++; | |
1445 | fcCounter=0; | |
1446 | break; | |
1447 | } | |
1448 | } | |
6426f6ba | 1449 | if (fcCounter>0 && fcLensFnd<15){ |
e0165dcf | 1450 | //add new fc length |
1451 | fcCnts[fcLensFnd]++; | |
1452 | fcLens[fcLensFnd++]=fcCounter; | |
1453 | } | |
1454 | fcCounter=0; | |
1455 | } else { | |
1456 | // count sample | |
1457 | fcCounter++; | |
1458 | } | |
1459 | } | |
1460 | ||
6426f6ba | 1461 | uint8_t best1=14, best2=14, best3=14; |
e0165dcf | 1462 | uint16_t maxCnt1=0; |
1463 | // go through fclens and find which ones are bigest 2 | |
6426f6ba | 1464 | for (i=0; i<15; i++){ |
e0165dcf | 1465 | // get the 3 best FC values |
1466 | if (fcCnts[i]>maxCnt1) { | |
1467 | best3=best2; | |
1468 | best2=best1; | |
1469 | maxCnt1=fcCnts[i]; | |
1470 | best1=i; | |
1471 | } else if(fcCnts[i]>fcCnts[best2]){ | |
1472 | best3=best2; | |
1473 | best2=i; | |
1474 | } else if(fcCnts[i]>fcCnts[best3]){ | |
1475 | best3=i; | |
1476 | } | |
a126332a | 1477 | 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 | 1478 | } |
6426f6ba | 1479 | if (fcLens[best1]==0) return 0; |
e0165dcf | 1480 | uint8_t fcH=0, fcL=0; |
1481 | if (fcLens[best1]>fcLens[best2]){ | |
1482 | fcH=fcLens[best1]; | |
1483 | fcL=fcLens[best2]; | |
1484 | } else{ | |
1485 | fcH=fcLens[best2]; | |
1486 | fcL=fcLens[best1]; | |
1487 | } | |
a126332a | 1488 | if ((size-180)/fcH/3 > fcCnts[best1]+fcCnts[best2]) { |
1489 | 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]); | |
1490 | return 0; //lots of waves not psk or fsk | |
1491 | } | |
e0165dcf | 1492 | // TODO: take top 3 answers and compare to known Field clocks to get top 2 |
1493 | ||
1494 | uint16_t fcs = (((uint16_t)fcH)<<8) | fcL; | |
2eec55c8 | 1495 | if (fskAdj) return fcs; |
1496 | return fcLens[best1]; | |
6de43508 | 1497 | } |
1498 | ||
1499 | //by marshmellow - demodulate PSK1 wave | |
1500 | //uses wave lengths (# Samples) | |
1501 | int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) | |
1502 | { | |
e0165dcf | 1503 | if (size == 0) return -1; |
2eec55c8 | 1504 | uint16_t loopCnt = 4096; //don't need to loop through entire array... |
e0165dcf | 1505 | if (*size<loopCnt) loopCnt = *size; |
1506 | ||
6426f6ba | 1507 | size_t numBits=0; |
e0165dcf | 1508 | uint8_t curPhase = *invert; |
1509 | size_t i, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0; | |
1510 | uint8_t fc=0, fullWaveLen=0, tol=1; | |
1511 | uint16_t errCnt=0, waveLenCnt=0; | |
2eec55c8 | 1512 | fc = countFC(dest, *size, 0); |
e0165dcf | 1513 | if (fc!=2 && fc!=4 && fc!=8) return -1; |
1514 | //PrintAndLog("DEBUG: FC: %d",fc); | |
1515 | *clock = DetectPSKClock(dest, *size, *clock); | |
2eec55c8 | 1516 | if (*clock == 0) return -1; |
e0165dcf | 1517 | int avgWaveVal=0, lastAvgWaveVal=0; |
1518 | //find first phase shift | |
1519 | for (i=0; i<loopCnt; i++){ | |
1520 | if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){ | |
1521 | waveEnd = i+1; | |
1522 | //PrintAndLog("DEBUG: waveEnd: %d",waveEnd); | |
1523 | waveLenCnt = waveEnd-waveStart; | |
6426f6ba | 1524 | if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+2)){ //not first peak and is a large wave but not out of whack |
e0165dcf | 1525 | lastAvgWaveVal = avgWaveVal/(waveLenCnt); |
1526 | firstFullWave = waveStart; | |
1527 | fullWaveLen=waveLenCnt; | |
1528 | //if average wave value is > graph 0 then it is an up wave or a 1 | |
2eec55c8 | 1529 | if (lastAvgWaveVal > 123) curPhase ^= 1; //fudge graph 0 a little 123 vs 128 |
e0165dcf | 1530 | break; |
1531 | } | |
1532 | waveStart = i+1; | |
1533 | avgWaveVal = 0; | |
1534 | } | |
2eec55c8 | 1535 | avgWaveVal += dest[i+2]; |
e0165dcf | 1536 | } |
6426f6ba | 1537 | if (firstFullWave == 0) { |
1538 | // no phase shift detected - could be all 1's or 0's - doesn't matter where we start | |
1539 | // so skip a little to ensure we are past any Start Signal | |
1540 | firstFullWave = 160; | |
1541 | memset(dest, curPhase, firstFullWave / *clock); | |
1542 | } else { | |
1543 | memset(dest, curPhase^1, firstFullWave / *clock); | |
1544 | } | |
1545 | //advance bits | |
1546 | numBits += (firstFullWave / *clock); | |
1547 | //set start of wave as clock align | |
1548 | lastClkBit = firstFullWave; | |
7fa7e812 | 1549 | if (g_debugMode==2) prnt("DEBUG PSK: firstFullWave: %u, waveLen: %u",firstFullWave,fullWaveLen); |
1550 | if (g_debugMode==2) prnt("DEBUG: clk: %d, lastClkBit: %u, fc: %u", *clock, lastClkBit,(unsigned int) fc); | |
e0165dcf | 1551 | waveStart = 0; |
e0165dcf | 1552 | dest[numBits++] = curPhase; //set first read bit |
2eec55c8 | 1553 | for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){ |
e0165dcf | 1554 | //top edge of wave = start of new wave |
1555 | if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){ | |
1556 | if (waveStart == 0) { | |
1557 | waveStart = i+1; | |
2eec55c8 | 1558 | waveLenCnt = 0; |
e0165dcf | 1559 | avgWaveVal = dest[i+1]; |
1560 | } else { //waveEnd | |
1561 | waveEnd = i+1; | |
1562 | waveLenCnt = waveEnd-waveStart; | |
1563 | lastAvgWaveVal = avgWaveVal/waveLenCnt; | |
1564 | if (waveLenCnt > fc){ | |
1565 | //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal); | |
2eec55c8 | 1566 | //this wave is a phase shift |
e0165dcf | 1567 | //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc); |
1568 | if (i+1 >= lastClkBit + *clock - tol){ //should be a clock bit | |
2eec55c8 | 1569 | curPhase ^= 1; |
e0165dcf | 1570 | dest[numBits++] = curPhase; |
1571 | lastClkBit += *clock; | |
2eec55c8 | 1572 | } else if (i < lastClkBit+10+fc){ |
e0165dcf | 1573 | //noise after a phase shift - ignore |
1574 | } else { //phase shift before supposed to based on clock | |
1575 | errCnt++; | |
2767fc02 | 1576 | dest[numBits++] = 7; |
e0165dcf | 1577 | } |
1578 | } else if (i+1 > lastClkBit + *clock + tol + fc){ | |
1579 | lastClkBit += *clock; //no phase shift but clock bit | |
1580 | dest[numBits++] = curPhase; | |
1581 | } | |
2eec55c8 | 1582 | avgWaveVal = 0; |
1583 | waveStart = i+1; | |
e0165dcf | 1584 | } |
1585 | } | |
2eec55c8 | 1586 | avgWaveVal += dest[i+1]; |
e0165dcf | 1587 | } |
1588 | *size = numBits; | |
1589 | return errCnt; | |
6de43508 | 1590 | } |
05164399 | 1591 | |
1592 | //by marshmellow | |
1593 | //attempt to identify a Sequence Terminator in ASK modulated raw wave | |
1594 | bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) { | |
1595 | size_t bufsize = *size; | |
1596 | //need to loop through all samples and identify our clock, look for the ST pattern | |
1597 | uint8_t fndClk[] = {8,16,32,40,50,64,128}; | |
1598 | int clk = 0; | |
1599 | int tol = 0; | |
1600 | int i, j, skip, start, end, low, high, minClk, waveStart; | |
1601 | bool complete = false; | |
1602 | int tmpbuff[bufsize / 64]; | |
1603 | int waveLen[bufsize / 64]; | |
1604 | size_t testsize = (bufsize < 512) ? bufsize : 512; | |
1605 | int phaseoff = 0; | |
1606 | high = low = 128; | |
1607 | memset(tmpbuff, 0, sizeof(tmpbuff)); | |
1608 | ||
1609 | if ( getHiLo(buffer, testsize, &high, &low, 80, 80) == -1 ) { | |
1610 | if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting"); | |
1611 | return false; //just noise | |
1612 | } | |
1613 | i = 0; | |
1614 | j = 0; | |
1615 | minClk = 255; | |
1616 | // get to first full low to prime loop and skip incomplete first pulse | |
1617 | while ((buffer[i] < high) && (i < bufsize)) | |
1618 | ++i; | |
1619 | while ((buffer[i] > low) && (i < bufsize)) | |
1620 | ++i; | |
1621 | skip = i; | |
1622 | ||
1623 | // populate tmpbuff buffer with pulse lengths | |
1624 | while (i < bufsize) { | |
1625 | // measure from low to low | |
1626 | while ((buffer[i] > low) && (i < bufsize)) | |
1627 | ++i; | |
1628 | start= i; | |
1629 | while ((buffer[i] < high) && (i < bufsize)) | |
1630 | ++i; | |
1631 | //first high point for this wave | |
1632 | waveStart = i; | |
1633 | while ((buffer[i] > low) && (i < bufsize)) | |
1634 | ++i; | |
1635 | if (j >= (bufsize/64)) { | |
1636 | break; | |
1637 | } | |
1638 | waveLen[j] = i - waveStart; //first high to first low | |
1639 | tmpbuff[j++] = i - start; | |
1640 | if (i-start < minClk && i < bufsize) { | |
1641 | minClk = i - start; | |
1642 | } | |
1643 | } | |
1644 | // set clock - might be able to get this externally and remove this work... | |
1645 | if (!clk) { | |
1646 | for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) { | |
1647 | tol = fndClk[clkCnt]/8; | |
1648 | if (minClk >= fndClk[clkCnt]-tol && minClk <= fndClk[clkCnt]+1) { | |
1649 | clk=fndClk[clkCnt]; | |
1650 | break; | |
1651 | } | |
1652 | } | |
1653 | // clock not found - ERROR | |
1654 | if (!clk) { | |
1655 | if (g_debugMode==2) prnt("DEBUG STT: clock not found - quitting"); | |
1656 | return false; | |
1657 | } | |
1658 | } else tol = clk/8; | |
1659 | ||
1660 | *foundclock = clk; | |
1661 | ||
1662 | // look for Sequence Terminator - should be pulses of clk*(1 or 1.5), clk*2, clk*(1.5 or 2) | |
1663 | start = -1; | |
1664 | for (i = 0; i < j - 4; ++i) { | |
1665 | skip += tmpbuff[i]; | |
1666 | if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol && waveLen[i] < clk+tol) { //1 to 2 clocks depending on 2 bits prior | |
1667 | 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 | |
1668 | 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 | |
1669 | if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit | |
1670 | start = i + 3; | |
1671 | break; | |
1672 | } | |
1673 | } | |
1674 | } | |
1675 | } | |
1676 | } | |
1677 | // first ST not found - ERROR | |
1678 | if (start < 0) { | |
1679 | if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting"); | |
1680 | return false; | |
1681 | } | |
1682 | if (waveLen[i+2] > clk*1+tol) | |
1683 | phaseoff = 0; | |
1684 | else | |
1685 | phaseoff = clk/2; | |
1686 | ||
1687 | // skip over the remainder of ST | |
1688 | skip += clk*7/2; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point | |
1689 | ||
1690 | // now do it again to find the end | |
1691 | end = skip; | |
1692 | for (i += 3; i < j - 4; ++i) { | |
1693 | end += tmpbuff[i]; | |
1694 | if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol) { //1 to 2 clocks depending on 2 bits prior | |
1695 | 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 | |
1696 | 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 | |
1697 | if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit | |
1698 | complete = true; | |
1699 | break; | |
1700 | } | |
1701 | } | |
1702 | } | |
1703 | } | |
1704 | } | |
1705 | end -= phaseoff; | |
1706 | //didn't find second ST - ERROR | |
1707 | if (!complete) { | |
1708 | if (g_debugMode==2) prnt("DEBUG STT: second STT not found - quitting"); | |
1709 | return false; | |
1710 | } | |
1711 | 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); | |
1712 | //now begin to trim out ST so we can use normal demod cmds | |
1713 | start = skip; | |
1714 | size_t datalen = end - start; | |
1715 | // check validity of datalen (should be even clock increments) - use a tolerance of up to 1/8th a clock | |
1716 | if (datalen % clk > clk/8) { | |
1717 | if (g_debugMode==2) prnt("DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting", datalen, clk, datalen % clk); | |
1718 | return false; | |
1719 | } else { | |
1720 | // padd the amount off - could be problematic... but shouldn't happen often | |
1721 | datalen += datalen % clk; | |
1722 | } | |
1723 | // if datalen is less than one t55xx block - ERROR | |
1724 | if (datalen/clk < 8*4) { | |
1725 | if (g_debugMode==2) prnt("DEBUG STT: datalen is less than 1 full t55xx block - quitting"); | |
1726 | return false; | |
1727 | } | |
1728 | size_t dataloc = start; | |
1729 | size_t newloc = 0; | |
1730 | i=0; | |
1731 | // warning - overwriting buffer given with raw wave data with ST removed... | |
1732 | while ( dataloc < bufsize-(clk/2) ) { | |
7fa7e812 | 1733 | //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 | 1734 | if (buffer[dataloc]<high && buffer[dataloc]>low && buffer[dataloc+3]<high && buffer[dataloc+3]>low) { |
1735 | for(i=0; i < clk/2-tol; ++i) { | |
1736 | buffer[dataloc+i] = high+5; | |
1737 | } | |
1738 | } | |
1739 | for (i=0; i<datalen; ++i) { | |
1740 | if (i+newloc < bufsize) { | |
1741 | if (i+newloc < dataloc) | |
1742 | buffer[i+newloc] = buffer[dataloc]; | |
1743 | ||
1744 | dataloc++; | |
1745 | } | |
1746 | } | |
1747 | newloc += i; | |
7fa7e812 | 1748 | //skip next ST - we just assume it will be there from now on... |
05164399 | 1749 | dataloc += clk*4; |
1750 | } | |
1751 | *size = newloc; | |
1752 | return true; | |
1753 | } |