]>
cvs.zerfleddert.de Git - proxmark3-svn/blob - common/lfdemod.c
9a4051c9b125a29bc7baabf1a82d2d4b1e37de73
1 //-----------------------------------------------------------------------------
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
7 //-----------------------------------------------------------------------------
8 // Low frequency demod/decode commands
9 //-----------------------------------------------------------------------------
14 uint8_t justNoise ( uint8_t * BitStream
, size_t size
)
16 static const uint8_t THRESHOLD
= 123 ;
17 //test samples are not just noise
18 uint8_t justNoise1
= 1 ;
19 for ( size_t idx
= 0 ; idx
< size
&& justNoise1
; idx
++){
20 justNoise1
= BitStream
[ idx
] < THRESHOLD
;
26 //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
27 int getHiLo ( uint8_t * BitStream
, size_t size
, int * high
, int * low
, uint8_t fuzzHi
, uint8_t fuzzLo
)
31 // get high and low thresholds
32 for ( size_t i
= 0 ; i
< size
; i
++){
33 if ( BitStream
[ i
] > * high
) * high
= BitStream
[ i
];
34 if ( BitStream
[ i
] < * low
) * low
= BitStream
[ i
];
36 if (* high
< 123 ) return - 1 ; // just noise
37 * high
= ((* high
- 128 )* fuzzHi
+ 12800 )/ 100 ;
38 * low
= ((* low
- 128 )* fuzzLo
+ 12800 )/ 100 ;
43 // pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType
44 // returns 1 if passed
45 uint8_t parityTest ( uint32_t bits
, uint8_t bitLen
, uint8_t pType
)
48 for ( uint8_t i
= 0 ; i
< bitLen
; i
++){
49 ans
^= (( bits
>> i
) & 1 );
51 //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType);
52 return ( ans
== pType
);
56 //search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length
57 uint8_t preambleSearch ( uint8_t * BitStream
, uint8_t * preamble
, size_t pLen
, size_t * size
, size_t * startIdx
)
60 for ( int idx
= 0 ; idx
< * size
- pLen
; idx
++){
61 if ( memcmp ( BitStream
+ idx
, preamble
, pLen
) == 0 ){
68 * size
= idx
- * startIdx
;
77 //takes 1s and 0s and searches for EM410x format - output EM ID
78 uint8_t Em410xDecode ( uint8_t * BitStream
, size_t * size
, size_t * startIdx
, uint32_t * hi
, uint64_t * lo
)
80 //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
81 // otherwise could be a void with no arguments
84 if ( BitStream
[ 1 ]> 1 ) return 0 ; //allow only 1s and 0s
86 // 111111111 bit pattern represent start of frame
87 // include 0 in front to help get start pos
88 uint8_t preamble
[] = { 0 , 1 , 1 , 1 , 1 , 1 , 1 , 1 , 1 , 1 };
90 uint32_t parityBits
= 0 ;
94 errChk
= preambleSearch ( BitStream
, preamble
, sizeof ( preamble
), size
, startIdx
);
95 if ( errChk
== 0 || * size
< 64 ) return 0 ;
96 if (* size
> 64 ) FmtLen
= 22 ;
97 * startIdx
+= 1 ; //get rid of 0 from preamble
99 for ( i
= 0 ; i
< FmtLen
; i
++){ //loop through 10 or 22 sets of 5 bits (50-10p = 40 bits or 88 bits)
100 parityBits
= bytebits_to_byte ( BitStream
+( i
* 5 )+ idx
, 5 );
101 //check even parity - quit if failed
102 if ( parityTest ( parityBits
, 5 , 0 ) == 0 ) return 0 ;
103 //set uint64 with ID from BitStream
104 for ( uint8_t ii
= 0 ; ii
< 4 ; ii
++){
105 * hi
= (* hi
<< 1 ) | (* lo
>> 63 );
106 * lo
= (* lo
<< 1 ) | ( BitStream
[( i
* 5 )+ ii
+ idx
]);
109 if ( errChk
!= 0 ) return 1 ;
110 //skip last 5 bit parity test for simplicity.
116 //demodulates strong heavily clipped samples
117 int cleanAskRawDemod ( uint8_t * BinStream
, size_t * size
, int clk
, int invert
, int high
, int low
)
119 size_t bitCnt
= 0 , smplCnt
= 0 , errCnt
= 0 ;
120 uint8_t waveHigh
= 0 ;
121 for ( size_t i
= 0 ; i
< * size
; i
++){
122 if ( BinStream
[ i
] >= high
&& waveHigh
){
124 } else if ( BinStream
[ i
] <= low
&& ! waveHigh
){
126 } else { //transition
127 if (( BinStream
[ i
] >= high
&& ! waveHigh
) || ( BinStream
[ i
] <= low
&& waveHigh
)){
128 if ( smplCnt
> clk
-( clk
/ 4 )- 1 ) { //full clock
129 if ( smplCnt
> clk
+ ( clk
/ 4 )+ 1 ) { //too many samples
131 BinStream
[ bitCnt
++]= 7 ;
132 } else if ( waveHigh
) {
133 BinStream
[ bitCnt
++] = invert
;
134 BinStream
[ bitCnt
++] = invert
;
135 } else if (! waveHigh
) {
136 BinStream
[ bitCnt
++] = invert
^ 1 ;
137 BinStream
[ bitCnt
++] = invert
^ 1 ;
141 } else if ( smplCnt
> ( clk
/ 2 ) - ( clk
/ 4 )- 1 ) {
143 BinStream
[ bitCnt
++] = invert
;
144 } else if (! waveHigh
) {
145 BinStream
[ bitCnt
++] = invert
^ 1 ;
149 } else if (! bitCnt
) {
151 waveHigh
= ( BinStream
[ i
] >= high
);
155 //transition bit oops
157 } else { //haven't hit new high or new low yet
167 void askAmp ( uint8_t * BitStream
, size_t size
)
169 for ( size_t i
= 1 ; i
< size
; i
++){
170 if ( BitStream
[ i
]- BitStream
[ i
- 1 ]>= 30 ) //large jump up
172 else if ( BitStream
[ i
]- BitStream
[ i
- 1 ]<=- 20 ) //large jump down
179 //attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester
180 int askdemod ( uint8_t * BinStream
, size_t * size
, int * clk
, int * invert
, int maxErr
, uint8_t amp
, uint8_t askType
)
182 if (* size
== 0 ) return - 1 ;
183 int start
= DetectASKClock ( BinStream
, * size
, clk
, maxErr
); //clock default
184 if (* clk
== 0 || start
< 0 ) return - 3 ;
185 if (* invert
!= 1 ) * invert
= 0 ;
186 if ( amp
== 1 ) askAmp ( BinStream
, * size
);
188 uint8_t initLoopMax
= 255 ;
189 if ( initLoopMax
> * size
) initLoopMax
= * size
;
190 // Detect high and lows
191 //25% clip in case highs and lows aren't clipped [marshmellow]
193 if ( getHiLo ( BinStream
, initLoopMax
, & high
, & low
, 75 , 75 ) < 1 )
194 return - 2 ; //just noise
197 // if clean clipped waves detected run alternate demod
198 if ( DetectCleanAskWave ( BinStream
, * size
, high
, low
)) {
199 errCnt
= cleanAskRawDemod ( BinStream
, size
, * clk
, * invert
, high
, low
);
200 if ( askType
) //askman
201 return manrawdecode ( BinStream
, size
, 0 );
206 int lastBit
; //set first clock check - can go negative
207 size_t i
, bitnum
= 0 ; //output counter
209 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
210 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
211 size_t MaxBits
= 1024 ;
212 lastBit
= start
- * clk
;
214 for ( i
= start
; i
< * size
; ++ i
) {
215 if ( i
- lastBit
>= * clk
- tol
){
216 if ( BinStream
[ i
] >= high
) {
217 BinStream
[ bitnum
++] = * invert
;
218 } else if ( BinStream
[ i
] <= low
) {
219 BinStream
[ bitnum
++] = * invert
^ 1 ;
220 } else if ( i
- lastBit
>= * clk
+ tol
) {
222 BinStream
[ bitnum
++]= 7 ;
225 } else { //in tolerance - looking for peak
230 } else if ( i
- lastBit
>= (* clk
/ 2 - tol
) && ! midBit
&& ! askType
){
231 if ( BinStream
[ i
] >= high
) {
232 BinStream
[ bitnum
++] = * invert
;
233 } else if ( BinStream
[ i
] <= low
) {
234 BinStream
[ bitnum
++] = * invert
^ 1 ;
235 } else if ( i
- lastBit
>= * clk
/ 2 + tol
) {
236 BinStream
[ bitnum
] = BinStream
[ bitnum
- 1 ];
238 } else { //in tolerance - looking for peak
243 if ( bitnum
>= MaxBits
) break ;
250 //take 10 and 01 and manchester decode
251 //run through 2 times and take least errCnt
252 int manrawdecode ( uint8_t * BitStream
, size_t * size
, uint8_t invert
)
254 uint16_t bitnum
= 0 , MaxBits
= 512 , errCnt
= 0 ;
256 uint16_t bestErr
= 1000 , bestRun
= 0 ;
257 if (* size
< 16 ) return - 1 ;
258 //find correct start position [alignment]
259 for ( ii
= 0 ; ii
< 2 ;++ ii
){
260 for ( i
= ii
; i
<* size
- 3 ; i
+= 2 )
261 if ( BitStream
[ i
]== BitStream
[ i
+ 1 ])
271 for ( i
= bestRun
; i
< * size
- 3 ; i
+= 2 ){
272 if ( BitStream
[ i
] == 1 && ( BitStream
[ i
+ 1 ] == 0 )){
273 BitStream
[ bitnum
++]= invert
;
274 } else if (( BitStream
[ i
] == 0 ) && BitStream
[ i
+ 1 ] == 1 ){
275 BitStream
[ bitnum
++]= invert
^ 1 ;
277 BitStream
[ bitnum
++]= 7 ;
279 if ( bitnum
> MaxBits
) break ;
285 uint32_t manchesterEncode2Bytes ( uint16_t datain
) {
288 for ( uint8_t i
= 0 ; i
< 16 ; i
++) {
289 curBit
= ( datain
>> ( 15 - i
) & 1 );
290 output
|= ( 1 <<((( 15 - i
)* 2 )+ curBit
));
296 //encode binary data into binary manchester
297 int ManchesterEncode ( uint8_t * BitStream
, size_t size
)
299 size_t modIdx
= 20000 , i
= 0 ;
300 if ( size
> modIdx
) return - 1 ;
301 for ( size_t idx
= 0 ; idx
< size
; idx
++){
302 BitStream
[ idx
+ modIdx
++] = BitStream
[ idx
];
303 BitStream
[ idx
+ modIdx
++] = BitStream
[ idx
]^ 1 ;
305 for (; i
<( size
* 2 ); i
++){
306 BitStream
[ i
] = BitStream
[ i
+ 20000 ];
312 //take 01 or 10 = 1 and 11 or 00 = 0
313 //check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010
314 //decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding
315 int BiphaseRawDecode ( uint8_t * BitStream
, size_t * size
, int offset
, int invert
)
320 uint16_t MaxBits
= 512 ;
321 //if not enough samples - error
322 if (* size
< 51 ) return - 1 ;
323 //check for phase change faults - skip one sample if faulty
324 uint8_t offsetA
= 1 , offsetB
= 1 ;
326 if ( BitStream
[ i
+ 1 ]== BitStream
[ i
+ 2 ]) offsetA
= 0 ;
327 if ( BitStream
[ i
+ 2 ]== BitStream
[ i
+ 3 ]) offsetB
= 0 ;
329 if (! offsetA
&& offsetB
) offset
++;
330 for ( i
= offset
; i
<* size
- 3 ; i
+= 2 ){
331 //check for phase error
332 if ( BitStream
[ i
+ 1 ]== BitStream
[ i
+ 2 ]) {
333 BitStream
[ bitnum
++]= 7 ;
336 if (( BitStream
[ i
]== 1 && BitStream
[ i
+ 1 ]== 0 ) || ( BitStream
[ i
]== 0 && BitStream
[ i
+ 1 ]== 1 )){
337 BitStream
[ bitnum
++]= 1 ^ invert
;
338 } else if (( BitStream
[ i
]== 0 && BitStream
[ i
+ 1 ]== 0 ) || ( BitStream
[ i
]== 1 && BitStream
[ i
+ 1 ]== 1 )){
339 BitStream
[ bitnum
++]= invert
;
341 BitStream
[ bitnum
++]= 7 ;
344 if ( bitnum
> MaxBits
) break ;
351 // demod gProxIIDemod
352 // error returns as -x
353 // success returns start position in BitStream
354 // BitStream must contain previously askrawdemod and biphasedemoded data
355 int gProxII_Demod ( uint8_t BitStream
[], size_t * size
)
358 uint8_t preamble
[] = { 1 , 1 , 1 , 1 , 1 , 0 };
360 uint8_t errChk
= preambleSearch ( BitStream
, preamble
, sizeof ( preamble
), size
, & startIdx
);
361 if ( errChk
== 0 ) return - 3 ; //preamble not found
362 if (* size
!= 96 ) return - 2 ; //should have found 96 bits
363 //check first 6 spacer bits to verify format
364 if (! BitStream
[ startIdx
+ 5 ] && ! BitStream
[ startIdx
+ 10 ] && ! BitStream
[ startIdx
+ 15 ] && ! BitStream
[ startIdx
+ 20 ] && ! BitStream
[ startIdx
+ 25 ] && ! BitStream
[ startIdx
+ 30 ]){
365 //confirmed proper separator bits found
366 //return start position
367 return ( int ) startIdx
;
372 //translate wave to 11111100000 (1 for each short wave 0 for each long wave)
373 size_t fsk_wave_demod ( uint8_t * dest
, size_t size
, uint8_t fchigh
, uint8_t fclow
)
375 size_t last_transition
= 0 ;
378 if ( fchigh
== 0 ) fchigh
= 10 ;
379 if ( fclow
== 0 ) fclow
= 8 ;
380 //set the threshold close to 0 (graph) or 128 std to avoid static
381 uint8_t threshold_value
= 123 ;
382 size_t preLastSample
= 0 ;
383 size_t LastSample
= 0 ;
384 size_t currSample
= 0 ;
385 // sync to first lo-hi transition, and threshold
387 // Need to threshold first sample
389 if ( dest
[ 0 ] < threshold_value
) dest
[ 0 ] = 0 ;
393 // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
394 // or 10 (fc/10) cycles but in practice due to noise etc we may end up with with anywhere
395 // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
396 for ( idx
= 1 ; idx
< size
; idx
++) {
397 // threshold current value
399 if ( dest
[ idx
] < threshold_value
) dest
[ idx
] = 0 ;
402 // Check for 0->1 transition
403 if ( dest
[ idx
- 1 ] < dest
[ idx
]) { // 0 -> 1 transition
404 preLastSample
= LastSample
;
405 LastSample
= currSample
;
406 currSample
= idx
- last_transition
;
407 if ( currSample
< ( fclow
- 2 )){ //0-5 = garbage noise
408 //do nothing with extra garbage
409 } else if ( currSample
< ( fchigh
- 1 )) { //6-8 = 8 sample waves
410 if ( LastSample
> ( fchigh
- 2 ) && preLastSample
< ( fchigh
- 1 )){
411 dest
[ numBits
- 1 ]= 1 ; //correct last 9 wave surrounded by 8 waves
415 } else if ( currSample
> ( fchigh
+ 1 ) && ! numBits
) { //12 + and first bit = garbage
416 //do nothing with beginning garbage
417 } else if ( currSample
== ( fclow
+ 1 ) && LastSample
== ( fclow
- 1 )) { // had a 7 then a 9 should be two 8's
419 } else { //9+ = 10 sample waves
422 last_transition
= idx
;
425 return numBits
; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
428 //translate 11111100000 to 10
429 size_t aggregate_bits ( uint8_t * dest
, size_t size
, uint8_t rfLen
,
430 uint8_t invert
, uint8_t fchigh
, uint8_t fclow
)
432 uint8_t lastval
= dest
[ 0 ];
436 for ( idx
= 1 ; idx
< size
; idx
++) {
438 if ( dest
[ idx
]== lastval
) continue ;
440 //if lastval was 1, we have a 1->0 crossing
441 if ( dest
[ idx
- 1 ]== 1 ) {
442 if (! numBits
&& n
< rfLen
/ fclow
) {
447 n
= ( n
* fclow
+ rfLen
/ 2 ) / rfLen
;
448 } else { // 0->1 crossing
449 //test first bitsample too small
450 if (! numBits
&& n
< rfLen
/ fchigh
) {
455 n
= ( n
* fchigh
+ rfLen
/ 2 ) / rfLen
;
459 memset ( dest
+ numBits
, dest
[ idx
- 1 ]^ invert
, n
);
464 // if valid extra bits at the end were all the same frequency - add them in
465 if ( n
> rfLen
/ fchigh
) {
466 if ( dest
[ idx
- 2 ]== 1 ) {
467 n
= ( n
* fclow
+ rfLen
/ 2 ) / rfLen
;
469 n
= ( n
* fchigh
+ rfLen
/ 2 ) / rfLen
;
471 memset ( dest
+ numBits
, dest
[ idx
- 1 ]^ invert
, n
);
476 //by marshmellow (from holiman's base)
477 // full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod)
478 int fskdemod ( uint8_t * dest
, size_t size
, uint8_t rfLen
, uint8_t invert
, uint8_t fchigh
, uint8_t fclow
)
481 size
= fsk_wave_demod ( dest
, size
, fchigh
, fclow
);
482 size
= aggregate_bits ( dest
, size
, rfLen
, invert
, fchigh
, fclow
);
486 // loop to get raw HID waveform then FSK demodulate the TAG ID from it
487 int HIDdemodFSK ( uint8_t * dest
, size_t * size
, uint32_t * hi2
, uint32_t * hi
, uint32_t * lo
)
489 if ( justNoise ( dest
, * size
)) return - 1 ;
491 size_t numStart
= 0 , size2
=* size
, startIdx
= 0 ;
493 * size
= fskdemod ( dest
, size2
, 50 , 1 , 10 , 8 ); //fsk2a
494 if (* size
< 96 * 2 ) return - 2 ;
495 // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
496 uint8_t preamble
[] = { 0 , 0 , 0 , 1 , 1 , 1 , 0 , 1 };
497 // find bitstring in array
498 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
499 if ( errChk
== 0 ) return - 3 ; //preamble not found
501 numStart
= startIdx
+ sizeof ( preamble
);
502 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
503 for ( size_t idx
= numStart
; ( idx
- numStart
) < * size
- sizeof ( preamble
); idx
+= 2 ){
504 if ( dest
[ idx
] == dest
[ idx
+ 1 ]){
505 return - 4 ; //not manchester data
507 * hi2
= (* hi2
<< 1 )|(* hi
>> 31 );
508 * hi
= (* hi
<< 1 )|(* lo
>> 31 );
509 //Then, shift in a 0 or one into low
510 if ( dest
[ idx
] && ! dest
[ idx
+ 1 ]) // 1 0
515 return ( int ) startIdx
;
518 // loop to get raw paradox waveform then FSK demodulate the TAG ID from it
519 int ParadoxdemodFSK ( uint8_t * dest
, size_t * size
, uint32_t * hi2
, uint32_t * hi
, uint32_t * lo
)
521 if ( justNoise ( dest
, * size
)) return - 1 ;
523 size_t numStart
= 0 , size2
=* size
, startIdx
= 0 ;
525 * size
= fskdemod ( dest
, size2
, 50 , 1 , 10 , 8 ); //fsk2a
526 if (* size
< 96 ) return - 2 ;
528 // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
529 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 1 , 1 , 1 , 1 };
531 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
532 if ( errChk
== 0 ) return - 3 ; //preamble not found
534 numStart
= startIdx
+ sizeof ( preamble
);
535 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
536 for ( size_t idx
= numStart
; ( idx
- numStart
) < * size
- sizeof ( preamble
); idx
+= 2 ){
537 if ( dest
[ idx
] == dest
[ idx
+ 1 ])
538 return - 4 ; //not manchester data
539 * hi2
= (* hi2
<< 1 )|(* hi
>> 31 );
540 * hi
= (* hi
<< 1 )|(* lo
>> 31 );
541 //Then, shift in a 0 or one into low
542 if ( dest
[ idx
] && ! dest
[ idx
+ 1 ]) // 1 0
547 return ( int ) startIdx
;
550 uint32_t bytebits_to_byte ( uint8_t * src
, size_t numbits
)
553 for ( int i
= 0 ; i
< numbits
; i
++)
555 num
= ( num
<< 1 ) | (* src
);
561 //least significant bit first
562 uint32_t bytebits_to_byteLSBF ( uint8_t * src
, size_t numbits
)
565 for ( int i
= 0 ; i
< numbits
; i
++)
567 num
= ( num
<< 1 ) | *( src
+ ( numbits
-( i
+ 1 )));
572 int IOdemodFSK ( uint8_t * dest
, size_t size
)
574 if ( justNoise ( dest
, size
)) return - 1 ;
575 //make sure buffer has data
576 if ( size
< 66 * 64 ) return - 2 ;
578 size
= fskdemod ( dest
, size
, 64 , 1 , 10 , 8 ); // FSK2a RF/64
579 if ( size
< 65 ) return - 3 ; //did we get a good demod?
581 //0 10 20 30 40 50 60
583 //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
584 //-----------------------------------------------------------------------------
585 //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
587 //XSF(version)facility:codeone+codetwo
590 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
591 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), & size
, & startIdx
);
592 if ( errChk
== 0 ) return - 4 ; //preamble not found
594 if (! dest
[ startIdx
+ 8 ] && dest
[ startIdx
+ 17 ]== 1 && dest
[ startIdx
+ 26 ]== 1 && dest
[ startIdx
+ 35 ]== 1 && dest
[ startIdx
+ 44 ]== 1 && dest
[ startIdx
+ 53 ]== 1 ){
595 //confirmed proper separator bits found
596 //return start position
597 return ( int ) startIdx
;
603 // takes a array of binary values, start position, length of bits per parity (includes parity bit),
604 // Parity Type (1 for odd; 0 for even; 2 Always 1's), and binary Length (length to run)
605 size_t removeParity ( uint8_t * BitStream
, size_t startIdx
, uint8_t pLen
, uint8_t pType
, size_t bLen
)
607 uint32_t parityWd
= 0 ;
608 size_t j
= 0 , bitCnt
= 0 ;
609 for ( int word
= 0 ; word
< ( bLen
); word
+= pLen
){
610 for ( int bit
= 0 ; bit
< pLen
; bit
++){
611 parityWd
= ( parityWd
<< 1 ) | BitStream
[ startIdx
+ word
+ bit
];
612 BitStream
[ j
++] = ( BitStream
[ startIdx
+ word
+ bit
]);
614 j
--; // overwrite parity with next data
615 // if parity fails then return 0
616 if ( pType
== 2 ) { // then marker bit which should be a 1
617 if (! BitStream
[ j
]) return 0 ;
619 if ( parityTest ( parityWd
, pLen
, pType
) == 0 ) return 0 ;
624 // if we got here then all the parities passed
625 //return ID start index and size
629 // Ask/Biphase Demod then try to locate an ISO 11784/85 ID
630 // BitStream must contain previously askrawdemod and biphasedemoded data
631 int FDXBdemodBI ( uint8_t * dest
, size_t * size
)
633 //make sure buffer has enough data
634 if (* size
< 128 ) return - 1 ;
637 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
639 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
640 if ( errChk
== 0 ) return - 2 ; //preamble not found
641 return ( int ) startIdx
;
645 // FSK Demod then try to locate an AWID ID
646 int AWIDdemodFSK ( uint8_t * dest
, size_t * size
)
648 //make sure buffer has enough data
649 if (* size
< 96 * 50 ) return - 1 ;
651 if ( justNoise ( dest
, * size
)) return - 2 ;
654 * size
= fskdemod ( dest
, * size
, 50 , 1 , 10 , 8 ); // fsk2a RF/50
655 if (* size
< 96 ) return - 3 ; //did we get a good demod?
657 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
659 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
660 if ( errChk
== 0 ) return - 4 ; //preamble not found
661 if (* size
!= 96 ) return - 5 ;
662 return ( int ) startIdx
;
666 // FSK Demod then try to locate an Farpointe Data (pyramid) ID
667 int PyramiddemodFSK ( uint8_t * dest
, size_t * size
)
669 //make sure buffer has data
670 if (* size
< 128 * 50 ) return - 5 ;
672 //test samples are not just noise
673 if ( justNoise ( dest
, * size
)) return - 1 ;
676 * size
= fskdemod ( dest
, * size
, 50 , 1 , 10 , 8 ); // fsk2a RF/50
677 if (* size
< 128 ) return - 2 ; //did we get a good demod?
679 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
681 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
682 if ( errChk
== 0 ) return - 4 ; //preamble not found
683 if (* size
!= 128 ) return - 3 ;
684 return ( int ) startIdx
;
688 // to detect a wave that has heavily clipped (clean) samples
689 uint8_t DetectCleanAskWave ( uint8_t dest
[], size_t size
, uint8_t high
, uint8_t low
)
693 size_t loopEnd
= 512 + 60 ;
694 if ( loopEnd
> size
) loopEnd
= size
;
695 for ( size_t i
= 60 ; i
< loopEnd
; i
++){
696 if ( dest
[ i
]> low
&& dest
[ i
]< high
)
702 if ( cntPeaks
> 300 ) return 1 ;
708 // to help detect clocks on heavily clipped samples
709 // based on count of low to low
710 int DetectStrongAskClock ( uint8_t dest
[], size_t size
, uint8_t high
, uint8_t low
)
712 uint8_t fndClk
[] = { 8 , 16 , 32 , 40 , 50 , 64 , 128 };
716 // get to first full low to prime loop and skip incomplete first pulse
717 while (( dest
[ i
] < high
) && ( i
< size
))
719 while (( dest
[ i
] > low
) && ( i
< size
))
722 // loop through all samples
724 // measure from low to low
725 while (( dest
[ i
] > low
) && ( i
< size
))
728 while (( dest
[ i
] < high
) && ( i
< size
))
730 while (( dest
[ i
] > low
) && ( i
< size
))
732 //get minimum measured distance
733 if ( i
- startwave
< minClk
&& i
< size
)
734 minClk
= i
- startwave
;
737 for ( uint8_t clkCnt
= 0 ; clkCnt
< 7 ; clkCnt
++) {
738 if ( minClk
>= fndClk
[ clkCnt
]-( fndClk
[ clkCnt
]/ 8 ) && minClk
<= fndClk
[ clkCnt
]+ 1 )
739 return fndClk
[ clkCnt
];
745 // not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)
746 // maybe somehow adjust peak trimming value based on samples to fix?
747 // return start index of best starting position for that clock and return clock (by reference)
748 int DetectASKClock ( uint8_t dest
[], size_t size
, int * clock
, int maxErr
)
751 uint8_t clk
[] = { 255 , 8 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 255 };
753 uint8_t loopCnt
= 255 ; //don't need to loop through entire array...
754 if ( size
<= loopCnt
) return - 1 ; //not enough samples
756 //if we already have a valid clock
759 if ( clk
[ i
] == * clock
) clockFnd
= i
;
760 //clock found but continue to find best startpos
762 //get high and low peak
764 if ( getHiLo ( dest
, loopCnt
, & peak
, & low
, 75 , 75 ) < 1 ) return - 1 ;
766 //test for large clean peaks
768 if ( DetectCleanAskWave ( dest
, size
, peak
, low
)== 1 ){
769 int ans
= DetectStrongAskClock ( dest
, size
, peak
, low
);
770 for ( i
= clkEnd
- 1 ; i
> 0 ; i
--){
774 return 0 ; // for strong waves i don't use the 'best start position' yet...
775 //break; //clock found but continue to find best startpos [not yet]
782 uint8_t clkCnt
, tol
= 0 ;
783 uint16_t bestErr
[]={ 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 };
784 uint8_t bestStart
[]={ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
786 size_t arrLoc
, loopEnd
;
794 //test each valid clock from smallest to greatest to see which lines up
795 for (; clkCnt
< clkEnd
; clkCnt
++){
796 if ( clk
[ clkCnt
] <= 32 ){
801 //if no errors allowed - keep start within the first clock
802 if (! maxErr
&& size
> clk
[ clkCnt
]* 2 + tol
&& clk
[ clkCnt
]< 128 ) loopCnt
= clk
[ clkCnt
]* 2 ;
803 bestErr
[ clkCnt
]= 1000 ;
804 //try lining up the peaks by moving starting point (try first few clocks)
805 for ( ii
= 0 ; ii
< loopCnt
; ii
++){
806 if ( dest
[ ii
] < peak
&& dest
[ ii
] > low
) continue ;
809 // now that we have the first one lined up test rest of wave array
810 loopEnd
= (( size
- ii
- tol
) / clk
[ clkCnt
]) - 1 ;
811 for ( i
= 0 ; i
< loopEnd
; ++ i
){
812 arrLoc
= ii
+ ( i
* clk
[ clkCnt
]);
813 if ( dest
[ arrLoc
] >= peak
|| dest
[ arrLoc
] <= low
){
814 } else if ( dest
[ arrLoc
- tol
] >= peak
|| dest
[ arrLoc
- tol
] <= low
){
815 } else if ( dest
[ arrLoc
+ tol
] >= peak
|| dest
[ arrLoc
+ tol
] <= low
){
816 } else { //error no peak detected
820 //if we found no errors then we can stop here and a low clock (common clocks)
821 // this is correct one - return this clock
822 //PrintAndLog("DEBUG: clk %d, err %d, ii %d, i %d",clk[clkCnt],errCnt,ii,i);
823 if ( errCnt
== 0 && clkCnt
< 7 ) {
824 if (! clockFnd
) * clock
= clk
[ clkCnt
];
827 //if we found errors see if it is lowest so far and save it as best run
828 if ( errCnt
< bestErr
[ clkCnt
]){
829 bestErr
[ clkCnt
]= errCnt
;
830 bestStart
[ clkCnt
]= ii
;
836 for ( iii
= 1 ; iii
< clkEnd
; ++ iii
){
837 if ( bestErr
[ iii
] < bestErr
[ best
]){
838 if ( bestErr
[ iii
] == 0 ) bestErr
[ iii
]= 1 ;
839 // current best bit to error ratio vs new bit to error ratio
840 if ( ( size
/ clk
[ best
])/ bestErr
[ best
] < ( size
/ clk
[ iii
])/ bestErr
[ iii
] ){
845 //if (bestErr[best] > maxErr) return -1;
846 if (! clockFnd
) * clock
= clk
[ best
];
847 return bestStart
[ best
];
851 //detect psk clock by reading each phase shift
852 // a phase shift is determined by measuring the sample length of each wave
853 int DetectPSKClock ( uint8_t dest
[], size_t size
, int clock
)
855 uint8_t clk
[]={ 255 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 255 }; //255 is not a valid clock
856 uint16_t loopCnt
= 4096 ; //don't need to loop through entire array...
857 if ( size
== 0 ) return 0 ;
858 if ( size
< loopCnt
) loopCnt
= size
;
860 //if we already have a valid clock quit
863 if ( clk
[ i
] == clock
) return clock
;
865 size_t waveStart
= 0 , waveEnd
= 0 , firstFullWave
= 0 , lastClkBit
= 0 ;
866 uint8_t clkCnt
, fc
= 0 , fullWaveLen
= 0 , tol
= 1 ;
867 uint16_t peakcnt
= 0 , errCnt
= 0 , waveLenCnt
= 0 ;
868 uint16_t bestErr
[]={ 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 };
869 uint16_t peaksdet
[]={ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
870 fc
= countFC ( dest
, size
, 0 );
871 if ( fc
!= 2 && fc
!= 4 && fc
!= 8 ) return - 1 ;
872 //PrintAndLog("DEBUG: FC: %d",fc);
874 //find first full wave
875 for ( i
= 0 ; i
< loopCnt
; i
++){
876 if ( dest
[ i
] < dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
877 if ( waveStart
== 0 ) {
879 //PrintAndLog("DEBUG: waveStart: %d",waveStart);
882 //PrintAndLog("DEBUG: waveEnd: %d",waveEnd);
883 waveLenCnt
= waveEnd
- waveStart
;
884 if ( waveLenCnt
> fc
){
885 firstFullWave
= waveStart
;
886 fullWaveLen
= waveLenCnt
;
893 //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);
895 //test each valid clock from greatest to smallest to see which lines up
896 for ( clkCnt
= 7 ; clkCnt
>= 1 ; clkCnt
--){
897 lastClkBit
= firstFullWave
; //set end of wave as clock align
901 //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit);
903 for ( i
= firstFullWave
+ fullWaveLen
- 1 ; i
< loopCnt
- 2 ; i
++){
904 //top edge of wave = start of new wave
905 if ( dest
[ i
] < dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
906 if ( waveStart
== 0 ) {
911 waveLenCnt
= waveEnd
- waveStart
;
912 if ( waveLenCnt
> fc
){
913 //if this wave is a phase shift
914 //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, ii: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+clk[clkCnt]-tol,ii+1,fc);
915 if ( i
+ 1 >= lastClkBit
+ clk
[ clkCnt
] - tol
){ //should be a clock bit
917 lastClkBit
+= clk
[ clkCnt
];
918 } else if ( i
< lastClkBit
+ 8 ){
919 //noise after a phase shift - ignore
920 } else { //phase shift before supposed to based on clock
923 } else if ( i
+ 1 > lastClkBit
+ clk
[ clkCnt
] + tol
+ fc
){
924 lastClkBit
+= clk
[ clkCnt
]; //no phase shift but clock bit
933 if ( errCnt
<= bestErr
[ clkCnt
]) bestErr
[ clkCnt
]= errCnt
;
934 if ( peakcnt
> peaksdet
[ clkCnt
]) peaksdet
[ clkCnt
]= peakcnt
;
936 //all tested with errors
937 //return the highest clk with the most peaks found
939 for ( i
= 7 ; i
>= 1 ; i
--){
940 if ( peaksdet
[ i
] > peaksdet
[ best
]) {
943 //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]);
949 //detect nrz clock by reading #peaks vs no peaks(or errors)
950 int DetectNRZClock ( uint8_t dest
[], size_t size
, int clock
)
953 uint8_t clk
[]={ 8 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 255 };
954 size_t loopCnt
= 4096 ; //don't need to loop through entire array...
955 if ( size
== 0 ) return 0 ;
956 if ( size
< loopCnt
) loopCnt
= size
;
958 //if we already have a valid clock quit
960 if ( clk
[ i
] == clock
) return clock
;
962 //get high and low peak
964 if ( getHiLo ( dest
, loopCnt
, & peak
, & low
, 75 , 75 ) < 1 ) return 0 ;
966 //PrintAndLog("DEBUG: peak: %d, low: %d",peak,low);
971 uint16_t peaksdet
[]={ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
973 //test for large clipped waves
974 for ( i
= 0 ; i
< loopCnt
; i
++){
975 if ( dest
[ i
] >= peak
|| dest
[ i
] <= low
){
978 if ( peakcnt
> 0 && maxPeak
< peakcnt
){
985 //test each valid clock from smallest to greatest to see which lines up
986 for ( clkCnt
= 0 ; clkCnt
< 8 ; ++ clkCnt
){
987 //ignore clocks smaller than largest peak
988 if ( clk
[ clkCnt
]< maxPeak
) continue ;
990 //try lining up the peaks by moving starting point (try first 256)
991 for ( ii
= 0 ; ii
< loopCnt
; ++ ii
){
992 if (( dest
[ ii
] >= peak
) || ( dest
[ ii
] <= low
)){
994 // now that we have the first one lined up test rest of wave array
995 for ( i
= 0 ; i
< (( int )(( size
- ii
- tol
)/ clk
[ clkCnt
])- 1 ); ++ i
){
996 if ( dest
[ ii
+( i
* clk
[ clkCnt
])]>= peak
|| dest
[ ii
+( i
* clk
[ clkCnt
])]<= low
){
1000 if ( peakcnt
> peaksdet
[ clkCnt
]) {
1001 peaksdet
[ clkCnt
]= peakcnt
;
1008 for ( iii
= 7 ; iii
> 0 ; iii
--){
1009 if ( peaksdet
[ iii
] > peaksdet
[ best
]){
1012 //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]);
1018 // convert psk1 demod to psk2 demod
1019 // only transition waves are 1s
1020 void psk1TOpsk2 ( uint8_t * BitStream
, size_t size
)
1023 uint8_t lastBit
= BitStream
[ 0 ];
1024 for (; i
< size
; i
++){
1025 if ( BitStream
[ i
]== 7 ){
1027 } else if ( lastBit
!= BitStream
[ i
]){
1028 lastBit
= BitStream
[ i
];
1038 // convert psk2 demod to psk1 demod
1039 // from only transition waves are 1s to phase shifts change bit
1040 void psk2TOpsk1 ( uint8_t * BitStream
, size_t size
)
1043 for ( size_t i
= 0 ; i
< size
; i
++){
1044 if ( BitStream
[ i
]== 1 ){
1052 // redesigned by marshmellow adjusted from existing decode functions
1053 // indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
1054 int indala26decode ( uint8_t * bitStream
, size_t * size
, uint8_t * invert
)
1056 //26 bit 40134 format (don't know other formats)
1058 int long_wait
= 29 ; //29 leading zeros in format
1064 // Finding the start of a UID
1065 for ( start
= 0 ; start
<= * size
- 250 ; start
++) {
1066 first
= bitStream
[ start
];
1067 for ( i
= start
; i
< start
+ long_wait
; i
++) {
1068 if ( bitStream
[ i
] != first
) {
1072 if ( i
== ( start
+ long_wait
)) {
1076 if ( start
== * size
- 250 + 1 ) {
1077 // did not find start sequence
1080 // Inverting signal if needed
1082 for ( i
= start
; i
< * size
; i
++) {
1083 bitStream
[ i
] = ! bitStream
[ i
];
1089 //found start once now test length by finding next one
1090 for ( ii
= start
+ 29 ; ii
<= * size
- 250 ; ii
++) {
1091 first2
= bitStream
[ ii
];
1092 for ( iii
= ii
; iii
< ii
+ long_wait
; iii
++) {
1093 if ( bitStream
[ iii
] != first2
) {
1097 if ( iii
== ( ii
+ long_wait
)) {
1101 if ( ii
== * size
- 250 + 1 ){
1102 // did not find second start sequence
1109 for ( ii
= 0 ; ii
< bitCnt
; ii
++) {
1110 bitStream
[ ii
] = bitStream
[ i
++];
1116 // by marshmellow - demodulate NRZ wave (both similar enough)
1117 // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
1118 // there probably is a much simpler way to do this....
1119 int nrzRawDemod ( uint8_t * dest
, size_t * size
, int * clk
, int * invert
, int maxErr
)
1121 if ( justNoise ( dest
, * size
)) return - 1 ;
1122 * clk
= DetectNRZClock ( dest
, * size
, * clk
);
1123 if (* clk
== 0 ) return - 2 ;
1124 size_t i
, gLen
= 4096 ;
1125 if ( gLen
>* size
) gLen
= * size
;
1127 if ( getHiLo ( dest
, gLen
, & high
, & low
, 75 , 75 ) < 1 ) return - 3 ; //25% fuzz on high 25% fuzz on low
1128 int lastBit
= 0 ; //set first clock check
1129 size_t iii
= 0 , bitnum
= 0 ; //bitnum counter
1130 uint16_t errCnt
= 0 , MaxBits
= 1000 ;
1131 size_t bestErrCnt
= maxErr
+ 1 ;
1132 size_t bestPeakCnt
= 0 , bestPeakStart
= 0 ;
1133 uint8_t bestFirstPeakHigh
= 0 , firstPeakHigh
= 0 , curBit
= 0 , bitHigh
= 0 , errBitHigh
= 0 ;
1134 uint8_t tol
= 1 ; //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave
1136 uint8_t ignoreWindow
= 4 ;
1137 uint8_t ignoreCnt
= ignoreWindow
; //in case of noise near peak
1138 //loop to find first wave that works - align to clock
1139 for ( iii
= 0 ; iii
< gLen
; ++ iii
){
1140 if (( dest
[ iii
]>= high
) || ( dest
[ iii
]<= low
)){
1141 if ( dest
[ iii
]>= high
) firstPeakHigh
= 1 ;
1142 else firstPeakHigh
= 0 ;
1146 //loop through to see if this start location works
1147 for ( i
= iii
; i
< * size
; ++ i
) {
1148 // if we are at a clock bit
1149 if (( i
>= lastBit
+ * clk
- tol
) && ( i
<= lastBit
+ * clk
+ tol
)) {
1151 if ( dest
[ i
] >= high
|| dest
[ i
] <= low
) {
1155 ignoreCnt
= ignoreWindow
;
1157 } else if ( i
== lastBit
+ * clk
+ tol
) {
1160 //else if no bars found
1161 } else if ( dest
[ i
] < high
&& dest
[ i
] > low
){
1164 if ( errBitHigh
== 1 ) errCnt
++;
1169 } else if (( dest
[ i
]>= high
|| dest
[ i
]<= low
) && ( bitHigh
== 0 )) {
1170 //error bar found no clock...
1173 if ((( i
- iii
) / * clk
)>= MaxBits
) break ;
1175 //we got more than 64 good bits and not all errors
1176 if ((( i
- iii
) / * clk
) > 64 && ( errCnt
<= ( maxErr
))) {
1177 //possible good read
1178 if (! errCnt
|| peakCnt
> bestPeakCnt
){
1179 bestFirstPeakHigh
= firstPeakHigh
;
1180 bestErrCnt
= errCnt
;
1181 bestPeakCnt
= peakCnt
;
1182 bestPeakStart
= iii
;
1183 if (! errCnt
) break ; //great read - finish
1188 //PrintAndLog("DEBUG: bestErrCnt: %d, maxErr: %d, bestStart: %d, bestPeakCnt: %d, bestPeakStart: %d",bestErrCnt,maxErr,bestStart,bestPeakCnt,bestPeakStart);
1189 if ( bestErrCnt
> maxErr
) return bestErrCnt
;
1191 //best run is good enough set to best run and set overwrite BinStream
1192 lastBit
= bestPeakStart
- * clk
;
1193 memset ( dest
, bestFirstPeakHigh
^ 1 , bestPeakStart
/ * clk
);
1194 bitnum
+= ( bestPeakStart
/ * clk
);
1195 for ( i
= bestPeakStart
; i
< * size
; ++ i
) {
1196 // if expecting a clock bit
1197 if (( i
>= lastBit
+ * clk
- tol
) && ( i
<= lastBit
+ * clk
+ tol
)) {
1199 if ( dest
[ i
] >= high
|| dest
[ i
] <= low
) {
1203 ignoreCnt
= ignoreWindow
;
1205 if ( dest
[ i
] >= high
) curBit
^= 1 ;
1206 dest
[ bitnum
++] = curBit
;
1208 //else no bars found in clock area
1209 } else if ( i
== lastBit
+ * clk
+ tol
) {
1210 dest
[ bitnum
++] = curBit
;
1213 //else if no bars found
1214 } else if ( dest
[ i
] < high
&& dest
[ i
] > low
){
1215 if ( ignoreCnt
== 0 ){
1217 if ( errBitHigh
== 1 ){
1225 } else if (( dest
[ i
] >= high
|| dest
[ i
] <= low
) && ( bitHigh
== 0 )) {
1226 //error bar found no clock...
1229 if ( bitnum
>= MaxBits
) break ;
1236 //detects the bit clock for FSK given the high and low Field Clocks
1237 uint8_t detectFSKClk ( uint8_t * BitStream
, size_t size
, uint8_t fcHigh
, uint8_t fcLow
)
1239 uint8_t clk
[] = { 8 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 0 };
1240 uint16_t rfLens
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1241 uint8_t rfCnts
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1242 uint8_t rfLensFnd
= 0 ;
1243 uint8_t lastFCcnt
= 0 ;
1244 uint16_t fcCounter
= 0 ;
1245 uint16_t rfCounter
= 0 ;
1246 uint8_t firstBitFnd
= 0 ;
1248 if ( size
== 0 ) return 0 ;
1250 uint8_t fcTol
= ( uint8_t )( 0.5 +( float )( fcHigh
- fcLow
)/ 2 );
1255 //PrintAndLog("DEBUG: fcTol: %d",fcTol);
1256 // prime i to first up transition
1257 for ( i
= 1 ; i
< size
- 1 ; i
++)
1258 if ( BitStream
[ i
] > BitStream
[ i
- 1 ] && BitStream
[ i
]>= BitStream
[ i
+ 1 ])
1261 for (; i
< size
- 1 ; i
++){
1265 if ( BitStream
[ i
] <= BitStream
[ i
- 1 ] || BitStream
[ i
] < BitStream
[ i
+ 1 ])
1268 // if we got less than the small fc + tolerance then set it to the small fc
1269 if ( fcCounter
< fcLow
+ fcTol
)
1271 else //set it to the large fc
1274 //look for bit clock (rf/xx)
1275 if (( fcCounter
< lastFCcnt
|| fcCounter
> lastFCcnt
)){
1276 //not the same size as the last wave - start of new bit sequence
1277 if ( firstBitFnd
> 1 ){ //skip first wave change - probably not a complete bit
1278 for ( int ii
= 0 ; ii
< 15 ; ii
++){
1279 if ( rfLens
[ ii
] == rfCounter
){
1285 if ( rfCounter
> 0 && rfLensFnd
< 15 ){
1286 //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
1287 rfCnts
[ rfLensFnd
]++;
1288 rfLens
[ rfLensFnd
++] = rfCounter
;
1294 lastFCcnt
= fcCounter
;
1298 uint8_t rfHighest
= 15 , rfHighest2
= 15 , rfHighest3
= 15 ;
1300 for ( i
= 0 ; i
< 15 ; i
++){
1301 //PrintAndLog("DEBUG: RF %d, cnts %d",rfLens[i], rfCnts[i]);
1302 //get highest 2 RF values (might need to get more values to compare or compare all?)
1303 if ( rfCnts
[ i
]> rfCnts
[ rfHighest
]){
1304 rfHighest3
= rfHighest2
;
1305 rfHighest2
= rfHighest
;
1307 } else if ( rfCnts
[ i
]> rfCnts
[ rfHighest2
]){
1308 rfHighest3
= rfHighest2
;
1310 } else if ( rfCnts
[ i
]> rfCnts
[ rfHighest3
]){
1314 // set allowed clock remainder tolerance to be 1 large field clock length+1
1315 // we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off
1316 uint8_t tol1
= fcHigh
+ 1 ;
1318 //PrintAndLog("DEBUG: hightest: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]);
1320 // loop to find the highest clock that has a remainder less than the tolerance
1321 // compare samples counted divided by
1323 for (; ii
>= 0 ; ii
--){
1324 if ( rfLens
[ rfHighest
] % clk
[ ii
] < tol1
|| rfLens
[ rfHighest
] % clk
[ ii
] > clk
[ ii
]- tol1
){
1325 if ( rfLens
[ rfHighest2
] % clk
[ ii
] < tol1
|| rfLens
[ rfHighest2
] % clk
[ ii
] > clk
[ ii
]- tol1
){
1326 if ( rfLens
[ rfHighest3
] % clk
[ ii
] < tol1
|| rfLens
[ rfHighest3
] % clk
[ ii
] > clk
[ ii
]- tol1
){
1333 if ( ii
< 0 ) return 0 ; // oops we went too far
1339 //countFC is to detect the field clock lengths.
1340 //counts and returns the 2 most common wave lengths
1341 //mainly used for FSK field clock detection
1342 uint16_t countFC ( uint8_t * BitStream
, size_t size
, uint8_t fskAdj
)
1344 uint8_t fcLens
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1345 uint16_t fcCnts
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1346 uint8_t fcLensFnd
= 0 ;
1347 uint8_t lastFCcnt
= 0 ;
1348 uint8_t fcCounter
= 0 ;
1350 if ( size
== 0 ) return 0 ;
1352 // prime i to first up transition
1353 for ( i
= 1 ; i
< size
- 1 ; i
++)
1354 if ( BitStream
[ i
] > BitStream
[ i
- 1 ] && BitStream
[ i
] >= BitStream
[ i
+ 1 ])
1357 for (; i
< size
- 1 ; i
++){
1358 if ( BitStream
[ i
] > BitStream
[ i
- 1 ] && BitStream
[ i
] >= BitStream
[ i
+ 1 ]){
1359 // new up transition
1362 //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8)
1363 if ( lastFCcnt
== 5 && fcCounter
== 9 ) fcCounter
--;
1364 //if fc=9 or 4 add one (for when we get a fc 9 instead of 10 or a 4 instead of a 5)
1365 if (( fcCounter
== 9 ) || fcCounter
== 4 ) fcCounter
++;
1366 // save last field clock count (fc/xx)
1367 lastFCcnt
= fcCounter
;
1369 // find which fcLens to save it to:
1370 for ( int ii
= 0 ; ii
< 10 ; ii
++){
1371 if ( fcLens
[ ii
]== fcCounter
){
1377 if ( fcCounter
> 0 && fcLensFnd
< 10 ){
1379 fcCnts
[ fcLensFnd
]++;
1380 fcLens
[ fcLensFnd
++]= fcCounter
;
1389 uint8_t best1
= 9 , best2
= 9 , best3
= 9 ;
1391 // go through fclens and find which ones are bigest 2
1392 for ( i
= 0 ; i
< 10 ; i
++){
1393 // PrintAndLog("DEBUG: FC %d, Cnt %d, Errs %d",fcLens[i],fcCnts[i],errCnt);
1394 // get the 3 best FC values
1395 if ( fcCnts
[ i
]> maxCnt1
) {
1400 } else if ( fcCnts
[ i
]> fcCnts
[ best2
]){
1403 } else if ( fcCnts
[ i
]> fcCnts
[ best3
]){
1407 uint8_t fcH
= 0 , fcL
= 0 ;
1408 if ( fcLens
[ best1
]> fcLens
[ best2
]){
1416 // TODO: take top 3 answers and compare to known Field clocks to get top 2
1418 uint16_t fcs
= ((( uint16_t ) fcH
)<< 8 ) | fcL
;
1419 // PrintAndLog("DEBUG: Best %d best2 %d best3 %d",fcLens[best1],fcLens[best2],fcLens[best3]);
1420 if ( fskAdj
) return fcs
;
1421 return fcLens
[ best1
];
1424 //by marshmellow - demodulate PSK1 wave
1425 //uses wave lengths (# Samples)
1426 int pskRawDemod ( uint8_t dest
[], size_t * size
, int * clock
, int * invert
)
1428 if ( size
== 0 ) return - 1 ;
1429 uint16_t loopCnt
= 4096 ; //don't need to loop through entire array...
1430 if (* size
< loopCnt
) loopCnt
= * size
;
1432 uint8_t curPhase
= * invert
;
1433 size_t i
, waveStart
= 1 , waveEnd
= 0 , firstFullWave
= 0 , lastClkBit
= 0 ;
1434 uint8_t fc
= 0 , fullWaveLen
= 0 , tol
= 1 ;
1435 uint16_t errCnt
= 0 , waveLenCnt
= 0 ;
1436 fc
= countFC ( dest
, * size
, 0 );
1437 if ( fc
!= 2 && fc
!= 4 && fc
!= 8 ) return - 1 ;
1438 //PrintAndLog("DEBUG: FC: %d",fc);
1439 * clock
= DetectPSKClock ( dest
, * size
, * clock
);
1440 if (* clock
== 0 ) return - 1 ;
1441 int avgWaveVal
= 0 , lastAvgWaveVal
= 0 ;
1442 //find first phase shift
1443 for ( i
= 0 ; i
< loopCnt
; i
++){
1444 if ( dest
[ i
]+ fc
< dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
1446 //PrintAndLog("DEBUG: waveEnd: %d",waveEnd);
1447 waveLenCnt
= waveEnd
- waveStart
;
1448 if ( waveLenCnt
> fc
&& waveStart
> fc
){ //not first peak and is a large wave
1449 lastAvgWaveVal
= avgWaveVal
/( waveLenCnt
);
1450 firstFullWave
= waveStart
;
1451 fullWaveLen
= waveLenCnt
;
1452 //if average wave value is > graph 0 then it is an up wave or a 1
1453 if ( lastAvgWaveVal
> 123 ) curPhase
^= 1 ; //fudge graph 0 a little 123 vs 128
1459 avgWaveVal
+= dest
[ i
+ 2 ];
1461 //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);
1462 lastClkBit
= firstFullWave
; //set start of wave as clock align
1463 //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d", *clock, lastClkBit);
1467 memset ( dest
, curPhase
^ 1 , firstFullWave
/ * clock
);
1468 numBits
+= ( firstFullWave
/ * clock
);
1469 dest
[ numBits
++] = curPhase
; //set first read bit
1470 for ( i
= firstFullWave
+ fullWaveLen
- 1 ; i
< * size
- 3 ; i
++){
1471 //top edge of wave = start of new wave
1472 if ( dest
[ i
]+ fc
< dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
1473 if ( waveStart
== 0 ) {
1476 avgWaveVal
= dest
[ i
+ 1 ];
1479 waveLenCnt
= waveEnd
- waveStart
;
1480 lastAvgWaveVal
= avgWaveVal
/ waveLenCnt
;
1481 if ( waveLenCnt
> fc
){
1482 //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);
1483 //this wave is a phase shift
1484 //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc);
1485 if ( i
+ 1 >= lastClkBit
+ * clock
- tol
){ //should be a clock bit
1487 dest
[ numBits
++] = curPhase
;
1488 lastClkBit
+= * clock
;
1489 } else if ( i
< lastClkBit
+ 10 + fc
){
1490 //noise after a phase shift - ignore
1491 } else { //phase shift before supposed to based on clock
1493 dest
[ numBits
++] = 7 ;
1495 } else if ( i
+ 1 > lastClkBit
+ * clock
+ tol
+ fc
){
1496 lastClkBit
+= * clock
; //no phase shift but clock bit
1497 dest
[ numBits
++] = curPhase
;
1503 avgWaveVal
+= dest
[ i
+ 1 ];
1508 // on successful return 1 otherwise return 0
1509 int VikingDecode ( uint8_t * BitStream
,
1513 size_t id_bits_size
)
1515 //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
1516 // otherwise could be a void with no arguments
1519 uint32_t lastcheckindex
= size
- ( id_bits_size
* 2 );
1521 while ( i
< lastcheckindex
)
1523 if ( memcmp ( BitStream
+ i
, id_bits
, id_bits_size
) == 0 )