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cvs.zerfleddert.de Git - proxmark3-svn/blob - common/lfdemod.c
aa3586f6cedd4a0af3677f1f9d4c5e90edcd2605
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 //-----------------------------------------------------------------------------
15 //un_comment to allow debug print calls when used not on device
16 void dummy ( char * fmt
, ...){}
20 #include "cmdparser.h"
22 #define prnt PrintAndLog
24 uint8_t g_debugMode
= 0 ;
28 //test samples are not just noise
29 uint8_t justNoise ( uint8_t * bits
, size_t size
) {
32 for ( size_t idx
= 0 ; idx
< size
&& val
; idx
++)
33 val
= bits
[ idx
] < THRESHOLD
;
38 //get high and low values of a wave with passed in fuzz factor. also return noise test = 1 for passed or 0 for only noise
39 int getHiLo ( uint8_t * BitStream
, size_t size
, int * high
, int * low
, uint8_t fuzzHi
, uint8_t fuzzLo
)
43 // get high and low thresholds
44 for ( size_t i
= 0 ; i
< size
; i
++){
45 if ( BitStream
[ i
] > * high
) * high
= BitStream
[ i
];
46 if ( BitStream
[ i
] < * low
) * low
= BitStream
[ i
];
48 if (* high
< 123 ) return - 1 ; // just noise
49 * high
= ((* high
- 128 )* fuzzHi
+ 12800 )/ 100 ;
50 * low
= ((* low
- 128 )* fuzzLo
+ 12800 )/ 100 ;
55 // pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType
56 // returns 1 if passed
57 uint8_t parityTest ( uint32_t bits
, uint8_t bitLen
, uint8_t pType
)
60 for ( uint8_t i
= 0 ; i
< bitLen
; i
++){
61 ans
^= (( bits
>> i
) & 1 );
63 //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType);
64 return ( ans
== pType
);
68 // takes a array of binary values, start position, length of bits per parity (includes parity bit),
69 // Parity Type (1 for odd; 0 for even; 2 for Always 1's; 3 for Always 0's), and binary Length (length to run)
70 size_t removeParity ( uint8_t * BitStream
, size_t startIdx
, uint8_t pLen
, uint8_t pType
, size_t bLen
)
72 uint32_t parityWd
= 0 ;
73 size_t j
= 0 , bitCnt
= 0 ;
74 for ( int word
= 0 ; word
< ( bLen
); word
+= pLen
){
75 for ( int bit
= 0 ; bit
< pLen
; bit
++){
76 parityWd
= ( parityWd
<< 1 ) | BitStream
[ startIdx
+ word
+ bit
];
77 BitStream
[ j
++] = ( BitStream
[ startIdx
+ word
+ bit
]);
79 j
--; // overwrite parity with next data
80 // if parity fails then return 0
82 case 3 : if ( BitStream
[ j
]== 1 ) { return 0 ; } break ; //should be 0 spacer bit
83 case 2 : if ( BitStream
[ j
]== 0 ) { return 0 ; } break ; //should be 1 spacer bit
84 default : if ( parityTest ( parityWd
, pLen
, pType
) == 0 ) { return 0 ; } break ; //test parity
89 // if we got here then all the parities passed
90 //return ID start index and size
95 // takes a array of binary values, length of bits per parity (includes parity bit),
96 // Parity Type (1 for odd; 0 for even; 2 Always 1's; 3 Always 0's), and binary Length (length to run)
97 // Make sure *dest is long enough to store original sourceLen + #_of_parities_to_be_added
98 size_t addParity ( uint8_t * BitSource
, uint8_t * dest
, uint8_t sourceLen
, uint8_t pLen
, uint8_t pType
)
100 uint32_t parityWd
= 0 ;
101 size_t j
= 0 , bitCnt
= 0 ;
102 for ( int word
= 0 ; word
< sourceLen
; word
+= pLen
- 1 ) {
103 for ( int bit
= 0 ; bit
< pLen
- 1 ; bit
++){
104 parityWd
= ( parityWd
<< 1 ) | BitSource
[ word
+ bit
];
105 dest
[ j
++] = ( BitSource
[ word
+ bit
]);
108 // if parity fails then return 0
110 case 3 : dest
[ j
++]= 0 ; break ; // marker bit which should be a 0
111 case 2 : dest
[ j
++]= 1 ; break ; // marker bit which should be a 1
113 dest
[ j
++] = parityTest ( parityWd
, pLen
- 1 , pType
) ^ 1 ;
119 // if we got here then all the parities passed
120 //return ID start index and size
124 uint32_t bytebits_to_byte ( uint8_t * src
, size_t numbits
)
127 for ( int i
= 0 ; i
< numbits
; i
++) {
128 num
= ( num
<< 1 ) | (* src
);
134 //least significant bit first
135 uint32_t bytebits_to_byteLSBF ( uint8_t * src
, size_t numbits
)
138 for ( int i
= 0 ; i
< numbits
; i
++) {
139 num
= ( num
<< 1 ) | *( src
+ ( numbits
-( i
+ 1 )));
145 //search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length
146 uint8_t preambleSearch ( uint8_t * BitStream
, uint8_t * preamble
, size_t pLen
, size_t * size
, size_t * startIdx
)
148 // Sanity check. If preamble length is bigger than bitstream length.
149 if ( * size
<= pLen
) return 0 ;
151 uint8_t foundCnt
= 0 ;
152 for ( int idx
= 0 ; idx
< * size
- pLen
; idx
++){
153 if ( memcmp ( BitStream
+ idx
, preamble
, pLen
) == 0 ){
160 * size
= idx
- * startIdx
;
169 //takes 1s and 0s and searches for EM410x format - output EM ID
170 int Em410xDecode ( uint8_t * BitStream
, size_t * size
, size_t * startIdx
, uint32_t * hi
, uint64_t * lo
)
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
176 if ( BitStream
[ 1 ]> 1 ) return - 1 ; //allow only 1s and 0s
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 };
182 uint32_t parityBits
= 0 ;
186 errChk
= preambleSearch ( BitStream
, preamble
, sizeof ( preamble
), size
, startIdx
);
187 if ( errChk
== 0 ) return - 4 ;
188 if (* size
< 64 ) return - 3 ;
189 if (* size
> 64 ) FmtLen
= 22 ;
190 * startIdx
+= 1 ; //get rid of 0 from preamble
192 for ( i
= 0 ; i
< FmtLen
; i
++){ //loop through 10 or 22 sets of 5 bits (50-10p = 40 bits or 88 bits)
193 parityBits
= bytebits_to_byte ( BitStream
+( i
* 5 )+ idx
, 5 );
194 //check even parity - quit if failed
195 if ( parityTest ( parityBits
, 5 , 0 ) == 0 ) return - 5 ;
196 //set uint64 with ID from BitStream
197 for ( uint8_t ii
= 0 ; ii
< 4 ; ii
++){
198 * hi
= (* hi
<< 1 ) | (* lo
>> 63 );
199 * lo
= (* lo
<< 1 ) | ( BitStream
[( i
* 5 )+ ii
+ idx
]);
202 if ( errChk
!= 0 ) return 1 ;
203 //skip last 5 bit parity test for simplicity.
209 //demodulates strong heavily clipped samples
210 int cleanAskRawDemod ( uint8_t * BinStream
, size_t * size
, int clk
, int invert
, int high
, int low
)
212 size_t bitCnt
= 0 , smplCnt
= 0 , errCnt
= 0 ;
213 uint8_t waveHigh
= 0 ;
214 for ( size_t i
= 0 ; i
< * size
; i
++){
215 if ( BinStream
[ i
] >= high
&& waveHigh
){
217 } else if ( BinStream
[ i
] <= low
&& ! waveHigh
){
219 } else { //transition
220 if (( BinStream
[ i
] >= high
&& ! waveHigh
) || ( BinStream
[ i
] <= low
&& waveHigh
)){
221 if ( smplCnt
> clk
-( clk
/ 4 )- 1 ) { //full clock
222 if ( smplCnt
> clk
+ ( clk
/ 4 )+ 1 ) { //too many samples
224 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Modulation Error at: %u" , i
);
225 BinStream
[ bitCnt
++]= 7 ;
226 } else if ( waveHigh
) {
227 BinStream
[ bitCnt
++] = invert
;
228 BinStream
[ bitCnt
++] = invert
;
229 } else if (! waveHigh
) {
230 BinStream
[ bitCnt
++] = invert
^ 1 ;
231 BinStream
[ bitCnt
++] = invert
^ 1 ;
235 } else if ( smplCnt
> ( clk
/ 2 ) - ( clk
/ 4 )- 1 ) {
237 BinStream
[ bitCnt
++] = invert
;
238 } else if (! waveHigh
) {
239 BinStream
[ bitCnt
++] = invert
^ 1 ;
243 } else if (! bitCnt
) {
245 waveHigh
= ( BinStream
[ i
] >= high
);
249 //transition bit oops
251 } else { //haven't hit new high or new low yet
261 void askAmp ( uint8_t * BitStream
, size_t size
)
264 for ( size_t i
= 1 ; i
< size
; ++ i
){
265 if ( BitStream
[ i
]- BitStream
[ i
- 1 ] >= 30 ) //large jump up
267 else if ( BitStream
[ i
- 1 ] - BitStream
[ i
] >= 20 ) //large jump down
275 //attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester
276 int askdemod ( uint8_t * BinStream
, size_t * size
, int * clk
, int * invert
, int maxErr
, uint8_t amp
, uint8_t askType
)
278 if (* size
== 0 ) return - 1 ;
279 int start
= DetectASKClock ( BinStream
, * size
, clk
, maxErr
); //clock default
280 if (* clk
== 0 || start
< 0 ) return - 3 ;
281 if (* invert
!= 1 ) * invert
= 0 ;
282 if ( amp
== 1 ) askAmp ( BinStream
, * size
);
283 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: clk %d, beststart %d" , * clk
, start
);
285 uint8_t initLoopMax
= 255 ;
286 if ( initLoopMax
> * size
) initLoopMax
= * size
;
287 // Detect high and lows
288 //25% clip in case highs and lows aren't clipped [marshmellow]
290 if ( getHiLo ( BinStream
, initLoopMax
, & high
, & low
, 75 , 75 ) < 1 )
291 return - 2 ; //just noise
294 // if clean clipped waves detected run alternate demod
295 if ( DetectCleanAskWave ( BinStream
, * size
, high
, low
)) {
296 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Clean Wave Detected - using clean wave demod" );
297 errCnt
= cleanAskRawDemod ( BinStream
, size
, * clk
, * invert
, high
, low
);
298 if ( askType
) //askman
299 return manrawdecode ( BinStream
, size
, 0 );
303 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Weak Wave Detected - using weak wave demod" );
305 int lastBit
; //set first clock check - can go negative
306 size_t i
, bitnum
= 0 ; //output counter
308 uint8_t tol
= 0 ; //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave
309 if (* clk
<= 32 ) tol
= 1 ; //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely
310 size_t MaxBits
= 3072 ; //max bits to collect
311 lastBit
= start
- * clk
;
313 for ( i
= start
; i
< * size
; ++ i
) {
314 if ( i
- lastBit
>= * clk
- tol
){
315 if ( BinStream
[ i
] >= high
) {
316 BinStream
[ bitnum
++] = * invert
;
317 } else if ( BinStream
[ i
] <= low
) {
318 BinStream
[ bitnum
++] = * invert
^ 1 ;
319 } else if ( i
- lastBit
>= * clk
+ tol
) {
321 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Modulation Error at: %u" , i
);
322 BinStream
[ bitnum
++]= 7 ;
325 } else { //in tolerance - looking for peak
330 } else if ( i
- lastBit
>= (* clk
/ 2 - tol
) && ! midBit
&& ! askType
){
331 if ( BinStream
[ i
] >= high
) {
332 BinStream
[ bitnum
++] = * invert
;
333 } else if ( BinStream
[ i
] <= low
) {
334 BinStream
[ bitnum
++] = * invert
^ 1 ;
335 } else if ( i
- lastBit
>= * clk
/ 2 + tol
) {
336 BinStream
[ bitnum
] = BinStream
[ bitnum
- 1 ];
338 } else { //in tolerance - looking for peak
343 if ( bitnum
>= MaxBits
) break ;
350 //take 10 and 01 and manchester decode
351 //run through 2 times and take least errCnt
352 int manrawdecode ( uint8_t * BitStream
, size_t * size
, uint8_t invert
)
354 uint16_t bitnum
= 0 , MaxBits
= 512 , errCnt
= 0 ;
356 uint16_t bestErr
= 1000 , bestRun
= 0 ;
357 if (* size
< 16 ) return - 1 ;
358 //find correct start position [alignment]
359 for ( ii
= 0 ; ii
< 2 ;++ ii
){
360 for ( i
= ii
; i
<* size
- 3 ; i
+= 2 )
361 if ( BitStream
[ i
]== BitStream
[ i
+ 1 ])
371 for ( i
= bestRun
; i
< * size
- 3 ; i
+= 2 ){
372 if ( BitStream
[ i
] == 1 && ( BitStream
[ i
+ 1 ] == 0 )){
373 BitStream
[ bitnum
++]= invert
;
374 } else if (( BitStream
[ i
] == 0 ) && BitStream
[ i
+ 1 ] == 1 ){
375 BitStream
[ bitnum
++]= invert
^ 1 ;
377 BitStream
[ bitnum
++]= 7 ;
379 if ( bitnum
> MaxBits
) break ;
385 uint32_t manchesterEncode2Bytes ( uint16_t datain
) {
388 for ( uint8_t i
= 0 ; i
< 16 ; i
++) {
389 curBit
= ( datain
>> ( 15 - i
) & 1 );
390 output
|= ( 1 <<((( 15 - i
)* 2 )+ curBit
));
396 //encode binary data into binary manchester
397 int ManchesterEncode ( uint8_t * BitStream
, size_t size
)
399 size_t modIdx
= 20000 , i
= 0 ;
400 if ( size
> modIdx
) return - 1 ;
401 for ( size_t idx
= 0 ; idx
< size
; idx
++){
402 BitStream
[ idx
+ modIdx
++] = BitStream
[ idx
];
403 BitStream
[ idx
+ modIdx
++] = BitStream
[ idx
]^ 1 ;
405 for (; i
<( size
* 2 ); i
++){
406 BitStream
[ i
] = BitStream
[ i
+ 20000 ];
412 //take 01 or 10 = 1 and 11 or 00 = 0
413 //check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010
414 //decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding
415 int BiphaseRawDecode ( uint8_t * BitStream
, size_t * size
, int offset
, int invert
)
420 uint16_t MaxBits
= 512 ;
421 //if not enough samples - error
422 if (* size
< 51 ) return - 1 ;
423 //check for phase change faults - skip one sample if faulty
424 uint8_t offsetA
= 1 , offsetB
= 1 ;
426 if ( BitStream
[ i
+ 1 ]== BitStream
[ i
+ 2 ]) offsetA
= 0 ;
427 if ( BitStream
[ i
+ 2 ]== BitStream
[ i
+ 3 ]) offsetB
= 0 ;
429 if (! offsetA
&& offsetB
) offset
++;
430 for ( i
= offset
; i
<* size
- 3 ; i
+= 2 ){
431 //check for phase error
432 if ( BitStream
[ i
+ 1 ]== BitStream
[ i
+ 2 ]) {
433 BitStream
[ bitnum
++]= 7 ;
436 if (( BitStream
[ i
]== 1 && BitStream
[ i
+ 1 ]== 0 ) || ( BitStream
[ i
]== 0 && BitStream
[ i
+ 1 ]== 1 )){
437 BitStream
[ bitnum
++]= 1 ^ invert
;
438 } else if (( BitStream
[ i
]== 0 && BitStream
[ i
+ 1 ]== 0 ) || ( BitStream
[ i
]== 1 && BitStream
[ i
+ 1 ]== 1 )){
439 BitStream
[ bitnum
++]= invert
;
441 BitStream
[ bitnum
++]= 7 ;
444 if ( bitnum
> MaxBits
) break ;
451 // demod gProxIIDemod
452 // error returns as -x
453 // success returns start position in BitStream
454 // BitStream must contain previously askrawdemod and biphasedemoded data
455 int gProxII_Demod ( uint8_t BitStream
[], size_t * size
)
458 uint8_t preamble
[] = { 1 , 1 , 1 , 1 , 1 , 0 };
460 uint8_t errChk
= preambleSearch ( BitStream
, preamble
, sizeof ( preamble
), size
, & startIdx
);
461 if ( errChk
== 0 ) return - 3 ; //preamble not found
462 if (* size
!= 96 ) return - 2 ; //should have found 96 bits
463 //check first 6 spacer bits to verify format
464 if (! BitStream
[ startIdx
+ 5 ] && ! BitStream
[ startIdx
+ 10 ] && ! BitStream
[ startIdx
+ 15 ] && ! BitStream
[ startIdx
+ 20 ] && ! BitStream
[ startIdx
+ 25 ] && ! BitStream
[ startIdx
+ 30 ]){
465 //confirmed proper separator bits found
466 //return start position
467 return ( int ) startIdx
;
469 return - 5 ; //spacer bits not found - not a valid gproxII
472 //translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq])
473 size_t fsk_wave_demod ( uint8_t * dest
, size_t size
, uint8_t fchigh
, uint8_t fclow
)
475 size_t last_transition
= 0 ;
478 if ( fchigh
== 0 ) fchigh
= 10 ;
479 if ( fclow
== 0 ) fclow
= 8 ;
480 //set the threshold close to 0 (graph) or 128 std to avoid static
481 uint8_t threshold_value
= 123 ;
482 size_t preLastSample
= 0 ;
483 size_t LastSample
= 0 ;
484 size_t currSample
= 0 ;
485 // sync to first lo-hi transition, and threshold
487 // Need to threshold first sample
488 // skip 160 samples to allow antenna/samples to settle
489 if ( dest
[ 160 ] < threshold_value
) dest
[ 0 ] = 0 ;
493 // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
494 // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere
495 // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
496 // (could also be fc/5 && fc/7 for fsk1 = 4-9)
497 for ( idx
= 161 ; idx
< size
- 20 ; idx
++) {
498 // threshold current value
500 if ( dest
[ idx
] < threshold_value
) dest
[ idx
] = 0 ;
503 // Check for 0->1 transition
504 if ( dest
[ idx
- 1 ] < dest
[ idx
]) {
505 preLastSample
= LastSample
;
506 LastSample
= currSample
;
507 currSample
= idx
- last_transition
;
508 if ( currSample
< ( fclow
- 2 )){ //0-5 = garbage noise (or 0-3)
509 //do nothing with extra garbage
510 } else if ( currSample
< ( fchigh
- 1 )) { //6-8 = 8 sample waves (or 3-6 = 5)
511 //correct previous 9 wave surrounded by 8 waves (or 6 surrounded by 5)
512 if ( LastSample
> ( fchigh
- 2 ) && ( preLastSample
< ( fchigh
- 1 ) || preLastSample
== 0 )){
517 } else if ( currSample
> ( fchigh
) && ! numBits
) { //12 + and first bit = unusable garbage
518 //do nothing with beginning garbage
519 } else if ( currSample
== ( fclow
+ 1 ) && LastSample
== ( fclow
- 1 )) { // had a 7 then a 9 should be two 8's (or 4 then a 6 should be two 5's)
521 } else { //9+ = 10 sample waves (or 6+ = 7)
524 last_transition
= idx
;
527 return numBits
; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
530 //translate 11111100000 to 10
531 //rfLen = clock, fchigh = larger field clock, fclow = smaller field clock
532 size_t aggregate_bits ( uint8_t * dest
, size_t size
, uint8_t rfLen
,
533 uint8_t invert
, uint8_t fchigh
, uint8_t fclow
)
535 uint8_t lastval
= dest
[ 0 ];
539 for ( idx
= 1 ; idx
< size
; idx
++) {
541 if ( dest
[ idx
]== lastval
) continue ;
543 //find out how many bits (n) we collected
544 //if lastval was 1, we have a 1->0 crossing
545 if ( dest
[ idx
- 1 ]== 1 ) {
546 n
= ( n
* fclow
+ rfLen
/ 2 ) / rfLen
;
547 } else { // 0->1 crossing
548 n
= ( n
* fchigh
+ rfLen
/ 2 ) / rfLen
;
552 //add to our destination the bits we collected
553 memset ( dest
+ numBits
, dest
[ idx
- 1 ]^ invert
, n
);
558 // if valid extra bits at the end were all the same frequency - add them in
559 if ( n
> rfLen
/ fchigh
) {
560 if ( dest
[ idx
- 2 ]== 1 ) {
561 n
= ( n
* fclow
+ rfLen
/ 2 ) / rfLen
;
563 n
= ( n
* fchigh
+ rfLen
/ 2 ) / rfLen
;
565 memset ( dest
+ numBits
, dest
[ idx
- 1 ]^ invert
, n
);
571 //by marshmellow (from holiman's base)
572 // full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod)
573 int fskdemod ( uint8_t * dest
, size_t size
, uint8_t rfLen
, uint8_t invert
, uint8_t fchigh
, uint8_t fclow
)
576 size
= fsk_wave_demod ( dest
, size
, fchigh
, fclow
);
577 size
= aggregate_bits ( dest
, size
, rfLen
, invert
, fchigh
, fclow
);
581 // loop to get raw HID waveform then FSK demodulate the TAG ID from it
582 int HIDdemodFSK ( uint8_t * dest
, size_t * size
, uint32_t * hi2
, uint32_t * hi
, uint32_t * lo
)
584 if ( justNoise ( dest
, * size
)) return - 1 ;
586 size_t numStart
= 0 , size2
= * size
, startIdx
= 0 ;
588 * size
= fskdemod ( dest
, size2
, 50 , 1 , 10 , 8 ); //fsk2a
589 if (* size
< 96 * 2 ) return - 2 ;
590 // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
591 uint8_t preamble
[] = { 0 , 0 , 0 , 1 , 1 , 1 , 0 , 1 };
592 // find bitstring in array
593 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
594 if ( errChk
== 0 ) return - 3 ; //preamble not found
596 numStart
= startIdx
+ sizeof ( preamble
);
597 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
598 for ( size_t idx
= numStart
; ( idx
- numStart
) < * size
- sizeof ( preamble
); idx
+= 2 ){
599 if ( dest
[ idx
] == dest
[ idx
+ 1 ]){
600 return - 4 ; //not manchester data
602 * hi2
= (* hi2
<< 1 )|(* hi
>> 31 );
603 * hi
= (* hi
<< 1 )|(* lo
>> 31 );
604 //Then, shift in a 0 or one into low
605 if ( dest
[ idx
] && ! dest
[ idx
+ 1 ]) // 1 0
610 return ( int ) startIdx
;
613 // loop to get raw paradox waveform then FSK demodulate the TAG ID from it
614 int ParadoxdemodFSK ( uint8_t * dest
, size_t * size
, uint32_t * hi2
, uint32_t * hi
, uint32_t * lo
)
616 if ( justNoise ( dest
, * size
)) return - 1 ;
618 size_t numStart
= 0 , size2
= * size
, startIdx
= 0 ;
620 * size
= fskdemod ( dest
, size2
, 50 , 1 , 10 , 8 ); //fsk2a
621 if (* size
< 96 ) return - 2 ;
623 // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
624 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 1 , 1 , 1 , 1 };
626 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
627 if ( errChk
== 0 ) return - 3 ; //preamble not found
629 numStart
= startIdx
+ sizeof ( preamble
);
630 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
631 for ( size_t idx
= numStart
; ( idx
- numStart
) < * size
- sizeof ( preamble
); idx
+= 2 ){
632 if ( dest
[ idx
] == dest
[ idx
+ 1 ])
633 return - 4 ; //not manchester data
634 * hi2
= (* hi2
<< 1 )|(* hi
>> 31 );
635 * hi
= (* hi
<< 1 )|(* lo
>> 31 );
636 //Then, shift in a 0 or one into low
637 if ( dest
[ idx
] && ! dest
[ idx
+ 1 ]) // 1 0
642 return ( int ) startIdx
;
645 int IOdemodFSK ( uint8_t * dest
, size_t size
)
647 if ( justNoise ( dest
, size
)) return - 1 ;
648 //make sure buffer has data
649 if ( size
< 66 * 64 ) return - 2 ;
651 size
= fskdemod ( dest
, size
, 64 , 1 , 10 , 8 ); // FSK2a RF/64
652 if ( size
< 65 ) return - 3 ; //did we get a good demod?
654 //0 10 20 30 40 50 60
656 //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
657 //-----------------------------------------------------------------------------
658 //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
660 //XSF(version)facility:codeone+codetwo
663 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
664 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), & size
, & startIdx
);
665 if ( errChk
== 0 ) return - 4 ; //preamble not found
667 if (! dest
[ startIdx
+ 8 ] && dest
[ startIdx
+ 17 ]== 1 && dest
[ startIdx
+ 26 ]== 1 && dest
[ startIdx
+ 35 ]== 1 && dest
[ startIdx
+ 44 ]== 1 && dest
[ startIdx
+ 53 ]== 1 ){
668 //confirmed proper separator bits found
669 //return start position
670 return ( int ) startIdx
;
676 // find viking preamble 0xF200 in already demoded data
677 int VikingDemod_AM ( uint8_t * dest
, size_t * size
) {
678 //make sure buffer has data
679 if (* size
< 64 * 2 ) return - 2 ;
682 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 };
683 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
684 if ( errChk
== 0 ) return - 4 ; //preamble not found
685 uint32_t checkCalc
= bytebits_to_byte ( dest
+ startIdx
, 8 ) ^
686 bytebits_to_byte ( dest
+ startIdx
+ 8 , 8 ) ^
687 bytebits_to_byte ( dest
+ startIdx
+ 16 , 8 ) ^
688 bytebits_to_byte ( dest
+ startIdx
+ 24 , 8 ) ^
689 bytebits_to_byte ( dest
+ startIdx
+ 32 , 8 ) ^
690 bytebits_to_byte ( dest
+ startIdx
+ 40 , 8 ) ^
691 bytebits_to_byte ( dest
+ startIdx
+ 48 , 8 ) ^
692 bytebits_to_byte ( dest
+ startIdx
+ 56 , 8 );
693 if ( checkCalc
!= 0xA8 ) return - 5 ;
694 if (* size
!= 64 ) return - 6 ;
695 //return start position
696 return ( int ) startIdx
;
700 // find Visa2000 preamble in already demoded data
701 int Visa2kDemod_AM ( uint8_t * dest
, size_t * size
) {
702 if (* size
< 96 * 2 ) return - 1 ; //make sure buffer has data
704 uint8_t preamble
[] = { 0 , 1 , 0 , 1 , 0 , 1 , 1 , 0 , 0 , 1 , 0 , 0 , 1 , 0 , 0 , 1 , 0 , 1 , 0 , 1 , 0 , 0 , 1 , 1 , 0 , 0 , 1 , 1 , 0 , 0 , 1 , 0 };
705 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
706 if ( errChk
== 0 ) return - 2 ; //preamble not found
707 if (* size
!= 96 ) return - 3 ; //wrong demoded size
708 //return start position
709 return ( int ) startIdx
;
712 // find Noralsy preamble in already demoded data
713 int NoralsyDemod_AM ( uint8_t * dest
, size_t * size
) {
714 if (* size
< 96 * 2 ) return - 1 ; //make sure buffer has data
716 uint8_t preamble
[] = { 1 , 0 , 1 , 1 , 1 , 0 , 1 , 1 , 0 , 0 , 0 , 0 };
717 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
718 if ( errChk
== 0 ) return - 2 ; //preamble not found
719 if (* size
!= 96 ) return - 3 ; //wrong demoded size
720 //return start position
721 return ( int ) startIdx
;
723 // find presco preamble 0x10D in already demoded data
724 int PrescoDemod ( uint8_t * dest
, size_t * size
) {
725 if (* size
< 128 * 2 ) return - 1 ; //make sure buffer has data
727 uint8_t preamble
[] = { 0 , 0 , 0 , 1 , 0 , 0 , 0 , 0 , 1 , 1 , 0 , 1 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
728 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
729 if ( errChk
== 0 ) return - 2 ; //preamble not found
730 if (* size
!= 128 ) return - 3 ; //wrong demoded size
731 //return start position
732 return ( int ) startIdx
;
735 // Ask/Biphase Demod then try to locate an ISO 11784/85 ID
736 // BitStream must contain previously askrawdemod and biphasedemoded data
737 int FDXBdemodBI ( uint8_t * dest
, size_t * size
)
739 //make sure buffer has enough data
740 if (* size
< 128 ) return - 1 ;
743 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
745 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
746 if ( errChk
== 0 ) return - 2 ; //preamble not found
747 return ( int ) startIdx
;
750 // ASK/Diphase fc/64 (inverted Biphase)
751 // Note: this i s not a demod, this is only a detection
752 // the parameter *dest needs to be demoded before call
753 int JablotronDemod ( uint8_t * dest
, size_t * size
){
754 //make sure buffer has enough data
755 if (* size
< 64 ) return - 1 ;
758 // 0xFFFF preamble, 64bits
759 uint8_t preamble
[] = {
767 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
768 if ( errChk
== 0 ) return - 4 ; //preamble not found
769 if (* size
!= 64 ) return - 3 ;
771 uint8_t checkchksum
= 0 ;
772 for ( int i
= 16 ; i
< 56 ; i
+= 8 ) {
773 checkchksum
+= bytebits_to_byte ( dest
+ startIdx
+ i
, 8 );
777 uint8_t crc
= bytebits_to_byte ( dest
+ startIdx
+ 56 , 8 );
779 if ( checkchksum
!= crc
) return - 5 ;
780 return ( int ) startIdx
;
784 // FSK Demod then try to locate an AWID ID
785 int AWIDdemodFSK ( uint8_t * dest
, size_t * size
)
787 //make sure buffer has enough data
788 if (* size
< 96 * 50 ) return - 1 ;
790 if ( justNoise ( dest
, * size
)) return - 2 ;
793 * size
= fskdemod ( dest
, * size
, 50 , 1 , 10 , 8 ); // fsk2a RF/50
794 if (* size
< 96 ) return - 3 ; //did we get a good demod?
796 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
798 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
799 if ( errChk
== 0 ) return - 4 ; //preamble not found
800 if (* size
!= 96 ) return - 5 ;
801 return ( int ) startIdx
;
805 // FSK Demod then try to locate a Farpointe Data (pyramid) ID
806 int PyramiddemodFSK ( uint8_t * dest
, size_t * size
)
808 //make sure buffer has data
809 if (* size
< 128 * 50 ) return - 5 ;
811 //test samples are not just noise
812 if ( justNoise ( dest
, * size
)) return - 1 ;
815 * size
= fskdemod ( dest
, * size
, 50 , 1 , 10 , 8 ); // fsk2a RF/50
816 if (* size
< 128 ) return - 2 ; //did we get a good demod?
818 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
820 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
821 if ( errChk
== 0 ) return - 4 ; //preamble not found
822 if (* size
!= 128 ) return - 3 ;
823 return ( int ) startIdx
;
826 // find nedap preamble in already demoded data
827 int NedapDemod ( uint8_t * dest
, size_t * size
) {
828 //make sure buffer has data
829 if (* size
< 128 ) return - 3 ;
832 //uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,0,0,0,1};
833 uint8_t preamble
[] = { 1 , 1 , 1 , 1 , 1 , 1 , 1 , 1 , 1 , 0 };
834 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
835 if ( errChk
== 0 ) return - 4 ; //preamble not found
836 return ( int ) startIdx
;
840 // to detect a wave that has heavily clipped (clean) samples
841 uint8_t DetectCleanAskWave ( uint8_t dest
[], size_t size
, uint8_t high
, uint8_t low
)
843 bool allArePeaks
= true ;
845 size_t loopEnd
= 512 + 160 ;
846 if ( loopEnd
> size
) loopEnd
= size
;
847 for ( size_t i
= 160 ; i
< loopEnd
; i
++){
848 if ( dest
[ i
]> low
&& dest
[ i
]< high
)
854 if ( cntPeaks
> 300 ) return true ;
859 // to help detect clocks on heavily clipped samples
860 // based on count of low to low
861 int DetectStrongAskClock ( uint8_t dest
[], size_t size
, uint8_t high
, uint8_t low
)
863 uint8_t fndClk
[] = { 8 , 16 , 32 , 40 , 50 , 64 , 128 };
867 // get to first full low to prime loop and skip incomplete first pulse
868 while (( dest
[ i
] < high
) && ( i
< size
))
870 while (( dest
[ i
] > low
) && ( i
< size
))
873 // loop through all samples
875 // measure from low to low
876 while (( dest
[ i
] > low
) && ( i
< size
))
879 while (( dest
[ i
] < high
) && ( i
< size
))
881 while (( dest
[ i
] > low
) && ( i
< size
))
883 //get minimum measured distance
884 if ( i
- startwave
< minClk
&& i
< size
)
885 minClk
= i
- startwave
;
888 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: detectstrongASKclk smallest wave: %d" , minClk
);
889 for ( uint8_t clkCnt
= 0 ; clkCnt
< 7 ; clkCnt
++) {
890 if ( minClk
>= fndClk
[ clkCnt
]-( fndClk
[ clkCnt
]/ 8 ) && minClk
<= fndClk
[ clkCnt
]+ 1 )
891 return fndClk
[ clkCnt
];
897 // not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)
898 // maybe somehow adjust peak trimming value based on samples to fix?
899 // return start index of best starting position for that clock and return clock (by reference)
900 int DetectASKClock ( uint8_t dest
[], size_t size
, int * clock
, int maxErr
)
903 uint8_t clk
[] = { 255 , 8 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 255 };
905 uint8_t loopCnt
= 255 ; //don't need to loop through entire array...
906 if ( size
<= loopCnt
+ 60 ) return - 1 ; //not enough samples
907 size
-= 60 ; //sometimes there is a strange end wave - filter out this....
908 //if we already have a valid clock
911 if ( clk
[ i
] == * clock
) clockFnd
= i
;
912 //clock found but continue to find best startpos
914 //get high and low peak
916 if ( getHiLo ( dest
, loopCnt
, & peak
, & low
, 75 , 75 ) < 1 ) return - 1 ;
918 //test for large clean peaks
920 if ( DetectCleanAskWave ( dest
, size
, peak
, low
)== 1 ){
921 int ans
= DetectStrongAskClock ( dest
, size
, peak
, low
);
922 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: detectaskclk Clean Ask Wave Detected: clk %d" , ans
);
923 for ( i
= clkEnd
- 1 ; i
> 0 ; i
--){
927 return 0 ; // for strong waves i don't use the 'best start position' yet...
928 //break; //clock found but continue to find best startpos [not yet]
934 uint8_t clkCnt
, tol
= 0 ;
935 uint16_t bestErr
[]={ 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 };
936 uint8_t bestStart
[]={ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
938 size_t arrLoc
, loopEnd
;
946 //test each valid clock from smallest to greatest to see which lines up
947 for (; clkCnt
< clkEnd
; clkCnt
++){
948 if ( clk
[ clkCnt
] <= 32 ){
953 //if no errors allowed - keep start within the first clock
954 if (! maxErr
&& size
> clk
[ clkCnt
]* 2 + tol
&& clk
[ clkCnt
]< 128 ) loopCnt
= clk
[ clkCnt
]* 2 ;
955 bestErr
[ clkCnt
]= 1000 ;
956 //try lining up the peaks by moving starting point (try first few clocks)
957 for ( ii
= 0 ; ii
< loopCnt
; ii
++){
958 if ( dest
[ ii
] < peak
&& dest
[ ii
] > low
) continue ;
961 // now that we have the first one lined up test rest of wave array
962 loopEnd
= (( size
- ii
- tol
) / clk
[ clkCnt
]) - 1 ;
963 for ( i
= 0 ; i
< loopEnd
; ++ i
){
964 arrLoc
= ii
+ ( i
* clk
[ clkCnt
]);
965 if ( dest
[ arrLoc
] >= peak
|| dest
[ arrLoc
] <= low
){
966 } else if ( dest
[ arrLoc
- tol
] >= peak
|| dest
[ arrLoc
- tol
] <= low
){
967 } else if ( dest
[ arrLoc
+ tol
] >= peak
|| dest
[ arrLoc
+ tol
] <= low
){
968 } else { //error no peak detected
972 //if we found no errors then we can stop here and a low clock (common clocks)
973 // this is correct one - return this clock
974 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: clk %d, err %d, startpos %d, endpos %d" , clk
[ clkCnt
], errCnt
, ii
, i
);
975 if ( errCnt
== 0 && clkCnt
< 7 ) {
976 if (! clockFnd
) * clock
= clk
[ clkCnt
];
979 //if we found errors see if it is lowest so far and save it as best run
980 if ( errCnt
< bestErr
[ clkCnt
]){
981 bestErr
[ clkCnt
]= errCnt
;
982 bestStart
[ clkCnt
]= ii
;
988 for ( iii
= 1 ; iii
< clkEnd
; ++ iii
){
989 if ( bestErr
[ iii
] < bestErr
[ best
]){
990 if ( bestErr
[ iii
] == 0 ) bestErr
[ iii
]= 1 ;
991 // current best bit to error ratio vs new bit to error ratio
992 if ( ( size
/ clk
[ best
])/ bestErr
[ best
] < ( size
/ clk
[ iii
])/ bestErr
[ iii
] ){
996 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
]);
998 if (! clockFnd
) * clock
= clk
[ best
];
999 return bestStart
[ best
];
1003 //detect psk clock by reading each phase shift
1004 // a phase shift is determined by measuring the sample length of each wave
1005 int DetectPSKClock ( uint8_t dest
[], size_t size
, int clock
)
1007 uint8_t clk
[]={ 255 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 255 }; //255 is not a valid clock
1008 uint16_t loopCnt
= 4096 ; //don't need to loop through entire array...
1009 if ( size
== 0 ) return 0 ;
1010 if ( size
< loopCnt
) loopCnt
= size
- 20 ;
1012 //if we already have a valid clock quit
1015 if ( clk
[ i
] == clock
) return clock
;
1017 size_t waveStart
= 0 , waveEnd
= 0 , firstFullWave
= 0 , lastClkBit
= 0 ;
1018 uint8_t clkCnt
, fc
= 0 , fullWaveLen
= 0 , tol
= 1 ;
1019 uint16_t peakcnt
= 0 , errCnt
= 0 , waveLenCnt
= 0 ;
1020 uint16_t bestErr
[]={ 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 };
1021 uint16_t peaksdet
[]={ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1022 fc
= countFC ( dest
, size
, 0 );
1023 if ( fc
!= 2 && fc
!= 4 && fc
!= 8 ) return - 1 ;
1024 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: FC: %d" , fc
);
1026 //find first full wave
1027 for ( i
= 160 ; i
< loopCnt
; i
++){
1028 if ( dest
[ i
] < dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
1029 if ( waveStart
== 0 ) {
1031 //prnt("DEBUG: waveStart: %d",waveStart);
1034 //prnt("DEBUG: waveEnd: %d",waveEnd);
1035 waveLenCnt
= waveEnd
- waveStart
;
1036 if ( waveLenCnt
> fc
){
1037 firstFullWave
= waveStart
;
1038 fullWaveLen
= waveLenCnt
;
1045 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: firstFullWave: %d, waveLen: %d" , firstFullWave
, fullWaveLen
);
1047 //test each valid clock from greatest to smallest to see which lines up
1048 for ( clkCnt
= 7 ; clkCnt
>= 1 ; clkCnt
--){
1049 lastClkBit
= firstFullWave
; //set end of wave as clock align
1053 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: clk: %d, lastClkBit: %d" , clk
[ clkCnt
], lastClkBit
);
1055 for ( i
= firstFullWave
+ fullWaveLen
- 1 ; i
< loopCnt
- 2 ; i
++){
1056 //top edge of wave = start of new wave
1057 if ( dest
[ i
] < dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
1058 if ( waveStart
== 0 ) {
1063 waveLenCnt
= waveEnd
- waveStart
;
1064 if ( waveLenCnt
> fc
){
1065 //if this wave is a phase shift
1066 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
);
1067 if ( i
+ 1 >= lastClkBit
+ clk
[ clkCnt
] - tol
){ //should be a clock bit
1069 lastClkBit
+= clk
[ clkCnt
];
1070 } else if ( i
< lastClkBit
+ 8 ){
1071 //noise after a phase shift - ignore
1072 } else { //phase shift before supposed to based on clock
1075 } else if ( i
+ 1 > lastClkBit
+ clk
[ clkCnt
] + tol
+ fc
){
1076 lastClkBit
+= clk
[ clkCnt
]; //no phase shift but clock bit
1085 if ( errCnt
<= bestErr
[ clkCnt
]) bestErr
[ clkCnt
]= errCnt
;
1086 if ( peakcnt
> peaksdet
[ clkCnt
]) peaksdet
[ clkCnt
]= peakcnt
;
1088 //all tested with errors
1089 //return the highest clk with the most peaks found
1091 for ( i
= 7 ; i
>= 1 ; i
--){
1092 if ( peaksdet
[ i
] > peaksdet
[ best
]) {
1095 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: Clk: %d, peaks: %d, errs: %d, bestClk: %d" , clk
[ i
], peaksdet
[ i
], bestErr
[ i
], clk
[ best
]);
1100 int DetectStrongNRZClk ( uint8_t * dest
, size_t size
, int peak
, int low
){
1101 //find shortest transition from high to low
1103 size_t transition1
= 0 ;
1104 int lowestTransition
= 255 ;
1105 bool lastWasHigh
= false ;
1107 //find first valid beginning of a high or low wave
1108 while (( dest
[ i
] >= peak
|| dest
[ i
] <= low
) && ( i
< size
))
1110 while (( dest
[ i
] < peak
&& dest
[ i
] > low
) && ( i
< size
))
1112 lastWasHigh
= ( dest
[ i
] >= peak
);
1114 if ( i
== size
) return 0 ;
1117 for (; i
< size
; i
++) {
1118 if (( dest
[ i
] >= peak
&& ! lastWasHigh
) || ( dest
[ i
] <= low
&& lastWasHigh
)) {
1119 lastWasHigh
= ( dest
[ i
] >= peak
);
1120 if ( i
- transition1
< lowestTransition
) lowestTransition
= i
- transition1
;
1124 if ( lowestTransition
== 255 ) lowestTransition
= 0 ;
1125 if ( g_debugMode
== 2 ) prnt ( "DEBUG NRZ: detectstrongNRZclk smallest wave: %d" , lowestTransition
);
1126 return lowestTransition
;
1130 //detect nrz clock by reading #peaks vs no peaks(or errors)
1131 int DetectNRZClock ( uint8_t dest
[], size_t size
, int clock
)
1134 uint8_t clk
[]={ 8 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 255 };
1135 size_t loopCnt
= 4096 ; //don't need to loop through entire array...
1136 if ( size
== 0 ) return 0 ;
1137 if ( size
< loopCnt
) loopCnt
= size
- 20 ;
1138 //if we already have a valid clock quit
1140 if ( clk
[ i
] == clock
) return clock
;
1142 //get high and low peak
1144 if ( getHiLo ( dest
, loopCnt
, & peak
, & low
, 75 , 75 ) < 1 ) return 0 ;
1146 int lowestTransition
= DetectStrongNRZClk ( dest
, size
- 20 , peak
, low
);
1150 uint16_t smplCnt
= 0 ;
1151 int16_t peakcnt
= 0 ;
1152 int16_t peaksdet
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1153 uint16_t maxPeak
= 255 ;
1154 bool firstpeak
= false ;
1155 //test for large clipped waves
1156 for ( i
= 0 ; i
< loopCnt
; i
++){
1157 if ( dest
[ i
] >= peak
|| dest
[ i
] <= low
){
1158 if (! firstpeak
) continue ;
1163 if ( maxPeak
> smplCnt
){
1165 //prnt("maxPk: %d",maxPeak);
1168 //prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt);
1173 bool errBitHigh
= 0 ;
1175 uint8_t ignoreCnt
= 0 ;
1176 uint8_t ignoreWindow
= 4 ;
1177 bool lastPeakHigh
= 0 ;
1180 //test each valid clock from smallest to greatest to see which lines up
1181 for ( clkCnt
= 0 ; clkCnt
< 8 ; ++ clkCnt
){
1182 //ignore clocks smaller than smallest peak
1183 if ( clk
[ clkCnt
] < maxPeak
- ( clk
[ clkCnt
]/ 4 )) continue ;
1184 //try lining up the peaks by moving starting point (try first 256)
1185 for ( ii
= 20 ; ii
< loopCnt
; ++ ii
){
1186 if (( dest
[ ii
] >= peak
) || ( dest
[ ii
] <= low
)){
1190 lastBit
= ii
- clk
[ clkCnt
];
1191 //loop through to see if this start location works
1192 for ( i
= ii
; i
< size
- 20 ; ++ i
) {
1193 //if we are at a clock bit
1194 if (( i
>= lastBit
+ clk
[ clkCnt
] - tol
) && ( i
<= lastBit
+ clk
[ clkCnt
] + tol
)) {
1196 if ( dest
[ i
] >= peak
|| dest
[ i
] <= low
) {
1197 //if same peak don't count it
1198 if (( dest
[ i
] >= peak
&& ! lastPeakHigh
) || ( dest
[ i
] <= low
&& lastPeakHigh
)) {
1201 lastPeakHigh
= ( dest
[ i
] >= peak
);
1204 ignoreCnt
= ignoreWindow
;
1205 lastBit
+= clk
[ clkCnt
];
1206 } else if ( i
== lastBit
+ clk
[ clkCnt
] + tol
) {
1207 lastBit
+= clk
[ clkCnt
];
1209 //else if not a clock bit and no peaks
1210 } else if ( dest
[ i
] < peak
&& dest
[ i
] > low
){
1213 if ( errBitHigh
== true ) peakcnt
--;
1218 // else if not a clock bit but we have a peak
1219 } else if (( dest
[ i
]>= peak
|| dest
[ i
]<= low
) && (! bitHigh
)) {
1220 //error bar found no clock...
1224 if ( peakcnt
> peaksdet
[ clkCnt
]) {
1225 peaksdet
[ clkCnt
]= peakcnt
;
1232 for ( iii
= 7 ; iii
> 0 ; iii
--){
1233 if (( peaksdet
[ iii
] >= ( peaksdet
[ best
]- 1 )) && ( peaksdet
[ iii
] <= peaksdet
[ best
]+ 1 ) && lowestTransition
) {
1234 if ( clk
[ iii
] > ( lowestTransition
- ( clk
[ iii
]/ 8 )) && clk
[ iii
] < ( lowestTransition
+ ( clk
[ iii
]/ 8 ))) {
1237 } else if ( peaksdet
[ iii
] > peaksdet
[ best
]){
1240 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
);
1247 // convert psk1 demod to psk2 demod
1248 // only transition waves are 1s
1249 void psk1TOpsk2 ( uint8_t * BitStream
, size_t size
)
1252 uint8_t lastBit
= BitStream
[ 0 ];
1253 for (; i
< size
; i
++){
1254 if ( BitStream
[ i
]== 7 ){
1256 } else if ( lastBit
!= BitStream
[ i
]){
1257 lastBit
= BitStream
[ i
];
1267 // convert psk2 demod to psk1 demod
1268 // from only transition waves are 1s to phase shifts change bit
1269 void psk2TOpsk1 ( uint8_t * BitStream
, size_t size
)
1272 for ( size_t i
= 0 ; i
< size
; i
++){
1273 if ( BitStream
[ i
]== 1 ){
1281 // redesigned by marshmellow adjusted from existing decode functions
1282 // indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
1283 int indala26decode ( uint8_t * bitStream
, size_t * size
, uint8_t * invert
)
1285 //26 bit 40134 format (don't know other formats)
1286 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 };
1287 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 };
1288 size_t startidx
= 0 ;
1289 if (! preambleSearch ( bitStream
, preamble
, sizeof ( preamble
), size
, & startidx
)){
1290 // if didn't find preamble try again inverting
1291 if (! preambleSearch ( bitStream
, preamble_i
, sizeof ( preamble_i
), size
, & startidx
)) return - 1 ;
1294 if (* size
!= 64 && * size
!= 224 ) return - 2 ;
1296 for ( size_t i
= startidx
; i
< * size
; i
++)
1299 return ( int ) startidx
;
1302 // by marshmellow - demodulate NRZ wave - requires a read with strong signal
1303 // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
1304 int nrzRawDemod ( uint8_t * dest
, size_t * size
, int * clk
, int * invert
){
1305 if ( justNoise ( dest
, * size
)) return - 1 ;
1306 * clk
= DetectNRZClock ( dest
, * size
, * clk
);
1307 if (* clk
== 0 ) return - 2 ;
1308 size_t i
, gLen
= 4096 ;
1309 if ( gLen
>* size
) gLen
= * size
- 20 ;
1311 if ( getHiLo ( dest
, gLen
, & high
, & low
, 75 , 75 ) < 1 ) return - 3 ; //25% fuzz on high 25% fuzz on low
1314 //convert wave samples to 1's and 0's
1315 for ( i
= 20 ; i
< * size
- 20 ; i
++){
1316 if ( dest
[ i
] >= high
) bit
= 1 ;
1317 if ( dest
[ i
] <= low
) bit
= 0 ;
1320 //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit)
1323 for ( i
= 21 ; i
< * size
- 20 ; i
++) {
1324 //if transition detected or large number of same bits - store the passed bits
1325 if ( dest
[ i
] != dest
[ i
- 1 ] || ( i
- lastBit
) == ( 10 * * clk
)) {
1326 memset ( dest
+ numBits
, dest
[ i
- 1 ] ^ * invert
, ( i
- lastBit
+ (* clk
/ 4 )) / * clk
);
1327 numBits
+= ( i
- lastBit
+ (* clk
/ 4 )) / * clk
;
1336 //detects the bit clock for FSK given the high and low Field Clocks
1337 uint8_t detectFSKClk ( uint8_t * BitStream
, size_t size
, uint8_t fcHigh
, uint8_t fcLow
)
1339 uint8_t clk
[] = { 8 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 0 };
1340 uint16_t rfLens
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1341 uint8_t rfCnts
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1342 uint8_t rfLensFnd
= 0 ;
1343 uint8_t lastFCcnt
= 0 ;
1344 uint16_t fcCounter
= 0 ;
1345 uint16_t rfCounter
= 0 ;
1346 uint8_t firstBitFnd
= 0 ;
1348 if ( size
== 0 ) return 0 ;
1350 uint8_t fcTol
= (( fcHigh
* 100 - fcLow
* 100 )/ 2 + 50 )/ 100 ; //(uint8_t)(0.5+(float)(fcHigh-fcLow)/2);
1355 //PrintAndLog("DEBUG: fcTol: %d",fcTol);
1356 // prime i to first peak / up transition
1357 for ( i
= 160 ; i
< size
- 20 ; i
++)
1358 if ( BitStream
[ i
] > BitStream
[ i
- 1 ] && BitStream
[ i
]>= BitStream
[ i
+ 1 ])
1361 for (; i
< size
- 20 ; i
++){
1365 if ( BitStream
[ i
] <= BitStream
[ i
- 1 ] || BitStream
[ i
] < BitStream
[ i
+ 1 ])
1368 // if we got less than the small fc + tolerance then set it to the small fc
1369 if ( fcCounter
< fcLow
+ fcTol
)
1371 else //set it to the large fc
1374 //look for bit clock (rf/xx)
1375 if (( fcCounter
< lastFCcnt
|| fcCounter
> lastFCcnt
)){
1376 //not the same size as the last wave - start of new bit sequence
1377 if ( firstBitFnd
> 1 ){ //skip first wave change - probably not a complete bit
1378 for ( int ii
= 0 ; ii
< 15 ; ii
++){
1379 if ( rfLens
[ ii
] >= ( rfCounter
- 4 ) && rfLens
[ ii
] <= ( rfCounter
+ 4 )){
1385 if ( rfCounter
> 0 && rfLensFnd
< 15 ){
1386 //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
1387 rfCnts
[ rfLensFnd
]++;
1388 rfLens
[ rfLensFnd
++] = rfCounter
;
1394 lastFCcnt
= fcCounter
;
1398 uint8_t rfHighest
= 15 , rfHighest2
= 15 , rfHighest3
= 15 ;
1400 for ( i
= 0 ; i
< 15 ; i
++){
1401 //get highest 2 RF values (might need to get more values to compare or compare all?)
1402 if ( rfCnts
[ i
]> rfCnts
[ rfHighest
]){
1403 rfHighest3
= rfHighest2
;
1404 rfHighest2
= rfHighest
;
1406 } else if ( rfCnts
[ i
]> rfCnts
[ rfHighest2
]){
1407 rfHighest3
= rfHighest2
;
1409 } else if ( rfCnts
[ i
]> rfCnts
[ rfHighest3
]){
1412 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: RF %d, cnts %d" , rfLens
[ i
], rfCnts
[ i
]);
1414 // set allowed clock remainder tolerance to be 1 large field clock length+1
1415 // we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off
1416 uint8_t tol1
= fcHigh
+ 1 ;
1418 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: most counted rf values: 1 %d, 2 %d, 3 %d" , rfLens
[ rfHighest
], rfLens
[ rfHighest2
], rfLens
[ rfHighest3
]);
1420 // loop to find the highest clock that has a remainder less than the tolerance
1421 // compare samples counted divided by
1422 // test 128 down to 32 (shouldn't be possible to have fc/10 & fc/8 and rf/16 or less)
1424 for (; ii
>= 2 ; ii
--){
1425 if ( rfLens
[ rfHighest
] % clk
[ ii
] < tol1
|| rfLens
[ rfHighest
] % clk
[ ii
] > clk
[ ii
]- tol1
){
1426 if ( rfLens
[ rfHighest2
] % clk
[ ii
] < tol1
|| rfLens
[ rfHighest2
] % clk
[ ii
] > clk
[ ii
]- tol1
){
1427 if ( rfLens
[ rfHighest3
] % clk
[ ii
] < tol1
|| rfLens
[ rfHighest3
] % clk
[ ii
] > clk
[ ii
]- tol1
){
1428 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: clk %d divides into the 3 most rf values within tolerance" , clk
[ ii
]);
1435 if ( ii
< 0 ) return 0 ; // oops we went too far
1441 //countFC is to detect the field clock lengths.
1442 //counts and returns the 2 most common wave lengths
1443 //mainly used for FSK field clock detection
1444 uint16_t countFC ( uint8_t * BitStream
, size_t size
, uint8_t fskAdj
)
1446 uint8_t fcLens
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1447 uint16_t fcCnts
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1448 uint8_t fcLensFnd
= 0 ;
1449 uint8_t lastFCcnt
= 0 ;
1450 uint8_t fcCounter
= 0 ;
1452 if ( size
== 0 ) return 0 ;
1454 // prime i to first up transition
1455 for ( i
= 160 ; i
< size
- 20 ; i
++)
1456 if ( BitStream
[ i
] > BitStream
[ i
- 1 ] && BitStream
[ i
] >= BitStream
[ i
+ 1 ])
1459 for (; i
< size
- 20 ; i
++){
1460 if ( BitStream
[ i
] > BitStream
[ i
- 1 ] && BitStream
[ i
] >= BitStream
[ i
+ 1 ]){
1461 // new up transition
1464 //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8)
1465 if ( lastFCcnt
== 5 && fcCounter
== 9 ) fcCounter
--;
1466 //if fc=9 or 4 add one (for when we get a fc 9 instead of 10 or a 4 instead of a 5)
1467 if (( fcCounter
== 9 ) || fcCounter
== 4 ) fcCounter
++;
1468 // save last field clock count (fc/xx)
1469 lastFCcnt
= fcCounter
;
1471 // find which fcLens to save it to:
1472 for ( int ii
= 0 ; ii
< 15 ; ii
++){
1473 if ( fcLens
[ ii
]== fcCounter
){
1479 if ( fcCounter
> 0 && fcLensFnd
< 15 ){
1481 fcCnts
[ fcLensFnd
]++;
1482 fcLens
[ fcLensFnd
++]= fcCounter
;
1491 uint8_t best1
= 14 , best2
= 14 , best3
= 14 ;
1493 // go through fclens and find which ones are bigest 2
1494 for ( i
= 0 ; i
< 15 ; i
++){
1495 // get the 3 best FC values
1496 if ( fcCnts
[ i
]> maxCnt1
) {
1501 } else if ( fcCnts
[ i
]> fcCnts
[ best2
]){
1504 } else if ( fcCnts
[ i
]> fcCnts
[ best3
]){
1507 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
]);
1509 if ( fcLens
[ best1
]== 0 ) return 0 ;
1510 uint8_t fcH
= 0 , fcL
= 0 ;
1511 if ( fcLens
[ best1
]> fcLens
[ best2
]){
1518 if (( size
- 180 )/ fcH
/ 3 > fcCnts
[ best1
]+ fcCnts
[ best2
]) {
1519 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
]);
1520 return 0 ; //lots of waves not psk or fsk
1522 // TODO: take top 3 answers and compare to known Field clocks to get top 2
1524 uint16_t fcs
= ((( uint16_t ) fcH
)<< 8 ) | fcL
;
1525 if ( fskAdj
) return fcs
;
1526 return fcLens
[ best1
];
1529 //by marshmellow - demodulate PSK1 wave
1530 //uses wave lengths (# Samples)
1531 int pskRawDemod ( uint8_t dest
[], size_t * size
, int * clock
, int * invert
)
1533 if ( size
== 0 ) return - 1 ;
1534 uint16_t loopCnt
= 4096 ; //don't need to loop through entire array...
1535 if (* size
< loopCnt
) loopCnt
= * size
;
1538 uint8_t curPhase
= * invert
;
1539 size_t i
, waveStart
= 1 , waveEnd
= 0 , firstFullWave
= 0 , lastClkBit
= 0 ;
1540 uint8_t fc
= 0 , fullWaveLen
= 0 , tol
= 1 ;
1541 uint16_t errCnt
= 0 , waveLenCnt
= 0 ;
1542 fc
= countFC ( dest
, * size
, 0 );
1543 if ( fc
!= 2 && fc
!= 4 && fc
!= 8 ) return - 1 ;
1544 //PrintAndLog("DEBUG: FC: %d",fc);
1545 * clock
= DetectPSKClock ( dest
, * size
, * clock
);
1546 if (* clock
== 0 ) return - 1 ;
1547 int avgWaveVal
= 0 , lastAvgWaveVal
= 0 ;
1548 //find first phase shift
1549 for ( i
= 0 ; i
< loopCnt
; i
++){
1550 if ( dest
[ i
]+ fc
< dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
1552 //PrintAndLog("DEBUG: waveEnd: %d",waveEnd);
1553 waveLenCnt
= waveEnd
- waveStart
;
1554 if ( waveLenCnt
> fc
&& waveStart
> fc
&& !( waveLenCnt
> fc
+ 2 )){ //not first peak and is a large wave but not out of whack
1555 lastAvgWaveVal
= avgWaveVal
/( waveLenCnt
);
1556 firstFullWave
= waveStart
;
1557 fullWaveLen
= waveLenCnt
;
1558 //if average wave value is > graph 0 then it is an up wave or a 1
1559 if ( lastAvgWaveVal
> 123 ) curPhase
^= 1 ; //fudge graph 0 a little 123 vs 128
1565 avgWaveVal
+= dest
[ i
+ 2 ];
1567 if ( firstFullWave
== 0 ) {
1568 // no phase shift detected - could be all 1's or 0's - doesn't matter where we start
1569 // so skip a little to ensure we are past any Start Signal
1570 firstFullWave
= 160 ;
1571 memset ( dest
, curPhase
, firstFullWave
/ * clock
);
1573 memset ( dest
, curPhase
^ 1 , firstFullWave
/ * clock
);
1576 numBits
+= ( firstFullWave
/ * clock
);
1577 //set start of wave as clock align
1578 lastClkBit
= firstFullWave
;
1579 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: firstFullWave: %u, waveLen: %u" , firstFullWave
, fullWaveLen
);
1580 if ( g_debugMode
== 2 ) prnt ( "DEBUG: clk: %d, lastClkBit: %u, fc: %u" , * clock
, lastClkBit
,( unsigned int ) fc
);
1582 dest
[ numBits
++] = curPhase
; //set first read bit
1583 for ( i
= firstFullWave
+ fullWaveLen
- 1 ; i
< * size
- 3 ; i
++){
1584 //top edge of wave = start of new wave
1585 if ( dest
[ i
]+ fc
< dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
1586 if ( waveStart
== 0 ) {
1589 avgWaveVal
= dest
[ i
+ 1 ];
1592 waveLenCnt
= waveEnd
- waveStart
;
1593 lastAvgWaveVal
= avgWaveVal
/ waveLenCnt
;
1594 if ( waveLenCnt
> fc
){
1595 //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);
1596 //this wave is a phase shift
1597 //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc);
1598 if ( i
+ 1 >= lastClkBit
+ * clock
- tol
){ //should be a clock bit
1600 dest
[ numBits
++] = curPhase
;
1601 lastClkBit
+= * clock
;
1602 } else if ( i
< lastClkBit
+ 10 + fc
){
1603 //noise after a phase shift - ignore
1604 } else { //phase shift before supposed to based on clock
1606 dest
[ numBits
++] = 7 ;
1608 } else if ( i
+ 1 > lastClkBit
+ * clock
+ tol
+ fc
){
1609 lastClkBit
+= * clock
; //no phase shift but clock bit
1610 dest
[ numBits
++] = curPhase
;
1616 avgWaveVal
+= dest
[ i
+ 1 ];
1623 //attempt to identify a Sequence Terminator in ASK modulated raw wave
1624 bool DetectST ( uint8_t buffer
[], size_t * size
, int * foundclock
) {
1625 size_t bufsize
= * size
;
1626 //need to loop through all samples and identify our clock, look for the ST pattern
1627 uint8_t fndClk
[] = { 8 , 16 , 32 , 40 , 50 , 64 , 128 };
1630 int i
, j
, skip
, start
, end
, low
, high
, minClk
, waveStart
;
1631 bool complete
= false ;
1632 int tmpbuff
[ bufsize
/ 64 ];
1633 int waveLen
[ bufsize
/ 64 ];
1634 size_t testsize
= ( bufsize
< 512 ) ? bufsize
: 512 ;
1637 memset ( tmpbuff
, 0 , sizeof ( tmpbuff
));
1639 if ( getHiLo ( buffer
, testsize
, & high
, & low
, 80 , 80 ) == - 1 ) {
1640 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: just noise detected - quitting" );
1641 return false ; //just noise
1646 // get to first full low to prime loop and skip incomplete first pulse
1647 while (( buffer
[ i
] < high
) && ( i
< bufsize
))
1649 while (( buffer
[ i
] > low
) && ( i
< bufsize
))
1653 // populate tmpbuff buffer with pulse lengths
1654 while ( i
< bufsize
) {
1655 // measure from low to low
1656 while (( buffer
[ i
] > low
) && ( i
< bufsize
))
1659 while (( buffer
[ i
] < high
) && ( i
< bufsize
))
1661 //first high point for this wave
1663 while (( buffer
[ i
] > low
) && ( i
< bufsize
))
1665 if ( j
>= ( bufsize
/ 64 )) {
1668 waveLen
[ j
] = i
- waveStart
; //first high to first low
1669 tmpbuff
[ j
++] = i
- start
;
1670 if ( i
- start
< minClk
&& i
< bufsize
) {
1674 // set clock - might be able to get this externally and remove this work...
1676 for ( uint8_t clkCnt
= 0 ; clkCnt
< 7 ; clkCnt
++) {
1677 tol
= fndClk
[ clkCnt
]/ 8 ;
1678 if ( minClk
>= fndClk
[ clkCnt
]- tol
&& minClk
<= fndClk
[ clkCnt
]+ 1 ) {
1683 // clock not found - ERROR
1685 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: clock not found - quitting" );
1692 // look for Sequence Terminator - should be pulses of clk*(1 or 1.5), clk*2, clk*(1.5 or 2)
1694 for ( i
= 0 ; i
< j
- 4 ; ++ i
) {
1696 if ( tmpbuff
[ i
] >= clk
* 1 - tol
&& tmpbuff
[ i
] <= ( clk
* 2 )+ tol
&& waveLen
[ i
] < clk
+ tol
) { //1 to 2 clocks depending on 2 bits prior
1697 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
1698 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
1699 if ( tmpbuff
[ i
+ 3 ] >= clk
* 1 - tol
&& tmpbuff
[ i
+ 3 ] <= clk
* 2 + tol
) { //1 to 2 clocks for end of ST + first bit
1707 // first ST not found - ERROR
1709 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: first STT not found - quitting" );
1712 if ( waveLen
[ i
+ 2 ] > clk
* 1 + tol
)
1717 // skip over the remainder of ST
1718 skip
+= clk
* 7 / 2 ; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point
1720 // now do it again to find the end
1722 for ( i
+= 3 ; i
< j
- 4 ; ++ i
) {
1724 if ( tmpbuff
[ i
] >= clk
* 1 - tol
&& tmpbuff
[ i
] <= ( clk
* 2 )+ tol
) { //1 to 2 clocks depending on 2 bits prior
1725 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
1726 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
1727 if ( tmpbuff
[ i
+ 3 ] >= clk
* 1 - tol
&& tmpbuff
[ i
+ 3 ] <= clk
* 2 + tol
) { //1 to 2 clocks for end of ST + first bit
1736 //didn't find second ST - ERROR
1738 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: second STT not found - quitting" );
1741 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
);
1742 //now begin to trim out ST so we can use normal demod cmds
1744 size_t datalen
= end
- start
;
1745 // check validity of datalen (should be even clock increments) - use a tolerance of up to 1/8th a clock
1746 if ( datalen
% clk
> clk
/ 8 ) {
1747 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting" , datalen
, clk
, datalen
% clk
);
1750 // padd the amount off - could be problematic... but shouldn't happen often
1751 datalen
+= datalen
% clk
;
1753 // if datalen is less than one t55xx block - ERROR
1754 if ( datalen
/ clk
< 8 * 4 ) {
1755 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: datalen is less than 1 full t55xx block - quitting" );
1758 size_t dataloc
= start
;
1761 // warning - overwriting buffer given with raw wave data with ST removed...
1762 while ( dataloc
< bufsize
-( clk
/ 2 ) ) {
1763 //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)
1764 if ( buffer
[ dataloc
]< high
&& buffer
[ dataloc
]> low
&& buffer
[ dataloc
+ 3 ]< high
&& buffer
[ dataloc
+ 3 ]> low
) {
1765 for ( i
= 0 ; i
< clk
/ 2 - tol
; ++ i
) {
1766 buffer
[ dataloc
+ i
] = high
+ 5 ;
1769 for ( i
= 0 ; i
< datalen
; ++ i
) {
1770 if ( i
+ newloc
< bufsize
) {
1771 if ( i
+ newloc
< dataloc
)
1772 buffer
[ i
+ newloc
] = buffer
[ dataloc
];
1778 //skip next ST - we just assume it will be there from now on...