]>
git.zerfleddert.de Git - proxmark3-svn/blob - common/lfdemod.c
125112088e09fc57b44768e0743bcb2b67a0c356
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 //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 uint8_t justNoise ( uint8_t * BitStream
, size_t size
)
30 static const uint8_t THRESHOLD
= 123 ;
31 //test samples are not just noise
32 uint8_t justNoise1
= 1 ;
33 for ( size_t idx
= 0 ; idx
< size
&& justNoise1
; idx
++){
34 justNoise1
= BitStream
[ idx
] < THRESHOLD
;
40 //get high and low values of a wave with passed in fuzz factor. also return noise test = 1 for passed or 0 for only noise
41 int getHiLo ( uint8_t * BitStream
, size_t size
, int * high
, int * low
, uint8_t fuzzHi
, uint8_t fuzzLo
)
45 // get high and low thresholds
46 for ( size_t i
= 0 ; i
< size
; i
++){
47 if ( BitStream
[ i
] > * high
) * high
= BitStream
[ i
];
48 if ( BitStream
[ i
] < * low
) * low
= BitStream
[ i
];
50 if (* high
< 123 ) return - 1 ; // just noise
51 * high
= ((* high
- 128 )* fuzzHi
+ 12800 )/ 100 ;
52 * low
= ((* low
- 128 )* fuzzLo
+ 12800 )/ 100 ;
57 // pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType
58 // returns 1 if passed
59 uint8_t parityTest ( uint32_t bits
, uint8_t bitLen
, uint8_t pType
)
62 for ( uint8_t i
= 0 ; i
< bitLen
; i
++){
63 ans
^= (( bits
>> i
) & 1 );
65 if ( g_debugMode
) prnt ( "DEBUG: ans: %d, ptype: %d, bits: %08X" , ans
, pType
, bits
);
66 return ( ans
== pType
);
70 // takes a array of binary values, start position, length of bits per parity (includes parity bit),
71 // Parity Type (1 for odd; 0 for even; 2 for Always 1's; 3 for Always 0's), and binary Length (length to run)
72 size_t removeParity ( uint8_t * BitStream
, size_t startIdx
, uint8_t pLen
, uint8_t pType
, size_t bLen
)
74 uint32_t parityWd
= 0 ;
75 size_t j
= 0 , bitCnt
= 0 ;
76 for ( int word
= 0 ; word
< ( bLen
); word
+= pLen
) {
77 for ( int bit
= 0 ; bit
< pLen
; bit
++) {
78 parityWd
= ( parityWd
<< 1 ) | BitStream
[ startIdx
+ word
+ bit
];
79 BitStream
[ j
++] = ( BitStream
[ startIdx
+ word
+ bit
]);
81 if ( word
+ pLen
> bLen
) break ;
83 j
--; // overwrite parity with next data
84 // if parity fails then return 0
86 case 3 : if ( BitStream
[ j
]== 1 ) { return 0 ;} break ; //should be 0 spacer bit
87 case 2 : if ( BitStream
[ j
]== 0 ) { return 0 ;} break ; //should be 1 spacer bit
88 default : if ( parityTest ( parityWd
, pLen
, pType
) == 0 ) { return 0 ;} break ; //test parity
93 // if we got here then all the parities passed
94 //return ID start index and size
99 // takes a array of binary values, length of bits per parity (includes parity bit),
100 // Parity Type (1 for odd; 0 for even; 2 Always 1's; 3 Always 0's), and binary Length (length to run)
101 // Make sure *dest is long enough to store original sourceLen + #_of_parities_to_be_added
102 size_t addParity ( uint8_t * BitSource
, uint8_t * dest
, uint8_t sourceLen
, uint8_t pLen
, uint8_t pType
)
104 uint32_t parityWd
= 0 ;
105 size_t j
= 0 , bitCnt
= 0 ;
106 for ( int word
= 0 ; word
< sourceLen
; word
+= pLen
- 1 ) {
107 for ( int bit
= 0 ; bit
< pLen
- 1 ; bit
++){
108 parityWd
= ( parityWd
<< 1 ) | BitSource
[ word
+ bit
];
109 dest
[ j
++] = ( BitSource
[ word
+ bit
]);
111 // if parity fails then return 0
113 case 3 : dest
[ j
++]= 0 ; break ; // marker bit which should be a 0
114 case 2 : dest
[ j
++]= 1 ; break ; // marker bit which should be a 1
116 dest
[ j
++] = parityTest ( parityWd
, pLen
- 1 , pType
) ^ 1 ;
122 // if we got here then all the parities passed
123 //return ID start index and size
127 uint32_t bytebits_to_byte ( uint8_t * src
, size_t numbits
)
130 for ( int i
= 0 ; i
< numbits
; i
++)
132 num
= ( num
<< 1 ) | (* src
);
138 //least significant bit first
139 uint32_t bytebits_to_byteLSBF ( uint8_t * src
, size_t numbits
)
142 for ( int i
= 0 ; i
< numbits
; i
++)
144 num
= ( num
<< 1 ) | *( src
+ ( numbits
-( i
+ 1 )));
150 //search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length
151 uint8_t preambleSearch ( uint8_t * BitStream
, uint8_t * preamble
, size_t pLen
, size_t * size
, size_t * startIdx
)
153 return ( preambleSearchEx ( BitStream
, preamble
, pLen
, size
, startIdx
, false )) ? 1 : 0 ;
156 // search for given preamble in given BitStream and return success=1 or fail=0 and startIndex (where it was found) and length if not fineone
157 // fineone does not look for a repeating preamble for em4x05/4x69 sends preamble once, so look for it once in the first pLen bits
158 bool preambleSearchEx ( uint8_t * BitStream
, uint8_t * preamble
, size_t pLen
, size_t * size
, size_t * startIdx
, bool findone
) {
159 // Sanity check. If preamble length is bigger than bitstream length.
160 if ( * size
<= pLen
) return false ;
162 uint8_t foundCnt
= 0 ;
163 for ( size_t idx
= 0 ; idx
< * size
- pLen
; idx
++) {
164 if ( memcmp ( BitStream
+ idx
, preamble
, pLen
) == 0 ) {
168 if ( g_debugMode
) prnt ( "DEBUG: preamble found at %u" , idx
);
170 if ( findone
) return true ;
171 } else if ( foundCnt
== 2 ) {
172 * size
= idx
- * startIdx
;
180 // find start of modulating data (for fsk and psk) in case of beginning noise or slow chip startup.
181 size_t findModStart ( uint8_t dest
[], size_t size
, uint8_t threshold_value
, uint8_t expWaveSize
) {
183 size_t waveSizeCnt
= 0 ;
184 uint8_t thresholdCnt
= 0 ;
185 bool isAboveThreshold
= dest
[ i
++] >= threshold_value
;
186 for (; i
< size
- 20 ; i
++ ) {
187 if ( dest
[ i
] < threshold_value
&& isAboveThreshold
) {
189 if ( thresholdCnt
> 2 && waveSizeCnt
< expWaveSize
+ 1 ) break ;
190 isAboveThreshold
= false ;
192 } else if ( dest
[ i
] >= threshold_value
&& ! isAboveThreshold
) {
194 if ( thresholdCnt
> 2 && waveSizeCnt
< expWaveSize
+ 1 ) break ;
195 isAboveThreshold
= true ;
200 if ( thresholdCnt
> 10 ) break ;
202 if ( g_debugMode
== 2 ) prnt ( "DEBUG: threshold Count reached at %u, count: %u" , i
, thresholdCnt
);
207 //takes 1s and 0s and searches for EM410x format - output EM ID
208 uint8_t Em410xDecode ( uint8_t * BitStream
, size_t * size
, size_t * startIdx
, uint32_t * hi
, uint64_t * lo
)
211 if (* size
< 64 ) return 0 ;
212 if ( BitStream
[ 1 ]> 1 ) return 0 ; //allow only 1s and 0s
214 // 111111111 bit pattern represent start of frame
215 // include 0 in front to help get start pos
216 uint8_t preamble
[] = { 0 , 1 , 1 , 1 , 1 , 1 , 1 , 1 , 1 , 1 };
218 uint8_t FmtLen
= 10 ; // sets of 4 bits = end data
220 errChk
= preambleSearch ( BitStream
, preamble
, sizeof ( preamble
), size
, startIdx
);
221 if ( errChk
== 0 || * size
< 64 ) return 0 ;
222 if (* size
== 110 ) FmtLen
= 22 ; // 22 sets of 4 bits
224 //skip last 4bit parity row for simplicity
225 * size
= removeParity ( BitStream
, * startIdx
+ sizeof ( preamble
), 5 , 0 , FmtLen
* 5 );
226 if (* size
== 40 ) { // std em410x format
228 * lo
= (( uint64_t )( bytebits_to_byte ( BitStream
, 8 )) << 32 ) | ( bytebits_to_byte ( BitStream
+ 8 , 32 ));
229 } else if (* size
== 88 ) { // long em format
230 * hi
= ( bytebits_to_byte ( BitStream
, 24 ));
231 * lo
= (( uint64_t )( bytebits_to_byte ( BitStream
+ 24 , 32 )) << 32 ) | ( bytebits_to_byte ( BitStream
+ 24 + 32 , 32 ));
239 //demodulates strong heavily clipped samples
240 int cleanAskRawDemod ( uint8_t * BinStream
, size_t * size
, int clk
, int invert
, int high
, int low
)
242 size_t bitCnt
= 0 , smplCnt
= 0 , errCnt
= 0 ;
243 uint8_t waveHigh
= 0 ;
244 for ( size_t i
= 0 ; i
< * size
; i
++){
245 if ( BinStream
[ i
] >= high
&& waveHigh
){
247 } else if ( BinStream
[ i
] <= low
&& ! waveHigh
){
249 } else { //transition
250 if (( BinStream
[ i
] >= high
&& ! waveHigh
) || ( BinStream
[ i
] <= low
&& waveHigh
)){
251 if ( smplCnt
> clk
-( clk
/ 4 )- 1 ) { //full clock
252 if ( smplCnt
> clk
+ ( clk
/ 4 )+ 1 ) { //too many samples
254 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Modulation Error at: %u" , i
);
255 BinStream
[ bitCnt
++]= 7 ;
256 } else if ( waveHigh
) {
257 BinStream
[ bitCnt
++] = invert
;
258 BinStream
[ bitCnt
++] = invert
;
259 } else if (! waveHigh
) {
260 BinStream
[ bitCnt
++] = invert
^ 1 ;
261 BinStream
[ bitCnt
++] = invert
^ 1 ;
265 } else if ( smplCnt
> ( clk
/ 2 ) - ( clk
/ 4 )- 1 ) {
267 BinStream
[ bitCnt
++] = invert
;
268 } else if (! waveHigh
) {
269 BinStream
[ bitCnt
++] = invert
^ 1 ;
273 } else if (! bitCnt
) {
275 waveHigh
= ( BinStream
[ i
] >= high
);
279 //transition bit oops
281 } else { //haven't hit new high or new low yet
291 //amplify based on ask edge detection
292 void askAmp ( uint8_t * BitStream
, size_t size
)
295 for ( size_t i
= 1 ; i
< size
; i
++){
296 if ( BitStream
[ i
]- BitStream
[ i
- 1 ]>= 30 ) //large jump up
298 else if ( BitStream
[ i
- 1 ]- BitStream
[ i
]>= 20 ) //large jump down
301 BitStream
[ i
- 1 ] = Last
;
307 //attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester
308 int askdemod ( uint8_t * BinStream
, size_t * size
, int * clk
, int * invert
, int maxErr
, uint8_t amp
, uint8_t askType
)
310 if (* size
== 0 ) return - 1 ;
311 int start
= DetectASKClock ( BinStream
, * size
, clk
, maxErr
); //clock default
312 if (* clk
== 0 || start
< 0 ) return - 3 ;
313 if (* invert
!= 1 ) * invert
= 0 ;
314 if ( amp
== 1 ) askAmp ( BinStream
, * size
);
315 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: clk %d, beststart %d, amp %d" , * clk
, start
, amp
);
317 uint8_t initLoopMax
= 255 ;
318 if ( initLoopMax
> * size
) initLoopMax
= * size
;
319 // Detect high and lows
320 //25% clip in case highs and lows aren't clipped [marshmellow]
322 if ( getHiLo ( BinStream
, initLoopMax
, & high
, & low
, 75 , 75 ) < 1 )
323 return - 2 ; //just noise
326 // if clean clipped waves detected run alternate demod
327 if ( DetectCleanAskWave ( BinStream
, * size
, high
, low
)) {
328 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Clean Wave Detected - using clean wave demod" );
329 errCnt
= cleanAskRawDemod ( BinStream
, size
, * clk
, * invert
, high
, low
);
330 if ( askType
) //askman
331 return manrawdecode ( BinStream
, size
, 0 );
335 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Weak Wave Detected - using weak wave demod" );
337 int lastBit
; //set first clock check - can go negative
338 size_t i
, bitnum
= 0 ; //output counter
340 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
341 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
342 size_t MaxBits
= 3072 ; //max bits to collect
343 lastBit
= start
- * clk
;
345 for ( i
= start
; i
< * size
; ++ i
) {
346 if ( i
- lastBit
>= * clk
- tol
){
347 if ( BinStream
[ i
] >= high
) {
348 BinStream
[ bitnum
++] = * invert
;
349 } else if ( BinStream
[ i
] <= low
) {
350 BinStream
[ bitnum
++] = * invert
^ 1 ;
351 } else if ( i
- lastBit
>= * clk
+ tol
) {
353 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Modulation Error at: %u" , i
);
354 BinStream
[ bitnum
++]= 7 ;
357 } else { //in tolerance - looking for peak
362 } else if ( i
- lastBit
>= (* clk
/ 2 - tol
) && ! midBit
&& ! askType
){
363 if ( BinStream
[ i
] >= high
) {
364 BinStream
[ bitnum
++] = * invert
;
365 } else if ( BinStream
[ i
] <= low
) {
366 BinStream
[ bitnum
++] = * invert
^ 1 ;
367 } else if ( i
- lastBit
>= * clk
/ 2 + tol
) {
368 BinStream
[ bitnum
] = BinStream
[ bitnum
- 1 ];
370 } else { //in tolerance - looking for peak
375 if ( bitnum
>= MaxBits
) break ;
382 //take 10 and 01 and manchester decode
383 //run through 2 times and take least errCnt
384 int manrawdecode ( uint8_t * BitStream
, size_t * size
, uint8_t invert
)
386 uint16_t bitnum
= 0 , MaxBits
= 512 , errCnt
= 0 ;
388 uint16_t bestErr
= 1000 , bestRun
= 0 ;
389 if (* size
< 16 ) return - 1 ;
390 //find correct start position [alignment]
391 for ( ii
= 0 ; ii
< 2 ;++ ii
){
392 for ( i
= ii
; i
<* size
- 3 ; i
+= 2 )
393 if ( BitStream
[ i
]== BitStream
[ i
+ 1 ])
403 for ( i
= bestRun
; i
< * size
- 3 ; i
+= 2 ){
404 if ( BitStream
[ i
] == 1 && ( BitStream
[ i
+ 1 ] == 0 )){
405 BitStream
[ bitnum
++]= invert
;
406 } else if (( BitStream
[ i
] == 0 ) && BitStream
[ i
+ 1 ] == 1 ){
407 BitStream
[ bitnum
++]= invert
^ 1 ;
409 BitStream
[ bitnum
++]= 7 ;
411 if ( bitnum
> MaxBits
) break ;
417 uint32_t manchesterEncode2Bytes ( uint16_t datain
) {
420 for ( uint8_t i
= 0 ; i
< 16 ; i
++) {
421 curBit
= ( datain
>> ( 15 - i
) & 1 );
422 output
|= ( 1 <<((( 15 - i
)* 2 )+ curBit
));
428 //encode binary data into binary manchester
429 int ManchesterEncode ( uint8_t * BitStream
, size_t size
)
431 size_t modIdx
= 20000 , i
= 0 ;
432 if ( size
> modIdx
) return - 1 ;
433 for ( size_t idx
= 0 ; idx
< size
; idx
++){
434 BitStream
[ idx
+ modIdx
++] = BitStream
[ idx
];
435 BitStream
[ idx
+ modIdx
++] = BitStream
[ idx
]^ 1 ;
437 for (; i
<( size
* 2 ); i
++){
438 BitStream
[ i
] = BitStream
[ i
+ 20000 ];
444 //take 01 or 10 = 1 and 11 or 00 = 0
445 //check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010
446 //decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding
447 int BiphaseRawDecode ( uint8_t * BitStream
, size_t * size
, int offset
, int invert
)
452 uint16_t MaxBits
= 512 ;
453 //if not enough samples - error
454 if (* size
< 51 ) return - 1 ;
455 //check for phase change faults - skip one sample if faulty
456 uint8_t offsetA
= 1 , offsetB
= 1 ;
458 if ( BitStream
[ i
+ 1 ]== BitStream
[ i
+ 2 ]) offsetA
= 0 ;
459 if ( BitStream
[ i
+ 2 ]== BitStream
[ i
+ 3 ]) offsetB
= 0 ;
461 if (! offsetA
&& offsetB
) offset
++;
462 for ( i
= offset
; i
<* size
- 3 ; i
+= 2 ){
463 //check for phase error
464 if ( BitStream
[ i
+ 1 ]== BitStream
[ i
+ 2 ]) {
465 BitStream
[ bitnum
++]= 7 ;
468 if (( BitStream
[ i
]== 1 && BitStream
[ i
+ 1 ]== 0 ) || ( BitStream
[ i
]== 0 && BitStream
[ i
+ 1 ]== 1 )){
469 BitStream
[ bitnum
++]= 1 ^ invert
;
470 } else if (( BitStream
[ i
]== 0 && BitStream
[ i
+ 1 ]== 0 ) || ( BitStream
[ i
]== 1 && BitStream
[ i
+ 1 ]== 1 )){
471 BitStream
[ bitnum
++]= invert
;
473 BitStream
[ bitnum
++]= 7 ;
476 if ( bitnum
> MaxBits
) break ;
483 // demod gProxIIDemod
484 // error returns as -x
485 // success returns start position in BitStream
486 // BitStream must contain previously askrawdemod and biphasedemoded data
487 int gProxII_Demod ( uint8_t BitStream
[], size_t * size
)
490 uint8_t preamble
[] = { 1 , 1 , 1 , 1 , 1 , 0 };
492 uint8_t errChk
= preambleSearch ( BitStream
, preamble
, sizeof ( preamble
), size
, & startIdx
);
493 if ( errChk
== 0 ) return - 3 ; //preamble not found
494 if (* size
!= 96 ) return - 2 ; //should have found 96 bits
495 //check first 6 spacer bits to verify format
496 if (! BitStream
[ startIdx
+ 5 ] && ! BitStream
[ startIdx
+ 10 ] && ! BitStream
[ startIdx
+ 15 ] && ! BitStream
[ startIdx
+ 20 ] && ! BitStream
[ startIdx
+ 25 ] && ! BitStream
[ startIdx
+ 30 ]){
497 //confirmed proper separator bits found
498 //return start position
499 return ( int ) startIdx
;
501 return - 5 ; //spacer bits not found - not a valid gproxII
504 //translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq])
505 size_t fsk_wave_demod ( uint8_t * dest
, size_t size
, uint8_t fchigh
, uint8_t fclow
)
507 size_t last_transition
= 0 ;
509 if ( fchigh
== 0 ) fchigh
= 10 ;
510 if ( fclow
== 0 ) fclow
= 8 ;
511 //set the threshold close to 0 (graph) or 128 std to avoid static
512 uint8_t threshold_value
= 123 ;
513 size_t preLastSample
= 0 ;
514 size_t LastSample
= 0 ;
515 size_t currSample
= 0 ;
516 if ( size
< 1024 ) return 0 ; // not enough samples
518 //find start of modulating data in trace
519 idx
= findModStart ( dest
, size
, threshold_value
, fchigh
);
521 // Need to threshold first sample
522 if ( dest
[ idx
] < threshold_value
) dest
[ 0 ] = 0 ;
527 // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
528 // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere
529 // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
530 // (could also be fc/5 && fc/7 for fsk1 = 4-9)
531 for (; idx
< size
- 20 ; idx
++) {
532 // threshold current value
534 if ( dest
[ idx
] < threshold_value
) dest
[ idx
] = 0 ;
537 // Check for 0->1 transition
538 if ( dest
[ idx
- 1 ] < dest
[ idx
]) {
539 preLastSample
= LastSample
;
540 LastSample
= currSample
;
541 currSample
= idx
- last_transition
;
542 if ( currSample
< ( fclow
- 2 )) { //0-5 = garbage noise (or 0-3)
543 //do nothing with extra garbage
544 } else if ( currSample
< ( fchigh
- 1 )) { //6-8 = 8 sample waves (or 3-6 = 5)
545 //correct previous 9 wave surrounded by 8 waves (or 6 surrounded by 5)
546 if ( LastSample
> ( fchigh
- 2 ) && ( preLastSample
< ( fchigh
- 1 ))){
551 } else if ( currSample
> ( fchigh
+ 1 ) && numBits
< 3 ) { //12 + and first two bit = unusable garbage
552 //do nothing with beginning garbage and reset.. should be rare..
554 } 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)
556 } else { //9+ = 10 sample waves (or 6+ = 7)
559 last_transition
= idx
;
562 return numBits
; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
565 //translate 11111100000 to 10
566 //rfLen = clock, fchigh = larger field clock, fclow = smaller field clock
567 size_t aggregate_bits ( uint8_t * dest
, size_t size
, uint8_t rfLen
,
568 uint8_t invert
, uint8_t fchigh
, uint8_t fclow
)
570 uint8_t lastval
= dest
[ 0 ];
574 for ( idx
= 1 ; idx
< size
; idx
++) {
576 if ( dest
[ idx
]== lastval
) continue ; //skip until we hit a transition
578 //find out how many bits (n) we collected
579 //if lastval was 1, we have a 1->0 crossing
580 if ( dest
[ idx
- 1 ]== 1 ) {
581 n
= ( n
* fclow
+ rfLen
/ 2 ) / rfLen
;
582 } else { // 0->1 crossing
583 n
= ( n
* fchigh
+ rfLen
/ 2 ) / rfLen
;
587 //add to our destination the bits we collected
588 memset ( dest
+ numBits
, dest
[ idx
- 1 ]^ invert
, n
);
593 // if valid extra bits at the end were all the same frequency - add them in
594 if ( n
> rfLen
/ fchigh
) {
595 if ( dest
[ idx
- 2 ]== 1 ) {
596 n
= ( n
* fclow
+ rfLen
/ 2 ) / rfLen
;
598 n
= ( n
* fchigh
+ rfLen
/ 2 ) / rfLen
;
600 memset ( dest
+ numBits
, dest
[ idx
- 1 ]^ invert
, n
);
606 //by marshmellow (from holiman's base)
607 // full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod)
608 int fskdemod ( uint8_t * dest
, size_t size
, uint8_t rfLen
, uint8_t invert
, uint8_t fchigh
, uint8_t fclow
)
611 size
= fsk_wave_demod ( dest
, size
, fchigh
, fclow
);
612 size
= aggregate_bits ( dest
, size
, rfLen
, invert
, fchigh
, fclow
);
616 // loop to get raw HID waveform then FSK demodulate the TAG ID from it
617 int HIDdemodFSK ( uint8_t * dest
, size_t * size
, uint32_t * hi2
, uint32_t * hi
, uint32_t * lo
)
619 if ( justNoise ( dest
, * size
)) return - 1 ;
621 size_t numStart
= 0 , size2
=* size
, startIdx
= 0 ;
623 * size
= fskdemod ( dest
, size2
, 50 , 1 , 10 , 8 ); //fsk2a
624 if (* size
< 96 * 2 ) return - 2 ;
625 // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
626 uint8_t preamble
[] = { 0 , 0 , 0 , 1 , 1 , 1 , 0 , 1 };
627 // find bitstring in array
628 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
629 if ( errChk
== 0 ) return - 3 ; //preamble not found
631 numStart
= startIdx
+ sizeof ( preamble
);
632 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
633 for ( size_t idx
= numStart
; ( idx
- numStart
) < * size
- sizeof ( preamble
); idx
+= 2 ){
634 if ( dest
[ idx
] == dest
[ idx
+ 1 ]){
635 return - 4 ; //not manchester data
637 * hi2
= (* hi2
<< 1 )|(* hi
>> 31 );
638 * hi
= (* hi
<< 1 )|(* lo
>> 31 );
639 //Then, shift in a 0 or one into low
640 if ( dest
[ idx
] && ! dest
[ idx
+ 1 ]) // 1 0
645 return ( int ) startIdx
;
648 // loop to get raw paradox waveform then FSK demodulate the TAG ID from it
649 int ParadoxdemodFSK ( uint8_t * dest
, size_t * size
, uint32_t * hi2
, uint32_t * hi
, uint32_t * lo
)
651 if ( justNoise ( dest
, * size
)) return - 1 ;
653 size_t numStart
= 0 , size2
=* size
, startIdx
= 0 ;
655 * size
= fskdemod ( dest
, size2
, 50 , 1 , 10 , 8 ); //fsk2a
656 if (* size
< 96 ) return - 2 ;
658 // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
659 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 1 , 1 , 1 , 1 };
661 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
662 if ( errChk
== 0 ) return - 3 ; //preamble not found
664 numStart
= startIdx
+ sizeof ( preamble
);
665 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
666 for ( size_t idx
= numStart
; ( idx
- numStart
) < * size
- sizeof ( preamble
); idx
+= 2 ){
667 if ( dest
[ idx
] == dest
[ idx
+ 1 ])
668 return - 4 ; //not manchester data
669 * hi2
= (* hi2
<< 1 )|(* hi
>> 31 );
670 * hi
= (* hi
<< 1 )|(* lo
>> 31 );
671 //Then, shift in a 0 or one into low
672 if ( dest
[ idx
] && ! dest
[ idx
+ 1 ]) // 1 0
677 return ( int ) startIdx
;
680 int IOdemodFSK ( uint8_t * dest
, size_t size
)
682 if ( justNoise ( dest
, size
)) return - 1 ;
683 //make sure buffer has data
684 if ( size
< 66 * 64 ) return - 2 ;
686 size
= fskdemod ( dest
, size
, 64 , 1 , 10 , 8 ); // FSK2a RF/64
687 if ( size
< 65 ) return - 3 ; //did we get a good demod?
689 //0 10 20 30 40 50 60
691 //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
692 //-----------------------------------------------------------------------------
693 //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
695 //XSF(version)facility:codeone+codetwo
698 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
699 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), & size
, & startIdx
);
700 if ( errChk
== 0 ) return - 4 ; //preamble not found
702 if (! dest
[ startIdx
+ 8 ] && dest
[ startIdx
+ 17 ]== 1 && dest
[ startIdx
+ 26 ]== 1 && dest
[ startIdx
+ 35 ]== 1 && dest
[ startIdx
+ 44 ]== 1 && dest
[ startIdx
+ 53 ]== 1 ){
703 //confirmed proper separator bits found
704 //return start position
705 return ( int ) startIdx
;
711 // find viking preamble 0xF200 in already demoded data
712 int VikingDemod_AM ( uint8_t * dest
, size_t * size
) {
713 //make sure buffer has data
714 if (* size
< 64 * 2 ) return - 2 ;
717 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 };
718 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
719 if ( errChk
== 0 ) return - 4 ; //preamble not found
720 uint32_t checkCalc
= bytebits_to_byte ( dest
+ startIdx
, 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 8 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 16 , 8 )
721 ^ bytebits_to_byte ( dest
+ startIdx
+ 24 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 32 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 40 , 8 )
722 ^ bytebits_to_byte ( dest
+ startIdx
+ 48 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 56 , 8 );
723 if ( checkCalc
!= 0xA8 ) return - 5 ;
724 if (* size
!= 64 ) return - 6 ;
725 //return start position
726 return ( int ) startIdx
;
729 // find presco preamble 0x10D in already demoded data
730 int PrescoDemod ( uint8_t * dest
, size_t * size
) {
731 //make sure buffer has data
732 if (* size
< 64 * 2 ) return - 2 ;
735 uint8_t preamble
[] = { 1 , 0 , 0 , 0 , 0 , 1 , 1 , 0 , 1 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
736 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
737 if ( errChk
== 0 ) return - 4 ; //preamble not found
738 //return start position
739 return ( int ) startIdx
;
742 // Ask/Biphase Demod then try to locate an ISO 11784/85 ID
743 // BitStream must contain previously askrawdemod and biphasedemoded data
744 int FDXBdemodBI ( uint8_t * dest
, size_t * size
)
746 //make sure buffer has enough data
747 if (* size
< 128 ) return - 1 ;
750 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
752 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
753 if ( errChk
== 0 ) return - 2 ; //preamble not found
754 return ( int ) startIdx
;
758 // FSK Demod then try to locate an AWID ID
759 int AWIDdemodFSK ( uint8_t * dest
, size_t * size
)
761 //make sure buffer has enough data
762 if (* size
< 96 * 50 ) return - 1 ;
764 if ( justNoise ( dest
, * size
)) return - 2 ;
767 * size
= fskdemod ( dest
, * size
, 50 , 1 , 10 , 8 ); // fsk2a RF/50
768 if (* size
< 96 ) return - 3 ; //did we get a good demod?
770 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
772 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
773 if ( errChk
== 0 ) return - 4 ; //preamble not found
774 if (* size
!= 96 ) return - 5 ;
775 return ( int ) startIdx
;
779 // FSK Demod then try to locate a Farpointe Data (pyramid) ID
780 int PyramiddemodFSK ( uint8_t * dest
, size_t * size
)
782 //make sure buffer has data
783 if (* size
< 128 * 50 ) return - 5 ;
785 //test samples are not just noise
786 if ( justNoise ( dest
, * size
)) return - 1 ;
789 * size
= fskdemod ( dest
, * size
, 50 , 1 , 10 , 8 ); // fsk2a RF/50
790 if (* size
< 128 ) return - 2 ; //did we get a good demod?
792 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
794 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
795 if ( errChk
== 0 ) return - 4 ; //preamble not found
796 if (* size
!= 128 ) return - 3 ;
797 return ( int ) startIdx
;
801 // to detect a wave that has heavily clipped (clean) samples
802 uint8_t DetectCleanAskWave ( uint8_t dest
[], size_t size
, uint8_t high
, uint8_t low
)
804 bool allArePeaks
= true ;
806 size_t loopEnd
= 512 + 160 ;
807 if ( loopEnd
> size
) loopEnd
= size
;
808 for ( size_t i
= 160 ; i
< loopEnd
; i
++){
809 if ( dest
[ i
]> low
&& dest
[ i
]< high
)
815 if ( cntPeaks
> 300 ) return true ;
820 // to help detect clocks on heavily clipped samples
821 // based on count of low to low
822 int DetectStrongAskClock ( uint8_t dest
[], size_t size
, uint8_t high
, uint8_t low
)
824 uint8_t fndClk
[] = { 8 , 16 , 32 , 40 , 50 , 64 , 128 };
828 // get to first full low to prime loop and skip incomplete first pulse
829 while (( dest
[ i
] < high
) && ( i
< size
))
831 while (( dest
[ i
] > low
) && ( i
< size
))
834 // loop through all samples
836 // measure from low to low
837 while (( dest
[ i
] > low
) && ( i
< size
))
840 while (( dest
[ i
] < high
) && ( i
< size
))
842 while (( dest
[ i
] > low
) && ( i
< size
))
844 //get minimum measured distance
845 if ( i
- startwave
< minClk
&& i
< size
)
846 minClk
= i
- startwave
;
849 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: detectstrongASKclk smallest wave: %d" , minClk
);
850 for ( uint8_t clkCnt
= 0 ; clkCnt
< 7 ; clkCnt
++) {
851 if ( minClk
>= fndClk
[ clkCnt
]-( fndClk
[ clkCnt
]/ 8 ) && minClk
<= fndClk
[ clkCnt
]+ 1 )
852 return fndClk
[ clkCnt
];
858 // not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)
859 // maybe somehow adjust peak trimming value based on samples to fix?
860 // return start index of best starting position for that clock and return clock (by reference)
861 int DetectASKClock ( uint8_t dest
[], size_t size
, int * clock
, int maxErr
)
864 uint8_t clk
[] = { 255 , 8 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 255 };
866 uint8_t loopCnt
= 255 ; //don't need to loop through entire array...
867 if ( size
<= loopCnt
+ 60 ) return - 1 ; //not enough samples
868 size
-= 60 ; //sometimes there is a strange end wave - filter out this....
869 //if we already have a valid clock
872 if ( clk
[ i
] == * clock
) clockFnd
= i
;
873 //clock found but continue to find best startpos
875 //get high and low peak
877 if ( getHiLo ( dest
, loopCnt
, & peak
, & low
, 75 , 75 ) < 1 ) return - 1 ;
879 //test for large clean peaks
881 if ( DetectCleanAskWave ( dest
, size
, peak
, low
)== 1 ){
882 int ans
= DetectStrongAskClock ( dest
, size
, peak
, low
);
883 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: detectaskclk Clean Ask Wave Detected: clk %d" , ans
);
884 for ( i
= clkEnd
- 1 ; i
> 0 ; i
--){
888 return 0 ; // for strong waves i don't use the 'best start position' yet...
889 //break; //clock found but continue to find best startpos [not yet]
895 uint8_t clkCnt
, tol
= 0 ;
896 uint16_t bestErr
[]={ 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 };
897 uint8_t bestStart
[]={ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
899 size_t arrLoc
, loopEnd
;
907 //test each valid clock from smallest to greatest to see which lines up
908 for (; clkCnt
< clkEnd
; clkCnt
++){
909 if ( clk
[ clkCnt
] <= 32 ){
914 //if no errors allowed - keep start within the first clock
915 if (! maxErr
&& size
> clk
[ clkCnt
]* 2 + tol
&& clk
[ clkCnt
]< 128 ) loopCnt
= clk
[ clkCnt
]* 2 ;
916 bestErr
[ clkCnt
]= 1000 ;
917 //try lining up the peaks by moving starting point (try first few clocks)
918 for ( ii
= 0 ; ii
< loopCnt
; ii
++){
919 if ( dest
[ ii
] < peak
&& dest
[ ii
] > low
) continue ;
922 // now that we have the first one lined up test rest of wave array
923 loopEnd
= (( size
- ii
- tol
) / clk
[ clkCnt
]) - 1 ;
924 for ( i
= 0 ; i
< loopEnd
; ++ i
){
925 arrLoc
= ii
+ ( i
* clk
[ clkCnt
]);
926 if ( dest
[ arrLoc
] >= peak
|| dest
[ arrLoc
] <= low
){
927 } else if ( dest
[ arrLoc
- tol
] >= peak
|| dest
[ arrLoc
- tol
] <= low
){
928 } else if ( dest
[ arrLoc
+ tol
] >= peak
|| dest
[ arrLoc
+ tol
] <= low
){
929 } else { //error no peak detected
933 //if we found no errors then we can stop here and a low clock (common clocks)
934 // this is correct one - return this clock
935 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: clk %d, err %d, startpos %d, endpos %d" , clk
[ clkCnt
], errCnt
, ii
, i
);
936 if ( errCnt
== 0 && clkCnt
< 7 ) {
937 if (! clockFnd
) * clock
= clk
[ clkCnt
];
940 //if we found errors see if it is lowest so far and save it as best run
941 if ( errCnt
< bestErr
[ clkCnt
]){
942 bestErr
[ clkCnt
]= errCnt
;
943 bestStart
[ clkCnt
]= ii
;
949 for ( iii
= 1 ; iii
< clkEnd
; ++ iii
){
950 if ( bestErr
[ iii
] < bestErr
[ best
]){
951 if ( bestErr
[ iii
] == 0 ) bestErr
[ iii
]= 1 ;
952 // current best bit to error ratio vs new bit to error ratio
953 if ( ( size
/ clk
[ best
])/ bestErr
[ best
] < ( size
/ clk
[ iii
])/ bestErr
[ iii
] ){
957 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
]);
959 if (! clockFnd
) * clock
= clk
[ best
];
960 return bestStart
[ best
];
964 //detect psk clock by reading each phase shift
965 // a phase shift is determined by measuring the sample length of each wave
966 int DetectPSKClock ( uint8_t dest
[], size_t size
, int clock
)
968 uint8_t clk
[]={ 255 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 255 }; //255 is not a valid clock
969 uint16_t loopCnt
= 4096 ; //don't need to loop through entire array...
970 if ( size
== 0 ) return 0 ;
971 if ( size
< loopCnt
) loopCnt
= size
- 20 ;
973 //if we already have a valid clock quit
976 if ( clk
[ i
] == clock
) return clock
;
978 size_t waveStart
= 0 , waveEnd
= 0 , firstFullWave
= 0 , lastClkBit
= 0 ;
979 uint8_t clkCnt
, fc
= 0 , fullWaveLen
= 0 , tol
= 1 ;
980 uint16_t peakcnt
= 0 , errCnt
= 0 , waveLenCnt
= 0 ;
981 uint16_t bestErr
[]={ 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 };
982 uint16_t peaksdet
[]={ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
983 fc
= countFC ( dest
, size
, 0 );
984 if ( fc
!= 2 && fc
!= 4 && fc
!= 8 ) return - 1 ;
985 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: FC: %d" , fc
);
987 //find first full wave
988 for ( i
= 160 ; i
< loopCnt
; i
++){
989 if ( dest
[ i
] < dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
990 if ( waveStart
== 0 ) {
992 //prnt("DEBUG: waveStart: %d",waveStart);
995 //prnt("DEBUG: waveEnd: %d",waveEnd);
996 waveLenCnt
= waveEnd
- waveStart
;
997 if ( waveLenCnt
> fc
){
998 firstFullWave
= waveStart
;
999 fullWaveLen
= waveLenCnt
;
1006 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: firstFullWave: %d, waveLen: %d" , firstFullWave
, fullWaveLen
);
1008 //test each valid clock from greatest to smallest to see which lines up
1009 for ( clkCnt
= 7 ; clkCnt
>= 1 ; clkCnt
--){
1010 lastClkBit
= firstFullWave
; //set end of wave as clock align
1014 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: clk: %d, lastClkBit: %d" , clk
[ clkCnt
], lastClkBit
);
1016 for ( i
= firstFullWave
+ fullWaveLen
- 1 ; i
< loopCnt
- 2 ; i
++){
1017 //top edge of wave = start of new wave
1018 if ( dest
[ i
] < dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
1019 if ( waveStart
== 0 ) {
1024 waveLenCnt
= waveEnd
- waveStart
;
1025 if ( waveLenCnt
> fc
){
1026 //if this wave is a phase shift
1027 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
);
1028 if ( i
+ 1 >= lastClkBit
+ clk
[ clkCnt
] - tol
){ //should be a clock bit
1030 lastClkBit
+= clk
[ clkCnt
];
1031 } else if ( i
< lastClkBit
+ 8 ){
1032 //noise after a phase shift - ignore
1033 } else { //phase shift before supposed to based on clock
1036 } else if ( i
+ 1 > lastClkBit
+ clk
[ clkCnt
] + tol
+ fc
){
1037 lastClkBit
+= clk
[ clkCnt
]; //no phase shift but clock bit
1046 if ( errCnt
<= bestErr
[ clkCnt
]) bestErr
[ clkCnt
]= errCnt
;
1047 if ( peakcnt
> peaksdet
[ clkCnt
]) peaksdet
[ clkCnt
]= peakcnt
;
1049 //all tested with errors
1050 //return the highest clk with the most peaks found
1052 for ( i
= 7 ; i
>= 1 ; i
--){
1053 if ( peaksdet
[ i
] > peaksdet
[ best
]) {
1056 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: Clk: %d, peaks: %d, errs: %d, bestClk: %d" , clk
[ i
], peaksdet
[ i
], bestErr
[ i
], clk
[ best
]);
1061 int DetectStrongNRZClk ( uint8_t * dest
, size_t size
, int peak
, int low
){
1062 //find shortest transition from high to low
1064 size_t transition1
= 0 ;
1065 int lowestTransition
= 255 ;
1066 bool lastWasHigh
= false ;
1068 //find first valid beginning of a high or low wave
1069 while (( dest
[ i
] >= peak
|| dest
[ i
] <= low
) && ( i
< size
))
1071 while (( dest
[ i
] < peak
&& dest
[ i
] > low
) && ( i
< size
))
1073 lastWasHigh
= ( dest
[ i
] >= peak
);
1075 if ( i
== size
) return 0 ;
1078 for (; i
< size
; i
++) {
1079 if (( dest
[ i
] >= peak
&& ! lastWasHigh
) || ( dest
[ i
] <= low
&& lastWasHigh
)) {
1080 lastWasHigh
= ( dest
[ i
] >= peak
);
1081 if ( i
- transition1
< lowestTransition
) lowestTransition
= i
- transition1
;
1085 if ( lowestTransition
== 255 ) lowestTransition
= 0 ;
1086 if ( g_debugMode
== 2 ) prnt ( "DEBUG NRZ: detectstrongNRZclk smallest wave: %d" , lowestTransition
);
1087 return lowestTransition
;
1091 //detect nrz clock by reading #peaks vs no peaks(or errors)
1092 int DetectNRZClock ( uint8_t dest
[], size_t size
, int clock
)
1095 uint8_t clk
[]={ 8 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 255 };
1096 size_t loopCnt
= 4096 ; //don't need to loop through entire array...
1097 if ( size
== 0 ) return 0 ;
1098 if ( size
< loopCnt
) loopCnt
= size
- 20 ;
1099 //if we already have a valid clock quit
1101 if ( clk
[ i
] == clock
) return clock
;
1103 //get high and low peak
1105 if ( getHiLo ( dest
, loopCnt
, & peak
, & low
, 75 , 75 ) < 1 ) return 0 ;
1107 int lowestTransition
= DetectStrongNRZClk ( dest
, size
- 20 , peak
, low
);
1111 uint16_t smplCnt
= 0 ;
1112 int16_t peakcnt
= 0 ;
1113 int16_t peaksdet
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1114 uint16_t maxPeak
= 255 ;
1115 bool firstpeak
= false ;
1116 //test for large clipped waves
1117 for ( i
= 0 ; i
< loopCnt
; i
++){
1118 if ( dest
[ i
] >= peak
|| dest
[ i
] <= low
){
1119 if (! firstpeak
) continue ;
1124 if ( maxPeak
> smplCnt
){
1126 //prnt("maxPk: %d",maxPeak);
1129 //prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt);
1134 bool errBitHigh
= 0 ;
1136 uint8_t ignoreCnt
= 0 ;
1137 uint8_t ignoreWindow
= 4 ;
1138 bool lastPeakHigh
= 0 ;
1141 //test each valid clock from smallest to greatest to see which lines up
1142 for ( clkCnt
= 0 ; clkCnt
< 8 ; ++ clkCnt
){
1143 //ignore clocks smaller than smallest peak
1144 if ( clk
[ clkCnt
] < maxPeak
- ( clk
[ clkCnt
]/ 4 )) continue ;
1145 //try lining up the peaks by moving starting point (try first 256)
1146 for ( ii
= 20 ; ii
< loopCnt
; ++ ii
){
1147 if (( dest
[ ii
] >= peak
) || ( dest
[ ii
] <= low
)){
1151 lastBit
= ii
- clk
[ clkCnt
];
1152 //loop through to see if this start location works
1153 for ( i
= ii
; i
< size
- 20 ; ++ i
) {
1154 //if we are at a clock bit
1155 if (( i
>= lastBit
+ clk
[ clkCnt
] - tol
) && ( i
<= lastBit
+ clk
[ clkCnt
] + tol
)) {
1157 if ( dest
[ i
] >= peak
|| dest
[ i
] <= low
) {
1158 //if same peak don't count it
1159 if (( dest
[ i
] >= peak
&& ! lastPeakHigh
) || ( dest
[ i
] <= low
&& lastPeakHigh
)) {
1162 lastPeakHigh
= ( dest
[ i
] >= peak
);
1165 ignoreCnt
= ignoreWindow
;
1166 lastBit
+= clk
[ clkCnt
];
1167 } else if ( i
== lastBit
+ clk
[ clkCnt
] + tol
) {
1168 lastBit
+= clk
[ clkCnt
];
1170 //else if not a clock bit and no peaks
1171 } else if ( dest
[ i
] < peak
&& dest
[ i
] > low
){
1174 if ( errBitHigh
== true ) peakcnt
--;
1179 // else if not a clock bit but we have a peak
1180 } else if (( dest
[ i
]>= peak
|| dest
[ i
]<= low
) && (! bitHigh
)) {
1181 //error bar found no clock...
1185 if ( peakcnt
> peaksdet
[ clkCnt
]) {
1186 peaksdet
[ clkCnt
]= peakcnt
;
1193 for ( iii
= 7 ; iii
> 0 ; iii
--){
1194 if (( peaksdet
[ iii
] >= ( peaksdet
[ best
]- 1 )) && ( peaksdet
[ iii
] <= peaksdet
[ best
]+ 1 ) && lowestTransition
) {
1195 if ( clk
[ iii
] > ( lowestTransition
- ( clk
[ iii
]/ 8 )) && clk
[ iii
] < ( lowestTransition
+ ( clk
[ iii
]/ 8 ))) {
1198 } else if ( peaksdet
[ iii
] > peaksdet
[ best
]){
1201 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
);
1208 // convert psk1 demod to psk2 demod
1209 // only transition waves are 1s
1210 void psk1TOpsk2 ( uint8_t * BitStream
, size_t size
)
1213 uint8_t lastBit
= BitStream
[ 0 ];
1214 for (; i
< size
; i
++){
1215 if ( BitStream
[ i
]== 7 ){
1217 } else if ( lastBit
!= BitStream
[ i
]){
1218 lastBit
= BitStream
[ i
];
1228 // convert psk2 demod to psk1 demod
1229 // from only transition waves are 1s to phase shifts change bit
1230 void psk2TOpsk1 ( uint8_t * BitStream
, size_t size
)
1233 for ( size_t i
= 0 ; i
< size
; i
++){
1234 if ( BitStream
[ i
]== 1 ){
1242 // redesigned by marshmellow adjusted from existing decode functions
1243 // indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
1244 int indala26decode ( uint8_t * bitStream
, size_t * size
, uint8_t * invert
)
1246 //26 bit 40134 format (don't know other formats)
1247 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 };
1248 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 };
1249 size_t startidx
= 0 ;
1250 if (! preambleSearch ( bitStream
, preamble
, sizeof ( preamble
), size
, & startidx
)){
1251 // if didn't find preamble try again inverting
1252 if (! preambleSearch ( bitStream
, preamble_i
, sizeof ( preamble_i
), size
, & startidx
)) return - 1 ;
1255 if (* size
!= 64 && * size
!= 224 ) return - 2 ;
1257 for ( size_t i
= startidx
; i
< * size
; i
++)
1260 return ( int ) startidx
;
1263 // by marshmellow - demodulate NRZ wave - requires a read with strong signal
1264 // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
1265 int nrzRawDemod ( uint8_t * dest
, size_t * size
, int * clk
, int * invert
){
1266 if ( justNoise ( dest
, * size
)) return - 1 ;
1267 * clk
= DetectNRZClock ( dest
, * size
, * clk
);
1268 if (* clk
== 0 ) return - 2 ;
1269 size_t i
, gLen
= 4096 ;
1270 if ( gLen
>* size
) gLen
= * size
- 20 ;
1272 if ( getHiLo ( dest
, gLen
, & high
, & low
, 75 , 75 ) < 1 ) return - 3 ; //25% fuzz on high 25% fuzz on low
1275 //convert wave samples to 1's and 0's
1276 for ( i
= 20 ; i
< * size
- 20 ; i
++){
1277 if ( dest
[ i
] >= high
) bit
= 1 ;
1278 if ( dest
[ i
] <= low
) bit
= 0 ;
1281 //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit)
1284 for ( i
= 21 ; i
< * size
- 20 ; i
++) {
1285 //if transition detected or large number of same bits - store the passed bits
1286 if ( dest
[ i
] != dest
[ i
- 1 ] || ( i
- lastBit
) == ( 10 * * clk
)) {
1287 memset ( dest
+ numBits
, dest
[ i
- 1 ] ^ * invert
, ( i
- lastBit
+ (* clk
/ 4 )) / * clk
);
1288 numBits
+= ( i
- lastBit
+ (* clk
/ 4 )) / * clk
;
1297 //detects the bit clock for FSK given the high and low Field Clocks
1298 uint8_t detectFSKClk ( uint8_t * BitStream
, size_t size
, uint8_t fcHigh
, uint8_t fcLow
)
1300 uint8_t clk
[] = { 8 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 0 };
1301 uint16_t rfLens
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1302 uint8_t rfCnts
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1303 uint8_t rfLensFnd
= 0 ;
1304 uint8_t lastFCcnt
= 0 ;
1305 uint16_t fcCounter
= 0 ;
1306 uint16_t rfCounter
= 0 ;
1307 uint8_t firstBitFnd
= 0 ;
1309 if ( size
== 0 ) return 0 ;
1311 uint8_t fcTol
= (( fcHigh
* 100 - fcLow
* 100 )/ 2 + 50 )/ 100 ; //(uint8_t)(0.5+(float)(fcHigh-fcLow)/2);
1316 //PrintAndLog("DEBUG: fcTol: %d",fcTol);
1317 // prime i to first peak / up transition
1318 for ( i
= 160 ; i
< size
- 20 ; i
++)
1319 if ( BitStream
[ i
] > BitStream
[ i
- 1 ] && BitStream
[ i
]>= BitStream
[ i
+ 1 ])
1322 for (; i
< size
- 20 ; i
++){
1326 if ( BitStream
[ i
] <= BitStream
[ i
- 1 ] || BitStream
[ i
] < BitStream
[ i
+ 1 ])
1329 // if we got less than the small fc + tolerance then set it to the small fc
1330 // if it is inbetween set it to the last counter
1331 if ( fcCounter
< fcHigh
&& fcCounter
> fcLow
)
1332 fcCounter
= lastFCcnt
;
1333 else if ( fcCounter
< fcLow
+ fcTol
)
1335 else //set it to the large fc
1338 //look for bit clock (rf/xx)
1339 if (( fcCounter
< lastFCcnt
|| fcCounter
> lastFCcnt
)){
1340 //not the same size as the last wave - start of new bit sequence
1341 if ( firstBitFnd
> 1 ){ //skip first wave change - probably not a complete bit
1342 for ( int ii
= 0 ; ii
< 15 ; ii
++){
1343 if ( rfLens
[ ii
] >= ( rfCounter
- 4 ) && rfLens
[ ii
] <= ( rfCounter
+ 4 )){
1349 if ( rfCounter
> 0 && rfLensFnd
< 15 ){
1350 //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
1351 rfCnts
[ rfLensFnd
]++;
1352 rfLens
[ rfLensFnd
++] = rfCounter
;
1358 lastFCcnt
= fcCounter
;
1362 uint8_t rfHighest
= 15 , rfHighest2
= 15 , rfHighest3
= 15 ;
1364 for ( i
= 0 ; i
< 15 ; i
++){
1365 //get highest 2 RF values (might need to get more values to compare or compare all?)
1366 if ( rfCnts
[ i
]> rfCnts
[ rfHighest
]){
1367 rfHighest3
= rfHighest2
;
1368 rfHighest2
= rfHighest
;
1370 } else if ( rfCnts
[ i
]> rfCnts
[ rfHighest2
]){
1371 rfHighest3
= rfHighest2
;
1373 } else if ( rfCnts
[ i
]> rfCnts
[ rfHighest3
]){
1376 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: RF %d, cnts %d" , rfLens
[ i
], rfCnts
[ i
]);
1378 // set allowed clock remainder tolerance to be 1 large field clock length+1
1379 // we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off
1380 uint8_t tol1
= fcHigh
+ 1 ;
1382 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: most counted rf values: 1 %d, 2 %d, 3 %d" , rfLens
[ rfHighest
], rfLens
[ rfHighest2
], rfLens
[ rfHighest3
]);
1384 // loop to find the highest clock that has a remainder less than the tolerance
1385 // compare samples counted divided by
1386 // test 128 down to 32 (shouldn't be possible to have fc/10 & fc/8 and rf/16 or less)
1388 for (; ii
>= 2 ; ii
--){
1389 if ( rfLens
[ rfHighest
] % clk
[ ii
] < tol1
|| rfLens
[ rfHighest
] % clk
[ ii
] > clk
[ ii
]- tol1
){
1390 if ( rfLens
[ rfHighest2
] % clk
[ ii
] < tol1
|| rfLens
[ rfHighest2
] % clk
[ ii
] > clk
[ ii
]- tol1
){
1391 if ( rfLens
[ rfHighest3
] % clk
[ ii
] < tol1
|| rfLens
[ rfHighest3
] % clk
[ ii
] > clk
[ ii
]- tol1
){
1392 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: clk %d divides into the 3 most rf values within tolerance" , clk
[ ii
]);
1399 if ( ii
< 2 ) return 0 ; // oops we went too far
1405 //countFC is to detect the field clock lengths.
1406 //counts and returns the 2 most common wave lengths
1407 //mainly used for FSK field clock detection
1408 uint16_t countFC ( uint8_t * BitStream
, size_t size
, uint8_t fskAdj
)
1410 uint8_t fcLens
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1411 uint16_t fcCnts
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1412 uint8_t fcLensFnd
= 0 ;
1413 uint8_t lastFCcnt
= 0 ;
1414 uint8_t fcCounter
= 0 ;
1416 if ( size
< 180 ) return 0 ;
1418 // prime i to first up transition
1419 for ( i
= 160 ; i
< size
- 20 ; i
++)
1420 if ( BitStream
[ i
] > BitStream
[ i
- 1 ] && BitStream
[ i
] >= BitStream
[ i
+ 1 ])
1423 for (; i
< size
- 20 ; i
++){
1424 if ( BitStream
[ i
] > BitStream
[ i
- 1 ] && BitStream
[ i
] >= BitStream
[ i
+ 1 ]){
1425 // new up transition
1428 //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8)
1429 if ( lastFCcnt
== 5 && fcCounter
== 9 ) fcCounter
--;
1430 //if fc=9 or 4 add one (for when we get a fc 9 instead of 10 or a 4 instead of a 5)
1431 if (( fcCounter
== 9 ) || fcCounter
== 4 ) fcCounter
++;
1432 // save last field clock count (fc/xx)
1433 lastFCcnt
= fcCounter
;
1435 // find which fcLens to save it to:
1436 for ( int ii
= 0 ; ii
< 15 ; ii
++){
1437 if ( fcLens
[ ii
]== fcCounter
){
1443 if ( fcCounter
> 0 && fcLensFnd
< 15 ){
1445 fcCnts
[ fcLensFnd
]++;
1446 fcLens
[ fcLensFnd
++]= fcCounter
;
1455 uint8_t best1
= 14 , best2
= 14 , best3
= 14 ;
1457 // go through fclens and find which ones are bigest 2
1458 for ( i
= 0 ; i
< 15 ; i
++){
1459 // get the 3 best FC values
1460 if ( fcCnts
[ i
]> maxCnt1
) {
1465 } else if ( fcCnts
[ i
]> fcCnts
[ best2
]){
1468 } else if ( fcCnts
[ i
]> fcCnts
[ best3
]){
1471 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
]);
1473 if ( fcLens
[ best1
]== 0 ) return 0 ;
1474 uint8_t fcH
= 0 , fcL
= 0 ;
1475 if ( fcLens
[ best1
]> fcLens
[ best2
]){
1482 if (( size
- 180 )/ fcH
/ 3 > fcCnts
[ best1
]+ fcCnts
[ best2
]) {
1483 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
]);
1484 return 0 ; //lots of waves not psk or fsk
1486 // TODO: take top 3 answers and compare to known Field clocks to get top 2
1488 uint16_t fcs
= ((( uint16_t ) fcH
)<< 8 ) | fcL
;
1489 if ( fskAdj
) return fcs
;
1490 return fcLens
[ best1
];
1493 //by marshmellow - demodulate PSK1 wave
1494 //uses wave lengths (# Samples)
1495 int pskRawDemod ( uint8_t dest
[], size_t * size
, int * clock
, int * invert
)
1497 if ( size
== 0 ) return - 1 ;
1498 uint16_t loopCnt
= 4096 ; //don't need to loop through entire array...
1499 if (* size
< loopCnt
) loopCnt
= * size
;
1502 uint8_t curPhase
= * invert
;
1503 size_t i
= 0 , waveStart
= 1 , waveEnd
= 0 , firstFullWave
= 0 , lastClkBit
= 0 ;
1504 uint16_t fc
= 0 , fullWaveLen
= 0 , tol
= 1 ;
1505 uint16_t errCnt
= 0 , waveLenCnt
= 0 , errCnt2
= 0 ;
1506 fc
= countFC ( dest
, * size
, 1 );
1507 uint8_t fc2
= fc
>> 8 ;
1508 if ( fc2
== 10 ) return - 1 ; //fsk found - quit
1510 if ( fc
!= 2 && fc
!= 4 && fc
!= 8 ) return - 1 ;
1511 //PrintAndLog("DEBUG: FC: %d",fc);
1512 * clock
= DetectPSKClock ( dest
, * size
, * clock
);
1513 if (* clock
== 0 ) return - 1 ;
1515 //find start of modulating data in trace
1516 uint8_t threshold_value
= 123 ; //-5
1517 i
= findModStart ( dest
, * size
, threshold_value
, fc
);
1519 //find first phase shift
1520 int avgWaveVal
= 0 , lastAvgWaveVal
= 0 ;
1522 for (; i
< loopCnt
; i
++) {
1524 if ( dest
[ i
]+ fc
< dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
1526 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: waveEnd: %u, waveStart: %u" , waveEnd
, waveStart
);
1527 waveLenCnt
= waveEnd
- waveStart
;
1528 if ( waveLenCnt
> fc
&& waveStart
> fc
&& !( waveLenCnt
> fc
+ 3 )){ //not first peak and is a large wave but not out of whack
1529 lastAvgWaveVal
= avgWaveVal
/( waveLenCnt
);
1530 firstFullWave
= waveStart
;
1531 fullWaveLen
= waveLenCnt
;
1532 //if average wave value is > graph 0 then it is an up wave or a 1 (could cause inverting)
1533 if ( lastAvgWaveVal
> threshold_value
) curPhase
^= 1 ;
1539 avgWaveVal
+= dest
[ i
+ 2 ];
1541 if ( firstFullWave
== 0 ) {
1542 // no phase shift detected - could be all 1's or 0's - doesn't matter where we start
1543 // so skip a little to ensure we are past any Start Signal
1544 firstFullWave
= 160 ;
1545 memset ( dest
, curPhase
, firstFullWave
/ * clock
);
1547 memset ( dest
, curPhase
^ 1 , firstFullWave
/ * clock
);
1550 numBits
+= ( firstFullWave
/ * clock
);
1551 //set start of wave as clock align
1552 lastClkBit
= firstFullWave
;
1553 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: firstFullWave: %u, waveLen: %u" , firstFullWave
, fullWaveLen
);
1554 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: clk: %d, lastClkBit: %u, fc: %u" , * clock
, lastClkBit
,( unsigned int ) fc
);
1556 dest
[ numBits
++] = curPhase
; //set first read bit
1557 for ( i
= firstFullWave
+ fullWaveLen
- 1 ; i
< * size
- 3 ; i
++){
1558 //top edge of wave = start of new wave
1559 if ( dest
[ i
]+ fc
< dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
1560 if ( waveStart
== 0 ) {
1563 avgWaveVal
= dest
[ i
+ 1 ];
1566 waveLenCnt
= waveEnd
- waveStart
;
1567 lastAvgWaveVal
= avgWaveVal
/ waveLenCnt
;
1568 if ( waveLenCnt
> fc
){
1569 //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);
1570 //this wave is a phase shift
1571 //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc);
1572 if ( i
+ 1 >= lastClkBit
+ * clock
- tol
){ //should be a clock bit
1574 dest
[ numBits
++] = curPhase
;
1575 lastClkBit
+= * clock
;
1576 } else if ( i
< lastClkBit
+ 10 + fc
){
1577 //noise after a phase shift - ignore
1578 } else { //phase shift before supposed to based on clock
1580 dest
[ numBits
++] = 7 ;
1582 } else if ( i
+ 1 > lastClkBit
+ * clock
+ tol
+ fc
){
1583 lastClkBit
+= * clock
; //no phase shift but clock bit
1584 dest
[ numBits
++] = curPhase
;
1585 } else if ( waveLenCnt
< fc
- 1 ) { //wave is smaller than field clock (shouldn't happen often)
1587 if ( errCnt2
> 101 ) return errCnt2
;
1593 avgWaveVal
+= dest
[ i
+ 1 ];
1600 //attempt to identify a Sequence Terminator in ASK modulated raw wave
1601 bool DetectST ( uint8_t buffer
[], size_t * size
, int * foundclock
) {
1602 size_t bufsize
= * size
;
1603 //need to loop through all samples and identify our clock, look for the ST pattern
1604 uint8_t fndClk
[] = { 8 , 16 , 32 , 40 , 50 , 64 , 128 };
1607 int i
, j
, skip
, start
, end
, low
, high
, minClk
, waveStart
;
1608 bool complete
= false ;
1609 int tmpbuff
[ bufsize
/ 32 ]; //guess rf/32 clock, if click is smaller we will only have room for a fraction of the samples captured
1610 int waveLen
[ bufsize
/ 32 ]; // if clock is larger then we waste memory in array size that is not needed...
1611 size_t testsize
= ( bufsize
< 512 ) ? bufsize
: 512 ;
1614 memset ( tmpbuff
, 0 , sizeof ( tmpbuff
));
1616 if ( getHiLo ( buffer
, testsize
, & high
, & low
, 80 , 80 ) == - 1 ) {
1617 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: just noise detected - quitting" );
1618 return false ; //just noise
1623 // get to first full low to prime loop and skip incomplete first pulse
1624 while (( buffer
[ i
] < high
) && ( i
< bufsize
))
1626 while (( buffer
[ i
] > low
) && ( i
< bufsize
))
1630 // populate tmpbuff buffer with pulse lengths
1631 while ( i
< bufsize
) {
1632 // measure from low to low
1633 while (( buffer
[ i
] > low
) && ( i
< bufsize
))
1636 while (( buffer
[ i
] < high
) && ( i
< bufsize
))
1638 //first high point for this wave
1640 while (( buffer
[ i
] > low
) && ( i
< bufsize
))
1642 if ( j
>= ( bufsize
/ 32 )) {
1645 waveLen
[ j
] = i
- waveStart
; //first high to first low
1646 tmpbuff
[ j
++] = i
- start
;
1647 if ( i
- start
< minClk
&& i
< bufsize
) {
1651 // set clock - might be able to get this externally and remove this work...
1653 for ( uint8_t clkCnt
= 0 ; clkCnt
< 7 ; clkCnt
++) {
1654 tol
= fndClk
[ clkCnt
]/ 8 ;
1655 if ( minClk
>= fndClk
[ clkCnt
]- tol
&& minClk
<= fndClk
[ clkCnt
]+ 1 ) {
1660 // clock not found - ERROR
1662 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: clock not found - quitting" );
1669 // look for Sequence Terminator - should be pulses of clk*(1 or 1.5), clk*2, clk*(1.5 or 2)
1671 for ( i
= 0 ; i
< j
- 4 ; ++ i
) {
1673 if ( tmpbuff
[ i
] >= clk
* 1 - tol
&& tmpbuff
[ i
] <= ( clk
* 2 )+ tol
&& waveLen
[ i
] < clk
+ tol
) { //1 to 2 clocks depending on 2 bits prior
1674 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
1675 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
1676 if ( tmpbuff
[ i
+ 3 ] >= clk
* 1 - tol
&& tmpbuff
[ i
+ 3 ] <= clk
* 2 + tol
) { //1 to 2 clocks for end of ST + first bit
1684 // first ST not found - ERROR
1686 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: first STT not found - quitting" );
1689 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: first STT found at: %d, j=%d" , start
, j
);
1691 if ( waveLen
[ i
+ 2 ] > clk
* 1 + tol
)
1696 // skip over the remainder of ST
1697 skip
+= clk
* 7 / 2 ; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point
1699 // now do it again to find the end
1701 for ( i
+= 3 ; i
< j
- 4 ; ++ i
) {
1703 if ( tmpbuff
[ i
] >= clk
* 1 - tol
&& tmpbuff
[ i
] <= ( clk
* 2 )+ tol
&& waveLen
[ i
] < clk
+ tol
) { //1 to 2 clocks depending on 2 bits prior
1704 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
1705 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
1706 if ( tmpbuff
[ i
+ 3 ] >= clk
* 1 - tol
&& tmpbuff
[ i
+ 3 ] <= clk
* 2 + tol
) { //1 to 2 clocks for end of ST + first bit
1715 //didn't find second ST - ERROR
1717 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: second STT not found - quitting" );
1720 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
);
1721 //now begin to trim out ST so we can use normal demod cmds
1723 size_t datalen
= end
- start
;
1724 // check validity of datalen (should be even clock increments) - use a tolerance of up to 1/8th a clock
1725 if ( clk
- ( datalen
% clk
) <= clk
/ 8 ) {
1726 // padd the amount off - could be problematic... but shouldn't happen often
1727 datalen
+= clk
- ( datalen
% clk
);
1728 } else if ( ( datalen
% clk
) <= clk
/ 8 ) {
1729 // padd the amount off - could be problematic... but shouldn't happen often
1730 datalen
-= datalen
% clk
;
1732 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting" , datalen
, clk
, datalen
% clk
);
1735 // if datalen is less than one t55xx block - ERROR
1736 if ( datalen
/ clk
< 8 * 4 ) {
1737 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: datalen is less than 1 full t55xx block - quitting" );
1740 size_t dataloc
= start
;
1741 if ( buffer
[ dataloc
-( clk
* 4 )-( clk
/ 8 )] <= low
&& buffer
[ dataloc
] <= low
&& buffer
[ dataloc
-( clk
* 4 )] >= high
) {
1742 //we have low drift (and a low just before the ST and a low just after the ST) - compensate by backing up the start
1743 for ( i
= 0 ; i
<= ( clk
/ 8 ); ++ i
) {
1744 if ( buffer
[ dataloc
- ( clk
* 4 ) - i
] <= low
) {
1753 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: Starting STT trim - start: %d, datalen: %d " , dataloc
, datalen
);
1755 // warning - overwriting buffer given with raw wave data with ST removed...
1756 while ( dataloc
< bufsize
-( clk
/ 2 ) ) {
1757 //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)
1758 if ( buffer
[ dataloc
]< high
&& buffer
[ dataloc
]> low
&& buffer
[ dataloc
+ 3 ]< high
&& buffer
[ dataloc
+ 3 ]> low
) {
1759 for ( i
= 0 ; i
< clk
/ 2 - tol
; ++ i
) {
1760 buffer
[ dataloc
+ i
] = high
+ 5 ;
1762 } //test for single sample outlier (high between two lows) in the case of very strong waves
1763 if ( buffer
[ dataloc
] >= high
&& buffer
[ dataloc
+ 2 ] <= low
) {
1764 buffer
[ dataloc
] = buffer
[ dataloc
+ 2 ];
1765 buffer
[ dataloc
+ 1 ] = buffer
[ dataloc
+ 2 ];
1767 for ( i
= 0 ; i
< datalen
; ++ i
) {
1768 if ( i
+ newloc
< bufsize
) {
1769 if ( i
+ newloc
< dataloc
)
1770 buffer
[ i
+ newloc
] = buffer
[ dataloc
];
1776 //skip next ST - we just assume it will be there from now on...
1777 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: skipping STT at %d to %d" , dataloc
, dataloc
+( clk
* 4 ));