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cvs.zerfleddert.de Git - proxmark3-svn/blob - common/lfdemod.c
982a724a018a02fca792b15636098ea57a8384ea
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 //-----------------------------------------------------------------------------
16 //un_comment to allow debug print calls when used not on device
17 void dummy ( char * fmt
, ...){}
21 #include "cmdparser.h"
23 #define prnt PrintAndLog
25 uint8_t g_debugMode
= 0 ;
29 uint8_t justNoise ( uint8_t * BitStream
, size_t size
)
31 static const uint8_t THRESHOLD
= 123 ;
32 //test samples are not just noise
33 uint8_t justNoise1
= 1 ;
34 for ( size_t idx
= 0 ; idx
< size
&& justNoise1
; idx
++){
35 justNoise1
= BitStream
[ idx
] < THRESHOLD
;
41 //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
42 int getHiLo ( uint8_t * BitStream
, size_t size
, int * high
, int * low
, uint8_t fuzzHi
, uint8_t fuzzLo
)
46 // get high and low thresholds
47 for ( size_t i
= 0 ; i
< size
; i
++){
48 if ( BitStream
[ i
] > * high
) * high
= BitStream
[ i
];
49 if ( BitStream
[ i
] < * low
) * low
= BitStream
[ i
];
51 if (* high
< 123 ) return - 1 ; // just noise
52 * high
= ((* high
- 128 )* fuzzHi
+ 12800 )/ 100 ;
53 * low
= ((* low
- 128 )* fuzzLo
+ 12800 )/ 100 ;
58 // pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType
59 // returns 1 if passed
60 uint8_t parityTest ( uint32_t bits
, uint8_t bitLen
, uint8_t pType
)
63 for ( uint8_t i
= 0 ; i
< bitLen
; i
++){
64 ans
^= (( bits
>> i
) & 1 );
66 //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType);
67 return ( ans
== pType
);
71 // takes a array of binary values, start position, length of bits per parity (includes parity bit),
72 // Parity Type (1 for odd; 0 for even; 2 Always 1's), and binary Length (length to run)
73 size_t removeParity ( uint8_t * BitStream
, size_t startIdx
, uint8_t pLen
, uint8_t pType
, size_t bLen
)
75 uint32_t parityWd
= 0 ;
76 size_t j
= 0 , bitCnt
= 0 ;
77 for ( int word
= 0 ; word
< ( bLen
); word
+= pLen
){
78 for ( int bit
= 0 ; bit
< pLen
; bit
++){
79 parityWd
= ( parityWd
<< 1 ) | BitStream
[ startIdx
+ word
+ bit
];
80 BitStream
[ j
++] = ( BitStream
[ startIdx
+ word
+ bit
]);
82 j
--; // overwrite parity with next data
83 // if parity fails then return 0
84 if ( pType
== 2 ) { // then marker bit which should be a 1
85 if (! BitStream
[ j
]) return 0 ;
87 if ( parityTest ( parityWd
, pLen
, pType
) == 0 ) return 0 ;
92 // if we got here then all the parities passed
93 //return ID start index and size
98 // takes a array of binary values, length of bits per parity (includes parity bit),
99 // Parity Type (1 for odd; 0 for even; 2 Always 1's), and binary Length (length to run)
100 size_t addParity ( uint8_t * BitSource
, uint8_t * dest
, uint8_t sourceLen
, uint8_t pLen
, uint8_t pType
)
102 uint32_t parityWd
= 0 ;
103 size_t j
= 0 , bitCnt
= 0 ;
104 for ( int word
= 0 ; word
< sourceLen
; word
+= pLen
- 1 ) {
105 for ( int bit
= 0 ; bit
< pLen
- 1 ; bit
++){
106 parityWd
= ( parityWd
<< 1 ) | BitSource
[ word
+ bit
];
107 dest
[ j
++] = ( BitSource
[ word
+ bit
]);
109 // if parity fails then return 0
110 if ( pType
== 2 ) { // then marker bit which should be a 1
113 dest
[ j
++] = parityTest ( parityWd
, pLen
- 1 , pType
) ^ 1 ;
118 // if we got here then all the parities passed
119 //return ID start index and size
123 uint32_t bytebits_to_byte ( uint8_t * src
, size_t numbits
)
126 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
++)
140 num
= ( num
<< 1 ) | *( src
+ ( numbits
-( i
+ 1 )));
146 //search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length
147 uint8_t preambleSearch ( uint8_t * BitStream
, uint8_t * preamble
, size_t pLen
, size_t * size
, size_t * startIdx
)
150 for ( int idx
= 0 ; idx
< * size
- pLen
; idx
++){
151 if ( memcmp ( BitStream
+ idx
, preamble
, pLen
) == 0 ){
158 * size
= idx
- * startIdx
;
167 //takes 1s and 0s and searches for EM410x format - output EM ID
168 uint8_t Em410xDecode ( uint8_t * BitStream
, size_t * size
, size_t * startIdx
, uint32_t * hi
, uint64_t * lo
)
170 //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
171 // otherwise could be a void with no arguments
174 if ( BitStream
[ 1 ]> 1 ) return 0 ; //allow only 1s and 0s
176 // 111111111 bit pattern represent start of frame
177 // include 0 in front to help get start pos
178 uint8_t preamble
[] = { 0 , 1 , 1 , 1 , 1 , 1 , 1 , 1 , 1 , 1 };
180 uint32_t parityBits
= 0 ;
184 errChk
= preambleSearch ( BitStream
, preamble
, sizeof ( preamble
), size
, startIdx
);
185 if ( errChk
== 0 || * size
< 64 ) return 0 ;
186 if (* size
> 64 ) FmtLen
= 22 ;
187 * startIdx
+= 1 ; //get rid of 0 from preamble
189 for ( i
= 0 ; i
< FmtLen
; i
++){ //loop through 10 or 22 sets of 5 bits (50-10p = 40 bits or 88 bits)
190 parityBits
= bytebits_to_byte ( BitStream
+( i
* 5 )+ idx
, 5 );
191 //check even parity - quit if failed
192 if ( parityTest ( parityBits
, 5 , 0 ) == 0 ) return 0 ;
193 //set uint64 with ID from BitStream
194 for ( uint8_t ii
= 0 ; ii
< 4 ; ii
++){
195 * hi
= (* hi
<< 1 ) | (* lo
>> 63 );
196 * lo
= (* lo
<< 1 ) | ( BitStream
[( i
* 5 )+ ii
+ idx
]);
199 if ( errChk
!= 0 ) return 1 ;
200 //skip last 5 bit parity test for simplicity.
206 //demodulates strong heavily clipped samples
207 int cleanAskRawDemod ( uint8_t * BinStream
, size_t * size
, int clk
, int invert
, int high
, int low
)
209 size_t bitCnt
= 0 , smplCnt
= 0 , errCnt
= 0 ;
210 uint8_t waveHigh
= 0 ;
211 for ( size_t i
= 0 ; i
< * size
; i
++){
212 if ( BinStream
[ i
] >= high
&& waveHigh
){
214 } else if ( BinStream
[ i
] <= low
&& ! waveHigh
){
216 } else { //transition
217 if (( BinStream
[ i
] >= high
&& ! waveHigh
) || ( BinStream
[ i
] <= low
&& waveHigh
)){
218 if ( smplCnt
> clk
-( clk
/ 4 )- 1 ) { //full clock
219 if ( smplCnt
> clk
+ ( clk
/ 4 )+ 1 ) { //too many samples
221 BinStream
[ bitCnt
++]= 7 ;
222 } else if ( waveHigh
) {
223 BinStream
[ bitCnt
++] = invert
;
224 BinStream
[ bitCnt
++] = invert
;
225 } else if (! waveHigh
) {
226 BinStream
[ bitCnt
++] = invert
^ 1 ;
227 BinStream
[ bitCnt
++] = invert
^ 1 ;
231 } else if ( smplCnt
> ( clk
/ 2 ) - ( clk
/ 4 )- 1 ) {
233 BinStream
[ bitCnt
++] = invert
;
234 } else if (! waveHigh
) {
235 BinStream
[ bitCnt
++] = invert
^ 1 ;
239 } else if (! bitCnt
) {
241 waveHigh
= ( BinStream
[ i
] >= high
);
245 //transition bit oops
247 } else { //haven't hit new high or new low yet
257 void askAmp ( uint8_t * BitStream
, size_t size
)
259 for ( size_t i
= 1 ; i
< size
; i
++){
260 if ( BitStream
[ i
]- BitStream
[ i
- 1 ]>= 30 ) //large jump up
262 else if ( BitStream
[ i
]- BitStream
[ i
- 1 ]<=- 20 ) //large jump down
269 //attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester
270 int askdemod ( uint8_t * BinStream
, size_t * size
, int * clk
, int * invert
, int maxErr
, uint8_t amp
, uint8_t askType
)
272 if (* size
== 0 ) return - 1 ;
273 int start
= DetectASKClock ( BinStream
, * size
, clk
, maxErr
); //clock default
274 if (* clk
== 0 || start
< 0 ) return - 3 ;
275 if (* invert
!= 1 ) * invert
= 0 ;
276 if ( amp
== 1 ) askAmp ( BinStream
, * size
);
277 if ( g_debugMode
== 2 ) prnt ( "DEBUG: clk %d, beststart %d" , * clk
, start
);
279 uint8_t initLoopMax
= 255 ;
280 if ( initLoopMax
> * size
) initLoopMax
= * size
;
281 // Detect high and lows
282 //25% clip in case highs and lows aren't clipped [marshmellow]
284 if ( getHiLo ( BinStream
, initLoopMax
, & high
, & low
, 75 , 75 ) < 1 )
285 return - 2 ; //just noise
288 // if clean clipped waves detected run alternate demod
289 if ( DetectCleanAskWave ( BinStream
, * size
, high
, low
)) {
290 if ( g_debugMode
== 2 ) prnt ( "DEBUG: Clean Wave Detected" );
291 errCnt
= cleanAskRawDemod ( BinStream
, size
, * clk
, * invert
, high
, low
);
292 if ( askType
) //askman
293 return manrawdecode ( BinStream
, size
, 0 );
298 int lastBit
; //set first clock check - can go negative
299 size_t i
, bitnum
= 0 ; //output counter
301 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
302 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
303 size_t MaxBits
= 3072 ;
304 lastBit
= start
- * clk
;
306 for ( i
= start
; i
< * size
; ++ i
) {
307 if ( i
- lastBit
>= * clk
- tol
){
308 if ( BinStream
[ i
] >= high
) {
309 BinStream
[ bitnum
++] = * invert
;
310 } else if ( BinStream
[ i
] <= low
) {
311 BinStream
[ bitnum
++] = * invert
^ 1 ;
312 } else if ( i
- lastBit
>= * clk
+ tol
) {
314 BinStream
[ bitnum
++]= 7 ;
317 } else { //in tolerance - looking for peak
322 } else if ( i
- lastBit
>= (* clk
/ 2 - tol
) && ! midBit
&& ! askType
){
323 if ( BinStream
[ i
] >= high
) {
324 BinStream
[ bitnum
++] = * invert
;
325 } else if ( BinStream
[ i
] <= low
) {
326 BinStream
[ bitnum
++] = * invert
^ 1 ;
327 } else if ( i
- lastBit
>= * clk
/ 2 + tol
) {
328 BinStream
[ bitnum
] = BinStream
[ bitnum
- 1 ];
330 } else { //in tolerance - looking for peak
335 if ( bitnum
>= MaxBits
) break ;
342 //take 10 and 01 and manchester decode
343 //run through 2 times and take least errCnt
344 int manrawdecode ( uint8_t * BitStream
, size_t * size
, uint8_t invert
)
346 uint16_t bitnum
= 0 , MaxBits
= 512 , errCnt
= 0 ;
348 uint16_t bestErr
= 1000 , bestRun
= 0 ;
349 if (* size
< 16 ) return - 1 ;
350 //find correct start position [alignment]
351 for ( ii
= 0 ; ii
< 2 ;++ ii
){
352 for ( i
= ii
; i
<* size
- 3 ; i
+= 2 )
353 if ( BitStream
[ i
]== BitStream
[ i
+ 1 ])
363 for ( i
= bestRun
; i
< * size
- 3 ; i
+= 2 ){
364 if ( BitStream
[ i
] == 1 && ( BitStream
[ i
+ 1 ] == 0 )){
365 BitStream
[ bitnum
++]= invert
;
366 } else if (( BitStream
[ i
] == 0 ) && BitStream
[ i
+ 1 ] == 1 ){
367 BitStream
[ bitnum
++]= invert
^ 1 ;
369 BitStream
[ bitnum
++]= 7 ;
371 if ( bitnum
> MaxBits
) break ;
377 uint32_t manchesterEncode2Bytes ( uint16_t datain
) {
380 for ( uint8_t i
= 0 ; i
< 16 ; i
++) {
381 curBit
= ( datain
>> ( 15 - i
) & 1 );
382 output
|= ( 1 <<((( 15 - i
)* 2 )+ curBit
));
388 //encode binary data into binary manchester
389 int ManchesterEncode ( uint8_t * BitStream
, size_t size
)
391 size_t modIdx
= 20000 , i
= 0 ;
392 if ( size
> modIdx
) return - 1 ;
393 for ( size_t idx
= 0 ; idx
< size
; idx
++){
394 BitStream
[ idx
+ modIdx
++] = BitStream
[ idx
];
395 BitStream
[ idx
+ modIdx
++] = BitStream
[ idx
]^ 1 ;
397 for (; i
<( size
* 2 ); i
++){
398 BitStream
[ i
] = BitStream
[ i
+ 20000 ];
404 //take 01 or 10 = 1 and 11 or 00 = 0
405 //check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010
406 //decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding
407 int BiphaseRawDecode ( uint8_t * BitStream
, size_t * size
, int offset
, int invert
)
412 uint16_t MaxBits
= 512 ;
413 //if not enough samples - error
414 if (* size
< 51 ) return - 1 ;
415 //check for phase change faults - skip one sample if faulty
416 uint8_t offsetA
= 1 , offsetB
= 1 ;
418 if ( BitStream
[ i
+ 1 ]== BitStream
[ i
+ 2 ]) offsetA
= 0 ;
419 if ( BitStream
[ i
+ 2 ]== BitStream
[ i
+ 3 ]) offsetB
= 0 ;
421 if (! offsetA
&& offsetB
) offset
++;
422 for ( i
= offset
; i
<* size
- 3 ; i
+= 2 ){
423 //check for phase error
424 if ( BitStream
[ i
+ 1 ]== BitStream
[ i
+ 2 ]) {
425 BitStream
[ bitnum
++]= 7 ;
428 if (( BitStream
[ i
]== 1 && BitStream
[ i
+ 1 ]== 0 ) || ( BitStream
[ i
]== 0 && BitStream
[ i
+ 1 ]== 1 )){
429 BitStream
[ bitnum
++]= 1 ^ invert
;
430 } else if (( BitStream
[ i
]== 0 && BitStream
[ i
+ 1 ]== 0 ) || ( BitStream
[ i
]== 1 && BitStream
[ i
+ 1 ]== 1 )){
431 BitStream
[ bitnum
++]= invert
;
433 BitStream
[ bitnum
++]= 7 ;
436 if ( bitnum
> MaxBits
) break ;
443 // demod gProxIIDemod
444 // error returns as -x
445 // success returns start position in BitStream
446 // BitStream must contain previously askrawdemod and biphasedemoded data
447 int gProxII_Demod ( uint8_t BitStream
[], size_t * size
)
450 uint8_t preamble
[] = { 1 , 1 , 1 , 1 , 1 , 0 };
452 uint8_t errChk
= preambleSearch ( BitStream
, preamble
, sizeof ( preamble
), size
, & startIdx
);
453 if ( errChk
== 0 ) return - 3 ; //preamble not found
454 if (* size
!= 96 ) return - 2 ; //should have found 96 bits
455 //check first 6 spacer bits to verify format
456 if (! BitStream
[ startIdx
+ 5 ] && ! BitStream
[ startIdx
+ 10 ] && ! BitStream
[ startIdx
+ 15 ] && ! BitStream
[ startIdx
+ 20 ] && ! BitStream
[ startIdx
+ 25 ] && ! BitStream
[ startIdx
+ 30 ]){
457 //confirmed proper separator bits found
458 //return start position
459 return ( int ) startIdx
;
464 //translate wave to 11111100000 (1 for each short wave 0 for each long wave)
465 size_t fsk_wave_demod ( uint8_t * dest
, size_t size
, uint8_t fchigh
, uint8_t fclow
)
467 size_t last_transition
= 0 ;
470 if ( fchigh
== 0 ) fchigh
= 10 ;
471 if ( fclow
== 0 ) fclow
= 8 ;
472 //set the threshold close to 0 (graph) or 128 std to avoid static
473 uint8_t threshold_value
= 123 ;
474 size_t preLastSample
= 0 ;
475 size_t LastSample
= 0 ;
476 size_t currSample
= 0 ;
477 // sync to first lo-hi transition, and threshold
479 // Need to threshold first sample
480 // skip 160 samples to allow antenna/samples to settle
481 if ( dest
[ 160 ] < threshold_value
) dest
[ 0 ] = 0 ;
485 // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
486 // or 10 (fc/10) cycles but in practice due to noise etc we may end up with with anywhere
487 // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
488 for ( idx
= 161 ; idx
< size
- 20 ; idx
++) {
489 // threshold current value
491 if ( dest
[ idx
] < threshold_value
) dest
[ idx
] = 0 ;
494 // Check for 0->1 transition
495 if ( dest
[ idx
- 1 ] < dest
[ idx
]) { // 0 -> 1 transition
496 preLastSample
= LastSample
;
497 LastSample
= currSample
;
498 currSample
= idx
- last_transition
;
499 if ( currSample
< ( fclow
- 2 )){ //0-5 = garbage noise (or 0-3)
500 //do nothing with extra garbage
501 } else if ( currSample
< ( fchigh
- 1 )) { //6-8 = 8 sample waves or 3-6 = 5
502 if ( LastSample
> ( fchigh
- 2 ) && ( preLastSample
< ( fchigh
- 1 ) || preLastSample
== 0 )){
503 dest
[ numBits
- 1 ]= 1 ; //correct previous 9 wave surrounded by 8 waves
507 } else if ( currSample
> ( fchigh
) && ! numBits
) { //12 + and first bit = garbage
508 //do nothing with beginning garbage
509 } else if ( currSample
== ( fclow
+ 1 ) && LastSample
== ( fclow
- 1 )) { // had a 7 then a 9 should be two 8's
511 } else { //9+ = 10 sample waves
514 last_transition
= idx
;
517 return numBits
; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
520 //translate 11111100000 to 10
521 size_t aggregate_bits ( uint8_t * dest
, size_t size
, uint8_t rfLen
,
522 uint8_t invert
, uint8_t fchigh
, uint8_t fclow
)
524 uint8_t lastval
= dest
[ 0 ];
528 for ( idx
= 1 ; idx
< size
; idx
++) {
530 if ( dest
[ idx
]== lastval
) continue ;
532 //if lastval was 1, we have a 1->0 crossing
533 if ( dest
[ idx
- 1 ]== 1 ) {
534 n
= ( n
* fclow
+ rfLen
/ 2 ) / rfLen
;
535 } else { // 0->1 crossing
536 n
= ( n
* fchigh
+ rfLen
/ 2 ) / rfLen
;
540 memset ( dest
+ numBits
, dest
[ idx
- 1 ]^ invert
, n
);
545 // if valid extra bits at the end were all the same frequency - add them in
546 if ( n
> rfLen
/ fchigh
) {
547 if ( dest
[ idx
- 2 ]== 1 ) {
548 n
= ( n
* fclow
+ rfLen
/ 2 ) / rfLen
;
550 n
= ( n
* fchigh
+ rfLen
/ 2 ) / rfLen
;
552 memset ( dest
+ numBits
, dest
[ idx
- 1 ]^ invert
, n
);
558 //by marshmellow (from holiman's base)
559 // full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod)
560 int fskdemod ( uint8_t * dest
, size_t size
, uint8_t rfLen
, uint8_t invert
, uint8_t fchigh
, uint8_t fclow
)
563 size
= fsk_wave_demod ( dest
, size
, fchigh
, fclow
);
564 size
= aggregate_bits ( dest
, size
, rfLen
, invert
, fchigh
, fclow
);
568 // loop to get raw HID waveform then FSK demodulate the TAG ID from it
569 int HIDdemodFSK ( uint8_t * dest
, size_t * size
, uint32_t * hi2
, uint32_t * hi
, uint32_t * lo
)
571 if ( justNoise ( dest
, * size
)) return - 1 ;
573 size_t numStart
= 0 , size2
=* size
, startIdx
= 0 ;
575 * size
= fskdemod ( dest
, size2
, 50 , 1 , 10 , 8 ); //fsk2a
576 if (* size
< 96 * 2 ) return - 2 ;
577 // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
578 uint8_t preamble
[] = { 0 , 0 , 0 , 1 , 1 , 1 , 0 , 1 };
579 // find bitstring in array
580 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
581 if ( errChk
== 0 ) return - 3 ; //preamble not found
583 numStart
= startIdx
+ sizeof ( preamble
);
584 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
585 for ( size_t idx
= numStart
; ( idx
- numStart
) < * size
- sizeof ( preamble
); idx
+= 2 ){
586 if ( dest
[ idx
] == dest
[ idx
+ 1 ]){
587 return - 4 ; //not manchester data
589 * hi2
= (* hi2
<< 1 )|(* hi
>> 31 );
590 * hi
= (* hi
<< 1 )|(* lo
>> 31 );
591 //Then, shift in a 0 or one into low
592 if ( dest
[ idx
] && ! dest
[ idx
+ 1 ]) // 1 0
597 return ( int ) startIdx
;
600 // loop to get raw paradox waveform then FSK demodulate the TAG ID from it
601 int ParadoxdemodFSK ( uint8_t * dest
, size_t * size
, uint32_t * hi2
, uint32_t * hi
, uint32_t * lo
)
603 if ( justNoise ( dest
, * size
)) return - 1 ;
605 size_t numStart
= 0 , size2
=* size
, startIdx
= 0 ;
607 * size
= fskdemod ( dest
, size2
, 50 , 1 , 10 , 8 ); //fsk2a
608 if (* size
< 96 ) return - 2 ;
610 // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
611 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 1 , 1 , 1 , 1 };
613 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
614 if ( errChk
== 0 ) return - 3 ; //preamble not found
616 numStart
= startIdx
+ sizeof ( preamble
);
617 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
618 for ( size_t idx
= numStart
; ( idx
- numStart
) < * size
- sizeof ( preamble
); idx
+= 2 ){
619 if ( dest
[ idx
] == dest
[ idx
+ 1 ])
620 return - 4 ; //not manchester data
621 * hi2
= (* hi2
<< 1 )|(* hi
>> 31 );
622 * hi
= (* hi
<< 1 )|(* lo
>> 31 );
623 //Then, shift in a 0 or one into low
624 if ( dest
[ idx
] && ! dest
[ idx
+ 1 ]) // 1 0
629 return ( int ) startIdx
;
632 int IOdemodFSK ( uint8_t * dest
, size_t size
)
634 if ( justNoise ( dest
, size
)) return - 1 ;
635 //make sure buffer has data
636 if ( size
< 66 * 64 ) return - 2 ;
638 size
= fskdemod ( dest
, size
, 64 , 1 , 10 , 8 ); // FSK2a RF/64
639 if ( size
< 65 ) return - 3 ; //did we get a good demod?
641 //0 10 20 30 40 50 60
643 //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
644 //-----------------------------------------------------------------------------
645 //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
647 //XSF(version)facility:codeone+codetwo
650 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
651 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), & size
, & startIdx
);
652 if ( errChk
== 0 ) return - 4 ; //preamble not found
654 if (! dest
[ startIdx
+ 8 ] && dest
[ startIdx
+ 17 ]== 1 && dest
[ startIdx
+ 26 ]== 1 && dest
[ startIdx
+ 35 ]== 1 && dest
[ startIdx
+ 44 ]== 1 && dest
[ startIdx
+ 53 ]== 1 ){
655 //confirmed proper separator bits found
656 //return start position
657 return ( int ) startIdx
;
663 // find viking preamble 0xF200 in already demoded data
664 int VikingDemod_AM ( uint8_t * dest
, size_t * size
) {
665 //make sure buffer has data
666 if (* size
< 64 * 2 ) return - 2 ;
669 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 };
670 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
671 if ( errChk
== 0 ) return - 4 ; //preamble not found
672 uint32_t checkCalc
= bytebits_to_byte ( dest
+ startIdx
, 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 8 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 16 , 8 )
673 ^ bytebits_to_byte ( dest
+ startIdx
+ 24 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 32 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 40 , 8 )
674 ^ bytebits_to_byte ( dest
+ startIdx
+ 48 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 56 , 8 );
675 if ( checkCalc
!= 0xA8 ) return - 5 ;
676 if (* size
!= 64 ) return - 6 ;
677 //return start position
678 return ( int ) startIdx
;
681 // Ask/Biphase Demod then try to locate an ISO 11784/85 ID
682 // BitStream must contain previously askrawdemod and biphasedemoded data
683 int FDXBdemodBI ( uint8_t * dest
, size_t * size
)
685 //make sure buffer has enough data
686 if (* size
< 128 ) return - 1 ;
689 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
691 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
692 if ( errChk
== 0 ) return - 2 ; //preamble not found
693 return ( int ) startIdx
;
697 // FSK Demod then try to locate an AWID ID
698 int AWIDdemodFSK ( uint8_t * dest
, size_t * size
)
700 //make sure buffer has enough data
701 if (* size
< 96 * 50 ) return - 1 ;
703 if ( justNoise ( dest
, * size
)) return - 2 ;
706 * size
= fskdemod ( dest
, * size
, 50 , 1 , 10 , 8 ); // fsk2a RF/50
707 if (* size
< 96 ) return - 3 ; //did we get a good demod?
709 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
711 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
712 if ( errChk
== 0 ) return - 4 ; //preamble not found
713 if (* size
!= 96 ) return - 5 ;
714 return ( int ) startIdx
;
718 // FSK Demod then try to locate a Farpointe Data (pyramid) ID
719 int PyramiddemodFSK ( uint8_t * dest
, size_t * size
)
721 //make sure buffer has data
722 if (* size
< 128 * 50 ) return - 5 ;
724 //test samples are not just noise
725 if ( justNoise ( dest
, * size
)) return - 1 ;
728 * size
= fskdemod ( dest
, * size
, 50 , 1 , 10 , 8 ); // fsk2a RF/50
729 if (* size
< 128 ) return - 2 ; //did we get a good demod?
731 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
733 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
734 if ( errChk
== 0 ) return - 4 ; //preamble not found
735 if (* size
!= 128 ) return - 3 ;
736 return ( int ) startIdx
;
740 // to detect a wave that has heavily clipped (clean) samples
741 uint8_t DetectCleanAskWave ( uint8_t dest
[], size_t size
, uint8_t high
, uint8_t low
)
743 bool allArePeaks
= true ;
745 size_t loopEnd
= 512 + 160 ;
746 if ( loopEnd
> size
) loopEnd
= size
;
747 for ( size_t i
= 160 ; i
< loopEnd
; i
++){
748 if ( dest
[ i
]> low
&& dest
[ i
]< high
)
754 if ( cntPeaks
> 300 ) return true ;
759 // to help detect clocks on heavily clipped samples
760 // based on count of low to low
761 int DetectStrongAskClock ( uint8_t dest
[], size_t size
, uint8_t high
, uint8_t low
)
763 uint8_t fndClk
[] = { 8 , 16 , 32 , 40 , 50 , 64 , 128 };
767 // get to first full low to prime loop and skip incomplete first pulse
768 while (( dest
[ i
] < high
) && ( i
< size
))
770 while (( dest
[ i
] > low
) && ( i
< size
))
773 // loop through all samples
775 // measure from low to low
776 while (( dest
[ i
] > low
) && ( i
< size
))
779 while (( dest
[ i
] < high
) && ( i
< size
))
781 while (( dest
[ i
] > low
) && ( i
< size
))
783 //get minimum measured distance
784 if ( i
- startwave
< minClk
&& i
< size
)
785 minClk
= i
- startwave
;
788 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: detectstrongASKclk smallest wave: %d" , minClk
);
789 for ( uint8_t clkCnt
= 0 ; clkCnt
< 7 ; clkCnt
++) {
790 if ( minClk
>= fndClk
[ clkCnt
]-( fndClk
[ clkCnt
]/ 8 ) && minClk
<= fndClk
[ clkCnt
]+ 1 )
791 return fndClk
[ clkCnt
];
797 // not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)
798 // maybe somehow adjust peak trimming value based on samples to fix?
799 // return start index of best starting position for that clock and return clock (by reference)
800 int DetectASKClock ( uint8_t dest
[], size_t size
, int * clock
, int maxErr
)
803 uint8_t clk
[] = { 255 , 8 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 255 };
805 uint8_t loopCnt
= 255 ; //don't need to loop through entire array...
806 if ( size
<= loopCnt
+ 60 ) return - 1 ; //not enough samples
807 size
-= 60 ; //sometimes there is a strange end wave - filter out this....
808 //if we already have a valid clock
811 if ( clk
[ i
] == * clock
) clockFnd
= i
;
812 //clock found but continue to find best startpos
814 //get high and low peak
816 if ( getHiLo ( dest
, loopCnt
, & peak
, & low
, 75 , 75 ) < 1 ) return - 1 ;
818 //test for large clean peaks
820 if ( DetectCleanAskWave ( dest
, size
, peak
, low
)== 1 ){
821 int ans
= DetectStrongAskClock ( dest
, size
, peak
, low
);
822 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: detectaskclk Clean Ask Wave Detected: clk %d" , ans
);
823 for ( i
= clkEnd
- 1 ; i
> 0 ; i
--){
827 return 0 ; // for strong waves i don't use the 'best start position' yet...
828 //break; //clock found but continue to find best startpos [not yet]
834 uint8_t clkCnt
, tol
= 0 ;
835 uint16_t bestErr
[]={ 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 };
836 uint8_t bestStart
[]={ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
838 size_t arrLoc
, loopEnd
;
846 //test each valid clock from smallest to greatest to see which lines up
847 for (; clkCnt
< clkEnd
; clkCnt
++){
848 if ( clk
[ clkCnt
] <= 32 ){
853 //if no errors allowed - keep start within the first clock
854 if (! maxErr
&& size
> clk
[ clkCnt
]* 2 + tol
&& clk
[ clkCnt
]< 128 ) loopCnt
= clk
[ clkCnt
]* 2 ;
855 bestErr
[ clkCnt
]= 1000 ;
856 //try lining up the peaks by moving starting point (try first few clocks)
857 for ( ii
= 0 ; ii
< loopCnt
; ii
++){
858 if ( dest
[ ii
] < peak
&& dest
[ ii
] > low
) continue ;
861 // now that we have the first one lined up test rest of wave array
862 loopEnd
= (( size
- ii
- tol
) / clk
[ clkCnt
]) - 1 ;
863 for ( i
= 0 ; i
< loopEnd
; ++ i
){
864 arrLoc
= ii
+ ( i
* clk
[ clkCnt
]);
865 if ( dest
[ arrLoc
] >= peak
|| dest
[ arrLoc
] <= low
){
866 } else if ( dest
[ arrLoc
- tol
] >= peak
|| dest
[ arrLoc
- tol
] <= low
){
867 } else if ( dest
[ arrLoc
+ tol
] >= peak
|| dest
[ arrLoc
+ tol
] <= low
){
868 } else { //error no peak detected
872 //if we found no errors then we can stop here and a low clock (common clocks)
873 // this is correct one - return this clock
874 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: clk %d, err %d, startpos %d, endpos %d" , clk
[ clkCnt
], errCnt
, ii
, i
);
875 if ( errCnt
== 0 && clkCnt
< 7 ) {
876 if (! clockFnd
) * clock
= clk
[ clkCnt
];
879 //if we found errors see if it is lowest so far and save it as best run
880 if ( errCnt
< bestErr
[ clkCnt
]){
881 bestErr
[ clkCnt
]= errCnt
;
882 bestStart
[ clkCnt
]= ii
;
888 for ( iii
= 1 ; iii
< clkEnd
; ++ iii
){
889 if ( bestErr
[ iii
] < bestErr
[ best
]){
890 if ( bestErr
[ iii
] == 0 ) bestErr
[ iii
]= 1 ;
891 // current best bit to error ratio vs new bit to error ratio
892 if ( ( size
/ clk
[ best
])/ bestErr
[ best
] < ( size
/ clk
[ iii
])/ bestErr
[ iii
] ){
896 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
]);
898 if (! clockFnd
) * clock
= clk
[ best
];
899 return bestStart
[ best
];
903 //detect psk clock by reading each phase shift
904 // a phase shift is determined by measuring the sample length of each wave
905 int DetectPSKClock ( uint8_t dest
[], size_t size
, int clock
)
907 uint8_t clk
[]={ 255 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 255 }; //255 is not a valid clock
908 uint16_t loopCnt
= 4096 ; //don't need to loop through entire array...
909 if ( size
== 0 ) return 0 ;
910 if ( size
< loopCnt
) loopCnt
= size
- 20 ;
912 //if we already have a valid clock quit
915 if ( clk
[ i
] == clock
) return clock
;
917 size_t waveStart
= 0 , waveEnd
= 0 , firstFullWave
= 0 , lastClkBit
= 0 ;
918 uint8_t clkCnt
, fc
= 0 , fullWaveLen
= 0 , tol
= 1 ;
919 uint16_t peakcnt
= 0 , errCnt
= 0 , waveLenCnt
= 0 ;
920 uint16_t bestErr
[]={ 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 };
921 uint16_t peaksdet
[]={ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
922 fc
= countFC ( dest
, size
, 0 );
923 if ( fc
!= 2 && fc
!= 4 && fc
!= 8 ) return - 1 ;
924 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: FC: %d" , fc
);
926 //find first full wave
927 for ( i
= 160 ; i
< loopCnt
; i
++){
928 if ( dest
[ i
] < dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
929 if ( waveStart
== 0 ) {
931 //prnt("DEBUG: waveStart: %d",waveStart);
934 //prnt("DEBUG: waveEnd: %d",waveEnd);
935 waveLenCnt
= waveEnd
- waveStart
;
936 if ( waveLenCnt
> fc
){
937 firstFullWave
= waveStart
;
938 fullWaveLen
= waveLenCnt
;
945 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: firstFullWave: %d, waveLen: %d" , firstFullWave
, fullWaveLen
);
947 //test each valid clock from greatest to smallest to see which lines up
948 for ( clkCnt
= 7 ; clkCnt
>= 1 ; clkCnt
--){
949 lastClkBit
= firstFullWave
; //set end of wave as clock align
953 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: clk: %d, lastClkBit: %d" , clk
[ clkCnt
], lastClkBit
);
955 for ( i
= firstFullWave
+ fullWaveLen
- 1 ; i
< loopCnt
- 2 ; i
++){
956 //top edge of wave = start of new wave
957 if ( dest
[ i
] < dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
958 if ( waveStart
== 0 ) {
963 waveLenCnt
= waveEnd
- waveStart
;
964 if ( waveLenCnt
> fc
){
965 //if this wave is a phase shift
966 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
);
967 if ( i
+ 1 >= lastClkBit
+ clk
[ clkCnt
] - tol
){ //should be a clock bit
969 lastClkBit
+= clk
[ clkCnt
];
970 } else if ( i
< lastClkBit
+ 8 ){
971 //noise after a phase shift - ignore
972 } else { //phase shift before supposed to based on clock
975 } else if ( i
+ 1 > lastClkBit
+ clk
[ clkCnt
] + tol
+ fc
){
976 lastClkBit
+= clk
[ clkCnt
]; //no phase shift but clock bit
985 if ( errCnt
<= bestErr
[ clkCnt
]) bestErr
[ clkCnt
]= errCnt
;
986 if ( peakcnt
> peaksdet
[ clkCnt
]) peaksdet
[ clkCnt
]= peakcnt
;
988 //all tested with errors
989 //return the highest clk with the most peaks found
991 for ( i
= 7 ; i
>= 1 ; i
--){
992 if ( peaksdet
[ i
] > peaksdet
[ best
]) {
995 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: Clk: %d, peaks: %d, errs: %d, bestClk: %d" , clk
[ i
], peaksdet
[ i
], bestErr
[ i
], clk
[ best
]);
1000 int DetectStrongNRZClk ( uint8_t * dest
, size_t size
, int peak
, int low
){
1001 //find shortest transition from high to low
1003 size_t transition1
= 0 ;
1004 int lowestTransition
= 255 ;
1005 bool lastWasHigh
= false ;
1007 //find first valid beginning of a high or low wave
1008 while (( dest
[ i
] >= peak
|| dest
[ i
] <= low
) && ( i
< size
))
1010 while (( dest
[ i
] < peak
&& dest
[ i
] > low
) && ( i
< size
))
1012 lastWasHigh
= ( dest
[ i
] >= peak
);
1014 if ( i
== size
) return 0 ;
1017 for (; i
< size
; i
++) {
1018 if (( dest
[ i
] >= peak
&& ! lastWasHigh
) || ( dest
[ i
] <= low
&& lastWasHigh
)) {
1019 lastWasHigh
= ( dest
[ i
] >= peak
);
1020 if ( i
- transition1
< lowestTransition
) lowestTransition
= i
- transition1
;
1024 if ( lowestTransition
== 255 ) lowestTransition
= 0 ;
1025 if ( g_debugMode
== 2 ) prnt ( "DEBUG NRZ: detectstrongNRZclk smallest wave: %d" , lowestTransition
);
1026 return lowestTransition
;
1030 //detect nrz clock by reading #peaks vs no peaks(or errors)
1031 int DetectNRZClock ( uint8_t dest
[], size_t size
, int clock
)
1034 uint8_t clk
[]={ 8 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 255 };
1035 size_t loopCnt
= 4096 ; //don't need to loop through entire array...
1036 if ( size
== 0 ) return 0 ;
1037 if ( size
< loopCnt
) loopCnt
= size
- 20 ;
1038 //if we already have a valid clock quit
1040 if ( clk
[ i
] == clock
) return clock
;
1042 //get high and low peak
1044 if ( getHiLo ( dest
, loopCnt
, & peak
, & low
, 75 , 75 ) < 1 ) return 0 ;
1046 int lowestTransition
= DetectStrongNRZClk ( dest
, size
- 20 , peak
, low
);
1050 uint16_t smplCnt
= 0 ;
1051 int16_t peakcnt
= 0 ;
1052 int16_t peaksdet
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1053 uint16_t maxPeak
= 255 ;
1054 bool firstpeak
= false ;
1055 //test for large clipped waves
1056 for ( i
= 0 ; i
< loopCnt
; i
++){
1057 if ( dest
[ i
] >= peak
|| dest
[ i
] <= low
){
1058 if (! firstpeak
) continue ;
1063 if ( maxPeak
> smplCnt
){
1065 //prnt("maxPk: %d",maxPeak);
1068 //prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt);
1073 bool errBitHigh
= 0 ;
1075 uint8_t ignoreCnt
= 0 ;
1076 uint8_t ignoreWindow
= 4 ;
1077 bool lastPeakHigh
= 0 ;
1080 //test each valid clock from smallest to greatest to see which lines up
1081 for ( clkCnt
= 0 ; clkCnt
< 8 ; ++ clkCnt
){
1082 //ignore clocks smaller than smallest peak
1083 if ( clk
[ clkCnt
] < maxPeak
- ( clk
[ clkCnt
]/ 4 )) continue ;
1084 //try lining up the peaks by moving starting point (try first 256)
1085 for ( ii
= 20 ; ii
< loopCnt
; ++ ii
){
1086 if (( dest
[ ii
] >= peak
) || ( dest
[ ii
] <= low
)){
1090 lastBit
= ii
- clk
[ clkCnt
];
1091 //loop through to see if this start location works
1092 for ( i
= ii
; i
< size
- 20 ; ++ i
) {
1093 //if we are at a clock bit
1094 if (( i
>= lastBit
+ clk
[ clkCnt
] - tol
) && ( i
<= lastBit
+ clk
[ clkCnt
] + tol
)) {
1096 if ( dest
[ i
] >= peak
|| dest
[ i
] <= low
) {
1097 //if same peak don't count it
1098 if (( dest
[ i
] >= peak
&& ! lastPeakHigh
) || ( dest
[ i
] <= low
&& lastPeakHigh
)) {
1101 lastPeakHigh
= ( dest
[ i
] >= peak
);
1104 ignoreCnt
= ignoreWindow
;
1105 lastBit
+= clk
[ clkCnt
];
1106 } else if ( i
== lastBit
+ clk
[ clkCnt
] + tol
) {
1107 lastBit
+= clk
[ clkCnt
];
1109 //else if not a clock bit and no peaks
1110 } else if ( dest
[ i
] < peak
&& dest
[ i
] > low
){
1113 if ( errBitHigh
== true ) peakcnt
--;
1118 // else if not a clock bit but we have a peak
1119 } else if (( dest
[ i
]>= peak
|| dest
[ i
]<= low
) && (! bitHigh
)) {
1120 //error bar found no clock...
1124 if ( peakcnt
> peaksdet
[ clkCnt
]) {
1125 peaksdet
[ clkCnt
]= peakcnt
;
1132 for ( iii
= 7 ; iii
> 0 ; iii
--){
1133 if (( peaksdet
[ iii
] >= ( peaksdet
[ best
]- 1 )) && ( peaksdet
[ iii
] <= peaksdet
[ best
]+ 1 ) && lowestTransition
) {
1134 if ( clk
[ iii
] > ( lowestTransition
- ( clk
[ iii
]/ 8 )) && clk
[ iii
] < ( lowestTransition
+ ( clk
[ iii
]/ 8 ))) {
1137 } else if ( peaksdet
[ iii
] > peaksdet
[ best
]){
1140 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
);
1147 // convert psk1 demod to psk2 demod
1148 // only transition waves are 1s
1149 void psk1TOpsk2 ( uint8_t * BitStream
, size_t size
)
1152 uint8_t lastBit
= BitStream
[ 0 ];
1153 for (; i
< size
; i
++){
1154 if ( BitStream
[ i
]== 7 ){
1156 } else if ( lastBit
!= BitStream
[ i
]){
1157 lastBit
= BitStream
[ i
];
1167 // convert psk2 demod to psk1 demod
1168 // from only transition waves are 1s to phase shifts change bit
1169 void psk2TOpsk1 ( uint8_t * BitStream
, size_t size
)
1172 for ( size_t i
= 0 ; i
< size
; i
++){
1173 if ( BitStream
[ i
]== 1 ){
1181 // redesigned by marshmellow adjusted from existing decode functions
1182 // indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
1183 int indala26decode ( uint8_t * bitStream
, size_t * size
, uint8_t * invert
)
1185 //26 bit 40134 format (don't know other formats)
1186 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 };
1187 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 };
1188 size_t startidx
= 0 ;
1189 if (! preambleSearch ( bitStream
, preamble
, sizeof ( preamble
), size
, & startidx
)){
1190 // if didn't find preamble try again inverting
1191 if (! preambleSearch ( bitStream
, preamble_i
, sizeof ( preamble_i
), size
, & startidx
)) return - 1 ;
1194 if (* size
!= 64 && * size
!= 224 ) return - 2 ;
1196 for ( size_t i
= startidx
; i
< * size
; i
++)
1199 return ( int ) startidx
;
1202 // by marshmellow - demodulate NRZ wave
1203 // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
1204 int nrzRawDemod ( uint8_t * dest
, size_t * size
, int * clk
, int * invert
){
1205 if ( justNoise ( dest
, * size
)) return - 1 ;
1206 * clk
= DetectNRZClock ( dest
, * size
, * clk
);
1207 if (* clk
== 0 ) return - 2 ;
1208 size_t i
, gLen
= 4096 ;
1209 if ( gLen
>* size
) gLen
= * size
- 20 ;
1211 if ( getHiLo ( dest
, gLen
, & high
, & low
, 75 , 75 ) < 1 ) return - 3 ; //25% fuzz on high 25% fuzz on low
1214 //convert wave samples to 1's and 0's
1215 for ( i
= 20 ; i
< * size
- 20 ; i
++){
1216 if ( dest
[ i
] >= high
) bit
= 1 ;
1217 if ( dest
[ i
] <= low
) bit
= 0 ;
1220 //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit)
1223 for ( i
= 21 ; i
< * size
- 20 ; i
++) {
1224 //if transition detected or large number of same bits - store the passed bits
1225 if ( dest
[ i
] != dest
[ i
- 1 ] || ( i
- lastBit
) == ( 10 * * clk
)) {
1226 memset ( dest
+ numBits
, dest
[ i
- 1 ] ^ * invert
, ( i
- lastBit
+ (* clk
/ 4 )) / * clk
);
1227 numBits
+= ( i
- lastBit
+ (* clk
/ 4 )) / * clk
;
1236 //detects the bit clock for FSK given the high and low Field Clocks
1237 uint8_t detectFSKClk ( uint8_t * BitStream
, size_t size
, uint8_t fcHigh
, uint8_t fcLow
)
1239 uint8_t clk
[] = { 8 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 0 };
1240 uint16_t rfLens
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1241 uint8_t rfCnts
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1242 uint8_t rfLensFnd
= 0 ;
1243 uint8_t lastFCcnt
= 0 ;
1244 uint16_t fcCounter
= 0 ;
1245 uint16_t rfCounter
= 0 ;
1246 uint8_t firstBitFnd
= 0 ;
1248 if ( size
== 0 ) return 0 ;
1250 uint8_t fcTol
= (( fcHigh
* 100 - fcLow
* 100 )/ 2 + 50 )/ 100 ; //(uint8_t)(0.5+(float)(fcHigh-fcLow)/2);
1255 //PrintAndLog("DEBUG: fcTol: %d",fcTol);
1256 // prime i to first peak / up transition
1257 for ( i
= 160 ; i
< size
- 20 ; i
++)
1258 if ( BitStream
[ i
] > BitStream
[ i
- 1 ] && BitStream
[ i
]>= BitStream
[ i
+ 1 ])
1261 for (; i
< size
- 20 ; i
++){
1265 if ( BitStream
[ i
] <= BitStream
[ i
- 1 ] || BitStream
[ i
] < BitStream
[ i
+ 1 ])
1268 // if we got less than the small fc + tolerance then set it to the small fc
1269 if ( fcCounter
< fcLow
+ fcTol
)
1271 else //set it to the large fc
1274 //look for bit clock (rf/xx)
1275 if (( fcCounter
< lastFCcnt
|| fcCounter
> lastFCcnt
)){
1276 //not the same size as the last wave - start of new bit sequence
1277 if ( firstBitFnd
> 1 ){ //skip first wave change - probably not a complete bit
1278 for ( int ii
= 0 ; ii
< 15 ; ii
++){
1279 if ( rfLens
[ ii
] >= ( rfCounter
- 4 ) && rfLens
[ ii
] <= ( rfCounter
+ 4 )){
1285 if ( rfCounter
> 0 && rfLensFnd
< 15 ){
1286 //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
1287 rfCnts
[ rfLensFnd
]++;
1288 rfLens
[ rfLensFnd
++] = rfCounter
;
1294 lastFCcnt
= fcCounter
;
1298 uint8_t rfHighest
= 15 , rfHighest2
= 15 , rfHighest3
= 15 ;
1300 for ( i
= 0 ; i
< 15 ; i
++){
1301 //get highest 2 RF values (might need to get more values to compare or compare all?)
1302 if ( rfCnts
[ i
]> rfCnts
[ rfHighest
]){
1303 rfHighest3
= rfHighest2
;
1304 rfHighest2
= rfHighest
;
1306 } else if ( rfCnts
[ i
]> rfCnts
[ rfHighest2
]){
1307 rfHighest3
= rfHighest2
;
1309 } else if ( rfCnts
[ i
]> rfCnts
[ rfHighest3
]){
1312 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: RF %d, cnts %d" , rfLens
[ i
], rfCnts
[ i
]);
1314 // set allowed clock remainder tolerance to be 1 large field clock length+1
1315 // we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off
1316 uint8_t tol1
= fcHigh
+ 1 ;
1318 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: most counted rf values: 1 %d, 2 %d, 3 %d" , rfLens
[ rfHighest
], rfLens
[ rfHighest2
], rfLens
[ rfHighest3
]);
1320 // loop to find the highest clock that has a remainder less than the tolerance
1321 // compare samples counted divided by
1322 // test 128 down to 32 (shouldn't be possible to have fc/10 & fc/8 and rf/16 or less)
1324 for (; ii
>= 2 ; ii
--){
1325 if ( rfLens
[ rfHighest
] % clk
[ ii
] < tol1
|| rfLens
[ rfHighest
] % clk
[ ii
] > clk
[ ii
]- tol1
){
1326 if ( rfLens
[ rfHighest2
] % clk
[ ii
] < tol1
|| rfLens
[ rfHighest2
] % clk
[ ii
] > clk
[ ii
]- tol1
){
1327 if ( rfLens
[ rfHighest3
] % clk
[ ii
] < tol1
|| rfLens
[ rfHighest3
] % clk
[ ii
] > clk
[ ii
]- tol1
){
1328 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: clk %d divides into the 3 most rf values within tolerance" , clk
[ ii
]);
1335 if ( ii
< 0 ) return 0 ; // oops we went too far
1341 //countFC is to detect the field clock lengths.
1342 //counts and returns the 2 most common wave lengths
1343 //mainly used for FSK field clock detection
1344 uint16_t countFC ( uint8_t * BitStream
, size_t size
, uint8_t fskAdj
)
1346 uint8_t fcLens
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1347 uint16_t fcCnts
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1348 uint8_t fcLensFnd
= 0 ;
1349 uint8_t lastFCcnt
= 0 ;
1350 uint8_t fcCounter
= 0 ;
1352 if ( size
== 0 ) return 0 ;
1354 // prime i to first up transition
1355 for ( i
= 160 ; i
< size
- 20 ; i
++)
1356 if ( BitStream
[ i
] > BitStream
[ i
- 1 ] && BitStream
[ i
] >= BitStream
[ i
+ 1 ])
1359 for (; i
< size
- 20 ; i
++){
1360 if ( BitStream
[ i
] > BitStream
[ i
- 1 ] && BitStream
[ i
] >= BitStream
[ i
+ 1 ]){
1361 // new up transition
1364 //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8)
1365 if ( lastFCcnt
== 5 && fcCounter
== 9 ) fcCounter
--;
1366 //if fc=9 or 4 add one (for when we get a fc 9 instead of 10 or a 4 instead of a 5)
1367 if (( fcCounter
== 9 ) || fcCounter
== 4 ) fcCounter
++;
1368 // save last field clock count (fc/xx)
1369 lastFCcnt
= fcCounter
;
1371 // find which fcLens to save it to:
1372 for ( int ii
= 0 ; ii
< 15 ; ii
++){
1373 if ( fcLens
[ ii
]== fcCounter
){
1379 if ( fcCounter
> 0 && fcLensFnd
< 15 ){
1381 fcCnts
[ fcLensFnd
]++;
1382 fcLens
[ fcLensFnd
++]= fcCounter
;
1391 uint8_t best1
= 14 , best2
= 14 , best3
= 14 ;
1393 // go through fclens and find which ones are bigest 2
1394 for ( i
= 0 ; i
< 15 ; i
++){
1395 // get the 3 best FC values
1396 if ( fcCnts
[ i
]> maxCnt1
) {
1401 } else if ( fcCnts
[ i
]> fcCnts
[ best2
]){
1404 } else if ( fcCnts
[ i
]> fcCnts
[ best3
]){
1407 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
]);
1409 if ( fcLens
[ best1
]== 0 ) return 0 ;
1410 uint8_t fcH
= 0 , fcL
= 0 ;
1411 if ( fcLens
[ best1
]> fcLens
[ best2
]){
1418 if (( size
- 180 )/ fcH
/ 3 > fcCnts
[ best1
]+ fcCnts
[ best2
]) {
1419 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
]);
1420 return 0 ; //lots of waves not psk or fsk
1422 // TODO: take top 3 answers and compare to known Field clocks to get top 2
1424 uint16_t fcs
= ((( uint16_t ) fcH
)<< 8 ) | fcL
;
1425 if ( fskAdj
) return fcs
;
1426 return fcLens
[ best1
];
1429 //by marshmellow - demodulate PSK1 wave
1430 //uses wave lengths (# Samples)
1431 int pskRawDemod ( uint8_t dest
[], size_t * size
, int * clock
, int * invert
)
1433 if ( size
== 0 ) return - 1 ;
1434 uint16_t loopCnt
= 4096 ; //don't need to loop through entire array...
1435 if (* size
< loopCnt
) loopCnt
= * size
;
1438 uint8_t curPhase
= * invert
;
1439 size_t i
, waveStart
= 1 , waveEnd
= 0 , firstFullWave
= 0 , lastClkBit
= 0 ;
1440 uint8_t fc
= 0 , fullWaveLen
= 0 , tol
= 1 ;
1441 uint16_t errCnt
= 0 , waveLenCnt
= 0 ;
1442 fc
= countFC ( dest
, * size
, 0 );
1443 if ( fc
!= 2 && fc
!= 4 && fc
!= 8 ) return - 1 ;
1444 //PrintAndLog("DEBUG: FC: %d",fc);
1445 * clock
= DetectPSKClock ( dest
, * size
, * clock
);
1446 if (* clock
== 0 ) return - 1 ;
1447 int avgWaveVal
= 0 , lastAvgWaveVal
= 0 ;
1448 //find first phase shift
1449 for ( i
= 0 ; i
< loopCnt
; i
++){
1450 if ( dest
[ i
]+ fc
< dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
1452 //PrintAndLog("DEBUG: waveEnd: %d",waveEnd);
1453 waveLenCnt
= waveEnd
- waveStart
;
1454 if ( waveLenCnt
> fc
&& waveStart
> fc
&& !( waveLenCnt
> fc
+ 2 )){ //not first peak and is a large wave but not out of whack
1455 lastAvgWaveVal
= avgWaveVal
/( waveLenCnt
);
1456 firstFullWave
= waveStart
;
1457 fullWaveLen
= waveLenCnt
;
1458 //if average wave value is > graph 0 then it is an up wave or a 1
1459 if ( lastAvgWaveVal
> 123 ) curPhase
^= 1 ; //fudge graph 0 a little 123 vs 128
1465 avgWaveVal
+= dest
[ i
+ 2 ];
1467 if ( firstFullWave
== 0 ) {
1468 // no phase shift detected - could be all 1's or 0's - doesn't matter where we start
1469 // so skip a little to ensure we are past any Start Signal
1470 firstFullWave
= 160 ;
1471 memset ( dest
, curPhase
, firstFullWave
/ * clock
);
1473 memset ( dest
, curPhase
^ 1 , firstFullWave
/ * clock
);
1476 numBits
+= ( firstFullWave
/ * clock
);
1477 //set start of wave as clock align
1478 lastClkBit
= firstFullWave
;
1479 //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);
1480 //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d", *clock, lastClkBit);
1482 dest
[ numBits
++] = curPhase
; //set first read bit
1483 for ( i
= firstFullWave
+ fullWaveLen
- 1 ; i
< * size
- 3 ; i
++){
1484 //top edge of wave = start of new wave
1485 if ( dest
[ i
]+ fc
< dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
1486 if ( waveStart
== 0 ) {
1489 avgWaveVal
= dest
[ i
+ 1 ];
1492 waveLenCnt
= waveEnd
- waveStart
;
1493 lastAvgWaveVal
= avgWaveVal
/ waveLenCnt
;
1494 if ( waveLenCnt
> fc
){
1495 //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);
1496 //this wave is a phase shift
1497 //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc);
1498 if ( i
+ 1 >= lastClkBit
+ * clock
- tol
){ //should be a clock bit
1500 dest
[ numBits
++] = curPhase
;
1501 lastClkBit
+= * clock
;
1502 } else if ( i
< lastClkBit
+ 10 + fc
){
1503 //noise after a phase shift - ignore
1504 } else { //phase shift before supposed to based on clock
1506 dest
[ numBits
++] = 7 ;
1508 } else if ( i
+ 1 > lastClkBit
+ * clock
+ tol
+ fc
){
1509 lastClkBit
+= * clock
; //no phase shift but clock bit
1510 dest
[ numBits
++] = curPhase
;
1516 avgWaveVal
+= dest
[ i
+ 1 ];