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git.zerfleddert.de Git - proxmark3-svn/blob - common/lfdemod.c
721c9d1c3520f8ce3952d5b06f203279faeea0cf
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 - by marshmellow, holiman, iceman and
9 // many others who came before
12 // LF Demod functions are placed here to allow the flexability to use client or
13 // device side. Most BUT NOT ALL of these functions are currenlty safe for
14 // device side use currently. (DetectST for example...)
16 // There are likely many improvements to the code that could be made, please
17 // make suggestions...
19 // we tried to include author comments so any questions could be directed to
22 // There are 4 main sections of code below:
24 // for general utilities used by multiple other functions
25 // Modulation Demods &/or Decoding Section:
26 // for main general modulation demodulating and encoding decoding code.
27 // Clock / Bitrate Detection Section:
28 // for clock detection functions for each modulation
29 // Tag format detection section:
30 // for detection of specific tag formats within demodulated data
33 //-----------------------------------------------------------------------------
39 //---------------------------------Utilities Section--------------------------------------------------
41 //to allow debug print calls when used not on device
42 void dummy ( char * fmt
, ...){}
45 #include "cmdparser.h"
47 #define prnt PrintAndLog
49 uint8_t g_debugMode
= 0 ;
53 uint8_t justNoise ( uint8_t * BitStream
, size_t size
) {
54 static const uint8_t THRESHOLD
= 123 ;
55 //test samples are not just noise
56 uint8_t justNoise1
= 1 ;
57 for ( size_t idx
= 0 ; idx
< size
&& justNoise1
; idx
++){
58 justNoise1
= BitStream
[ idx
] < THRESHOLD
;
64 //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
65 int getHiLo ( uint8_t * BitStream
, size_t size
, int * high
, int * low
, uint8_t fuzzHi
, uint8_t fuzzLo
) {
68 // get high and low thresholds
69 for ( size_t i
= 0 ; i
< size
; i
++){
70 if ( BitStream
[ i
] > * high
) * high
= BitStream
[ i
];
71 if ( BitStream
[ i
] < * low
) * low
= BitStream
[ i
];
73 if (* high
< 123 ) return - 1 ; // just noise
74 * high
= ((* high
- 128 )* fuzzHi
+ 12800 )/ 100 ;
75 * low
= ((* low
- 128 )* fuzzLo
+ 12800 )/ 100 ;
80 // pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType
81 // returns 1 if passed
82 uint8_t parityTest ( uint32_t bits
, uint8_t bitLen
, uint8_t pType
) {
84 for ( uint8_t i
= 0 ; i
< bitLen
; i
++){
85 ans
^= (( bits
>> i
) & 1 );
87 if ( g_debugMode
) prnt ( "DEBUG: ans: %d, ptype: %d, bits: %08X" , ans
, pType
, bits
);
88 return ( ans
== pType
);
92 // takes a array of binary values, start position, length of bits per parity (includes parity bit),
93 // Parity Type (1 for odd; 0 for even; 2 for Always 1's; 3 for Always 0's), and binary Length (length to run)
94 size_t removeParity ( uint8_t * BitStream
, size_t startIdx
, uint8_t pLen
, uint8_t pType
, size_t bLen
) {
95 uint32_t parityWd
= 0 ;
96 size_t j
= 0 , bitCnt
= 0 ;
97 for ( int word
= 0 ; word
< ( bLen
); word
+= pLen
) {
98 for ( int bit
= 0 ; bit
< pLen
; bit
++) {
99 parityWd
= ( parityWd
<< 1 ) | BitStream
[ startIdx
+ word
+ bit
];
100 BitStream
[ j
++] = ( BitStream
[ startIdx
+ word
+ bit
]);
102 if ( word
+ pLen
> bLen
) break ;
104 j
--; // overwrite parity with next data
105 // if parity fails then return 0
107 case 3 : if ( BitStream
[ j
]== 1 ) { return 0 ;} break ; //should be 0 spacer bit
108 case 2 : if ( BitStream
[ j
]== 0 ) { return 0 ;} break ; //should be 1 spacer bit
109 default : if ( parityTest ( parityWd
, pLen
, pType
) == 0 ) { return 0 ;} break ; //test parity
114 // if we got here then all the parities passed
115 //return ID start index and size
120 // takes a array of binary values, length of bits per parity (includes parity bit),
121 // Parity Type (1 for odd; 0 for even; 2 Always 1's; 3 Always 0's), and binary Length (length to run)
122 // Make sure *dest is long enough to store original sourceLen + #_of_parities_to_be_added
123 size_t addParity ( uint8_t * BitSource
, uint8_t * dest
, uint8_t sourceLen
, uint8_t pLen
, uint8_t pType
) {
124 uint32_t parityWd
= 0 ;
125 size_t j
= 0 , bitCnt
= 0 ;
126 for ( int word
= 0 ; word
< sourceLen
; word
+= pLen
- 1 ) {
127 for ( int bit
= 0 ; bit
< pLen
- 1 ; bit
++){
128 parityWd
= ( parityWd
<< 1 ) | BitSource
[ word
+ bit
];
129 dest
[ j
++] = ( BitSource
[ word
+ bit
]);
131 // if parity fails then return 0
133 case 3 : dest
[ j
++]= 0 ; break ; // marker bit which should be a 0
134 case 2 : dest
[ j
++]= 1 ; break ; // marker bit which should be a 1
136 dest
[ j
++] = parityTest ( parityWd
, pLen
- 1 , pType
) ^ 1 ;
142 // if we got here then all the parities passed
143 //return ID start index and size
147 uint32_t bytebits_to_byte ( uint8_t * src
, size_t numbits
) {
149 for ( int i
= 0 ; i
< numbits
; i
++)
151 num
= ( num
<< 1 ) | (* src
);
157 //least significant bit first
158 uint32_t bytebits_to_byteLSBF ( uint8_t * src
, size_t numbits
) {
160 for ( int i
= 0 ; i
< numbits
; i
++)
162 num
= ( num
<< 1 ) | *( src
+ ( numbits
-( i
+ 1 )));
167 // 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
168 // fineone does not look for a repeating preamble for em4x05/4x69 sends preamble once, so look for it once in the first pLen bits
169 bool preambleSearchEx ( uint8_t * BitStream
, uint8_t * preamble
, size_t pLen
, size_t * size
, size_t * startIdx
, bool findone
) {
170 // Sanity check. If preamble length is bigger than bitstream length.
171 if ( * size
<= pLen
) return false ;
173 uint8_t foundCnt
= 0 ;
174 for ( size_t idx
= 0 ; idx
< * size
- pLen
; idx
++) {
175 if ( memcmp ( BitStream
+ idx
, preamble
, pLen
) == 0 ) {
179 if ( g_debugMode
) prnt ( "DEBUG: preamble found at %u" , idx
);
181 if ( findone
) return true ;
182 } else if ( foundCnt
== 2 ) {
183 * size
= idx
- * startIdx
;
192 //search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length
193 uint8_t preambleSearch ( uint8_t * BitStream
, uint8_t * preamble
, size_t pLen
, size_t * size
, size_t * startIdx
) {
194 return ( preambleSearchEx ( BitStream
, preamble
, pLen
, size
, startIdx
, false )) ? 1 : 0 ;
197 // find start of modulating data (for fsk and psk) in case of beginning noise or slow chip startup.
198 size_t findModStart ( uint8_t dest
[], size_t size
, uint8_t threshold_value
, uint8_t expWaveSize
) {
200 size_t waveSizeCnt
= 0 ;
201 uint8_t thresholdCnt
= 0 ;
202 bool isAboveThreshold
= dest
[ i
++] >= threshold_value
;
203 for (; i
< size
- 20 ; i
++ ) {
204 if ( dest
[ i
] < threshold_value
&& isAboveThreshold
) {
206 if ( thresholdCnt
> 2 && waveSizeCnt
< expWaveSize
+ 1 ) break ;
207 isAboveThreshold
= false ;
209 } else if ( dest
[ i
] >= threshold_value
&& ! isAboveThreshold
) {
211 if ( thresholdCnt
> 2 && waveSizeCnt
< expWaveSize
+ 1 ) break ;
212 isAboveThreshold
= true ;
217 if ( thresholdCnt
> 10 ) break ;
219 if ( g_debugMode
== 2 ) prnt ( "DEBUG: threshold Count reached at %u, count: %u" , i
, thresholdCnt
);
224 //amplify based on ask edge detection - not accurate enough to use all the time
225 void askAmp ( uint8_t * BitStream
, size_t size
) {
227 for ( size_t i
= 1 ; i
< size
; i
++){
228 if ( BitStream
[ i
]- BitStream
[ i
- 1 ]>= 30 ) //large jump up
230 else if ( BitStream
[ i
- 1 ]- BitStream
[ i
]>= 20 ) //large jump down
233 BitStream
[ i
- 1 ] = Last
;
238 uint32_t manchesterEncode2Bytes ( uint16_t datain
) {
241 for ( uint8_t i
= 0 ; i
< 16 ; i
++) {
242 curBit
= ( datain
>> ( 15 - i
) & 1 );
243 output
|= ( 1 <<((( 15 - i
)* 2 )+ curBit
));
249 //encode binary data into binary manchester
250 //NOTE: BitStream must have double the size available in memory to do the swap
251 int ManchesterEncode ( uint8_t * BitStream
, size_t size
) {
252 size_t modIdx
= size
, i
= 0 ;
253 if ( size
> modIdx
) return - 1 ;
254 for ( size_t idx
= 0 ; idx
< size
; idx
++){
255 BitStream
[ idx
+ modIdx
++] = BitStream
[ idx
];
256 BitStream
[ idx
+ modIdx
++] = BitStream
[ idx
]^ 1 ;
258 for (; i
<( size
* 2 ); i
++){
259 BitStream
[ i
] = BitStream
[ i
+ size
];
264 //------------------------------Modulation Demods &/or Decoding Section------------------------------------------------------
266 // look for Sequence Terminator - should be pulses of clk*(1 or 2), clk*2, clk*(1.5 or 2), by idx we mean graph position index...
267 bool findST ( int * stStopLoc
, int * stStartIdx
, int lowToLowWaveLen
[], int highToLowWaveLen
[], int clk
, int tol
, int buffSize
, int i
) {
268 for (; i
< buffSize
- 4 ; ++ i
) {
269 * stStartIdx
+= lowToLowWaveLen
[ i
]; //caution part of this wave may be data and part may be ST.... to be accounted for in main function for now...
270 if ( lowToLowWaveLen
[ i
] >= clk
* 1 - tol
&& lowToLowWaveLen
[ i
] <= ( clk
* 2 )+ tol
&& highToLowWaveLen
[ i
] < clk
+ tol
) { //1 to 2 clocks depending on 2 bits prior
271 if ( lowToLowWaveLen
[ i
+ 1 ] >= clk
* 2 - tol
&& lowToLowWaveLen
[ i
+ 1 ] <= clk
* 2 + tol
&& highToLowWaveLen
[ i
+ 1 ] > clk
* 3 / 2 - tol
) { //2 clocks and wave size is 1 1/2
272 if ( lowToLowWaveLen
[ i
+ 2 ] >= ( clk
* 3 )/ 2 - tol
&& lowToLowWaveLen
[ i
+ 2 ] <= clk
* 2 + tol
&& highToLowWaveLen
[ i
+ 2 ] > clk
- tol
) { //1 1/2 to 2 clocks and at least one full clock wave
273 if ( lowToLowWaveLen
[ i
+ 3 ] >= clk
* 1 - tol
&& lowToLowWaveLen
[ i
+ 3 ] <= clk
* 2 + tol
) { //1 to 2 clocks for end of ST + first bit
284 //attempt to identify a Sequence Terminator in ASK modulated raw wave
285 bool DetectST_ext ( uint8_t buffer
[], size_t * size
, int * foundclock
, size_t * ststart
, size_t * stend
) {
286 size_t bufsize
= * size
;
287 //need to loop through all samples and identify our clock, look for the ST pattern
288 uint8_t fndClk
[] = { 8 , 16 , 32 , 40 , 50 , 64 , 128 };
291 int i
, j
, skip
, start
, end
, low
, high
, minClk
, waveStart
;
292 //probably should malloc... || test if memory is available ... handle device side? memory danger!!! [marshmellow]
293 int tmpbuff
[ bufsize
/ 32 ]; // low to low wave count //guess rf/32 clock, if click is smaller we will only have room for a fraction of the samples captured
294 int waveLen
[ bufsize
/ 32 ]; // high to low wave count //if clock is larger then we waste memory in array size that is not needed...
295 size_t testsize
= ( bufsize
< 512 ) ? bufsize
: 512 ;
298 memset ( tmpbuff
, 0 , sizeof ( tmpbuff
));
300 if ( getHiLo ( buffer
, testsize
, & high
, & low
, 80 , 80 ) == - 1 ) {
301 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: just noise detected - quitting" );
302 return false ; //just noise
307 // get to first full low to prime loop and skip incomplete first pulse
308 while (( buffer
[ i
] < high
) && ( i
< bufsize
))
310 while (( buffer
[ i
] > low
) && ( i
< bufsize
))
314 // populate tmpbuff buffer with pulse lengths
315 while ( i
< bufsize
) {
316 // measure from low to low
317 while (( buffer
[ i
] > low
) && ( i
< bufsize
))
320 while (( buffer
[ i
] < high
) && ( i
< bufsize
))
322 //first high point for this wave
324 while (( buffer
[ i
] > low
) && ( i
< bufsize
))
326 if ( j
>= ( bufsize
/ 32 )) {
329 waveLen
[ j
] = i
- waveStart
; //first high to first low
330 tmpbuff
[ j
++] = i
- start
;
331 if ( i
- start
< minClk
&& i
< bufsize
) {
335 // set clock - might be able to get this externally and remove this work...
337 for ( uint8_t clkCnt
= 0 ; clkCnt
< 7 ; clkCnt
++) {
338 tol
= fndClk
[ clkCnt
]/ 8 ;
339 if ( minClk
>= fndClk
[ clkCnt
]- tol
&& minClk
<= fndClk
[ clkCnt
]+ 1 ) {
344 // clock not found - ERROR
346 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: clock not found - quitting" );
353 if (! findST (& start
, & skip
, tmpbuff
, waveLen
, clk
, tol
, j
, i
)) {
354 // first ST not found - ERROR
355 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: first STT not found - quitting" );
358 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: first STT found at: %d, j=%d" , start
, j
);
360 if ( waveLen
[ i
+ 2 ] > clk
* 1 + tol
)
365 // skip over the remainder of ST
366 skip
+= clk
* 7 / 2 ; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point
368 // now do it again to find the end
371 if (! findST (& dummy1
, & end
, tmpbuff
, waveLen
, clk
, tol
, j
, i
+ 3 )) {
372 //didn't find second ST - ERROR
373 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: second STT not found - quitting" );
377 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
);
378 //now begin to trim out ST so we can use normal demod cmds
380 size_t datalen
= end
- start
;
381 // check validity of datalen (should be even clock increments) - use a tolerance of up to 1/8th a clock
382 if ( clk
- ( datalen
% clk
) <= clk
/ 8 ) {
383 // padd the amount off - could be problematic... but shouldn't happen often
384 datalen
+= clk
- ( datalen
% clk
);
385 } else if ( ( datalen
% clk
) <= clk
/ 8 ) {
386 // padd the amount off - could be problematic... but shouldn't happen often
387 datalen
-= datalen
% clk
;
389 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting" , datalen
, clk
, datalen
% clk
);
392 // if datalen is less than one t55xx block - ERROR
393 if ( datalen
/ clk
< 8 * 4 ) {
394 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: datalen is less than 1 full t55xx block - quitting" );
397 size_t dataloc
= start
;
398 if ( buffer
[ dataloc
-( clk
* 4 )-( clk
/ 8 )] <= low
&& buffer
[ dataloc
] <= low
&& buffer
[ dataloc
-( clk
* 4 )] >= high
) {
399 //we have low drift (and a low just before the ST and a low just after the ST) - compensate by backing up the start
400 for ( i
= 0 ; i
<= ( clk
/ 8 ); ++ i
) {
401 if ( buffer
[ dataloc
- ( clk
* 4 ) - i
] <= low
) {
410 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: Starting STT trim - start: %d, datalen: %d " , dataloc
, datalen
);
411 bool firstrun
= true ;
412 // warning - overwriting buffer given with raw wave data with ST removed...
413 while ( dataloc
< bufsize
-( clk
/ 2 ) ) {
414 //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)
415 if ( buffer
[ dataloc
]< high
&& buffer
[ dataloc
]> low
&& buffer
[ dataloc
+ 3 ]< high
&& buffer
[ dataloc
+ 3 ]> low
) {
416 for ( i
= 0 ; i
< clk
/ 2 - tol
; ++ i
) {
417 buffer
[ dataloc
+ i
] = high
+ 5 ;
419 } //test for single sample outlier (high between two lows) in the case of very strong waves
420 if ( buffer
[ dataloc
] >= high
&& buffer
[ dataloc
+ 2 ] <= low
) {
421 buffer
[ dataloc
] = buffer
[ dataloc
+ 2 ];
422 buffer
[ dataloc
+ 1 ] = buffer
[ dataloc
+ 2 ];
426 * ststart
= dataloc
-( clk
* 4 );
429 for ( i
= 0 ; i
< datalen
; ++ i
) {
430 if ( i
+ newloc
< bufsize
) {
431 if ( i
+ newloc
< dataloc
)
432 buffer
[ i
+ newloc
] = buffer
[ dataloc
];
438 //skip next ST - we just assume it will be there from now on...
439 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: skipping STT at %d to %d" , dataloc
, dataloc
+( clk
* 4 ));
445 bool DetectST ( uint8_t buffer
[], size_t * size
, int * foundclock
) {
446 size_t ststart
= 0 , stend
= 0 ;
447 return DetectST_ext ( buffer
, size
, foundclock
, & ststart
, & stend
);
451 //take 01 or 10 = 1 and 11 or 00 = 0
452 //check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010
453 //decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding
454 int BiphaseRawDecode ( uint8_t * BitStream
, size_t * size
, int offset
, int invert
) {
458 uint16_t MaxBits
= 512 ;
459 //if not enough samples - error
460 if (* size
< 51 ) return - 1 ;
461 //check for phase change faults - skip one sample if faulty
462 uint8_t offsetA
= 1 , offsetB
= 1 ;
464 if ( BitStream
[ i
+ 1 ]== BitStream
[ i
+ 2 ]) offsetA
= 0 ;
465 if ( BitStream
[ i
+ 2 ]== BitStream
[ i
+ 3 ]) offsetB
= 0 ;
467 if (! offsetA
&& offsetB
) offset
++;
468 for ( i
= offset
; i
<* size
- 3 ; i
+= 2 ){
469 //check for phase error
470 if ( BitStream
[ i
+ 1 ]== BitStream
[ i
+ 2 ]) {
471 BitStream
[ bitnum
++]= 7 ;
474 if (( BitStream
[ i
]== 1 && BitStream
[ i
+ 1 ]== 0 ) || ( BitStream
[ i
]== 0 && BitStream
[ i
+ 1 ]== 1 )){
475 BitStream
[ bitnum
++]= 1 ^ invert
;
476 } else if (( BitStream
[ i
]== 0 && BitStream
[ i
+ 1 ]== 0 ) || ( BitStream
[ i
]== 1 && BitStream
[ i
+ 1 ]== 1 )){
477 BitStream
[ bitnum
++]= invert
;
479 BitStream
[ bitnum
++]= 7 ;
482 if ( bitnum
> MaxBits
) break ;
489 //take 10 and 01 and manchester decode
490 //run through 2 times and take least errCnt
491 int manrawdecode ( uint8_t * BitStream
, size_t * size
, uint8_t invert
, uint8_t * alignPos
) {
492 uint16_t bitnum
= 0 , MaxBits
= 512 , errCnt
= 0 ;
494 uint16_t bestErr
= 1000 , bestRun
= 0 ;
495 if (* size
< 16 ) return - 1 ;
496 //find correct start position [alignment]
497 for ( ii
= 0 ; ii
< 2 ;++ ii
){
498 for ( i
= ii
; i
<* size
- 3 ; i
+= 2 )
499 if ( BitStream
[ i
]== BitStream
[ i
+ 1 ])
510 for ( i
= bestRun
; i
< * size
- 3 ; i
+= 2 ){
511 if ( BitStream
[ i
] == 1 && ( BitStream
[ i
+ 1 ] == 0 )){
512 BitStream
[ bitnum
++]= invert
;
513 } else if (( BitStream
[ i
] == 0 ) && BitStream
[ i
+ 1 ] == 1 ){
514 BitStream
[ bitnum
++]= invert
^ 1 ;
516 BitStream
[ bitnum
++]= 7 ;
518 if ( bitnum
> MaxBits
) break ;
525 // to detect a wave that has heavily clipped (clean) samples
526 uint8_t DetectCleanAskWave ( uint8_t dest
[], size_t size
, uint8_t high
, uint8_t low
) {
527 bool allArePeaks
= true ;
529 size_t loopEnd
= 512 + 160 ;
530 if ( loopEnd
> size
) loopEnd
= size
;
531 for ( size_t i
= 160 ; i
< loopEnd
; i
++){
532 if ( dest
[ i
]> low
&& dest
[ i
]< high
)
538 if ( cntPeaks
> 300 ) return true ;
544 //demodulates strong heavily clipped samples
545 int cleanAskRawDemod ( uint8_t * BinStream
, size_t * size
, int clk
, int invert
, int high
, int low
, int * startIdx
)
548 size_t bitCnt
= 0 , smplCnt
= 1 , errCnt
= 0 ;
549 bool waveHigh
= ( BinStream
[ 0 ] >= high
);
550 for ( size_t i
= 1 ; i
< * size
; i
++){
551 if ( BinStream
[ i
] >= high
&& waveHigh
){
553 } else if ( BinStream
[ i
] <= low
&& ! waveHigh
){
555 } else { //transition
556 if (( BinStream
[ i
] >= high
&& ! waveHigh
) || ( BinStream
[ i
] <= low
&& waveHigh
)){
557 if ( smplCnt
> clk
-( clk
/ 4 )- 1 ) { //full clock
558 if ( smplCnt
> clk
+ ( clk
/ 4 )+ 1 ) { //too many samples
560 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Modulation Error at: %u" , i
);
561 BinStream
[ bitCnt
++] = 7 ;
562 } else if ( waveHigh
) {
563 BinStream
[ bitCnt
++] = invert
;
564 BinStream
[ bitCnt
++] = invert
;
565 } else if (! waveHigh
) {
566 BinStream
[ bitCnt
++] = invert
^ 1 ;
567 BinStream
[ bitCnt
++] = invert
^ 1 ;
569 if (* startIdx
== 0 ) * startIdx
= i
- clk
;
570 waveHigh
= ! waveHigh
;
572 } else if ( smplCnt
> ( clk
/ 2 ) - ( clk
/ 4 )- 1 ) { //half clock
574 BinStream
[ bitCnt
++] = invert
;
575 } else if (! waveHigh
) {
576 BinStream
[ bitCnt
++] = invert
^ 1 ;
578 if (* startIdx
== 0 ) * startIdx
= i
-( clk
/ 2 );
579 waveHigh
= ! waveHigh
;
583 //transition bit oops
585 } else { //haven't hit new high or new low yet
595 //attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester
596 int askdemod_ext ( uint8_t * BinStream
, size_t * size
, int * clk
, int * invert
, int maxErr
, uint8_t amp
, uint8_t askType
, int * startIdx
) {
597 if (* size
== 0 ) return - 1 ;
598 int start
= DetectASKClock ( BinStream
, * size
, clk
, maxErr
); //clock default
599 if (* clk
== 0 || start
< 0 ) return - 3 ;
600 if (* invert
!= 1 ) * invert
= 0 ;
601 if ( amp
== 1 ) askAmp ( BinStream
, * size
);
602 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: clk %d, beststart %d, amp %d" , * clk
, start
, amp
);
604 //start pos from detect ask clock is 1/2 clock offset
605 // NOTE: can be negative (demod assumes rest of wave was there)
606 * startIdx
= start
- (* clk
/ 2 );
607 uint8_t initLoopMax
= 255 ;
608 if ( initLoopMax
> * size
) initLoopMax
= * size
;
609 // Detect high and lows
610 //25% clip in case highs and lows aren't clipped [marshmellow]
612 if ( getHiLo ( BinStream
, initLoopMax
, & high
, & low
, 75 , 75 ) < 1 )
613 return - 2 ; //just noise
616 // if clean clipped waves detected run alternate demod
617 if ( DetectCleanAskWave ( BinStream
, * size
, high
, low
)) {
618 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Clean Wave Detected - using clean wave demod" );
619 errCnt
= cleanAskRawDemod ( BinStream
, size
, * clk
, * invert
, high
, low
, startIdx
);
620 if ( askType
) { //askman
621 uint8_t alignPos
= 0 ;
622 errCnt
= manrawdecode ( BinStream
, size
, 0 , & alignPos
);
623 * startIdx
+= * clk
/ 2 * alignPos
;
624 if ( g_debugMode
) prnt ( "DEBUG ASK CLEAN: startIdx %i, alignPos %u" , * startIdx
, alignPos
);
630 if ( g_debugMode
) prnt ( "DEBUG ASK WEAK: startIdx %i" , * startIdx
);
631 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Weak Wave Detected - using weak wave demod" );
633 int lastBit
; //set first clock check - can go negative
634 size_t i
, bitnum
= 0 ; //output counter
636 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
637 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
638 size_t MaxBits
= 3072 ; //max bits to collect
639 lastBit
= start
- * clk
;
641 for ( i
= start
; i
< * size
; ++ i
) {
642 if ( i
- lastBit
>= * clk
- tol
){
643 if ( BinStream
[ i
] >= high
) {
644 BinStream
[ bitnum
++] = * invert
;
645 } else if ( BinStream
[ i
] <= low
) {
646 BinStream
[ bitnum
++] = * invert
^ 1 ;
647 } else if ( i
- lastBit
>= * clk
+ tol
) {
649 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Modulation Error at: %u" , i
);
650 BinStream
[ bitnum
++]= 7 ;
653 } else { //in tolerance - looking for peak
658 } else if ( i
- lastBit
>= (* clk
/ 2 - tol
) && ! midBit
&& ! askType
){
659 if ( BinStream
[ i
] >= high
) {
660 BinStream
[ bitnum
++] = * invert
;
661 } else if ( BinStream
[ i
] <= low
) {
662 BinStream
[ bitnum
++] = * invert
^ 1 ;
663 } else if ( i
- lastBit
>= * clk
/ 2 + tol
) {
664 BinStream
[ bitnum
] = BinStream
[ bitnum
- 1 ];
666 } else { //in tolerance - looking for peak
671 if ( bitnum
>= MaxBits
) break ;
677 int askdemod ( uint8_t * BinStream
, size_t * size
, int * clk
, int * invert
, int maxErr
, uint8_t amp
, uint8_t askType
) {
679 return askdemod_ext ( BinStream
, size
, clk
, invert
, maxErr
, amp
, askType
, & start
);
682 // by marshmellow - demodulate NRZ wave - requires a read with strong signal
683 // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
684 int nrzRawDemod_ext ( uint8_t * dest
, size_t * size
, int * clk
, int * invert
, int * startIdx
) {
685 if ( justNoise ( dest
, * size
)) return - 1 ;
686 * clk
= DetectNRZClock ( dest
, * size
, * clk
);
687 if (* clk
== 0 ) return - 2 ;
688 size_t i
, gLen
= 4096 ;
689 if ( gLen
>* size
) gLen
= * size
- 20 ;
691 if ( getHiLo ( dest
, gLen
, & high
, & low
, 75 , 75 ) < 1 ) return - 3 ; //25% fuzz on high 25% fuzz on low
694 //convert wave samples to 1's and 0's
695 for ( i
= 20 ; i
< * size
- 20 ; i
++){
696 if ( dest
[ i
] >= high
) bit
= 1 ;
697 if ( dest
[ i
] <= low
) bit
= 0 ;
700 //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit)
703 for ( i
= 21 ; i
< * size
- 20 ; i
++) {
704 //if transition detected or large number of same bits - store the passed bits
705 if ( dest
[ i
] != dest
[ i
- 1 ] || ( i
- lastBit
) == ( 10 * * clk
)) {
706 memset ( dest
+ numBits
, dest
[ i
- 1 ] ^ * invert
, ( i
- lastBit
+ (* clk
/ 4 )) / * clk
);
707 numBits
+= ( i
- lastBit
+ (* clk
/ 4 )) / * clk
;
709 * startIdx
= i
- ( numBits
* * clk
);
710 if ( g_debugMode
== 2 ) prnt ( "DEBUG NRZ: startIdx %i" , * startIdx
);
718 int nrzRawDemod ( uint8_t * dest
, size_t * size
, int * clk
, int * invert
) {
720 return nrzRawDemod_ext ( dest
, size
, clk
, invert
, & startIdx
);
723 //translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq])
724 size_t fsk_wave_demod ( uint8_t * dest
, size_t size
, uint8_t fchigh
, uint8_t fclow
, int * startIdx
) {
725 size_t last_transition
= 0 ;
727 if ( fchigh
== 0 ) fchigh
= 10 ;
728 if ( fclow
== 0 ) fclow
= 8 ;
729 //set the threshold close to 0 (graph) or 128 std to avoid static
730 uint8_t threshold_value
= 123 ;
731 size_t preLastSample
= 0 ;
732 size_t LastSample
= 0 ;
733 size_t currSample
= 0 ;
734 if ( size
< 1024 ) return 0 ; // not enough samples
736 //find start of modulating data in trace
737 idx
= findModStart ( dest
, size
, threshold_value
, fchigh
);
738 // Need to threshold first sample
739 if ( dest
[ idx
] < threshold_value
) dest
[ 0 ] = 0 ;
742 last_transition
= idx
;
745 // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
746 // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere
747 // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
748 // (could also be fc/5 && fc/7 for fsk1 = 4-9)
749 for (; idx
< size
; idx
++) {
750 // threshold current value
751 if ( dest
[ idx
] < threshold_value
) dest
[ idx
] = 0 ;
754 // Check for 0->1 transition
755 if ( dest
[ idx
- 1 ] < dest
[ idx
]) {
756 preLastSample
= LastSample
;
757 LastSample
= currSample
;
758 currSample
= idx
- last_transition
;
759 if ( currSample
< ( fclow
- 2 )) { //0-5 = garbage noise (or 0-3)
760 //do nothing with extra garbage
761 } else if ( currSample
< ( fchigh
- 1 )) { //6-8 = 8 sample waves (or 3-6 = 5)
762 //correct previous 9 wave surrounded by 8 waves (or 6 surrounded by 5)
763 if ( numBits
> 1 && LastSample
> ( fchigh
- 2 ) && ( preLastSample
< ( fchigh
- 1 ))){
767 if ( numBits
> 0 && * startIdx
== 0 ) * startIdx
= idx
- fclow
;
768 } else if ( currSample
> ( fchigh
+ 1 ) && numBits
< 3 ) { //12 + and first two bit = unusable garbage
769 //do nothing with beginning garbage and reset.. should be rare..
771 } 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)
773 if ( numBits
> 0 && * startIdx
== 0 ) * startIdx
= idx
- fclow
;
774 } else { //9+ = 10 sample waves (or 6+ = 7)
776 if ( numBits
> 0 && * startIdx
== 0 ) * startIdx
= idx
- fchigh
;
778 last_transition
= idx
;
781 return numBits
; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
784 //translate 11111100000 to 10
785 //rfLen = clock, fchigh = larger field clock, fclow = smaller field clock
786 size_t aggregate_bits ( uint8_t * dest
, size_t size
, uint8_t rfLen
, uint8_t invert
, uint8_t fchigh
, uint8_t fclow
, int * startIdx
) {
787 uint8_t lastval
= dest
[ 0 ];
791 for ( idx
= 1 ; idx
< size
; idx
++) {
793 if ( dest
[ idx
]== lastval
) continue ; //skip until we hit a transition
795 //find out how many bits (n) we collected (use 1/2 clk tolerance)
796 //if lastval was 1, we have a 1->0 crossing
797 if ( dest
[ idx
- 1 ]== 1 ) {
798 n
= ( n
* fclow
+ rfLen
/ 2 ) / rfLen
;
799 } else { // 0->1 crossing
800 n
= ( n
* fchigh
+ rfLen
/ 2 ) / rfLen
;
804 //first transition - save startidx
806 if ( lastval
== 1 ) { //high to low
807 * startIdx
+= ( fclow
* idx
) - ( n
* rfLen
);
808 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: startIdx %i, fclow*idx %i, n*rflen %u" , * startIdx
, fclow
*( idx
), n
* rfLen
);
810 * startIdx
+= ( fchigh
* idx
) - ( n
* rfLen
);
811 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: startIdx %i, fchigh*idx %i, n*rflen %u" , * startIdx
, fchigh
*( idx
), n
* rfLen
);
815 //add to our destination the bits we collected
816 memset ( dest
+ numBits
, dest
[ idx
- 1 ]^ invert
, n
);
821 // if valid extra bits at the end were all the same frequency - add them in
822 if ( n
> rfLen
/ fchigh
) {
823 if ( dest
[ idx
- 2 ]== 1 ) {
824 n
= ( n
* fclow
+ rfLen
/ 2 ) / rfLen
;
826 n
= ( n
* fchigh
+ rfLen
/ 2 ) / rfLen
;
828 memset ( dest
+ numBits
, dest
[ idx
- 1 ]^ invert
, n
);
834 //by marshmellow (from holiman's base)
835 // full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod)
836 int fskdemod_ext ( uint8_t * dest
, size_t size
, uint8_t rfLen
, uint8_t invert
, uint8_t fchigh
, uint8_t fclow
, int * startIdx
) {
838 size
= fsk_wave_demod ( dest
, size
, fchigh
, fclow
, startIdx
);
839 size
= aggregate_bits ( dest
, size
, rfLen
, invert
, fchigh
, fclow
, startIdx
);
843 int fskdemod ( uint8_t * dest
, size_t size
, uint8_t rfLen
, uint8_t invert
, uint8_t fchigh
, uint8_t fclow
) {
845 return fskdemod_ext ( dest
, size
, rfLen
, invert
, fchigh
, fclow
, & startIdx
);
849 // convert psk1 demod to psk2 demod
850 // only transition waves are 1s
851 void psk1TOpsk2 ( uint8_t * BitStream
, size_t size
) {
853 uint8_t lastBit
= BitStream
[ 0 ];
855 if ( BitStream
[ i
]== 7 ){
857 } else if ( lastBit
!= BitStream
[ i
]){
858 lastBit
= BitStream
[ i
];
868 // convert psk2 demod to psk1 demod
869 // from only transition waves are 1s to phase shifts change bit
870 void psk2TOpsk1 ( uint8_t * BitStream
, size_t size
) {
872 for ( size_t i
= 0 ; i
< size
; i
++){
873 if ( BitStream
[ i
]== 1 ){
881 //by marshmellow - demodulate PSK1 wave
882 //uses wave lengths (# Samples)
883 int pskRawDemod_ext ( uint8_t dest
[], size_t * size
, int * clock
, int * invert
, int * startIdx
) {
884 if ( size
== 0 ) return - 1 ;
885 uint16_t loopCnt
= 4096 ; //don't need to loop through entire array...
886 if (* size
< loopCnt
) loopCnt
= * size
;
889 uint8_t curPhase
= * invert
;
890 size_t i
= 0 , waveStart
= 1 , waveEnd
= 0 , firstFullWave
= 0 , lastClkBit
= 0 ;
891 uint16_t fc
= 0 , fullWaveLen
= 0 , tol
= 1 ;
892 uint16_t errCnt
= 0 , waveLenCnt
= 0 , errCnt2
= 0 ;
893 fc
= countFC ( dest
, * size
, 1 );
894 uint8_t fc2
= fc
>> 8 ;
895 if ( fc2
== 10 ) return - 1 ; //fsk found - quit
897 if ( fc
!= 2 && fc
!= 4 && fc
!= 8 ) return - 1 ;
898 //PrintAndLog("DEBUG: FC: %d",fc);
899 * clock
= DetectPSKClock ( dest
, * size
, * clock
);
900 if (* clock
== 0 ) return - 1 ;
902 //find start of modulating data in trace
903 uint8_t threshold_value
= 123 ; //-5
904 i
= findModStart ( dest
, * size
, threshold_value
, fc
);
906 //find first phase shift
907 int avgWaveVal
= 0 , lastAvgWaveVal
= 0 ;
909 for (; i
< loopCnt
; i
++) {
911 if ( dest
[ i
]+ fc
< dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
913 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: waveEnd: %u, waveStart: %u" , waveEnd
, waveStart
);
914 waveLenCnt
= waveEnd
- waveStart
;
915 if ( waveLenCnt
> fc
&& waveStart
> fc
&& !( waveLenCnt
> fc
+ 3 )){ //not first peak and is a large wave but not out of whack
916 lastAvgWaveVal
= avgWaveVal
/( waveLenCnt
);
917 firstFullWave
= waveStart
;
918 fullWaveLen
= waveLenCnt
;
919 //if average wave value is > graph 0 then it is an up wave or a 1 (could cause inverting)
920 if ( lastAvgWaveVal
> threshold_value
) curPhase
^= 1 ;
927 avgWaveVal
+= dest
[ i
+ 2 ];
929 if ( firstFullWave
== 0 ) {
930 // no phase shift detected - could be all 1's or 0's - doesn't matter where we start
931 // so skip a little to ensure we are past any Start Signal
933 memset ( dest
, curPhase
, firstFullWave
/ * clock
);
935 memset ( dest
, curPhase
^ 1 , firstFullWave
/ * clock
);
938 numBits
+= ( firstFullWave
/ * clock
);
939 * startIdx
= firstFullWave
- (* clock
* numBits
)+ 2 ;
940 //set start of wave as clock align
941 lastClkBit
= firstFullWave
;
942 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: firstFullWave: %u, waveLen: %u, startIdx %i" , firstFullWave
, fullWaveLen
, * startIdx
);
943 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: clk: %d, lastClkBit: %u, fc: %u" , * clock
, lastClkBit
,( unsigned int ) fc
);
945 dest
[ numBits
++] = curPhase
; //set first read bit
946 for ( i
= firstFullWave
+ fullWaveLen
- 1 ; i
< * size
- 3 ; i
++){
947 //top edge of wave = start of new wave
948 if ( dest
[ i
]+ fc
< dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
949 if ( waveStart
== 0 ) {
952 avgWaveVal
= dest
[ i
+ 1 ];
955 waveLenCnt
= waveEnd
- waveStart
;
956 lastAvgWaveVal
= avgWaveVal
/ waveLenCnt
;
957 if ( waveLenCnt
> fc
){
958 //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);
959 //this wave is a phase shift
960 //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc);
961 if ( i
+ 1 >= lastClkBit
+ * clock
- tol
){ //should be a clock bit
963 dest
[ numBits
++] = curPhase
;
964 lastClkBit
+= * clock
;
965 } else if ( i
< lastClkBit
+ 10 + fc
){
966 //noise after a phase shift - ignore
967 } else { //phase shift before supposed to based on clock
971 } else if ( i
+ 1 > lastClkBit
+ * clock
+ tol
+ fc
){
972 lastClkBit
+= * clock
; //no phase shift but clock bit
973 dest
[ numBits
++] = curPhase
;
974 } else if ( waveLenCnt
< fc
- 1 ) { //wave is smaller than field clock (shouldn't happen often)
976 if ( errCnt2
> 101 ) return errCnt2
;
982 avgWaveVal
+= dest
[ i
+ 1 ];
988 int pskRawDemod ( uint8_t dest
[], size_t * size
, int * clock
, int * invert
) {
990 return pskRawDemod_ext ( dest
, size
, clock
, invert
, & startIdx
);
993 //-------------------Clock / Bitrate Detection Section------------------------------------------------------------------------------------
996 // to help detect clocks on heavily clipped samples
997 // based on count of low to low
998 int DetectStrongAskClock ( uint8_t dest
[], size_t size
, uint8_t high
, uint8_t low
, int * clock
) {
999 uint8_t fndClk
[] = { 8 , 16 , 32 , 40 , 50 , 64 , 128 };
1002 size_t minClk
= 255 ;
1003 int shortestWaveIdx
= 0 ;
1004 // get to first full low to prime loop and skip incomplete first pulse
1005 while (( dest
[ i
] < high
) && ( i
< size
))
1007 while (( dest
[ i
] > low
) && ( i
< size
))
1010 // loop through all samples
1012 // measure from low to low
1013 while (( dest
[ i
] > low
) && ( i
< size
))
1016 while (( dest
[ i
] < high
) && ( i
< size
))
1018 while (( dest
[ i
] > low
) && ( i
< size
))
1020 //get minimum measured distance
1021 if ( i
- startwave
< minClk
&& i
< size
) {
1022 minClk
= i
- startwave
;
1023 shortestWaveIdx
= startwave
;
1027 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: detectstrongASKclk smallest wave: %d" , minClk
);
1028 for ( uint8_t clkCnt
= 0 ; clkCnt
< 7 ; clkCnt
++) {
1029 if ( minClk
>= fndClk
[ clkCnt
]-( fndClk
[ clkCnt
]/ 8 ) && minClk
<= fndClk
[ clkCnt
]+ 1 ) {
1030 * clock
= fndClk
[ clkCnt
];
1031 return shortestWaveIdx
;
1038 // not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)
1039 // maybe somehow adjust peak trimming value based on samples to fix?
1040 // return start index of best starting position for that clock and return clock (by reference)
1041 int DetectASKClock ( uint8_t dest
[], size_t size
, int * clock
, int maxErr
) {
1043 uint8_t clk
[] = { 255 , 8 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 255 };
1045 uint8_t loopCnt
= 255 ; //don't need to loop through entire array...
1046 if ( size
<= loopCnt
+ 60 ) return - 1 ; //not enough samples
1047 size
-= 60 ; //sometimes there is a strange end wave - filter out this....
1048 //if we already have a valid clock
1051 if ( clk
[ i
] == * clock
) clockFnd
= i
;
1052 //clock found but continue to find best startpos
1054 //get high and low peak
1056 if ( getHiLo ( dest
, loopCnt
, & peak
, & low
, 75 , 75 ) < 1 ) return - 1 ;
1058 //test for large clean peaks
1060 if ( DetectCleanAskWave ( dest
, size
, peak
, low
)== 1 ){
1061 int ans
= DetectStrongAskClock ( dest
, size
, peak
, low
, clock
);
1062 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: detectaskclk Clean Ask Wave Detected: clk %i, ShortestWave: %i" , clock
, ans
);
1064 return ans
; //return shortest wave start position
1069 uint8_t clkCnt
, tol
= 0 ;
1070 uint16_t bestErr
[]={ 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 };
1071 uint8_t bestStart
[]={ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1073 size_t arrLoc
, loopEnd
;
1077 clkEnd
= clockFnd
+ 1 ;
1081 //test each valid clock from smallest to greatest to see which lines up
1082 for (; clkCnt
< clkEnd
; clkCnt
++){
1083 if ( clk
[ clkCnt
] <= 32 ){
1088 //if no errors allowed - keep start within the first clock
1089 if (! maxErr
&& size
> clk
[ clkCnt
]* 2 + tol
&& clk
[ clkCnt
]< 128 ) loopCnt
= clk
[ clkCnt
]* 2 ;
1090 bestErr
[ clkCnt
]= 1000 ;
1091 //try lining up the peaks by moving starting point (try first few clocks)
1092 for ( ii
= 0 ; ii
< loopCnt
; ii
++){
1093 if ( dest
[ ii
] < peak
&& dest
[ ii
] > low
) continue ;
1096 // now that we have the first one lined up test rest of wave array
1097 loopEnd
= (( size
- ii
- tol
) / clk
[ clkCnt
]) - 1 ;
1098 for ( i
= 0 ; i
< loopEnd
; ++ i
){
1099 arrLoc
= ii
+ ( i
* clk
[ clkCnt
]);
1100 if ( dest
[ arrLoc
] >= peak
|| dest
[ arrLoc
] <= low
){
1101 } else if ( dest
[ arrLoc
- tol
] >= peak
|| dest
[ arrLoc
- tol
] <= low
){
1102 } else if ( dest
[ arrLoc
+ tol
] >= peak
|| dest
[ arrLoc
+ tol
] <= low
){
1103 } else { //error no peak detected
1107 //if we found no errors then we can stop here and a low clock (common clocks)
1108 // this is correct one - return this clock
1109 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: clk %d, err %d, startpos %d, endpos %d" , clk
[ clkCnt
], errCnt
, ii
, i
);
1110 if ( errCnt
== 0 && clkCnt
< 7 ) {
1111 if (! clockFnd
) * clock
= clk
[ clkCnt
];
1114 //if we found errors see if it is lowest so far and save it as best run
1115 if ( errCnt
< bestErr
[ clkCnt
]){
1116 bestErr
[ clkCnt
]= errCnt
;
1117 bestStart
[ clkCnt
]= ii
;
1123 for ( iii
= 1 ; iii
< clkEnd
; ++ iii
){
1124 if ( bestErr
[ iii
] < bestErr
[ best
]){
1125 if ( bestErr
[ iii
] == 0 ) bestErr
[ iii
]= 1 ;
1126 // current best bit to error ratio vs new bit to error ratio
1127 if ( ( size
/ clk
[ best
])/ bestErr
[ best
] < ( size
/ clk
[ iii
])/ bestErr
[ iii
] ){
1131 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
]);
1133 if (! clockFnd
) * clock
= clk
[ best
];
1134 return bestStart
[ best
];
1137 int DetectStrongNRZClk ( uint8_t * dest
, size_t size
, int peak
, int low
){
1138 //find shortest transition from high to low
1140 size_t transition1
= 0 ;
1141 int lowestTransition
= 255 ;
1142 bool lastWasHigh
= false ;
1144 //find first valid beginning of a high or low wave
1145 while (( dest
[ i
] >= peak
|| dest
[ i
] <= low
) && ( i
< size
))
1147 while (( dest
[ i
] < peak
&& dest
[ i
] > low
) && ( i
< size
))
1149 lastWasHigh
= ( dest
[ i
] >= peak
);
1151 if ( i
== size
) return 0 ;
1154 for (; i
< size
; i
++) {
1155 if (( dest
[ i
] >= peak
&& ! lastWasHigh
) || ( dest
[ i
] <= low
&& lastWasHigh
)) {
1156 lastWasHigh
= ( dest
[ i
] >= peak
);
1157 if ( i
- transition1
< lowestTransition
) lowestTransition
= i
- transition1
;
1161 if ( lowestTransition
== 255 ) lowestTransition
= 0 ;
1162 if ( g_debugMode
== 2 ) prnt ( "DEBUG NRZ: detectstrongNRZclk smallest wave: %d" , lowestTransition
);
1163 return lowestTransition
;
1167 //detect nrz clock by reading #peaks vs no peaks(or errors)
1168 int DetectNRZClock_ext ( uint8_t dest
[], size_t size
, int clock
, size_t * clockStartIdx
) {
1170 uint8_t clk
[]={ 8 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 255 };
1171 size_t loopCnt
= 4096 ; //don't need to loop through entire array...
1172 if ( size
== 0 ) return 0 ;
1173 if ( size
< loopCnt
) loopCnt
= size
- 20 ;
1174 //if we already have a valid clock quit
1176 if ( clk
[ i
] == clock
) return clock
;
1178 //get high and low peak
1180 if ( getHiLo ( dest
, loopCnt
, & peak
, & low
, 75 , 75 ) < 1 ) return 0 ;
1182 int lowestTransition
= DetectStrongNRZClk ( dest
, size
- 20 , peak
, low
);
1186 uint16_t smplCnt
= 0 ;
1187 int16_t peakcnt
= 0 ;
1188 int16_t peaksdet
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1189 uint16_t maxPeak
= 255 ;
1190 bool firstpeak
= false ;
1191 //test for large clipped waves
1192 for ( i
= 0 ; i
< loopCnt
; i
++){
1193 if ( dest
[ i
] >= peak
|| dest
[ i
] <= low
){
1194 if (! firstpeak
) continue ;
1199 if ( maxPeak
> smplCnt
){
1201 //prnt("maxPk: %d",maxPeak);
1204 //prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt);
1209 bool errBitHigh
= 0 ;
1211 uint8_t ignoreCnt
= 0 ;
1212 uint8_t ignoreWindow
= 4 ;
1213 bool lastPeakHigh
= 0 ;
1215 size_t bestStart
[]={ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1217 //test each valid clock from smallest to greatest to see which lines up
1218 for ( clkCnt
= 0 ; clkCnt
< 8 ; ++ clkCnt
){
1219 //ignore clocks smaller than smallest peak
1220 if ( clk
[ clkCnt
] < maxPeak
- ( clk
[ clkCnt
]/ 4 )) continue ;
1221 //try lining up the peaks by moving starting point (try first 256)
1222 for ( ii
= 20 ; ii
< loopCnt
; ++ ii
){
1223 if (( dest
[ ii
] >= peak
) || ( dest
[ ii
] <= low
)){
1227 lastBit
= ii
- clk
[ clkCnt
];
1228 //loop through to see if this start location works
1229 for ( i
= ii
; i
< size
- 20 ; ++ i
) {
1230 //if we are at a clock bit
1231 if (( i
>= lastBit
+ clk
[ clkCnt
] - tol
) && ( i
<= lastBit
+ clk
[ clkCnt
] + tol
)) {
1233 if ( dest
[ i
] >= peak
|| dest
[ i
] <= low
) {
1234 //if same peak don't count it
1235 if (( dest
[ i
] >= peak
&& ! lastPeakHigh
) || ( dest
[ i
] <= low
&& lastPeakHigh
)) {
1238 lastPeakHigh
= ( dest
[ i
] >= peak
);
1241 ignoreCnt
= ignoreWindow
;
1242 lastBit
+= clk
[ clkCnt
];
1243 } else if ( i
== lastBit
+ clk
[ clkCnt
] + tol
) {
1244 lastBit
+= clk
[ clkCnt
];
1246 //else if not a clock bit and no peaks
1247 } else if ( dest
[ i
] < peak
&& dest
[ i
] > low
){
1250 if ( errBitHigh
== true ) peakcnt
--;
1255 // else if not a clock bit but we have a peak
1256 } else if (( dest
[ i
]>= peak
|| dest
[ i
]<= low
) && (! bitHigh
)) {
1257 //error bar found no clock...
1261 if ( peakcnt
> peaksdet
[ clkCnt
]) {
1262 bestStart
[ clkCnt
]= ii
;
1263 peaksdet
[ clkCnt
]= peakcnt
;
1270 for ( iii
= 7 ; iii
> 0 ; iii
--){
1271 if (( peaksdet
[ iii
] >= ( peaksdet
[ best
]- 1 )) && ( peaksdet
[ iii
] <= peaksdet
[ best
]+ 1 ) && lowestTransition
) {
1272 if ( clk
[ iii
] > ( lowestTransition
- ( clk
[ iii
]/ 8 )) && clk
[ iii
] < ( lowestTransition
+ ( clk
[ iii
]/ 8 ))) {
1275 } else if ( peaksdet
[ iii
] > peaksdet
[ best
]){
1278 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
);
1280 * clockStartIdx
= bestStart
[ best
];
1284 int DetectNRZClock ( uint8_t dest
[], size_t size
, int clock
) {
1286 return DetectNRZClock_ext ( dest
, size
, clock
, & bestStart
);
1290 //countFC is to detect the field clock lengths.
1291 //counts and returns the 2 most common wave lengths
1292 //mainly used for FSK field clock detection
1293 uint16_t countFC ( uint8_t * BitStream
, size_t size
, uint8_t fskAdj
) {
1294 uint8_t fcLens
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1295 uint16_t fcCnts
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1296 uint8_t fcLensFnd
= 0 ;
1297 uint8_t lastFCcnt
= 0 ;
1298 uint8_t fcCounter
= 0 ;
1300 if ( size
< 180 ) return 0 ;
1302 // prime i to first up transition
1303 for ( i
= 160 ; i
< size
- 20 ; i
++)
1304 if ( BitStream
[ i
] > BitStream
[ i
- 1 ] && BitStream
[ i
] >= BitStream
[ i
+ 1 ])
1307 for (; i
< size
- 20 ; i
++){
1308 if ( BitStream
[ i
] > BitStream
[ i
- 1 ] && BitStream
[ i
] >= BitStream
[ i
+ 1 ]){
1309 // new up transition
1312 //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8)
1313 if ( lastFCcnt
== 5 && fcCounter
== 9 ) fcCounter
--;
1314 //if fc=9 or 4 add one (for when we get a fc 9 instead of 10 or a 4 instead of a 5)
1315 if (( fcCounter
== 9 ) || fcCounter
== 4 ) fcCounter
++;
1316 // save last field clock count (fc/xx)
1317 lastFCcnt
= fcCounter
;
1319 // find which fcLens to save it to:
1320 for ( int ii
= 0 ; ii
< 15 ; ii
++){
1321 if ( fcLens
[ ii
]== fcCounter
){
1327 if ( fcCounter
> 0 && fcLensFnd
< 15 ){
1329 fcCnts
[ fcLensFnd
]++;
1330 fcLens
[ fcLensFnd
++]= fcCounter
;
1339 uint8_t best1
= 14 , best2
= 14 , best3
= 14 ;
1341 // go through fclens and find which ones are bigest 2
1342 for ( i
= 0 ; i
< 15 ; i
++){
1343 // get the 3 best FC values
1344 if ( fcCnts
[ i
]> maxCnt1
) {
1349 } else if ( fcCnts
[ i
]> fcCnts
[ best2
]){
1352 } else if ( fcCnts
[ i
]> fcCnts
[ best3
]){
1355 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
]);
1357 if ( fcLens
[ best1
]== 0 ) return 0 ;
1358 uint8_t fcH
= 0 , fcL
= 0 ;
1359 if ( fcLens
[ best1
]> fcLens
[ best2
]){
1366 if (( size
- 180 )/ fcH
/ 3 > fcCnts
[ best1
]+ fcCnts
[ best2
]) {
1367 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
]);
1368 return 0 ; //lots of waves not psk or fsk
1370 // TODO: take top 3 answers and compare to known Field clocks to get top 2
1372 uint16_t fcs
= ((( uint16_t ) fcH
)<< 8 ) | fcL
;
1373 if ( fskAdj
) return fcs
;
1374 return fcLens
[ best1
];
1378 //detect psk clock by reading each phase shift
1379 // a phase shift is determined by measuring the sample length of each wave
1380 int DetectPSKClock_ext ( uint8_t dest
[], size_t size
, int clock
, int * firstPhaseShift
) {
1381 uint8_t clk
[]={ 255 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 255 }; //255 is not a valid clock
1382 uint16_t loopCnt
= 4096 ; //don't need to loop through entire array...
1383 if ( size
== 0 ) return 0 ;
1384 if ( size
< loopCnt
) loopCnt
= size
- 20 ;
1386 //if we already have a valid clock quit
1389 if ( clk
[ i
] == clock
) return clock
;
1391 size_t waveStart
= 0 , waveEnd
= 0 , firstFullWave
= 0 , lastClkBit
= 0 ;
1392 uint8_t clkCnt
, fc
= 0 , fullWaveLen
= 0 , tol
= 1 ;
1393 uint16_t peakcnt
= 0 , errCnt
= 0 , waveLenCnt
= 0 ;
1394 uint16_t bestErr
[]={ 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 };
1395 uint16_t peaksdet
[]={ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1396 fc
= countFC ( dest
, size
, 0 );
1397 if ( fc
!= 2 && fc
!= 4 && fc
!= 8 ) return - 1 ;
1398 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: FC: %d" , fc
);
1400 //find first full wave
1401 for ( i
= 160 ; i
< loopCnt
; i
++){
1402 if ( dest
[ i
] < dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
1403 if ( waveStart
== 0 ) {
1405 //prnt("DEBUG: waveStart: %d",waveStart);
1408 //prnt("DEBUG: waveEnd: %d",waveEnd);
1409 waveLenCnt
= waveEnd
- waveStart
;
1410 if ( waveLenCnt
> fc
){
1411 firstFullWave
= waveStart
;
1412 fullWaveLen
= waveLenCnt
;
1419 * firstPhaseShift
= firstFullWave
;
1420 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: firstFullWave: %d, waveLen: %d" , firstFullWave
, fullWaveLen
);
1421 //test each valid clock from greatest to smallest to see which lines up
1422 for ( clkCnt
= 7 ; clkCnt
>= 1 ; clkCnt
--){
1423 lastClkBit
= firstFullWave
; //set end of wave as clock align
1427 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: clk: %d, lastClkBit: %d" , clk
[ clkCnt
], lastClkBit
);
1429 for ( i
= firstFullWave
+ fullWaveLen
- 1 ; i
< loopCnt
- 2 ; i
++){
1430 //top edge of wave = start of new wave
1431 if ( dest
[ i
] < dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
1432 if ( waveStart
== 0 ) {
1437 waveLenCnt
= waveEnd
- waveStart
;
1438 if ( waveLenCnt
> fc
){
1439 //if this wave is a phase shift
1440 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
);
1441 if ( i
+ 1 >= lastClkBit
+ clk
[ clkCnt
] - tol
){ //should be a clock bit
1443 lastClkBit
+= clk
[ clkCnt
];
1444 } else if ( i
< lastClkBit
+ 8 ){
1445 //noise after a phase shift - ignore
1446 } else { //phase shift before supposed to based on clock
1449 } else if ( i
+ 1 > lastClkBit
+ clk
[ clkCnt
] + tol
+ fc
){
1450 lastClkBit
+= clk
[ clkCnt
]; //no phase shift but clock bit
1459 if ( errCnt
<= bestErr
[ clkCnt
]) bestErr
[ clkCnt
]= errCnt
;
1460 if ( peakcnt
> peaksdet
[ clkCnt
]) peaksdet
[ clkCnt
]= peakcnt
;
1462 //all tested with errors
1463 //return the highest clk with the most peaks found
1465 for ( i
= 7 ; i
>= 1 ; i
--){
1466 if ( peaksdet
[ i
] > peaksdet
[ best
]) {
1469 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: Clk: %d, peaks: %d, errs: %d, bestClk: %d" , clk
[ i
], peaksdet
[ i
], bestErr
[ i
], clk
[ best
]);
1474 int DetectPSKClock ( uint8_t dest
[], size_t size
, int clock
) {
1475 int firstPhaseShift
= 0 ;
1476 return DetectPSKClock_ext ( dest
, size
, clock
, & firstPhaseShift
);
1480 //detects the bit clock for FSK given the high and low Field Clocks
1481 uint8_t detectFSKClk_ext ( uint8_t * BitStream
, size_t size
, uint8_t fcHigh
, uint8_t fcLow
, int * firstClockEdge
) {
1482 uint8_t clk
[] = { 8 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 0 };
1483 uint16_t rfLens
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1484 uint8_t rfCnts
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1485 uint8_t rfLensFnd
= 0 ;
1486 uint8_t lastFCcnt
= 0 ;
1487 uint16_t fcCounter
= 0 ;
1488 uint16_t rfCounter
= 0 ;
1489 uint8_t firstBitFnd
= 0 ;
1491 if ( size
== 0 ) return 0 ;
1493 uint8_t fcTol
= (( fcHigh
* 100 - fcLow
* 100 )/ 2 + 50 )/ 100 ; //(uint8_t)(0.5+(float)(fcHigh-fcLow)/2);
1498 //PrintAndLog("DEBUG: fcTol: %d",fcTol);
1499 // prime i to first peak / up transition
1500 for ( i
= 160 ; i
< size
- 20 ; i
++)
1501 if ( BitStream
[ i
] > BitStream
[ i
- 1 ] && BitStream
[ i
]>= BitStream
[ i
+ 1 ])
1504 for (; i
< size
- 20 ; i
++){
1508 if ( BitStream
[ i
] <= BitStream
[ i
- 1 ] || BitStream
[ i
] < BitStream
[ i
+ 1 ])
1511 // if we got less than the small fc + tolerance then set it to the small fc
1512 // if it is inbetween set it to the last counter
1513 if ( fcCounter
< fcHigh
&& fcCounter
> fcLow
)
1514 fcCounter
= lastFCcnt
;
1515 else if ( fcCounter
< fcLow
+ fcTol
)
1517 else //set it to the large fc
1520 //look for bit clock (rf/xx)
1521 if (( fcCounter
< lastFCcnt
|| fcCounter
> lastFCcnt
)){
1522 //not the same size as the last wave - start of new bit sequence
1523 if ( firstBitFnd
> 1 ){ //skip first wave change - probably not a complete bit
1524 for ( int ii
= 0 ; ii
< 15 ; ii
++){
1525 if ( rfLens
[ ii
] >= ( rfCounter
- 4 ) && rfLens
[ ii
] <= ( rfCounter
+ 4 )){
1531 if ( rfCounter
> 0 && rfLensFnd
< 15 ){
1532 //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
1533 rfCnts
[ rfLensFnd
]++;
1534 rfLens
[ rfLensFnd
++] = rfCounter
;
1537 * firstClockEdge
= i
;
1541 lastFCcnt
= fcCounter
;
1545 uint8_t rfHighest
= 15 , rfHighest2
= 15 , rfHighest3
= 15 ;
1547 for ( i
= 0 ; i
< 15 ; i
++){
1548 //get highest 2 RF values (might need to get more values to compare or compare all?)
1549 if ( rfCnts
[ i
]> rfCnts
[ rfHighest
]){
1550 rfHighest3
= rfHighest2
;
1551 rfHighest2
= rfHighest
;
1553 } else if ( rfCnts
[ i
]> rfCnts
[ rfHighest2
]){
1554 rfHighest3
= rfHighest2
;
1556 } else if ( rfCnts
[ i
]> rfCnts
[ rfHighest3
]){
1559 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: RF %d, cnts %d" , rfLens
[ i
], rfCnts
[ i
]);
1561 // set allowed clock remainder tolerance to be 1 large field clock length+1
1562 // we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off
1563 uint8_t tol1
= fcHigh
+ 1 ;
1565 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: most counted rf values: 1 %d, 2 %d, 3 %d" , rfLens
[ rfHighest
], rfLens
[ rfHighest2
], rfLens
[ rfHighest3
]);
1567 // loop to find the highest clock that has a remainder less than the tolerance
1568 // compare samples counted divided by
1569 // test 128 down to 32 (shouldn't be possible to have fc/10 & fc/8 and rf/16 or less)
1571 for (; ii
>= 2 ; ii
--){
1572 if ( rfLens
[ rfHighest
] % clk
[ ii
] < tol1
|| rfLens
[ rfHighest
] % clk
[ ii
] > clk
[ ii
]- tol1
){
1573 if ( rfLens
[ rfHighest2
] % clk
[ ii
] < tol1
|| rfLens
[ rfHighest2
] % clk
[ ii
] > clk
[ ii
]- tol1
){
1574 if ( rfLens
[ rfHighest3
] % clk
[ ii
] < tol1
|| rfLens
[ rfHighest3
] % clk
[ ii
] > clk
[ ii
]- tol1
){
1575 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: clk %d divides into the 3 most rf values within tolerance" , clk
[ ii
]);
1582 if ( ii
< 2 ) return 0 ; // oops we went too far
1587 uint8_t detectFSKClk ( uint8_t * BitStream
, size_t size
, uint8_t fcHigh
, uint8_t fcLow
) {
1588 int firstClockEdge
= 0 ;
1589 return detectFSKClk_ext ( BitStream
, size
, fcHigh
, fcLow
, & firstClockEdge
);
1592 //-----------------Tag format detection section--------------------------------------------------------------
1595 // FSK Demod then try to locate an AWID ID
1596 int AWIDdemodFSK ( uint8_t * dest
, size_t * size
) {
1597 //make sure buffer has enough data
1598 if (* size
< 96 * 50 ) return - 1 ;
1600 if ( justNoise ( dest
, * size
)) return - 2 ;
1603 * size
= fskdemod ( dest
, * size
, 50 , 1 , 10 , 8 ); // fsk2a RF/50
1604 if (* size
< 96 ) return - 3 ; //did we get a good demod?
1606 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
1607 size_t startIdx
= 0 ;
1608 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1609 if ( errChk
== 0 ) return - 4 ; //preamble not found
1610 if (* size
!= 96 ) return - 5 ;
1611 return ( int ) startIdx
;
1615 //takes 1s and 0s and searches for EM410x format - output EM ID
1616 uint8_t Em410xDecode ( uint8_t * BitStream
, size_t * size
, size_t * startIdx
, uint32_t * hi
, uint64_t * lo
)
1619 if (* size
< 64 ) return 0 ;
1620 if ( BitStream
[ 1 ]> 1 ) return 0 ; //allow only 1s and 0s
1622 // 111111111 bit pattern represent start of frame
1623 // include 0 in front to help get start pos
1624 uint8_t preamble
[] = { 0 , 1 , 1 , 1 , 1 , 1 , 1 , 1 , 1 , 1 };
1626 uint8_t FmtLen
= 10 ; // sets of 4 bits = end data
1628 errChk
= preambleSearch ( BitStream
, preamble
, sizeof ( preamble
), size
, startIdx
);
1629 if ( errChk
== 0 || (* size
!= 64 && * size
!= 128 ) ) return 0 ;
1630 if (* size
== 128 ) FmtLen
= 22 ; // 22 sets of 4 bits
1632 //skip last 4bit parity row for simplicity
1633 * size
= removeParity ( BitStream
, * startIdx
+ sizeof ( preamble
), 5 , 0 , FmtLen
* 5 );
1634 if (* size
== 40 ) { // std em410x format
1636 * lo
= (( uint64_t )( bytebits_to_byte ( BitStream
, 8 )) << 32 ) | ( bytebits_to_byte ( BitStream
+ 8 , 32 ));
1637 } else if (* size
== 88 ) { // long em format
1638 * hi
= ( bytebits_to_byte ( BitStream
, 24 ));
1639 * lo
= (( uint64_t )( bytebits_to_byte ( BitStream
+ 24 , 32 )) << 32 ) | ( bytebits_to_byte ( BitStream
+ 24 + 32 , 32 ));
1646 // Ask/Biphase Demod then try to locate an ISO 11784/85 ID
1647 // BitStream must contain previously askrawdemod and biphasedemoded data
1648 int FDXBdemodBI ( uint8_t * dest
, size_t * size
) {
1649 //make sure buffer has enough data
1650 if (* size
< 128 ) return - 1 ;
1652 size_t startIdx
= 0 ;
1653 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
1655 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1656 if ( errChk
== 0 ) return - 2 ; //preamble not found
1657 return ( int ) startIdx
;
1661 // demod gProxIIDemod
1662 // error returns as -x
1663 // success returns start position in BitStream
1664 // BitStream must contain previously askrawdemod and biphasedemoded data
1665 int gProxII_Demod ( uint8_t BitStream
[], size_t * size
) {
1667 uint8_t preamble
[] = { 1 , 1 , 1 , 1 , 1 , 0 };
1669 uint8_t errChk
= preambleSearch ( BitStream
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1670 if ( errChk
== 0 ) return - 3 ; //preamble not found
1671 if (* size
!= 96 ) return - 2 ; //should have found 96 bits
1672 //check first 6 spacer bits to verify format
1673 if (! BitStream
[ startIdx
+ 5 ] && ! BitStream
[ startIdx
+ 10 ] && ! BitStream
[ startIdx
+ 15 ] && ! BitStream
[ startIdx
+ 20 ] && ! BitStream
[ startIdx
+ 25 ] && ! BitStream
[ startIdx
+ 30 ]){
1674 //confirmed proper separator bits found
1675 //return start position
1676 return ( int ) startIdx
;
1678 return - 5 ; //spacer bits not found - not a valid gproxII
1681 // loop to get raw HID waveform then FSK demodulate the TAG ID from it
1682 int HIDdemodFSK ( uint8_t * dest
, size_t * size
, uint32_t * hi2
, uint32_t * hi
, uint32_t * lo
) {
1683 if ( justNoise ( dest
, * size
)) return - 1 ;
1685 size_t numStart
= 0 , size2
=* size
, startIdx
= 0 ;
1687 * size
= fskdemod ( dest
, size2
, 50 , 1 , 10 , 8 ); //fsk2a
1688 if (* size
< 96 * 2 ) return - 2 ;
1689 // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
1690 uint8_t preamble
[] = { 0 , 0 , 0 , 1 , 1 , 1 , 0 , 1 };
1691 // find bitstring in array
1692 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1693 if ( errChk
== 0 ) return - 3 ; //preamble not found
1695 numStart
= startIdx
+ sizeof ( preamble
);
1696 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
1697 for ( size_t idx
= numStart
; ( idx
- numStart
) < * size
- sizeof ( preamble
); idx
+= 2 ){
1698 if ( dest
[ idx
] == dest
[ idx
+ 1 ]){
1699 return - 4 ; //not manchester data
1701 * hi2
= (* hi2
<< 1 )|(* hi
>> 31 );
1702 * hi
= (* hi
<< 1 )|(* lo
>> 31 );
1703 //Then, shift in a 0 or one into low
1704 if ( dest
[ idx
] && ! dest
[ idx
+ 1 ]) // 1 0
1709 return ( int ) startIdx
;
1712 int IOdemodFSK ( uint8_t * dest
, size_t size
) {
1713 if ( justNoise ( dest
, size
)) return - 1 ;
1714 //make sure buffer has data
1715 if ( size
< 66 * 64 ) return - 2 ;
1717 size
= fskdemod ( dest
, size
, 64 , 1 , 10 , 8 ); // FSK2a RF/64
1718 if ( size
< 65 ) return - 3 ; //did we get a good demod?
1720 //0 10 20 30 40 50 60
1722 //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
1723 //-----------------------------------------------------------------------------
1724 //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
1726 //XSF(version)facility:codeone+codetwo
1728 size_t startIdx
= 0 ;
1729 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
1730 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), & size
, & startIdx
);
1731 if ( errChk
== 0 ) return - 4 ; //preamble not found
1733 if (! dest
[ startIdx
+ 8 ] && dest
[ startIdx
+ 17 ]== 1 && dest
[ startIdx
+ 26 ]== 1 && dest
[ startIdx
+ 35 ]== 1 && dest
[ startIdx
+ 44 ]== 1 && dest
[ startIdx
+ 53 ]== 1 ){
1734 //confirmed proper separator bits found
1735 //return start position
1736 return ( int ) startIdx
;
1741 // redesigned by marshmellow adjusted from existing decode functions
1742 // indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
1743 int indala26decode ( uint8_t * bitStream
, size_t * size
, uint8_t * invert
) {
1744 //26 bit 40134 format (don't know other formats)
1745 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 };
1746 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 };
1747 size_t startidx
= 0 ;
1748 if (! preambleSearch ( bitStream
, preamble
, sizeof ( preamble
), size
, & startidx
)){
1749 // if didn't find preamble try again inverting
1750 if (! preambleSearch ( bitStream
, preamble_i
, sizeof ( preamble_i
), size
, & startidx
)) return - 1 ;
1753 if (* size
!= 64 && * size
!= 224 ) return - 2 ;
1755 for ( size_t i
= startidx
; i
< * size
; i
++)
1758 return ( int ) startidx
;
1761 // loop to get raw paradox waveform then FSK demodulate the TAG ID from it
1762 int ParadoxdemodFSK ( uint8_t * dest
, size_t * size
, uint32_t * hi2
, uint32_t * hi
, uint32_t * lo
) {
1763 if ( justNoise ( dest
, * size
)) return - 1 ;
1765 size_t numStart
= 0 , size2
=* size
, startIdx
= 0 ;
1767 * size
= fskdemod ( dest
, size2
, 50 , 1 , 10 , 8 ); //fsk2a
1768 if (* size
< 96 ) return - 2 ;
1770 // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
1771 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 1 , 1 , 1 , 1 };
1773 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1774 if ( errChk
== 0 ) return - 3 ; //preamble not found
1776 numStart
= startIdx
+ sizeof ( preamble
);
1777 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
1778 for ( size_t idx
= numStart
; ( idx
- numStart
) < * size
- sizeof ( preamble
); idx
+= 2 ){
1779 if ( dest
[ idx
] == dest
[ idx
+ 1 ])
1780 return - 4 ; //not manchester data
1781 * hi2
= (* hi2
<< 1 )|(* hi
>> 31 );
1782 * hi
= (* hi
<< 1 )|(* lo
>> 31 );
1783 //Then, shift in a 0 or one into low
1784 if ( dest
[ idx
] && ! dest
[ idx
+ 1 ]) // 1 0
1789 return ( int ) startIdx
;
1792 // find presco preamble 0x10D in already demoded data
1793 int PrescoDemod ( uint8_t * dest
, size_t * size
) {
1794 //make sure buffer has data
1795 if (* size
< 64 * 2 ) return - 2 ;
1797 size_t startIdx
= 0 ;
1798 uint8_t preamble
[] = { 1 , 0 , 0 , 0 , 0 , 1 , 1 , 0 , 1 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1799 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1800 if ( errChk
== 0 ) return - 4 ; //preamble not found
1801 //return start position
1802 return ( int ) startIdx
;
1806 // FSK Demod then try to locate a Farpointe Data (pyramid) ID
1807 int PyramiddemodFSK ( uint8_t * dest
, size_t * size
) {
1808 //make sure buffer has data
1809 if (* size
< 128 * 50 ) return - 5 ;
1811 //test samples are not just noise
1812 if ( justNoise ( dest
, * size
)) return - 1 ;
1815 * size
= fskdemod ( dest
, * size
, 50 , 1 , 10 , 8 ); // fsk2a RF/50
1816 if (* size
< 128 ) return - 2 ; //did we get a good demod?
1818 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
1819 size_t startIdx
= 0 ;
1820 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1821 if ( errChk
== 0 ) return - 4 ; //preamble not found
1822 if (* size
!= 128 ) return - 3 ;
1823 return ( int ) startIdx
;
1827 // find viking preamble 0xF200 in already demoded data
1828 int VikingDemod_AM ( uint8_t * dest
, size_t * size
) {
1829 //make sure buffer has data
1830 if (* size
< 64 * 2 ) return - 2 ;
1832 size_t startIdx
= 0 ;
1833 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 };
1834 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1835 if ( errChk
== 0 ) return - 4 ; //preamble not found
1836 uint32_t checkCalc
= bytebits_to_byte ( dest
+ startIdx
, 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 8 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 16 , 8 )
1837 ^ bytebits_to_byte ( dest
+ startIdx
+ 24 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 32 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 40 , 8 )
1838 ^ bytebits_to_byte ( dest
+ startIdx
+ 48 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 56 , 8 );
1839 if ( checkCalc
!= 0xA8 ) return - 5 ;
1840 if (* size
!= 64 ) return - 6 ;
1841 //return start position
1842 return ( int ) startIdx
;
1847 // find Visa2000 preamble in already demoded data
1848 int Visa2kDemod_AM ( uint8_t * dest
, size_t * size
) {
1849 if (* size
< 96 ) return - 1 ; //make sure buffer has data
1850 size_t startIdx
= 0 ;
1851 uint8_t preamble
[] = { 0 , 1 , 0 , 1 , 0 , 1 , 1 , 0 , 0 , 1 , 0 , 0 , 1 , 0 , 0 , 1 , 0 , 1 , 0 , 1 , 0 , 0 , 1 , 1 , 0 , 0 , 1 , 1 , 0 , 0 , 1 , 0 };
1852 if ( preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
) == 0 )
1853 return - 2 ; //preamble not found
1854 if (* size
!= 96 ) return - 3 ; //wrong demoded size
1855 //return start position
1856 return ( int ) startIdx
;