]>
cvs.zerfleddert.de Git - proxmark3-svn/blob - common/lfdemod.c
750dbf1b43a17bd1d2c011abde63f752748fff0e
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 // Clock / Bitrate Detection Section:
26 // for clock detection functions for each modulation
27 // Modulation Demods &/or Decoding Section:
28 // for main general modulation demodulating and encoding decoding code.
29 // Tag format detection section:
30 // for detection of specific tag formats within demodulated data
33 //-----------------------------------------------------------------------------
35 #include <string.h> // for memset, memcmp and size_t
36 #include <stdint.h> // for uint_32+
37 #include <stdbool.h> // for bool
39 //**********************************************************************************************
40 //---------------------------------Utilities Section--------------------------------------------
41 //**********************************************************************************************
43 //to allow debug print calls when used not on device
44 void dummy ( char * fmt
, ...){}
47 #include "cmdparser.h"
49 #define prnt PrintAndLog
51 uint8_t g_debugMode
= 0 ;
55 uint8_t justNoise ( uint8_t * BitStream
, size_t size
) {
56 static const uint8_t THRESHOLD
= 123 ;
57 //test samples are not just noise
58 uint8_t justNoise1
= 1 ;
59 for ( size_t idx
= 0 ; idx
< size
&& justNoise1
; idx
++){
60 justNoise1
= BitStream
[ idx
] < THRESHOLD
;
66 //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
67 int getHiLo ( uint8_t * BitStream
, size_t size
, int * high
, int * low
, uint8_t fuzzHi
, uint8_t fuzzLo
) {
70 // get high and low thresholds
71 for ( size_t i
= 0 ; i
< size
; i
++){
72 if ( BitStream
[ i
] > * high
) * high
= BitStream
[ i
];
73 if ( BitStream
[ i
] < * low
) * low
= BitStream
[ i
];
75 if (* high
< 123 ) return - 1 ; // just noise
76 * high
= ((* high
- 128 )* fuzzHi
+ 12800 )/ 100 ;
77 * low
= ((* low
- 128 )* fuzzLo
+ 12800 )/ 100 ;
82 // pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType
83 // returns 1 if passed
84 uint8_t parityTest ( uint32_t bits
, uint8_t bitLen
, uint8_t pType
) {
86 for ( uint8_t i
= 0 ; i
< bitLen
; i
++){
87 ans
^= (( bits
>> i
) & 1 );
89 if ( g_debugMode
) prnt ( "DEBUG: ans: %d, ptype: %d, bits: %08X" , ans
, pType
, bits
);
90 return ( ans
== pType
);
94 // takes a array of binary values, start position, length of bits per parity (includes parity bit),
95 // Parity Type (1 for odd; 0 for even; 2 for Always 1's; 3 for Always 0's), and binary Length (length to run)
96 size_t removeParity ( uint8_t * BitStream
, size_t startIdx
, uint8_t pLen
, uint8_t pType
, size_t bLen
) {
97 uint32_t parityWd
= 0 ;
98 size_t j
= 0 , bitCnt
= 0 ;
99 for ( int word
= 0 ; word
< ( bLen
); word
+= pLen
) {
100 for ( int bit
= 0 ; bit
< pLen
; bit
++) {
101 parityWd
= ( parityWd
<< 1 ) | BitStream
[ startIdx
+ word
+ bit
];
102 BitStream
[ j
++] = ( BitStream
[ startIdx
+ word
+ bit
]);
104 if ( word
+ pLen
> bLen
) break ;
106 j
--; // overwrite parity with next data
107 // if parity fails then return 0
109 case 3 : if ( BitStream
[ j
]== 1 ) { return 0 ;} break ; //should be 0 spacer bit
110 case 2 : if ( BitStream
[ j
]== 0 ) { return 0 ;} break ; //should be 1 spacer bit
111 default : if ( parityTest ( parityWd
, pLen
, pType
) == 0 ) { return 0 ;} break ; //test parity
116 // if we got here then all the parities passed
117 //return ID start index and size
122 // takes a array of binary values, length of bits per parity (includes parity bit),
123 // Parity Type (1 for odd; 0 for even; 2 Always 1's; 3 Always 0's), and binary Length (length to run)
124 // Make sure *dest is long enough to store original sourceLen + #_of_parities_to_be_added
125 size_t addParity ( uint8_t * BitSource
, uint8_t * dest
, uint8_t sourceLen
, uint8_t pLen
, uint8_t pType
) {
126 uint32_t parityWd
= 0 ;
127 size_t j
= 0 , bitCnt
= 0 ;
128 for ( int word
= 0 ; word
< sourceLen
; word
+= pLen
- 1 ) {
129 for ( int bit
= 0 ; bit
< pLen
- 1 ; bit
++){
130 parityWd
= ( parityWd
<< 1 ) | BitSource
[ word
+ bit
];
131 dest
[ j
++] = ( BitSource
[ word
+ bit
]);
133 // if parity fails then return 0
135 case 3 : dest
[ j
++]= 0 ; break ; // marker bit which should be a 0
136 case 2 : dest
[ j
++]= 1 ; break ; // marker bit which should be a 1
138 dest
[ j
++] = parityTest ( parityWd
, pLen
- 1 , pType
) ^ 1 ;
144 // if we got here then all the parities passed
145 //return ID start index and size
149 uint32_t bytebits_to_byte ( uint8_t * src
, size_t numbits
) {
151 for ( int i
= 0 ; i
< numbits
; i
++)
153 num
= ( num
<< 1 ) | (* src
);
159 //least significant bit first
160 uint32_t bytebits_to_byteLSBF ( uint8_t * src
, size_t numbits
) {
162 for ( int i
= 0 ; i
< numbits
; i
++)
164 num
= ( num
<< 1 ) | *( src
+ ( numbits
-( i
+ 1 )));
169 // 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
170 // fineone does not look for a repeating preamble for em4x05/4x69 sends preamble once, so look for it once in the first pLen bits
171 bool preambleSearchEx ( uint8_t * BitStream
, uint8_t * preamble
, size_t pLen
, size_t * size
, size_t * startIdx
, bool findone
) {
172 // Sanity check. If preamble length is bigger than bitstream length.
173 if ( * size
<= pLen
) return false ;
175 uint8_t foundCnt
= 0 ;
176 for ( size_t idx
= 0 ; idx
< * size
- pLen
; idx
++) {
177 if ( memcmp ( BitStream
+ idx
, preamble
, pLen
) == 0 ) {
181 if ( g_debugMode
) prnt ( "DEBUG: preamble found at %u" , idx
);
183 if ( findone
) return true ;
184 } else if ( foundCnt
== 2 ) {
185 * size
= idx
- * startIdx
;
194 //search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length
195 uint8_t preambleSearch ( uint8_t * BitStream
, uint8_t * preamble
, size_t pLen
, size_t * size
, size_t * startIdx
) {
196 return ( preambleSearchEx ( BitStream
, preamble
, pLen
, size
, startIdx
, false )) ? 1 : 0 ;
199 // find start of modulating data (for fsk and psk) in case of beginning noise or slow chip startup.
200 size_t findModStart ( uint8_t dest
[], size_t size
, uint8_t threshold_value
, uint8_t expWaveSize
) {
202 size_t waveSizeCnt
= 0 ;
203 uint8_t thresholdCnt
= 0 ;
204 bool isAboveThreshold
= dest
[ i
++] >= threshold_value
;
205 for (; i
< size
- 20 ; i
++ ) {
206 if ( dest
[ i
] < threshold_value
&& isAboveThreshold
) {
208 if ( thresholdCnt
> 2 && waveSizeCnt
< expWaveSize
+ 1 ) break ;
209 isAboveThreshold
= false ;
211 } else if ( dest
[ i
] >= threshold_value
&& ! isAboveThreshold
) {
213 if ( thresholdCnt
> 2 && waveSizeCnt
< expWaveSize
+ 1 ) break ;
214 isAboveThreshold
= true ;
219 if ( thresholdCnt
> 10 ) break ;
221 if ( g_debugMode
== 2 ) prnt ( "DEBUG: threshold Count reached at %u, count: %u" , i
, thresholdCnt
);
226 //amplify based on ask edge detection - not accurate enough to use all the time
227 void askAmp ( uint8_t * BitStream
, size_t size
) {
229 for ( size_t i
= 1 ; i
< size
; i
++){
230 if ( BitStream
[ i
]- BitStream
[ i
- 1 ]>= 30 ) //large jump up
232 else if ( BitStream
[ i
- 1 ]- BitStream
[ i
]>= 20 ) //large jump down
235 BitStream
[ i
- 1 ] = Last
;
240 uint32_t manchesterEncode2Bytes ( uint16_t datain
) {
243 for ( uint8_t i
= 0 ; i
< 16 ; i
++) {
244 curBit
= ( datain
>> ( 15 - i
) & 1 );
245 output
|= ( 1 <<((( 15 - i
)* 2 )+ curBit
));
251 //encode binary data into binary manchester
252 //NOTE: BitStream must have double the size available in memory to do the swap
253 int ManchesterEncode ( uint8_t * BitStream
, size_t size
) {
254 size_t modIdx
= size
, i
= 0 ;
255 if ( size
> modIdx
) return - 1 ;
256 for ( size_t idx
= 0 ; idx
< size
; idx
++){
257 BitStream
[ idx
+ modIdx
++] = BitStream
[ idx
];
258 BitStream
[ idx
+ modIdx
++] = BitStream
[ idx
]^ 1 ;
260 for (; i
<( size
* 2 ); i
++){
261 BitStream
[ i
] = BitStream
[ i
+ size
];
267 // to detect a wave that has heavily clipped (clean) samples
268 uint8_t DetectCleanAskWave ( uint8_t dest
[], size_t size
, uint8_t high
, uint8_t low
) {
269 bool allArePeaks
= true ;
271 size_t loopEnd
= 512 + 160 ;
272 if ( loopEnd
> size
) loopEnd
= size
;
273 for ( size_t i
= 160 ; i
< loopEnd
; i
++){
274 if ( dest
[ i
]> low
&& dest
[ i
]< high
)
280 if ( cntPeaks
> 300 ) return true ;
285 //**********************************************************************************************
286 //-------------------Clock / Bitrate Detection Section------------------------------------------
287 //**********************************************************************************************
290 // to help detect clocks on heavily clipped samples
291 // based on count of low to low
292 int DetectStrongAskClock ( uint8_t dest
[], size_t size
, uint8_t high
, uint8_t low
, int * clock
) {
293 uint8_t fndClk
[] = { 8 , 16 , 32 , 40 , 50 , 64 , 128 };
297 int shortestWaveIdx
= 0 ;
298 // get to first full low to prime loop and skip incomplete first pulse
299 while (( dest
[ i
] < high
) && ( i
< size
))
301 while (( dest
[ i
] > low
) && ( i
< size
))
304 // loop through all samples
306 // measure from low to low
307 while (( dest
[ i
] > low
) && ( i
< size
))
310 while (( dest
[ i
] < high
) && ( i
< size
))
312 while (( dest
[ i
] > low
) && ( i
< size
))
314 //get minimum measured distance
315 if ( i
- startwave
< minClk
&& i
< size
) {
316 minClk
= i
- startwave
;
317 shortestWaveIdx
= startwave
;
321 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: detectstrongASKclk smallest wave: %d" , minClk
);
322 for ( uint8_t clkCnt
= 0 ; clkCnt
< 7 ; clkCnt
++) {
323 if ( minClk
>= fndClk
[ clkCnt
]-( fndClk
[ clkCnt
]/ 8 ) && minClk
<= fndClk
[ clkCnt
]+ 1 ) {
324 * clock
= fndClk
[ clkCnt
];
325 return shortestWaveIdx
;
332 // not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)
333 // maybe somehow adjust peak trimming value based on samples to fix?
334 // return start index of best starting position for that clock and return clock (by reference)
335 int DetectASKClock ( uint8_t dest
[], size_t size
, int * clock
, int maxErr
) {
337 uint8_t clk
[] = { 255 , 8 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 255 };
339 uint8_t loopCnt
= 255 ; //don't need to loop through entire array...
340 if ( size
<= loopCnt
+ 60 ) return - 1 ; //not enough samples
341 size
-= 60 ; //sometimes there is a strange end wave - filter out this....
342 //if we already have a valid clock
345 if ( clk
[ i
] == * clock
) clockFnd
= i
;
346 //clock found but continue to find best startpos
348 //get high and low peak
350 if ( getHiLo ( dest
, loopCnt
, & peak
, & low
, 75 , 75 ) < 1 ) return - 1 ;
352 //test for large clean peaks
354 if ( DetectCleanAskWave ( dest
, size
, peak
, low
)== 1 ){
355 int ans
= DetectStrongAskClock ( dest
, size
, peak
, low
, clock
);
356 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: detectaskclk Clean Ask Wave Detected: clk %i, ShortestWave: %i" , clock
, ans
);
358 return ans
; //return shortest wave start position
363 uint8_t clkCnt
, tol
= 0 ;
364 uint16_t bestErr
[]={ 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 };
365 uint8_t bestStart
[]={ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
367 size_t arrLoc
, loopEnd
;
375 //test each valid clock from smallest to greatest to see which lines up
376 for (; clkCnt
< clkEnd
; clkCnt
++){
377 if ( clk
[ clkCnt
] <= 32 ){
382 //if no errors allowed - keep start within the first clock
383 if (! maxErr
&& size
> clk
[ clkCnt
]* 2 + tol
&& clk
[ clkCnt
]< 128 ) loopCnt
= clk
[ clkCnt
]* 2 ;
384 bestErr
[ clkCnt
]= 1000 ;
385 //try lining up the peaks by moving starting point (try first few clocks)
386 for ( ii
= 0 ; ii
< loopCnt
; ii
++){
387 if ( dest
[ ii
] < peak
&& dest
[ ii
] > low
) continue ;
390 // now that we have the first one lined up test rest of wave array
391 loopEnd
= (( size
- ii
- tol
) / clk
[ clkCnt
]) - 1 ;
392 for ( i
= 0 ; i
< loopEnd
; ++ i
){
393 arrLoc
= ii
+ ( i
* clk
[ clkCnt
]);
394 if ( dest
[ arrLoc
] >= peak
|| dest
[ arrLoc
] <= low
){
395 } else if ( dest
[ arrLoc
- tol
] >= peak
|| dest
[ arrLoc
- tol
] <= low
){
396 } else if ( dest
[ arrLoc
+ tol
] >= peak
|| dest
[ arrLoc
+ tol
] <= low
){
397 } else { //error no peak detected
401 //if we found no errors then we can stop here and a low clock (common clocks)
402 // this is correct one - return this clock
403 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: clk %d, err %d, startpos %d, endpos %d" , clk
[ clkCnt
], errCnt
, ii
, i
);
404 if ( errCnt
== 0 && clkCnt
< 7 ) {
405 if (! clockFnd
) * clock
= clk
[ clkCnt
];
408 //if we found errors see if it is lowest so far and save it as best run
409 if ( errCnt
< bestErr
[ clkCnt
]){
410 bestErr
[ clkCnt
]= errCnt
;
411 bestStart
[ clkCnt
]= ii
;
417 for ( iii
= 1 ; iii
< clkEnd
; ++ iii
){
418 if ( bestErr
[ iii
] < bestErr
[ best
]){
419 if ( bestErr
[ iii
] == 0 ) bestErr
[ iii
]= 1 ;
420 // current best bit to error ratio vs new bit to error ratio
421 if ( ( size
/ clk
[ best
])/ bestErr
[ best
] < ( size
/ clk
[ iii
])/ bestErr
[ iii
] ){
425 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
]);
427 if (! clockFnd
) * clock
= clk
[ best
];
428 return bestStart
[ best
];
431 int DetectStrongNRZClk ( uint8_t * dest
, size_t size
, int peak
, int low
){
432 //find shortest transition from high to low
434 size_t transition1
= 0 ;
435 int lowestTransition
= 255 ;
436 bool lastWasHigh
= false ;
438 //find first valid beginning of a high or low wave
439 while (( dest
[ i
] >= peak
|| dest
[ i
] <= low
) && ( i
< size
))
441 while (( dest
[ i
] < peak
&& dest
[ i
] > low
) && ( i
< size
))
443 lastWasHigh
= ( dest
[ i
] >= peak
);
445 if ( i
== size
) return 0 ;
448 for (; i
< size
; i
++) {
449 if (( dest
[ i
] >= peak
&& ! lastWasHigh
) || ( dest
[ i
] <= low
&& lastWasHigh
)) {
450 lastWasHigh
= ( dest
[ i
] >= peak
);
451 if ( i
- transition1
< lowestTransition
) lowestTransition
= i
- transition1
;
455 if ( lowestTransition
== 255 ) lowestTransition
= 0 ;
456 if ( g_debugMode
== 2 ) prnt ( "DEBUG NRZ: detectstrongNRZclk smallest wave: %d" , lowestTransition
);
457 return lowestTransition
;
461 //detect nrz clock by reading #peaks vs no peaks(or errors)
462 int DetectNRZClock_ext ( uint8_t dest
[], size_t size
, int clock
, size_t * clockStartIdx
) {
464 uint8_t clk
[]={ 8 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 255 };
465 size_t loopCnt
= 4096 ; //don't need to loop through entire array...
466 if ( size
== 0 ) return 0 ;
467 if ( size
< loopCnt
) loopCnt
= size
- 20 ;
468 //if we already have a valid clock quit
470 if ( clk
[ i
] == clock
) return clock
;
472 //get high and low peak
474 if ( getHiLo ( dest
, loopCnt
, & peak
, & low
, 75 , 75 ) < 1 ) return 0 ;
476 int lowestTransition
= DetectStrongNRZClk ( dest
, size
- 20 , peak
, low
);
480 uint16_t smplCnt
= 0 ;
482 int16_t peaksdet
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
483 uint16_t maxPeak
= 255 ;
484 bool firstpeak
= false ;
485 //test for large clipped waves
486 for ( i
= 0 ; i
< loopCnt
; i
++){
487 if ( dest
[ i
] >= peak
|| dest
[ i
] <= low
){
488 if (! firstpeak
) continue ;
493 if ( maxPeak
> smplCnt
){
495 //prnt("maxPk: %d",maxPeak);
498 //prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt);
505 uint8_t ignoreCnt
= 0 ;
506 uint8_t ignoreWindow
= 4 ;
507 bool lastPeakHigh
= 0 ;
509 size_t bestStart
[]={ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
511 //test each valid clock from smallest to greatest to see which lines up
512 for ( clkCnt
= 0 ; clkCnt
< 8 ; ++ clkCnt
){
513 //ignore clocks smaller than smallest peak
514 if ( clk
[ clkCnt
] < maxPeak
- ( clk
[ clkCnt
]/ 4 )) continue ;
515 //try lining up the peaks by moving starting point (try first 256)
516 for ( ii
= 20 ; ii
< loopCnt
; ++ ii
){
517 if (( dest
[ ii
] >= peak
) || ( dest
[ ii
] <= low
)){
521 lastBit
= ii
- clk
[ clkCnt
];
522 //loop through to see if this start location works
523 for ( i
= ii
; i
< size
- 20 ; ++ i
) {
524 //if we are at a clock bit
525 if (( i
>= lastBit
+ clk
[ clkCnt
] - tol
) && ( i
<= lastBit
+ clk
[ clkCnt
] + tol
)) {
527 if ( dest
[ i
] >= peak
|| dest
[ i
] <= low
) {
528 //if same peak don't count it
529 if (( dest
[ i
] >= peak
&& ! lastPeakHigh
) || ( dest
[ i
] <= low
&& lastPeakHigh
)) {
532 lastPeakHigh
= ( dest
[ i
] >= peak
);
535 ignoreCnt
= ignoreWindow
;
536 lastBit
+= clk
[ clkCnt
];
537 } else if ( i
== lastBit
+ clk
[ clkCnt
] + tol
) {
538 lastBit
+= clk
[ clkCnt
];
540 //else if not a clock bit and no peaks
541 } else if ( dest
[ i
] < peak
&& dest
[ i
] > low
){
544 if ( errBitHigh
== true ) peakcnt
--;
549 // else if not a clock bit but we have a peak
550 } else if (( dest
[ i
]>= peak
|| dest
[ i
]<= low
) && (! bitHigh
)) {
551 //error bar found no clock...
555 if ( peakcnt
> peaksdet
[ clkCnt
]) {
556 bestStart
[ clkCnt
]= ii
;
557 peaksdet
[ clkCnt
]= peakcnt
;
564 for ( iii
= 7 ; iii
> 0 ; iii
--){
565 if (( peaksdet
[ iii
] >= ( peaksdet
[ best
]- 1 )) && ( peaksdet
[ iii
] <= peaksdet
[ best
]+ 1 ) && lowestTransition
) {
566 if ( clk
[ iii
] > ( lowestTransition
- ( clk
[ iii
]/ 8 )) && clk
[ iii
] < ( lowestTransition
+ ( clk
[ iii
]/ 8 ))) {
569 } else if ( peaksdet
[ iii
] > peaksdet
[ best
]){
572 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
);
574 * clockStartIdx
= bestStart
[ best
];
578 int DetectNRZClock ( uint8_t dest
[], size_t size
, int clock
) {
580 return DetectNRZClock_ext ( dest
, size
, clock
, & bestStart
);
584 //countFC is to detect the field clock lengths.
585 //counts and returns the 2 most common wave lengths
586 //mainly used for FSK field clock detection
587 uint16_t countFC ( uint8_t * BitStream
, size_t size
, uint8_t fskAdj
) {
588 uint8_t fcLens
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
589 uint16_t fcCnts
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
590 uint8_t fcLensFnd
= 0 ;
591 uint8_t lastFCcnt
= 0 ;
592 uint8_t fcCounter
= 0 ;
594 if ( size
< 180 ) return 0 ;
596 // prime i to first up transition
597 for ( i
= 160 ; i
< size
- 20 ; i
++)
598 if ( BitStream
[ i
] > BitStream
[ i
- 1 ] && BitStream
[ i
] >= BitStream
[ i
+ 1 ])
601 for (; i
< size
- 20 ; i
++){
602 if ( BitStream
[ i
] > BitStream
[ i
- 1 ] && BitStream
[ i
] >= BitStream
[ i
+ 1 ]){
606 //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8)
607 if ( lastFCcnt
== 5 && fcCounter
== 9 ) fcCounter
--;
608 //if fc=9 or 4 add one (for when we get a fc 9 instead of 10 or a 4 instead of a 5)
609 if (( fcCounter
== 9 ) || fcCounter
== 4 ) fcCounter
++;
610 // save last field clock count (fc/xx)
611 lastFCcnt
= fcCounter
;
613 // find which fcLens to save it to:
614 for ( int ii
= 0 ; ii
< 15 ; ii
++){
615 if ( fcLens
[ ii
]== fcCounter
){
621 if ( fcCounter
> 0 && fcLensFnd
< 15 ){
624 fcLens
[ fcLensFnd
++]= fcCounter
;
633 uint8_t best1
= 14 , best2
= 14 , best3
= 14 ;
635 // go through fclens and find which ones are bigest 2
636 for ( i
= 0 ; i
< 15 ; i
++){
637 // get the 3 best FC values
638 if ( fcCnts
[ i
]> maxCnt1
) {
643 } else if ( fcCnts
[ i
]> fcCnts
[ best2
]){
646 } else if ( fcCnts
[ i
]> fcCnts
[ best3
]){
649 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
]);
651 if ( fcLens
[ best1
]== 0 ) return 0 ;
652 uint8_t fcH
= 0 , fcL
= 0 ;
653 if ( fcLens
[ best1
]> fcLens
[ best2
]){
660 if (( size
- 180 )/ fcH
/ 3 > fcCnts
[ best1
]+ fcCnts
[ best2
]) {
661 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
]);
662 return 0 ; //lots of waves not psk or fsk
664 // TODO: take top 3 answers and compare to known Field clocks to get top 2
666 uint16_t fcs
= ((( uint16_t ) fcH
)<< 8 ) | fcL
;
667 if ( fskAdj
) return fcs
;
668 return fcLens
[ best1
];
672 //detect psk clock by reading each phase shift
673 // a phase shift is determined by measuring the sample length of each wave
674 int DetectPSKClock_ext ( uint8_t dest
[], size_t size
, int clock
, int * firstPhaseShift
) {
675 uint8_t clk
[]={ 255 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 255 }; //255 is not a valid clock
676 uint16_t loopCnt
= 4096 ; //don't need to loop through entire array...
677 if ( size
== 0 ) return 0 ;
678 if ( size
< loopCnt
) loopCnt
= size
- 20 ;
680 //if we already have a valid clock quit
683 if ( clk
[ i
] == clock
) return clock
;
685 size_t waveStart
= 0 , waveEnd
= 0 , firstFullWave
= 0 , lastClkBit
= 0 ;
686 uint8_t clkCnt
, fc
= 0 , fullWaveLen
= 0 , tol
= 1 ;
687 uint16_t peakcnt
= 0 , errCnt
= 0 , waveLenCnt
= 0 ;
688 uint16_t bestErr
[]={ 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 };
689 uint16_t peaksdet
[]={ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
690 fc
= countFC ( dest
, size
, 0 );
691 if ( fc
!= 2 && fc
!= 4 && fc
!= 8 ) return - 1 ;
692 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: FC: %d" , fc
);
694 //find first full wave
695 for ( i
= 160 ; i
< loopCnt
; i
++){
696 if ( dest
[ i
] < dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
697 if ( waveStart
== 0 ) {
699 //prnt("DEBUG: waveStart: %d",waveStart);
702 //prnt("DEBUG: waveEnd: %d",waveEnd);
703 waveLenCnt
= waveEnd
- waveStart
;
704 if ( waveLenCnt
> fc
){
705 firstFullWave
= waveStart
;
706 fullWaveLen
= waveLenCnt
;
713 * firstPhaseShift
= firstFullWave
;
714 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: firstFullWave: %d, waveLen: %d" , firstFullWave
, fullWaveLen
);
715 //test each valid clock from greatest to smallest to see which lines up
716 for ( clkCnt
= 7 ; clkCnt
>= 1 ; clkCnt
--){
717 lastClkBit
= firstFullWave
; //set end of wave as clock align
721 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: clk: %d, lastClkBit: %d" , clk
[ clkCnt
], lastClkBit
);
723 for ( i
= firstFullWave
+ fullWaveLen
- 1 ; i
< loopCnt
- 2 ; i
++){
724 //top edge of wave = start of new wave
725 if ( dest
[ i
] < dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
726 if ( waveStart
== 0 ) {
731 waveLenCnt
= waveEnd
- waveStart
;
732 if ( waveLenCnt
> fc
){
733 //if this wave is a phase shift
734 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
);
735 if ( i
+ 1 >= lastClkBit
+ clk
[ clkCnt
] - tol
){ //should be a clock bit
737 lastClkBit
+= clk
[ clkCnt
];
738 } else if ( i
< lastClkBit
+ 8 ){
739 //noise after a phase shift - ignore
740 } else { //phase shift before supposed to based on clock
743 } else if ( i
+ 1 > lastClkBit
+ clk
[ clkCnt
] + tol
+ fc
){
744 lastClkBit
+= clk
[ clkCnt
]; //no phase shift but clock bit
753 if ( errCnt
<= bestErr
[ clkCnt
]) bestErr
[ clkCnt
]= errCnt
;
754 if ( peakcnt
> peaksdet
[ clkCnt
]) peaksdet
[ clkCnt
]= peakcnt
;
756 //all tested with errors
757 //return the highest clk with the most peaks found
759 for ( i
= 7 ; i
>= 1 ; i
--){
760 if ( peaksdet
[ i
] > peaksdet
[ best
]) {
763 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: Clk: %d, peaks: %d, errs: %d, bestClk: %d" , clk
[ i
], peaksdet
[ i
], bestErr
[ i
], clk
[ best
]);
768 int DetectPSKClock ( uint8_t dest
[], size_t size
, int clock
) {
769 int firstPhaseShift
= 0 ;
770 return DetectPSKClock_ext ( dest
, size
, clock
, & firstPhaseShift
);
774 //detects the bit clock for FSK given the high and low Field Clocks
775 uint8_t detectFSKClk_ext ( uint8_t * BitStream
, size_t size
, uint8_t fcHigh
, uint8_t fcLow
, int * firstClockEdge
) {
776 uint8_t clk
[] = { 8 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 0 };
777 uint16_t rfLens
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
778 uint8_t rfCnts
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
779 uint8_t rfLensFnd
= 0 ;
780 uint8_t lastFCcnt
= 0 ;
781 uint16_t fcCounter
= 0 ;
782 uint16_t rfCounter
= 0 ;
783 uint8_t firstBitFnd
= 0 ;
785 if ( size
== 0 ) return 0 ;
787 uint8_t fcTol
= (( fcHigh
* 100 - fcLow
* 100 )/ 2 + 50 )/ 100 ; //(uint8_t)(0.5+(float)(fcHigh-fcLow)/2);
792 //PrintAndLog("DEBUG: fcTol: %d",fcTol);
793 // prime i to first peak / up transition
794 for ( i
= 160 ; i
< size
- 20 ; i
++)
795 if ( BitStream
[ i
] > BitStream
[ i
- 1 ] && BitStream
[ i
]>= BitStream
[ i
+ 1 ])
798 for (; i
< size
- 20 ; i
++){
802 if ( BitStream
[ i
] <= BitStream
[ i
- 1 ] || BitStream
[ i
] < BitStream
[ i
+ 1 ])
805 // if we got less than the small fc + tolerance then set it to the small fc
806 // if it is inbetween set it to the last counter
807 if ( fcCounter
< fcHigh
&& fcCounter
> fcLow
)
808 fcCounter
= lastFCcnt
;
809 else if ( fcCounter
< fcLow
+ fcTol
)
811 else //set it to the large fc
814 //look for bit clock (rf/xx)
815 if (( fcCounter
< lastFCcnt
|| fcCounter
> lastFCcnt
)){
816 //not the same size as the last wave - start of new bit sequence
817 if ( firstBitFnd
> 1 ){ //skip first wave change - probably not a complete bit
818 for ( int ii
= 0 ; ii
< 15 ; ii
++){
819 if ( rfLens
[ ii
] >= ( rfCounter
- 4 ) && rfLens
[ ii
] <= ( rfCounter
+ 4 )){
825 if ( rfCounter
> 0 && rfLensFnd
< 15 ){
826 //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
828 rfLens
[ rfLensFnd
++] = rfCounter
;
839 uint8_t rfHighest
= 15 , rfHighest2
= 15 , rfHighest3
= 15 ;
841 for ( i
= 0 ; i
< 15 ; i
++){
842 //get highest 2 RF values (might need to get more values to compare or compare all?)
843 if ( rfCnts
[ i
]> rfCnts
[ rfHighest
]){
844 rfHighest3
= rfHighest2
;
845 rfHighest2
= rfHighest
;
847 } else if ( rfCnts
[ i
]> rfCnts
[ rfHighest2
]){
848 rfHighest3
= rfHighest2
;
850 } else if ( rfCnts
[ i
]> rfCnts
[ rfHighest3
]){
853 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: RF %d, cnts %d" , rfLens
[ i
], rfCnts
[ i
]);
855 // set allowed clock remainder tolerance to be 1 large field clock length+1
856 // we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off
857 uint8_t tol1
= fcHigh
+ 1 ;
859 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: most counted rf values: 1 %d, 2 %d, 3 %d" , rfLens
[ rfHighest
], rfLens
[ rfHighest2
], rfLens
[ rfHighest3
]);
861 // loop to find the highest clock that has a remainder less than the tolerance
862 // compare samples counted divided by
863 // test 128 down to 32 (shouldn't be possible to have fc/10 & fc/8 and rf/16 or less)
866 if ( rfLens
[ rfHighest
] % clk
[ ii
] < tol1
|| rfLens
[ rfHighest
] % clk
[ ii
] > clk
[ ii
]- tol1
){
867 if ( rfLens
[ rfHighest2
] % clk
[ ii
] < tol1
|| rfLens
[ rfHighest2
] % clk
[ ii
] > clk
[ ii
]- tol1
){
868 if ( rfLens
[ rfHighest3
] % clk
[ ii
] < tol1
|| rfLens
[ rfHighest3
] % clk
[ ii
] > clk
[ ii
]- tol1
){
869 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: clk %d divides into the 3 most rf values within tolerance" , clk
[ ii
]);
876 if ( ii
< 2 ) return 0 ; // oops we went too far
881 uint8_t detectFSKClk ( uint8_t * BitStream
, size_t size
, uint8_t fcHigh
, uint8_t fcLow
) {
882 int firstClockEdge
= 0 ;
883 return detectFSKClk_ext ( BitStream
, size
, fcHigh
, fcLow
, & firstClockEdge
);
886 //**********************************************************************************************
887 //--------------------Modulation Demods &/or Decoding Section-----------------------------------
888 //**********************************************************************************************
890 // 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...
891 bool findST ( int * stStopLoc
, int * stStartIdx
, int lowToLowWaveLen
[], int highToLowWaveLen
[], int clk
, int tol
, int buffSize
, int * i
) {
892 for (; * i
< buffSize
- 4 ; * i
+= 1 ) {
893 * 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...
894 if ( lowToLowWaveLen
[* i
] >= clk
* 1 - tol
&& lowToLowWaveLen
[* i
] <= ( clk
* 2 )+ tol
&& highToLowWaveLen
[* i
] < clk
+ tol
) { //1 to 2 clocks depending on 2 bits prior
895 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
896 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
897 if ( lowToLowWaveLen
[* i
+ 3 ] >= clk
* 1 - tol
&& lowToLowWaveLen
[* i
+ 3 ] <= clk
* 2 + tol
) { //1 to 2 clocks for end of ST + first bit
908 //attempt to identify a Sequence Terminator in ASK modulated raw wave
909 bool DetectST_ext ( uint8_t buffer
[], size_t * size
, int * foundclock
, size_t * ststart
, size_t * stend
) {
910 size_t bufsize
= * size
;
911 //need to loop through all samples and identify our clock, look for the ST pattern
912 uint8_t fndClk
[] = { 8 , 16 , 32 , 40 , 50 , 64 , 128 };
915 int i
, j
, skip
, start
, end
, low
, high
, minClk
, waveStart
;
916 //probably should malloc... || test if memory is available ... handle device side? memory danger!!! [marshmellow]
917 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
918 int waveLen
[ bufsize
/ 32 ]; // high to low wave count //if clock is larger then we waste memory in array size that is not needed...
919 size_t testsize
= ( bufsize
< 512 ) ? bufsize
: 512 ;
922 memset ( tmpbuff
, 0 , sizeof ( tmpbuff
));
923 memset ( waveLen
, 0 , sizeof ( waveLen
));
925 if ( getHiLo ( buffer
, testsize
, & high
, & low
, 80 , 80 ) == - 1 ) {
926 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: just noise detected - quitting" );
927 return false ; //just noise
932 // get to first full low to prime loop and skip incomplete first pulse
933 while (( buffer
[ i
] < high
) && ( i
< bufsize
))
935 while (( buffer
[ i
] > low
) && ( i
< bufsize
))
939 // populate tmpbuff buffer with pulse lengths
940 while ( i
< bufsize
) {
941 // measure from low to low
942 while (( buffer
[ i
] > low
) && ( i
< bufsize
))
945 while (( buffer
[ i
] < high
) && ( i
< bufsize
))
947 //first high point for this wave
949 while (( buffer
[ i
] > low
) && ( i
< bufsize
))
951 if ( j
>= ( bufsize
/ 32 )) {
954 waveLen
[ j
] = i
- waveStart
; //first high to first low
955 tmpbuff
[ j
++] = i
- start
;
956 if ( i
- start
< minClk
&& i
< bufsize
) {
960 // set clock - might be able to get this externally and remove this work...
962 for ( uint8_t clkCnt
= 0 ; clkCnt
< 7 ; clkCnt
++) {
963 tol
= fndClk
[ clkCnt
]/ 8 ;
964 if ( minClk
>= fndClk
[ clkCnt
]- tol
&& minClk
<= fndClk
[ clkCnt
]+ 1 ) {
969 // clock not found - ERROR
971 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: clock not found - quitting" );
978 if (! findST (& start
, & skip
, tmpbuff
, waveLen
, clk
, tol
, j
, & i
)) {
979 // first ST not found - ERROR
980 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: first STT not found - quitting" );
983 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: first STT found at wave: %i, skip: %i, j=%i" , start
, skip
, j
);
985 if ( waveLen
[ i
+ 2 ] > clk
* 1 + tol
)
990 // skip over the remainder of ST
991 skip
+= clk
* 7 / 2 ; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point
993 // now do it again to find the end
997 if (! findST (& dummy1
, & end
, tmpbuff
, waveLen
, clk
, tol
, j
, & i
)) {
998 //didn't find second ST - ERROR
999 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: second STT not found - quitting" );
1003 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
);
1004 //now begin to trim out ST so we can use normal demod cmds
1006 size_t datalen
= end
- start
;
1007 // check validity of datalen (should be even clock increments) - use a tolerance of up to 1/8th a clock
1008 if ( clk
- ( datalen
% clk
) <= clk
/ 8 ) {
1009 // padd the amount off - could be problematic... but shouldn't happen often
1010 datalen
+= clk
- ( datalen
% clk
);
1011 } else if ( ( datalen
% clk
) <= clk
/ 8 ) {
1012 // padd the amount off - could be problematic... but shouldn't happen often
1013 datalen
-= datalen
% clk
;
1015 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting" , datalen
, clk
, datalen
% clk
);
1018 // if datalen is less than one t55xx block - ERROR
1019 if ( datalen
/ clk
< 8 * 4 ) {
1020 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: datalen is less than 1 full t55xx block - quitting" );
1023 size_t dataloc
= start
;
1024 if ( buffer
[ dataloc
-( clk
* 4 )-( clk
/ 8 )] <= low
&& buffer
[ dataloc
] <= low
&& buffer
[ dataloc
-( clk
* 4 )] >= high
) {
1025 //we have low drift (and a low just before the ST and a low just after the ST) - compensate by backing up the start
1026 for ( i
= 0 ; i
<= ( clk
/ 8 ); ++ i
) {
1027 if ( buffer
[ dataloc
- ( clk
* 4 ) - i
] <= low
) {
1036 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: Starting STT trim - start: %d, datalen: %d " , dataloc
, datalen
);
1037 bool firstrun
= true ;
1038 // warning - overwriting buffer given with raw wave data with ST removed...
1039 while ( dataloc
< bufsize
-( clk
/ 2 ) ) {
1040 //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)
1041 if ( buffer
[ dataloc
]< high
&& buffer
[ dataloc
]> low
&& buffer
[ dataloc
+ 3 ]< high
&& buffer
[ dataloc
+ 3 ]> low
) {
1042 for ( i
= 0 ; i
< clk
/ 2 - tol
; ++ i
) {
1043 buffer
[ dataloc
+ i
] = high
+ 5 ;
1045 } //test for single sample outlier (high between two lows) in the case of very strong waves
1046 if ( buffer
[ dataloc
] >= high
&& buffer
[ dataloc
+ 2 ] <= low
) {
1047 buffer
[ dataloc
] = buffer
[ dataloc
+ 2 ];
1048 buffer
[ dataloc
+ 1 ] = buffer
[ dataloc
+ 2 ];
1052 * ststart
= dataloc
-( clk
* 4 );
1055 for ( i
= 0 ; i
< datalen
; ++ i
) {
1056 if ( i
+ newloc
< bufsize
) {
1057 if ( i
+ newloc
< dataloc
)
1058 buffer
[ i
+ newloc
] = buffer
[ dataloc
];
1064 //skip next ST - we just assume it will be there from now on...
1065 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: skipping STT at %d to %d" , dataloc
, dataloc
+( clk
* 4 ));
1071 bool DetectST ( uint8_t buffer
[], size_t * size
, int * foundclock
) {
1072 size_t ststart
= 0 , stend
= 0 ;
1073 return DetectST_ext ( buffer
, size
, foundclock
, & ststart
, & stend
);
1077 //take 11 10 01 11 00 and make 01100 ... miller decoding
1078 //check for phase errors - should never have half a 1 or 0 by itself and should never exceed 1111 or 0000 in a row
1079 //decodes miller encoded binary
1080 //NOTE askrawdemod will NOT demod miller encoded ask unless the clock is manually set to 1/2 what it is detected as!
1081 /*int millerRawDecode(uint8_t *BitStream, size_t *size, int invert) {
1082 if (*size < 16) return -1;
1083 uint16_t MaxBits = 512, errCnt = 0, bestErr = 1000, bestRun = 0;
1084 size_t i, ii, bitCnt=0;
1085 uint8_t alignCnt = 0, curBit = BitStream[0];
1086 //find alignment, needs 4 1s or 0s to properly align
1087 for (i=1; i < *size; i++) {
1088 alignCnt = (BitStream[i] == curBit) ? alignCnt+1 : 0;
1089 curBit = BitStream[i];
1090 if (alignCnt == 4) break;
1092 // for now error if alignment not found. later add option to run it with multiple offsets...
1093 if (alignCnt != 4) {
1094 if (g_debugMode) prnt("ERROR MillerDecode: alignment not found so either your bitstream is not miller or your data does not have a 101 in it");
1101 //take 01 or 10 = 1 and 11 or 00 = 0
1102 //check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010
1103 //decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding
1104 int BiphaseRawDecode ( uint8_t * BitStream
, size_t * size
, int offset
, int invert
) {
1105 uint16_t bitnum
= 0 ;
1106 uint16_t errCnt
= 0 ;
1108 uint16_t MaxBits
= 512 ;
1109 //if not enough samples - error
1110 if (* size
< 51 ) return - 1 ;
1111 //check for phase change faults - skip one sample if faulty
1112 uint8_t offsetA
= 1 , offsetB
= 1 ;
1114 if ( BitStream
[ i
+ 1 ]== BitStream
[ i
+ 2 ]) offsetA
= 0 ;
1115 if ( BitStream
[ i
+ 2 ]== BitStream
[ i
+ 3 ]) offsetB
= 0 ;
1117 if (! offsetA
&& offsetB
) offset
++;
1118 for ( i
= offset
; i
<* size
- 3 ; i
+= 2 ){
1119 //check for phase error
1120 if ( BitStream
[ i
+ 1 ]== BitStream
[ i
+ 2 ]) {
1121 BitStream
[ bitnum
++]= 7 ;
1124 if (( BitStream
[ i
]== 1 && BitStream
[ i
+ 1 ]== 0 ) || ( BitStream
[ i
]== 0 && BitStream
[ i
+ 1 ]== 1 )){
1125 BitStream
[ bitnum
++]= 1 ^ invert
;
1126 } else if (( BitStream
[ i
]== 0 && BitStream
[ i
+ 1 ]== 0 ) || ( BitStream
[ i
]== 1 && BitStream
[ i
+ 1 ]== 1 )){
1127 BitStream
[ bitnum
++]= invert
;
1129 BitStream
[ bitnum
++]= 7 ;
1132 if ( bitnum
> MaxBits
) break ;
1139 //take 10 and 01 and manchester decode
1140 //run through 2 times and take least errCnt
1141 int manrawdecode ( uint8_t * BitStream
, size_t * size
, uint8_t invert
, uint8_t * alignPos
) {
1142 uint16_t bitnum
= 0 , MaxBits
= 512 , errCnt
= 0 ;
1144 uint16_t bestErr
= 1000 , bestRun
= 0 ;
1145 if (* size
< 16 ) return - 1 ;
1146 //find correct start position [alignment]
1147 for ( ii
= 0 ; ii
< 2 ;++ ii
){
1148 for ( i
= ii
; i
<* size
- 3 ; i
+= 2 )
1149 if ( BitStream
[ i
]== BitStream
[ i
+ 1 ])
1152 if ( bestErr
> errCnt
){
1160 for ( i
= bestRun
; i
< * size
- 3 ; i
+= 2 ){
1161 if ( BitStream
[ i
] == 1 && ( BitStream
[ i
+ 1 ] == 0 )){
1162 BitStream
[ bitnum
++]= invert
;
1163 } else if (( BitStream
[ i
] == 0 ) && BitStream
[ i
+ 1 ] == 1 ){
1164 BitStream
[ bitnum
++]= invert
^ 1 ;
1166 BitStream
[ bitnum
++]= 7 ;
1168 if ( bitnum
> MaxBits
) break ;
1175 //demodulates strong heavily clipped samples
1176 int cleanAskRawDemod ( uint8_t * BinStream
, size_t * size
, int clk
, int invert
, int high
, int low
, int * startIdx
)
1179 size_t bitCnt
= 0 , smplCnt
= 1 , errCnt
= 0 ;
1180 bool waveHigh
= ( BinStream
[ 0 ] >= high
);
1181 for ( size_t i
= 1 ; i
< * size
; i
++){
1182 if ( BinStream
[ i
] >= high
&& waveHigh
){
1184 } else if ( BinStream
[ i
] <= low
&& ! waveHigh
){
1186 } else { //transition
1187 if (( BinStream
[ i
] >= high
&& ! waveHigh
) || ( BinStream
[ i
] <= low
&& waveHigh
)){
1188 if ( smplCnt
> clk
-( clk
/ 4 )- 1 ) { //full clock
1189 if ( smplCnt
> clk
+ ( clk
/ 4 )+ 1 ) { //too many samples
1191 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Modulation Error at: %u" , i
);
1192 BinStream
[ bitCnt
++] = 7 ;
1193 } else if ( waveHigh
) {
1194 BinStream
[ bitCnt
++] = invert
;
1195 BinStream
[ bitCnt
++] = invert
;
1196 } else if (! waveHigh
) {
1197 BinStream
[ bitCnt
++] = invert
^ 1 ;
1198 BinStream
[ bitCnt
++] = invert
^ 1 ;
1200 if (* startIdx
== 0 ) * startIdx
= i
- clk
;
1201 waveHigh
= ! waveHigh
;
1203 } else if ( smplCnt
> ( clk
/ 2 ) - ( clk
/ 4 )- 1 ) { //half clock
1205 BinStream
[ bitCnt
++] = invert
;
1206 } else if (! waveHigh
) {
1207 BinStream
[ bitCnt
++] = invert
^ 1 ;
1209 if (* startIdx
== 0 ) * startIdx
= i
-( clk
/ 2 );
1210 waveHigh
= ! waveHigh
;
1214 //transition bit oops
1216 } else { //haven't hit new high or new low yet
1226 //attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester
1227 int askdemod_ext ( uint8_t * BinStream
, size_t * size
, int * clk
, int * invert
, int maxErr
, uint8_t amp
, uint8_t askType
, int * startIdx
) {
1228 if (* size
== 0 ) return - 1 ;
1229 int start
= DetectASKClock ( BinStream
, * size
, clk
, maxErr
); //clock default
1230 if (* clk
== 0 || start
< 0 ) return - 3 ;
1231 if (* invert
!= 1 ) * invert
= 0 ;
1232 if ( amp
== 1 ) askAmp ( BinStream
, * size
);
1233 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: clk %d, beststart %d, amp %d" , * clk
, start
, amp
);
1235 //start pos from detect ask clock is 1/2 clock offset
1236 // NOTE: can be negative (demod assumes rest of wave was there)
1237 * startIdx
= start
- (* clk
/ 2 );
1238 uint8_t initLoopMax
= 255 ;
1239 if ( initLoopMax
> * size
) initLoopMax
= * size
;
1240 // Detect high and lows
1241 //25% clip in case highs and lows aren't clipped [marshmellow]
1243 if ( getHiLo ( BinStream
, initLoopMax
, & high
, & low
, 75 , 75 ) < 1 )
1244 return - 2 ; //just noise
1247 // if clean clipped waves detected run alternate demod
1248 if ( DetectCleanAskWave ( BinStream
, * size
, high
, low
)) {
1249 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Clean Wave Detected - using clean wave demod" );
1250 errCnt
= cleanAskRawDemod ( BinStream
, size
, * clk
, * invert
, high
, low
, startIdx
);
1251 if ( askType
) { //askman
1252 uint8_t alignPos
= 0 ;
1253 errCnt
= manrawdecode ( BinStream
, size
, 0 , & alignPos
);
1254 * startIdx
+= * clk
/ 2 * alignPos
;
1255 if ( g_debugMode
) prnt ( "DEBUG ASK CLEAN: startIdx %i, alignPos %u" , * startIdx
, alignPos
);
1261 if ( g_debugMode
) prnt ( "DEBUG ASK WEAK: startIdx %i" , * startIdx
);
1262 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Weak Wave Detected - using weak wave demod" );
1264 int lastBit
; //set first clock check - can go negative
1265 size_t i
, bitnum
= 0 ; //output counter
1267 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
1268 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
1269 size_t MaxBits
= 3072 ; //max bits to collect
1270 lastBit
= start
- * clk
;
1272 for ( i
= start
; i
< * size
; ++ i
) {
1273 if ( i
- lastBit
>= * clk
- tol
){
1274 if ( BinStream
[ i
] >= high
) {
1275 BinStream
[ bitnum
++] = * invert
;
1276 } else if ( BinStream
[ i
] <= low
) {
1277 BinStream
[ bitnum
++] = * invert
^ 1 ;
1278 } else if ( i
- lastBit
>= * clk
+ tol
) {
1280 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Modulation Error at: %u" , i
);
1281 BinStream
[ bitnum
++]= 7 ;
1284 } else { //in tolerance - looking for peak
1289 } else if ( i
- lastBit
>= (* clk
/ 2 - tol
) && ! midBit
&& ! askType
){
1290 if ( BinStream
[ i
] >= high
) {
1291 BinStream
[ bitnum
++] = * invert
;
1292 } else if ( BinStream
[ i
] <= low
) {
1293 BinStream
[ bitnum
++] = * invert
^ 1 ;
1294 } else if ( i
- lastBit
>= * clk
/ 2 + tol
) {
1295 BinStream
[ bitnum
] = BinStream
[ bitnum
- 1 ];
1297 } else { //in tolerance - looking for peak
1302 if ( bitnum
>= MaxBits
) break ;
1308 int askdemod ( uint8_t * BinStream
, size_t * size
, int * clk
, int * invert
, int maxErr
, uint8_t amp
, uint8_t askType
) {
1310 return askdemod_ext ( BinStream
, size
, clk
, invert
, maxErr
, amp
, askType
, & start
);
1313 // by marshmellow - demodulate NRZ wave - requires a read with strong signal
1314 // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
1315 int nrzRawDemod_ext ( uint8_t * dest
, size_t * size
, int * clk
, int * invert
, int * startIdx
) {
1316 if ( justNoise ( dest
, * size
)) return - 1 ;
1317 * clk
= DetectNRZClock ( dest
, * size
, * clk
);
1318 if (* clk
== 0 ) return - 2 ;
1319 size_t i
, gLen
= 4096 ;
1320 if ( gLen
>* size
) gLen
= * size
- 20 ;
1322 if ( getHiLo ( dest
, gLen
, & high
, & low
, 75 , 75 ) < 1 ) return - 3 ; //25% fuzz on high 25% fuzz on low
1325 //convert wave samples to 1's and 0's
1326 for ( i
= 20 ; i
< * size
- 20 ; i
++){
1327 if ( dest
[ i
] >= high
) bit
= 1 ;
1328 if ( dest
[ i
] <= low
) bit
= 0 ;
1331 //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit)
1334 for ( i
= 21 ; i
< * size
- 20 ; i
++) {
1335 //if transition detected or large number of same bits - store the passed bits
1336 if ( dest
[ i
] != dest
[ i
- 1 ] || ( i
- lastBit
) == ( 10 * * clk
)) {
1337 memset ( dest
+ numBits
, dest
[ i
- 1 ] ^ * invert
, ( i
- lastBit
+ (* clk
/ 4 )) / * clk
);
1338 numBits
+= ( i
- lastBit
+ (* clk
/ 4 )) / * clk
;
1340 * startIdx
= i
- ( numBits
* * clk
);
1341 if ( g_debugMode
== 2 ) prnt ( "DEBUG NRZ: startIdx %i" , * startIdx
);
1349 int nrzRawDemod ( uint8_t * dest
, size_t * size
, int * clk
, int * invert
) {
1351 return nrzRawDemod_ext ( dest
, size
, clk
, invert
, & startIdx
);
1354 //translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq])
1355 size_t fsk_wave_demod ( uint8_t * dest
, size_t size
, uint8_t fchigh
, uint8_t fclow
, int * startIdx
) {
1356 size_t last_transition
= 0 ;
1358 if ( fchigh
== 0 ) fchigh
= 10 ;
1359 if ( fclow
== 0 ) fclow
= 8 ;
1360 //set the threshold close to 0 (graph) or 128 std to avoid static
1361 uint8_t threshold_value
= 123 ;
1362 size_t preLastSample
= 0 ;
1363 size_t LastSample
= 0 ;
1364 size_t currSample
= 0 ;
1365 if ( size
< 1024 ) return 0 ; // not enough samples
1367 //find start of modulating data in trace
1368 idx
= findModStart ( dest
, size
, threshold_value
, fchigh
);
1369 // Need to threshold first sample
1370 if ( dest
[ idx
] < threshold_value
) dest
[ 0 ] = 0 ;
1373 last_transition
= idx
;
1376 // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
1377 // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere
1378 // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
1379 // (could also be fc/5 && fc/7 for fsk1 = 4-9)
1380 for (; idx
< size
; idx
++) {
1381 // threshold current value
1382 if ( dest
[ idx
] < threshold_value
) dest
[ idx
] = 0 ;
1385 // Check for 0->1 transition
1386 if ( dest
[ idx
- 1 ] < dest
[ idx
]) {
1387 preLastSample
= LastSample
;
1388 LastSample
= currSample
;
1389 currSample
= idx
- last_transition
;
1390 if ( currSample
< ( fclow
- 2 )) { //0-5 = garbage noise (or 0-3)
1391 //do nothing with extra garbage
1392 } else if ( currSample
< ( fchigh
- 1 )) { //6-8 = 8 sample waves (or 3-6 = 5)
1393 //correct previous 9 wave surrounded by 8 waves (or 6 surrounded by 5)
1394 if ( numBits
> 1 && LastSample
> ( fchigh
- 2 ) && ( preLastSample
< ( fchigh
- 1 ))){
1398 if ( numBits
> 0 && * startIdx
== 0 ) * startIdx
= idx
- fclow
;
1399 } else if ( currSample
> ( fchigh
+ 1 ) && numBits
< 3 ) { //12 + and first two bit = unusable garbage
1400 //do nothing with beginning garbage and reset.. should be rare..
1402 } 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)
1404 if ( numBits
> 0 && * startIdx
== 0 ) * startIdx
= idx
- fclow
;
1405 } else { //9+ = 10 sample waves (or 6+ = 7)
1407 if ( numBits
> 0 && * startIdx
== 0 ) * startIdx
= idx
- fchigh
;
1409 last_transition
= idx
;
1412 return numBits
; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
1415 //translate 11111100000 to 10
1416 //rfLen = clock, fchigh = larger field clock, fclow = smaller field clock
1417 size_t aggregate_bits ( uint8_t * dest
, size_t size
, uint8_t rfLen
, uint8_t invert
, uint8_t fchigh
, uint8_t fclow
, int * startIdx
) {
1418 uint8_t lastval
= dest
[ 0 ];
1422 for ( idx
= 1 ; idx
< size
; idx
++) {
1424 if ( dest
[ idx
]== lastval
) continue ; //skip until we hit a transition
1426 //find out how many bits (n) we collected (use 1/2 clk tolerance)
1427 //if lastval was 1, we have a 1->0 crossing
1428 if ( dest
[ idx
- 1 ]== 1 ) {
1429 n
= ( n
* fclow
+ rfLen
/ 2 ) / rfLen
;
1430 } else { // 0->1 crossing
1431 n
= ( n
* fchigh
+ rfLen
/ 2 ) / rfLen
;
1435 //first transition - save startidx
1437 if ( lastval
== 1 ) { //high to low
1438 * startIdx
+= ( fclow
* idx
) - ( n
* rfLen
);
1439 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: startIdx %i, fclow*idx %i, n*rflen %u" , * startIdx
, fclow
*( idx
), n
* rfLen
);
1441 * startIdx
+= ( fchigh
* idx
) - ( n
* rfLen
);
1442 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: startIdx %i, fchigh*idx %i, n*rflen %u" , * startIdx
, fchigh
*( idx
), n
* rfLen
);
1446 //add to our destination the bits we collected
1447 memset ( dest
+ numBits
, dest
[ idx
- 1 ]^ invert
, n
);
1452 // if valid extra bits at the end were all the same frequency - add them in
1453 if ( n
> rfLen
/ fchigh
) {
1454 if ( dest
[ idx
- 2 ]== 1 ) {
1455 n
= ( n
* fclow
+ rfLen
/ 2 ) / rfLen
;
1457 n
= ( n
* fchigh
+ rfLen
/ 2 ) / rfLen
;
1459 memset ( dest
+ numBits
, dest
[ idx
- 1 ]^ invert
, n
);
1465 //by marshmellow (from holiman's base)
1466 // full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod)
1467 int fskdemod_ext ( uint8_t * dest
, size_t size
, uint8_t rfLen
, uint8_t invert
, uint8_t fchigh
, uint8_t fclow
, int * startIdx
) {
1469 size
= fsk_wave_demod ( dest
, size
, fchigh
, fclow
, startIdx
);
1470 size
= aggregate_bits ( dest
, size
, rfLen
, invert
, fchigh
, fclow
, startIdx
);
1474 int fskdemod ( uint8_t * dest
, size_t size
, uint8_t rfLen
, uint8_t invert
, uint8_t fchigh
, uint8_t fclow
) {
1476 return fskdemod_ext ( dest
, size
, rfLen
, invert
, fchigh
, fclow
, & startIdx
);
1480 // convert psk1 demod to psk2 demod
1481 // only transition waves are 1s
1482 void psk1TOpsk2 ( uint8_t * BitStream
, size_t size
) {
1484 uint8_t lastBit
= BitStream
[ 0 ];
1485 for (; i
< size
; i
++){
1486 if ( BitStream
[ i
]== 7 ){
1488 } else if ( lastBit
!= BitStream
[ i
]){
1489 lastBit
= BitStream
[ i
];
1499 // convert psk2 demod to psk1 demod
1500 // from only transition waves are 1s to phase shifts change bit
1501 void psk2TOpsk1 ( uint8_t * BitStream
, size_t size
) {
1503 for ( size_t i
= 0 ; i
< size
; i
++){
1504 if ( BitStream
[ i
]== 1 ){
1512 //by marshmellow - demodulate PSK1 wave
1513 //uses wave lengths (# Samples)
1514 int pskRawDemod_ext ( uint8_t dest
[], size_t * size
, int * clock
, int * invert
, int * startIdx
) {
1515 if ( size
== 0 ) return - 1 ;
1516 uint16_t loopCnt
= 4096 ; //don't need to loop through entire array...
1517 if (* size
< loopCnt
) loopCnt
= * size
;
1520 uint8_t curPhase
= * invert
;
1521 size_t i
= 0 , waveStart
= 1 , waveEnd
= 0 , firstFullWave
= 0 , lastClkBit
= 0 ;
1522 uint16_t fc
= 0 , fullWaveLen
= 0 , tol
= 1 ;
1523 uint16_t errCnt
= 0 , waveLenCnt
= 0 , errCnt2
= 0 ;
1524 fc
= countFC ( dest
, * size
, 1 );
1525 uint8_t fc2
= fc
>> 8 ;
1526 if ( fc2
== 10 ) return - 1 ; //fsk found - quit
1528 if ( fc
!= 2 && fc
!= 4 && fc
!= 8 ) return - 1 ;
1529 //PrintAndLog("DEBUG: FC: %d",fc);
1530 * clock
= DetectPSKClock ( dest
, * size
, * clock
);
1531 if (* clock
== 0 ) return - 1 ;
1533 //find start of modulating data in trace
1534 uint8_t threshold_value
= 123 ; //-5
1535 i
= findModStart ( dest
, * size
, threshold_value
, fc
);
1537 //find first phase shift
1538 int avgWaveVal
= 0 , lastAvgWaveVal
= 0 ;
1540 for (; i
< loopCnt
; i
++) {
1542 if ( dest
[ i
]+ fc
< dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
1544 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: waveEnd: %u, waveStart: %u" , waveEnd
, waveStart
);
1545 waveLenCnt
= waveEnd
- waveStart
;
1546 if ( waveLenCnt
> fc
&& waveStart
> fc
&& !( waveLenCnt
> fc
+ 3 )){ //not first peak and is a large wave but not out of whack
1547 lastAvgWaveVal
= avgWaveVal
/( waveLenCnt
);
1548 firstFullWave
= waveStart
;
1549 fullWaveLen
= waveLenCnt
;
1550 //if average wave value is > graph 0 then it is an up wave or a 1 (could cause inverting)
1551 if ( lastAvgWaveVal
> threshold_value
) curPhase
^= 1 ;
1558 avgWaveVal
+= dest
[ i
+ 2 ];
1560 if ( firstFullWave
== 0 ) {
1561 // no phase shift detected - could be all 1's or 0's - doesn't matter where we start
1562 // so skip a little to ensure we are past any Start Signal
1563 firstFullWave
= 160 ;
1564 memset ( dest
, curPhase
, firstFullWave
/ * clock
);
1566 memset ( dest
, curPhase
^ 1 , firstFullWave
/ * clock
);
1569 numBits
+= ( firstFullWave
/ * clock
);
1570 * startIdx
= firstFullWave
- (* clock
* numBits
)+ 2 ;
1571 //set start of wave as clock align
1572 lastClkBit
= firstFullWave
;
1573 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: firstFullWave: %u, waveLen: %u, startIdx %i" , firstFullWave
, fullWaveLen
, * startIdx
);
1574 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: clk: %d, lastClkBit: %u, fc: %u" , * clock
, lastClkBit
,( unsigned int ) fc
);
1576 dest
[ numBits
++] = curPhase
; //set first read bit
1577 for ( i
= firstFullWave
+ fullWaveLen
- 1 ; i
< * size
- 3 ; i
++){
1578 //top edge of wave = start of new wave
1579 if ( dest
[ i
]+ fc
< dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
1580 if ( waveStart
== 0 ) {
1583 avgWaveVal
= dest
[ i
+ 1 ];
1586 waveLenCnt
= waveEnd
- waveStart
;
1587 lastAvgWaveVal
= avgWaveVal
/ waveLenCnt
;
1588 if ( waveLenCnt
> fc
){
1589 //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);
1590 //this wave is a phase shift
1591 //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc);
1592 if ( i
+ 1 >= lastClkBit
+ * clock
- tol
){ //should be a clock bit
1594 dest
[ numBits
++] = curPhase
;
1595 lastClkBit
+= * clock
;
1596 } else if ( i
< lastClkBit
+ 10 + fc
){
1597 //noise after a phase shift - ignore
1598 } else { //phase shift before supposed to based on clock
1600 dest
[ numBits
++] = 7 ;
1602 } else if ( i
+ 1 > lastClkBit
+ * clock
+ tol
+ fc
){
1603 lastClkBit
+= * clock
; //no phase shift but clock bit
1604 dest
[ numBits
++] = curPhase
;
1605 } else if ( waveLenCnt
< fc
- 1 ) { //wave is smaller than field clock (shouldn't happen often)
1607 if ( errCnt2
> 101 ) return errCnt2
;
1613 avgWaveVal
+= dest
[ i
+ 1 ];
1619 int pskRawDemod ( uint8_t dest
[], size_t * size
, int * clock
, int * invert
) {
1621 return pskRawDemod_ext ( dest
, size
, clock
, invert
, & startIdx
);
1624 //**********************************************************************************************
1625 //-----------------Tag format detection section-------------------------------------------------
1626 //**********************************************************************************************
1629 // FSK Demod then try to locate an AWID ID
1630 int AWIDdemodFSK ( uint8_t * dest
, size_t * size
) {
1631 //make sure buffer has enough data
1632 if (* size
< 96 * 50 ) return - 1 ;
1634 if ( justNoise ( dest
, * size
)) return - 2 ;
1637 * size
= fskdemod ( dest
, * size
, 50 , 1 , 10 , 8 ); // fsk2a RF/50
1638 if (* size
< 96 ) return - 3 ; //did we get a good demod?
1640 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
1641 size_t startIdx
= 0 ;
1642 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1643 if ( errChk
== 0 ) return - 4 ; //preamble not found
1644 if (* size
!= 96 ) return - 5 ;
1645 return ( int ) startIdx
;
1649 //takes 1s and 0s and searches for EM410x format - output EM ID
1650 uint8_t Em410xDecode ( uint8_t * BitStream
, size_t * size
, size_t * startIdx
, uint32_t * hi
, uint64_t * lo
)
1653 if (* size
< 64 ) return 0 ;
1654 if ( BitStream
[ 1 ]> 1 ) return 0 ; //allow only 1s and 0s
1656 // 111111111 bit pattern represent start of frame
1657 // include 0 in front to help get start pos
1658 uint8_t preamble
[] = { 0 , 1 , 1 , 1 , 1 , 1 , 1 , 1 , 1 , 1 };
1660 uint8_t FmtLen
= 10 ; // sets of 4 bits = end data
1662 errChk
= preambleSearch ( BitStream
, preamble
, sizeof ( preamble
), size
, startIdx
);
1663 if ( errChk
== 0 || (* size
!= 64 && * size
!= 128 ) ) return 0 ;
1664 if (* size
== 128 ) FmtLen
= 22 ; // 22 sets of 4 bits
1666 //skip last 4bit parity row for simplicity
1667 * size
= removeParity ( BitStream
, * startIdx
+ sizeof ( preamble
), 5 , 0 , FmtLen
* 5 );
1668 if (* size
== 40 ) { // std em410x format
1670 * lo
= (( uint64_t )( bytebits_to_byte ( BitStream
, 8 )) << 32 ) | ( bytebits_to_byte ( BitStream
+ 8 , 32 ));
1671 } else if (* size
== 88 ) { // long em format
1672 * hi
= ( bytebits_to_byte ( BitStream
, 24 ));
1673 * lo
= (( uint64_t )( bytebits_to_byte ( BitStream
+ 24 , 32 )) << 32 ) | ( bytebits_to_byte ( BitStream
+ 24 + 32 , 32 ));
1680 // Ask/Biphase Demod then try to locate an ISO 11784/85 ID
1681 // BitStream must contain previously askrawdemod and biphasedemoded data
1682 int FDXBdemodBI ( uint8_t * dest
, size_t * size
) {
1683 //make sure buffer has enough data
1684 if (* size
< 128 ) return - 1 ;
1686 size_t startIdx
= 0 ;
1687 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
1689 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1690 if ( errChk
== 0 ) return - 2 ; //preamble not found
1691 return ( int ) startIdx
;
1695 // demod gProxIIDemod
1696 // error returns as -x
1697 // success returns start position in BitStream
1698 // BitStream must contain previously askrawdemod and biphasedemoded data
1699 int gProxII_Demod ( uint8_t BitStream
[], size_t * size
) {
1701 uint8_t preamble
[] = { 1 , 1 , 1 , 1 , 1 , 0 };
1703 uint8_t errChk
= preambleSearch ( BitStream
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1704 if ( errChk
== 0 ) return - 3 ; //preamble not found
1705 if (* size
!= 96 ) return - 2 ; //should have found 96 bits
1706 //check first 6 spacer bits to verify format
1707 if (! BitStream
[ startIdx
+ 5 ] && ! BitStream
[ startIdx
+ 10 ] && ! BitStream
[ startIdx
+ 15 ] && ! BitStream
[ startIdx
+ 20 ] && ! BitStream
[ startIdx
+ 25 ] && ! BitStream
[ startIdx
+ 30 ]){
1708 //confirmed proper separator bits found
1709 //return start position
1710 return ( int ) startIdx
;
1712 return - 5 ; //spacer bits not found - not a valid gproxII
1715 // loop to get raw HID waveform then FSK demodulate the TAG ID from it
1716 int HIDdemodFSK ( uint8_t * dest
, size_t * size
, uint32_t * hi2
, uint32_t * hi
, uint32_t * lo
) {
1717 if ( justNoise ( dest
, * size
)) return - 1 ;
1719 size_t numStart
= 0 , size2
=* size
, startIdx
= 0 ;
1721 * size
= fskdemod ( dest
, size2
, 50 , 1 , 10 , 8 ); //fsk2a
1722 if (* size
< 96 * 2 ) return - 2 ;
1723 // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
1724 uint8_t preamble
[] = { 0 , 0 , 0 , 1 , 1 , 1 , 0 , 1 };
1725 // find bitstring in array
1726 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1727 if ( errChk
== 0 ) return - 3 ; //preamble not found
1729 numStart
= startIdx
+ sizeof ( preamble
);
1730 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
1731 for ( size_t idx
= numStart
; ( idx
- numStart
) < * size
- sizeof ( preamble
); idx
+= 2 ){
1732 if ( dest
[ idx
] == dest
[ idx
+ 1 ]){
1733 return - 4 ; //not manchester data
1735 * hi2
= (* hi2
<< 1 )|(* hi
>> 31 );
1736 * hi
= (* hi
<< 1 )|(* lo
>> 31 );
1737 //Then, shift in a 0 or one into low
1738 if ( dest
[ idx
] && ! dest
[ idx
+ 1 ]) // 1 0
1743 return ( int ) startIdx
;
1746 int IOdemodFSK ( uint8_t * dest
, size_t size
) {
1747 if ( justNoise ( dest
, size
)) return - 1 ;
1748 //make sure buffer has data
1749 if ( size
< 66 * 64 ) return - 2 ;
1751 size
= fskdemod ( dest
, size
, 64 , 1 , 10 , 8 ); // FSK2a RF/64
1752 if ( size
< 65 ) return - 3 ; //did we get a good demod?
1754 //0 10 20 30 40 50 60
1756 //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
1757 //-----------------------------------------------------------------------------
1758 //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
1760 //XSF(version)facility:codeone+codetwo
1762 size_t startIdx
= 0 ;
1763 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
1764 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), & size
, & startIdx
);
1765 if ( errChk
== 0 ) return - 4 ; //preamble not found
1767 if (! dest
[ startIdx
+ 8 ] && dest
[ startIdx
+ 17 ]== 1 && dest
[ startIdx
+ 26 ]== 1 && dest
[ startIdx
+ 35 ]== 1 && dest
[ startIdx
+ 44 ]== 1 && dest
[ startIdx
+ 53 ]== 1 ){
1768 //confirmed proper separator bits found
1769 //return start position
1770 return ( int ) startIdx
;
1775 // redesigned by marshmellow adjusted from existing decode functions
1776 // indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
1777 int indala26decode ( uint8_t * bitStream
, size_t * size
, uint8_t * invert
) {
1778 //26 bit 40134 format (don't know other formats)
1779 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 };
1780 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 };
1781 size_t startidx
= 0 ;
1782 if (! preambleSearch ( bitStream
, preamble
, sizeof ( preamble
), size
, & startidx
)){
1783 // if didn't find preamble try again inverting
1784 if (! preambleSearch ( bitStream
, preamble_i
, sizeof ( preamble_i
), size
, & startidx
)) return - 1 ;
1787 if (* size
!= 64 && * size
!= 224 ) return - 2 ;
1789 for ( size_t i
= startidx
; i
< * size
; i
++)
1792 return ( int ) startidx
;
1795 // loop to get raw paradox waveform then FSK demodulate the TAG ID from it
1796 int ParadoxdemodFSK ( uint8_t * dest
, size_t * size
, uint32_t * hi2
, uint32_t * hi
, uint32_t * lo
) {
1797 if ( justNoise ( dest
, * size
)) return - 1 ;
1799 size_t numStart
= 0 , size2
=* size
, startIdx
= 0 ;
1801 * size
= fskdemod ( dest
, size2
, 50 , 1 , 10 , 8 ); //fsk2a
1802 if (* size
< 96 ) return - 2 ;
1804 // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
1805 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 1 , 1 , 1 , 1 };
1807 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1808 if ( errChk
== 0 ) return - 3 ; //preamble not found
1810 numStart
= startIdx
+ sizeof ( preamble
);
1811 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
1812 for ( size_t idx
= numStart
; ( idx
- numStart
) < * size
- sizeof ( preamble
); idx
+= 2 ){
1813 if ( dest
[ idx
] == dest
[ idx
+ 1 ])
1814 return - 4 ; //not manchester data
1815 * hi2
= (* hi2
<< 1 )|(* hi
>> 31 );
1816 * hi
= (* hi
<< 1 )|(* lo
>> 31 );
1817 //Then, shift in a 0 or one into low
1818 if ( dest
[ idx
] && ! dest
[ idx
+ 1 ]) // 1 0
1823 return ( int ) startIdx
;
1826 // find presco preamble 0x10D in already demoded data
1827 int PrescoDemod ( uint8_t * dest
, size_t * size
) {
1828 //make sure buffer has data
1829 if (* size
< 64 * 2 ) return - 2 ;
1831 size_t startIdx
= 0 ;
1832 uint8_t preamble
[] = { 1 , 0 , 0 , 0 , 0 , 1 , 1 , 0 , 1 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1833 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1834 if ( errChk
== 0 ) return - 4 ; //preamble not found
1835 //return start position
1836 return ( int ) startIdx
;
1840 // FSK Demod then try to locate a Farpointe Data (pyramid) ID
1841 int PyramiddemodFSK ( uint8_t * dest
, size_t * size
) {
1842 //make sure buffer has data
1843 if (* size
< 128 * 50 ) return - 5 ;
1845 //test samples are not just noise
1846 if ( justNoise ( dest
, * size
)) return - 1 ;
1849 * size
= fskdemod ( dest
, * size
, 50 , 1 , 10 , 8 ); // fsk2a RF/50
1850 if (* size
< 128 ) return - 2 ; //did we get a good demod?
1852 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
1853 size_t startIdx
= 0 ;
1854 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1855 if ( errChk
== 0 ) return - 4 ; //preamble not found
1856 if (* size
!= 128 ) return - 3 ;
1857 return ( int ) startIdx
;
1861 // find viking preamble 0xF200 in already demoded data
1862 int VikingDemod_AM ( uint8_t * dest
, size_t * size
) {
1863 //make sure buffer has data
1864 if (* size
< 64 * 2 ) return - 2 ;
1866 size_t startIdx
= 0 ;
1867 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 };
1868 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1869 if ( errChk
== 0 ) return - 4 ; //preamble not found
1870 uint32_t checkCalc
= bytebits_to_byte ( dest
+ startIdx
, 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 8 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 16 , 8 )
1871 ^ bytebits_to_byte ( dest
+ startIdx
+ 24 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 32 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 40 , 8 )
1872 ^ bytebits_to_byte ( dest
+ startIdx
+ 48 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 56 , 8 );
1873 if ( checkCalc
!= 0xA8 ) return - 5 ;
1874 if (* size
!= 64 ) return - 6 ;
1875 //return start position
1876 return ( int ) startIdx
;
1881 // find Visa2000 preamble in already demoded data
1882 int Visa2kDemod_AM ( uint8_t * dest
, size_t * size
) {
1883 if (* size
< 96 ) return - 1 ; //make sure buffer has data
1884 size_t startIdx
= 0 ;
1885 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 };
1886 if ( preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
) == 0 )
1887 return - 2 ; //preamble not found
1888 if (* size
!= 96 ) return - 3 ; //wrong demoded size
1889 //return start position
1890 return ( int ) startIdx
;