]>
cvs.zerfleddert.de Git - proxmark3-svn/blob - common/lfdemod.c
395b44b155eb060324287f3435693f9d9e632c98
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 void getNextLow ( uint8_t samples
[], size_t size
, int low
, int * i
) {
891 while (( samples
[* i
] > low
) && (* i
< size
))
894 void getNextHigh ( uint8_t samples
[], size_t size
, int high
, int * i
) {
895 while (( samples
[* i
] < high
) && (* i
< size
))
899 // load wave counters
900 bool loadWaveCounters ( uint8_t samples
[], size_t size
, int lowToLowWaveLen
[], int highToLowWaveLen
[], int * waveCnt
, int * skip
, int * minClk
, int * high
, int * low
) {
901 int i
= 0 , start
, waveStart
;
902 size_t testsize
= ( size
< 512 ) ? size
: 512 ;
904 if ( getHiLo ( samples
, testsize
, high
, low
, 80 , 80 ) == - 1 ) {
905 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: just noise detected - quitting" );
906 return false ; //just noise
909 // get to first full low to prime loop and skip incomplete first pulse
910 getNextHigh ( samples
, size
, * high
, & i
);
911 getNextLow ( samples
, size
, * low
, & i
);
914 // populate tmpbuff buffer with pulse lengths
916 // measure from low to low
917 getNextLow ( samples
, size
, * low
, & i
);
920 //find first high point for this wave
921 getNextHigh ( samples
, size
, * high
, & i
);
924 getNextLow ( samples
, size
, * low
, & i
);
926 if (* waveCnt
>= ( size
/ 32 ))
929 highToLowWaveLen
[* waveCnt
] = i
- waveStart
; //first high to first low
930 lowToLowWaveLen
[* waveCnt
] = i
- start
;
932 if ( i
- start
< * minClk
&& i
< size
) {
939 // 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...
940 bool findST ( int * stStopLoc
, int * stStartIdx
, int lowToLowWaveLen
[], int highToLowWaveLen
[], int clk
, int tol
, int buffSize
, int * i
) {
941 for (; * i
< buffSize
- 4 ; * i
+= 1 ) {
942 * 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...
943 if ( lowToLowWaveLen
[* i
] >= clk
* 1 - tol
&& lowToLowWaveLen
[* i
] <= ( clk
* 2 )+ tol
&& highToLowWaveLen
[* i
] < clk
+ tol
) { //1 to 2 clocks depending on 2 bits prior
944 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
945 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
946 if ( lowToLowWaveLen
[* i
+ 3 ] >= clk
* 1 - tol
&& lowToLowWaveLen
[* i
+ 3 ] <= clk
* 2 + tol
) { //1 to 2 clocks for end of ST + first bit
957 //attempt to identify a Sequence Terminator in ASK modulated raw wave
958 bool DetectST_ext ( uint8_t buffer
[], size_t * size
, int * foundclock
, size_t * ststart
, size_t * stend
) {
959 size_t bufsize
= * size
;
960 //need to loop through all samples and identify our clock, look for the ST pattern
961 uint8_t fndClk
[] = { 8 , 16 , 32 , 40 , 50 , 64 , 128 };
964 int i
= 0 , j
, skip
, start
, end
, low
, high
, minClk
= 255 ;
965 //probably should malloc... || test if memory is available ... handle device side? memory danger!!! [marshmellow]
966 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
967 int waveLen
[ bufsize
/ 32 ]; // high to low wave count //if clock is larger then we waste memory in array size that is not needed...
968 //size_t testsize = (bufsize < 512) ? bufsize : 512;
971 memset ( tmpbuff
, 0 , sizeof ( tmpbuff
));
972 memset ( waveLen
, 0 , sizeof ( waveLen
));
974 if (! loadWaveCounters ( buffer
, bufsize
, tmpbuff
, waveLen
, & j
, & skip
, & minClk
, & high
, & low
)) return false ;
975 // set clock - might be able to get this externally and remove this work...
977 for ( uint8_t clkCnt
= 0 ; clkCnt
< 7 ; clkCnt
++) {
978 tol
= fndClk
[ clkCnt
]/ 8 ;
979 if ( minClk
>= fndClk
[ clkCnt
]- tol
&& minClk
<= fndClk
[ clkCnt
]+ 1 ) {
984 // clock not found - ERROR
986 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: clock not found - quitting" );
992 if (! findST (& start
, & skip
, tmpbuff
, waveLen
, clk
, tol
, j
, & i
)) {
993 // first ST not found - ERROR
994 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: first STT not found - quitting" );
997 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: first STT found at wave: %i, skip: %i, j=%i" , start
, skip
, j
);
999 if ( waveLen
[ i
+ 2 ] > clk
* 1 + tol
)
1004 // skip over the remainder of ST
1005 skip
+= clk
* 7 / 2 ; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point
1007 // now do it again to find the end
1011 if (! findST (& dummy1
, & end
, tmpbuff
, waveLen
, clk
, tol
, j
, & i
)) {
1012 //didn't find second ST - ERROR
1013 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: second STT not found - quitting" );
1017 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
);
1018 //now begin to trim out ST so we can use normal demod cmds
1020 size_t datalen
= end
- start
;
1021 // check validity of datalen (should be even clock increments) - use a tolerance of up to 1/8th a clock
1022 if ( clk
- ( datalen
% clk
) <= clk
/ 8 ) {
1023 // padd the amount off - could be problematic... but shouldn't happen often
1024 datalen
+= clk
- ( datalen
% clk
);
1025 } else if ( ( datalen
% clk
) <= clk
/ 8 ) {
1026 // padd the amount off - could be problematic... but shouldn't happen often
1027 datalen
-= datalen
% clk
;
1029 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting" , datalen
, clk
, datalen
% clk
);
1032 // if datalen is less than one t55xx block - ERROR
1033 if ( datalen
/ clk
< 8 * 4 ) {
1034 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: datalen is less than 1 full t55xx block - quitting" );
1037 size_t dataloc
= start
;
1038 if ( buffer
[ dataloc
-( clk
* 4 )-( clk
/ 8 )] <= low
&& buffer
[ dataloc
] <= low
&& buffer
[ dataloc
-( clk
* 4 )] >= high
) {
1039 //we have low drift (and a low just before the ST and a low just after the ST) - compensate by backing up the start
1040 for ( i
= 0 ; i
<= ( clk
/ 8 ); ++ i
) {
1041 if ( buffer
[ dataloc
- ( clk
* 4 ) - i
] <= low
) {
1050 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: Starting STT trim - start: %d, datalen: %d " , dataloc
, datalen
);
1051 bool firstrun
= true ;
1052 // warning - overwriting buffer given with raw wave data with ST removed...
1053 while ( dataloc
< bufsize
-( clk
/ 2 ) ) {
1054 //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)
1055 if ( buffer
[ dataloc
]< high
&& buffer
[ dataloc
]> low
&& buffer
[ dataloc
+ 3 ]< high
&& buffer
[ dataloc
+ 3 ]> low
) {
1056 for ( i
= 0 ; i
< clk
/ 2 - tol
; ++ i
) {
1057 buffer
[ dataloc
+ i
] = high
+ 5 ;
1059 } //test for single sample outlier (high between two lows) in the case of very strong waves
1060 if ( buffer
[ dataloc
] >= high
&& buffer
[ dataloc
+ 2 ] <= low
) {
1061 buffer
[ dataloc
] = buffer
[ dataloc
+ 2 ];
1062 buffer
[ dataloc
+ 1 ] = buffer
[ dataloc
+ 2 ];
1066 * ststart
= dataloc
-( clk
* 4 );
1069 for ( i
= 0 ; i
< datalen
; ++ i
) {
1070 if ( i
+ newloc
< bufsize
) {
1071 if ( i
+ newloc
< dataloc
)
1072 buffer
[ i
+ newloc
] = buffer
[ dataloc
];
1078 //skip next ST - we just assume it will be there from now on...
1079 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: skipping STT at %d to %d" , dataloc
, dataloc
+( clk
* 4 ));
1085 bool DetectST ( uint8_t buffer
[], size_t * size
, int * foundclock
) {
1086 size_t ststart
= 0 , stend
= 0 ;
1087 return DetectST_ext ( buffer
, size
, foundclock
, & ststart
, & stend
);
1091 //take 11 10 01 11 00 and make 01100 ... miller decoding
1092 //check for phase errors - should never have half a 1 or 0 by itself and should never exceed 1111 or 0000 in a row
1093 //decodes miller encoded binary
1094 //NOTE askrawdemod will NOT demod miller encoded ask unless the clock is manually set to 1/2 what it is detected as!
1095 int millerRawDecode ( uint8_t * BitStream
, size_t * size
, int invert
) {
1096 if (* size
< 16 ) return - 1 ;
1097 uint16_t MaxBits
= 512 , errCnt
= 0 ;
1099 uint8_t alignCnt
= 0 , curBit
= BitStream
[ 0 ], alignedIdx
= 0 ;
1100 uint8_t halfClkErr
= 0 ;
1101 //find alignment, needs 4 1s or 0s to properly align
1102 for ( i
= 1 ; i
< * size
- 1 ; i
++) {
1103 alignCnt
= ( BitStream
[ i
] == curBit
) ? alignCnt
+ 1 : 0 ;
1104 curBit
= BitStream
[ i
];
1105 if ( alignCnt
== 4 ) break ;
1107 // for now error if alignment not found. later add option to run it with multiple offsets...
1108 if ( alignCnt
!= 4 ) {
1109 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" );
1112 alignedIdx
= ( i
- 1 ) % 2 ;
1113 for ( i
= alignedIdx
; i
< * size
- 3 ; i
+= 2 ) {
1114 halfClkErr
= ( uint8_t )(( halfClkErr
<< 1 | BitStream
[ i
]) & 0xFF );
1115 if ( ( halfClkErr
& 0x7 ) == 5 || ( halfClkErr
& 0x7 ) == 2 || ( i
> 2 && ( halfClkErr
& 0x7 ) == 0 ) || ( halfClkErr
& 0x1F ) == 0x1F ) {
1117 BitStream
[ bitCnt
++] = 7 ;
1120 BitStream
[ bitCnt
++] = BitStream
[ i
] ^ BitStream
[ i
+ 1 ] ^ invert
;
1122 if ( bitCnt
> MaxBits
) break ;
1129 //take 01 or 10 = 1 and 11 or 00 = 0
1130 //check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010
1131 //decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding
1132 int BiphaseRawDecode ( uint8_t * BitStream
, size_t * size
, int offset
, int invert
) {
1133 uint16_t bitnum
= 0 ;
1134 uint16_t errCnt
= 0 ;
1136 uint16_t MaxBits
= 512 ;
1137 //if not enough samples - error
1138 if (* size
< 51 ) return - 1 ;
1139 //check for phase change faults - skip one sample if faulty
1140 uint8_t offsetA
= 1 , offsetB
= 1 ;
1142 if ( BitStream
[ i
+ 1 ]== BitStream
[ i
+ 2 ]) offsetA
= 0 ;
1143 if ( BitStream
[ i
+ 2 ]== BitStream
[ i
+ 3 ]) offsetB
= 0 ;
1145 if (! offsetA
&& offsetB
) offset
++;
1146 for ( i
= offset
; i
<* size
- 3 ; i
+= 2 ){
1147 //check for phase error
1148 if ( BitStream
[ i
+ 1 ]== BitStream
[ i
+ 2 ]) {
1149 BitStream
[ bitnum
++]= 7 ;
1152 if (( BitStream
[ i
]== 1 && BitStream
[ i
+ 1 ]== 0 ) || ( BitStream
[ i
]== 0 && BitStream
[ i
+ 1 ]== 1 )){
1153 BitStream
[ bitnum
++]= 1 ^ invert
;
1154 } else if (( BitStream
[ i
]== 0 && BitStream
[ i
+ 1 ]== 0 ) || ( BitStream
[ i
]== 1 && BitStream
[ i
+ 1 ]== 1 )){
1155 BitStream
[ bitnum
++]= invert
;
1157 BitStream
[ bitnum
++]= 7 ;
1160 if ( bitnum
> MaxBits
) break ;
1167 //take 10 and 01 and manchester decode
1168 //run through 2 times and take least errCnt
1169 int manrawdecode ( uint8_t * BitStream
, size_t * size
, uint8_t invert
, uint8_t * alignPos
) {
1170 uint16_t bitnum
= 0 , MaxBits
= 512 , errCnt
= 0 ;
1172 uint16_t bestErr
= 1000 , bestRun
= 0 ;
1173 if (* size
< 16 ) return - 1 ;
1174 //find correct start position [alignment]
1175 for ( ii
= 0 ; ii
< 2 ;++ ii
){
1176 for ( i
= ii
; i
<* size
- 3 ; i
+= 2 )
1177 if ( BitStream
[ i
]== BitStream
[ i
+ 1 ])
1180 if ( bestErr
> errCnt
){
1188 for ( i
= bestRun
; i
< * size
- 3 ; i
+= 2 ){
1189 if ( BitStream
[ i
] == 1 && ( BitStream
[ i
+ 1 ] == 0 )){
1190 BitStream
[ bitnum
++]= invert
;
1191 } else if (( BitStream
[ i
] == 0 ) && BitStream
[ i
+ 1 ] == 1 ){
1192 BitStream
[ bitnum
++]= invert
^ 1 ;
1194 BitStream
[ bitnum
++]= 7 ;
1196 if ( bitnum
> MaxBits
) break ;
1203 //demodulates strong heavily clipped samples
1204 int cleanAskRawDemod ( uint8_t * BinStream
, size_t * size
, int clk
, int invert
, int high
, int low
, int * startIdx
)
1207 size_t bitCnt
= 0 , smplCnt
= 1 , errCnt
= 0 ;
1208 bool waveHigh
= ( BinStream
[ 0 ] >= high
);
1209 for ( size_t i
= 1 ; i
< * size
; i
++){
1210 if ( BinStream
[ i
] >= high
&& waveHigh
){
1212 } else if ( BinStream
[ i
] <= low
&& ! waveHigh
){
1214 } else { //transition
1215 if (( BinStream
[ i
] >= high
&& ! waveHigh
) || ( BinStream
[ i
] <= low
&& waveHigh
)){
1216 if ( smplCnt
> clk
-( clk
/ 4 )- 1 ) { //full clock
1217 if ( smplCnt
> clk
+ ( clk
/ 4 )+ 1 ) { //too many samples
1219 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Modulation Error at: %u" , i
);
1220 BinStream
[ bitCnt
++] = 7 ;
1221 } else if ( waveHigh
) {
1222 BinStream
[ bitCnt
++] = invert
;
1223 BinStream
[ bitCnt
++] = invert
;
1224 } else if (! waveHigh
) {
1225 BinStream
[ bitCnt
++] = invert
^ 1 ;
1226 BinStream
[ bitCnt
++] = invert
^ 1 ;
1228 if (* startIdx
== 0 ) * startIdx
= i
- clk
;
1229 waveHigh
= ! waveHigh
;
1231 } else if ( smplCnt
> ( clk
/ 2 ) - ( clk
/ 4 )- 1 ) { //half clock
1233 BinStream
[ bitCnt
++] = invert
;
1234 } else if (! waveHigh
) {
1235 BinStream
[ bitCnt
++] = invert
^ 1 ;
1237 if (* startIdx
== 0 ) * startIdx
= i
-( clk
/ 2 );
1238 waveHigh
= ! waveHigh
;
1242 //transition bit oops
1244 } else { //haven't hit new high or new low yet
1254 //attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester
1255 int askdemod_ext ( uint8_t * BinStream
, size_t * size
, int * clk
, int * invert
, int maxErr
, uint8_t amp
, uint8_t askType
, int * startIdx
) {
1256 if (* size
== 0 ) return - 1 ;
1257 int start
= DetectASKClock ( BinStream
, * size
, clk
, maxErr
); //clock default
1258 if (* clk
== 0 || start
< 0 ) return - 3 ;
1259 if (* invert
!= 1 ) * invert
= 0 ;
1260 if ( amp
== 1 ) askAmp ( BinStream
, * size
);
1261 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: clk %d, beststart %d, amp %d" , * clk
, start
, amp
);
1263 //start pos from detect ask clock is 1/2 clock offset
1264 // NOTE: can be negative (demod assumes rest of wave was there)
1265 * startIdx
= start
- (* clk
/ 2 );
1266 uint8_t initLoopMax
= 255 ;
1267 if ( initLoopMax
> * size
) initLoopMax
= * size
;
1268 // Detect high and lows
1269 //25% clip in case highs and lows aren't clipped [marshmellow]
1271 if ( getHiLo ( BinStream
, initLoopMax
, & high
, & low
, 75 , 75 ) < 1 )
1272 return - 2 ; //just noise
1275 // if clean clipped waves detected run alternate demod
1276 if ( DetectCleanAskWave ( BinStream
, * size
, high
, low
)) {
1277 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Clean Wave Detected - using clean wave demod" );
1278 errCnt
= cleanAskRawDemod ( BinStream
, size
, * clk
, * invert
, high
, low
, startIdx
);
1279 if ( askType
) { //askman
1280 uint8_t alignPos
= 0 ;
1281 errCnt
= manrawdecode ( BinStream
, size
, 0 , & alignPos
);
1282 * startIdx
+= * clk
/ 2 * alignPos
;
1283 if ( g_debugMode
) prnt ( "DEBUG ASK CLEAN: startIdx %i, alignPos %u" , * startIdx
, alignPos
);
1289 if ( g_debugMode
) prnt ( "DEBUG ASK WEAK: startIdx %i" , * startIdx
);
1290 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Weak Wave Detected - using weak wave demod" );
1292 int lastBit
; //set first clock check - can go negative
1293 size_t i
, bitnum
= 0 ; //output counter
1295 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
1296 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
1297 size_t MaxBits
= 3072 ; //max bits to collect
1298 lastBit
= start
- * clk
;
1300 for ( i
= start
; i
< * size
; ++ i
) {
1301 if ( i
- lastBit
>= * clk
- tol
){
1302 if ( BinStream
[ i
] >= high
) {
1303 BinStream
[ bitnum
++] = * invert
;
1304 } else if ( BinStream
[ i
] <= low
) {
1305 BinStream
[ bitnum
++] = * invert
^ 1 ;
1306 } else if ( i
- lastBit
>= * clk
+ tol
) {
1308 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Modulation Error at: %u" , i
);
1309 BinStream
[ bitnum
++]= 7 ;
1312 } else { //in tolerance - looking for peak
1317 } else if ( i
- lastBit
>= (* clk
/ 2 - tol
) && ! midBit
&& ! askType
){
1318 if ( BinStream
[ i
] >= high
) {
1319 BinStream
[ bitnum
++] = * invert
;
1320 } else if ( BinStream
[ i
] <= low
) {
1321 BinStream
[ bitnum
++] = * invert
^ 1 ;
1322 } else if ( i
- lastBit
>= * clk
/ 2 + tol
) {
1323 BinStream
[ bitnum
] = BinStream
[ bitnum
- 1 ];
1325 } else { //in tolerance - looking for peak
1330 if ( bitnum
>= MaxBits
) break ;
1336 int askdemod ( uint8_t * BinStream
, size_t * size
, int * clk
, int * invert
, int maxErr
, uint8_t amp
, uint8_t askType
) {
1338 return askdemod_ext ( BinStream
, size
, clk
, invert
, maxErr
, amp
, askType
, & start
);
1341 // by marshmellow - demodulate NRZ wave - requires a read with strong signal
1342 // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
1343 int nrzRawDemod_ext ( uint8_t * dest
, size_t * size
, int * clk
, int * invert
, int * startIdx
) {
1344 if ( justNoise ( dest
, * size
)) return - 1 ;
1345 * clk
= DetectNRZClock ( dest
, * size
, * clk
);
1346 if (* clk
== 0 ) return - 2 ;
1347 size_t i
, gLen
= 4096 ;
1348 if ( gLen
>* size
) gLen
= * size
- 20 ;
1350 if ( getHiLo ( dest
, gLen
, & high
, & low
, 75 , 75 ) < 1 ) return - 3 ; //25% fuzz on high 25% fuzz on low
1353 //convert wave samples to 1's and 0's
1354 for ( i
= 20 ; i
< * size
- 20 ; i
++){
1355 if ( dest
[ i
] >= high
) bit
= 1 ;
1356 if ( dest
[ i
] <= low
) bit
= 0 ;
1359 //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit)
1362 for ( i
= 21 ; i
< * size
- 20 ; i
++) {
1363 //if transition detected or large number of same bits - store the passed bits
1364 if ( dest
[ i
] != dest
[ i
- 1 ] || ( i
- lastBit
) == ( 10 * * clk
)) {
1365 memset ( dest
+ numBits
, dest
[ i
- 1 ] ^ * invert
, ( i
- lastBit
+ (* clk
/ 4 )) / * clk
);
1366 numBits
+= ( i
- lastBit
+ (* clk
/ 4 )) / * clk
;
1368 * startIdx
= i
- ( numBits
* * clk
);
1369 if ( g_debugMode
== 2 ) prnt ( "DEBUG NRZ: startIdx %i" , * startIdx
);
1377 int nrzRawDemod ( uint8_t * dest
, size_t * size
, int * clk
, int * invert
) {
1379 return nrzRawDemod_ext ( dest
, size
, clk
, invert
, & startIdx
);
1382 //translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq])
1383 size_t fsk_wave_demod ( uint8_t * dest
, size_t size
, uint8_t fchigh
, uint8_t fclow
, int * startIdx
) {
1384 size_t last_transition
= 0 ;
1386 if ( fchigh
== 0 ) fchigh
= 10 ;
1387 if ( fclow
== 0 ) fclow
= 8 ;
1388 //set the threshold close to 0 (graph) or 128 std to avoid static
1389 uint8_t threshold_value
= 123 ;
1390 size_t preLastSample
= 0 ;
1391 size_t LastSample
= 0 ;
1392 size_t currSample
= 0 ;
1393 if ( size
< 1024 ) return 0 ; // not enough samples
1395 //find start of modulating data in trace
1396 idx
= findModStart ( dest
, size
, threshold_value
, fchigh
);
1397 // Need to threshold first sample
1398 if ( dest
[ idx
] < threshold_value
) dest
[ 0 ] = 0 ;
1401 last_transition
= idx
;
1404 // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
1405 // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere
1406 // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
1407 // (could also be fc/5 && fc/7 for fsk1 = 4-9)
1408 for (; idx
< size
; idx
++) {
1409 // threshold current value
1410 if ( dest
[ idx
] < threshold_value
) dest
[ idx
] = 0 ;
1413 // Check for 0->1 transition
1414 if ( dest
[ idx
- 1 ] < dest
[ idx
]) {
1415 preLastSample
= LastSample
;
1416 LastSample
= currSample
;
1417 currSample
= idx
- last_transition
;
1418 if ( currSample
< ( fclow
- 2 )) { //0-5 = garbage noise (or 0-3)
1419 //do nothing with extra garbage
1420 } else if ( currSample
< ( fchigh
- 1 )) { //6-8 = 8 sample waves (or 3-6 = 5)
1421 //correct previous 9 wave surrounded by 8 waves (or 6 surrounded by 5)
1422 if ( numBits
> 1 && LastSample
> ( fchigh
- 2 ) && ( preLastSample
< ( fchigh
- 1 ))){
1426 if ( numBits
> 0 && * startIdx
== 0 ) * startIdx
= idx
- fclow
;
1427 } else if ( currSample
> ( fchigh
+ 1 ) && numBits
< 3 ) { //12 + and first two bit = unusable garbage
1428 //do nothing with beginning garbage and reset.. should be rare..
1430 } 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)
1432 if ( numBits
> 0 && * startIdx
== 0 ) * startIdx
= idx
- fclow
;
1433 } else { //9+ = 10 sample waves (or 6+ = 7)
1435 if ( numBits
> 0 && * startIdx
== 0 ) * startIdx
= idx
- fchigh
;
1437 last_transition
= idx
;
1440 return numBits
; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
1443 //translate 11111100000 to 10
1444 //rfLen = clock, fchigh = larger field clock, fclow = smaller field clock
1445 size_t aggregate_bits ( uint8_t * dest
, size_t size
, uint8_t rfLen
, uint8_t invert
, uint8_t fchigh
, uint8_t fclow
, int * startIdx
) {
1446 uint8_t lastval
= dest
[ 0 ];
1450 for ( idx
= 1 ; idx
< size
; idx
++) {
1452 if ( dest
[ idx
]== lastval
) continue ; //skip until we hit a transition
1454 //find out how many bits (n) we collected (use 1/2 clk tolerance)
1455 //if lastval was 1, we have a 1->0 crossing
1456 if ( dest
[ idx
- 1 ]== 1 ) {
1457 n
= ( n
* fclow
+ rfLen
/ 2 ) / rfLen
;
1458 } else { // 0->1 crossing
1459 n
= ( n
* fchigh
+ rfLen
/ 2 ) / rfLen
;
1463 //first transition - save startidx
1465 if ( lastval
== 1 ) { //high to low
1466 * startIdx
+= ( fclow
* idx
) - ( n
* rfLen
);
1467 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: startIdx %i, fclow*idx %i, n*rflen %u" , * startIdx
, fclow
*( idx
), n
* rfLen
);
1469 * startIdx
+= ( fchigh
* idx
) - ( n
* rfLen
);
1470 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: startIdx %i, fchigh*idx %i, n*rflen %u" , * startIdx
, fchigh
*( idx
), n
* rfLen
);
1474 //add to our destination the bits we collected
1475 memset ( dest
+ numBits
, dest
[ idx
- 1 ]^ invert
, n
);
1480 // if valid extra bits at the end were all the same frequency - add them in
1481 if ( n
> rfLen
/ fchigh
) {
1482 if ( dest
[ idx
- 2 ]== 1 ) {
1483 n
= ( n
* fclow
+ rfLen
/ 2 ) / rfLen
;
1485 n
= ( n
* fchigh
+ rfLen
/ 2 ) / rfLen
;
1487 memset ( dest
+ numBits
, dest
[ idx
- 1 ]^ invert
, n
);
1493 //by marshmellow (from holiman's base)
1494 // full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod)
1495 int fskdemod_ext ( uint8_t * dest
, size_t size
, uint8_t rfLen
, uint8_t invert
, uint8_t fchigh
, uint8_t fclow
, int * startIdx
) {
1497 size
= fsk_wave_demod ( dest
, size
, fchigh
, fclow
, startIdx
);
1498 size
= aggregate_bits ( dest
, size
, rfLen
, invert
, fchigh
, fclow
, startIdx
);
1502 int fskdemod ( uint8_t * dest
, size_t size
, uint8_t rfLen
, uint8_t invert
, uint8_t fchigh
, uint8_t fclow
) {
1504 return fskdemod_ext ( dest
, size
, rfLen
, invert
, fchigh
, fclow
, & startIdx
);
1508 // convert psk1 demod to psk2 demod
1509 // only transition waves are 1s
1510 void psk1TOpsk2 ( uint8_t * BitStream
, size_t size
) {
1512 uint8_t lastBit
= BitStream
[ 0 ];
1513 for (; i
< size
; i
++){
1514 if ( BitStream
[ i
]== 7 ){
1516 } else if ( lastBit
!= BitStream
[ i
]){
1517 lastBit
= BitStream
[ i
];
1527 // convert psk2 demod to psk1 demod
1528 // from only transition waves are 1s to phase shifts change bit
1529 void psk2TOpsk1 ( uint8_t * BitStream
, size_t size
) {
1531 for ( size_t i
= 0 ; i
< size
; i
++){
1532 if ( BitStream
[ i
]== 1 ){
1540 //by marshmellow - demodulate PSK1 wave
1541 //uses wave lengths (# Samples)
1542 int pskRawDemod_ext ( uint8_t dest
[], size_t * size
, int * clock
, int * invert
, int * startIdx
) {
1543 if ( size
== 0 ) return - 1 ;
1544 uint16_t loopCnt
= 4096 ; //don't need to loop through entire array...
1545 if (* size
< loopCnt
) loopCnt
= * size
;
1548 uint8_t curPhase
= * invert
;
1549 size_t i
= 0 , waveStart
= 1 , waveEnd
= 0 , firstFullWave
= 0 , lastClkBit
= 0 ;
1550 uint16_t fc
= 0 , fullWaveLen
= 0 , tol
= 1 ;
1551 uint16_t errCnt
= 0 , waveLenCnt
= 0 , errCnt2
= 0 ;
1552 fc
= countFC ( dest
, * size
, 1 );
1553 uint8_t fc2
= fc
>> 8 ;
1554 if ( fc2
== 10 ) return - 1 ; //fsk found - quit
1556 if ( fc
!= 2 && fc
!= 4 && fc
!= 8 ) return - 1 ;
1557 //PrintAndLog("DEBUG: FC: %d",fc);
1558 * clock
= DetectPSKClock ( dest
, * size
, * clock
);
1559 if (* clock
== 0 ) return - 1 ;
1561 //find start of modulating data in trace
1562 uint8_t threshold_value
= 123 ; //-5
1563 i
= findModStart ( dest
, * size
, threshold_value
, fc
);
1565 //find first phase shift
1566 int avgWaveVal
= 0 , lastAvgWaveVal
= 0 ;
1568 for (; i
< loopCnt
; i
++) {
1570 if ( dest
[ i
]+ fc
< dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
1572 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: waveEnd: %u, waveStart: %u" , waveEnd
, waveStart
);
1573 waveLenCnt
= waveEnd
- waveStart
;
1574 if ( waveLenCnt
> fc
&& waveStart
> fc
&& !( waveLenCnt
> fc
+ 3 )){ //not first peak and is a large wave but not out of whack
1575 lastAvgWaveVal
= avgWaveVal
/( waveLenCnt
);
1576 firstFullWave
= waveStart
;
1577 fullWaveLen
= waveLenCnt
;
1578 //if average wave value is > graph 0 then it is an up wave or a 1 (could cause inverting)
1579 if ( lastAvgWaveVal
> threshold_value
) curPhase
^= 1 ;
1586 avgWaveVal
+= dest
[ i
+ 2 ];
1588 if ( firstFullWave
== 0 ) {
1589 // no phase shift detected - could be all 1's or 0's - doesn't matter where we start
1590 // so skip a little to ensure we are past any Start Signal
1591 firstFullWave
= 160 ;
1592 memset ( dest
, curPhase
, firstFullWave
/ * clock
);
1594 memset ( dest
, curPhase
^ 1 , firstFullWave
/ * clock
);
1597 numBits
+= ( firstFullWave
/ * clock
);
1598 * startIdx
= firstFullWave
- (* clock
* numBits
)+ 2 ;
1599 //set start of wave as clock align
1600 lastClkBit
= firstFullWave
;
1601 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: firstFullWave: %u, waveLen: %u, startIdx %i" , firstFullWave
, fullWaveLen
, * startIdx
);
1602 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: clk: %d, lastClkBit: %u, fc: %u" , * clock
, lastClkBit
,( unsigned int ) fc
);
1604 dest
[ numBits
++] = curPhase
; //set first read bit
1605 for ( i
= firstFullWave
+ fullWaveLen
- 1 ; i
< * size
- 3 ; i
++){
1606 //top edge of wave = start of new wave
1607 if ( dest
[ i
]+ fc
< dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
1608 if ( waveStart
== 0 ) {
1611 avgWaveVal
= dest
[ i
+ 1 ];
1614 waveLenCnt
= waveEnd
- waveStart
;
1615 lastAvgWaveVal
= avgWaveVal
/ waveLenCnt
;
1616 if ( waveLenCnt
> fc
){
1617 //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);
1618 //this wave is a phase shift
1619 //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc);
1620 if ( i
+ 1 >= lastClkBit
+ * clock
- tol
){ //should be a clock bit
1622 dest
[ numBits
++] = curPhase
;
1623 lastClkBit
+= * clock
;
1624 } else if ( i
< lastClkBit
+ 10 + fc
){
1625 //noise after a phase shift - ignore
1626 } else { //phase shift before supposed to based on clock
1628 dest
[ numBits
++] = 7 ;
1630 } else if ( i
+ 1 > lastClkBit
+ * clock
+ tol
+ fc
){
1631 lastClkBit
+= * clock
; //no phase shift but clock bit
1632 dest
[ numBits
++] = curPhase
;
1633 } else if ( waveLenCnt
< fc
- 1 ) { //wave is smaller than field clock (shouldn't happen often)
1635 if ( errCnt2
> 101 ) return errCnt2
;
1641 avgWaveVal
+= dest
[ i
+ 1 ];
1647 int pskRawDemod ( uint8_t dest
[], size_t * size
, int * clock
, int * invert
) {
1649 return pskRawDemod_ext ( dest
, size
, clock
, invert
, & startIdx
);
1652 //**********************************************************************************************
1653 //-----------------Tag format detection section-------------------------------------------------
1654 //**********************************************************************************************
1657 // FSK Demod then try to locate an AWID ID
1658 int AWIDdemodFSK ( uint8_t * dest
, size_t * size
) {
1659 //make sure buffer has enough data
1660 if (* size
< 96 * 50 ) return - 1 ;
1662 if ( justNoise ( dest
, * size
)) return - 2 ;
1665 * size
= fskdemod ( dest
, * size
, 50 , 1 , 10 , 8 ); // fsk2a RF/50
1666 if (* size
< 96 ) return - 3 ; //did we get a good demod?
1668 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
1669 size_t startIdx
= 0 ;
1670 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1671 if ( errChk
== 0 ) return - 4 ; //preamble not found
1672 if (* size
!= 96 ) return - 5 ;
1673 return ( int ) startIdx
;
1677 //takes 1s and 0s and searches for EM410x format - output EM ID
1678 uint8_t Em410xDecode ( uint8_t * BitStream
, size_t * size
, size_t * startIdx
, uint32_t * hi
, uint64_t * lo
)
1681 if (* size
< 64 ) return 0 ;
1682 if ( BitStream
[ 1 ]> 1 ) return 0 ; //allow only 1s and 0s
1684 // 111111111 bit pattern represent start of frame
1685 // include 0 in front to help get start pos
1686 uint8_t preamble
[] = { 0 , 1 , 1 , 1 , 1 , 1 , 1 , 1 , 1 , 1 };
1688 uint8_t FmtLen
= 10 ; // sets of 4 bits = end data
1690 errChk
= preambleSearch ( BitStream
, preamble
, sizeof ( preamble
), size
, startIdx
);
1691 if ( errChk
== 0 || (* size
!= 64 && * size
!= 128 ) ) return 0 ;
1692 if (* size
== 128 ) FmtLen
= 22 ; // 22 sets of 4 bits
1694 //skip last 4bit parity row for simplicity
1695 * size
= removeParity ( BitStream
, * startIdx
+ sizeof ( preamble
), 5 , 0 , FmtLen
* 5 );
1696 if (* size
== 40 ) { // std em410x format
1698 * lo
= (( uint64_t )( bytebits_to_byte ( BitStream
, 8 )) << 32 ) | ( bytebits_to_byte ( BitStream
+ 8 , 32 ));
1699 } else if (* size
== 88 ) { // long em format
1700 * hi
= ( bytebits_to_byte ( BitStream
, 24 ));
1701 * lo
= (( uint64_t )( bytebits_to_byte ( BitStream
+ 24 , 32 )) << 32 ) | ( bytebits_to_byte ( BitStream
+ 24 + 32 , 32 ));
1708 // Ask/Biphase Demod then try to locate an ISO 11784/85 ID
1709 // BitStream must contain previously askrawdemod and biphasedemoded data
1710 int FDXBdemodBI ( uint8_t * dest
, size_t * size
) {
1711 //make sure buffer has enough data
1712 if (* size
< 128 ) return - 1 ;
1714 size_t startIdx
= 0 ;
1715 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
1717 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1718 if ( errChk
== 0 ) return - 2 ; //preamble not found
1719 return ( int ) startIdx
;
1723 // demod gProxIIDemod
1724 // error returns as -x
1725 // success returns start position in BitStream
1726 // BitStream must contain previously askrawdemod and biphasedemoded data
1727 int gProxII_Demod ( uint8_t BitStream
[], size_t * size
) {
1729 uint8_t preamble
[] = { 1 , 1 , 1 , 1 , 1 , 0 };
1731 uint8_t errChk
= preambleSearch ( BitStream
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1732 if ( errChk
== 0 ) return - 3 ; //preamble not found
1733 if (* size
!= 96 ) return - 2 ; //should have found 96 bits
1734 //check first 6 spacer bits to verify format
1735 if (! BitStream
[ startIdx
+ 5 ] && ! BitStream
[ startIdx
+ 10 ] && ! BitStream
[ startIdx
+ 15 ] && ! BitStream
[ startIdx
+ 20 ] && ! BitStream
[ startIdx
+ 25 ] && ! BitStream
[ startIdx
+ 30 ]){
1736 //confirmed proper separator bits found
1737 //return start position
1738 return ( int ) startIdx
;
1740 return - 5 ; //spacer bits not found - not a valid gproxII
1743 // loop to get raw HID waveform then FSK demodulate the TAG ID from it
1744 int HIDdemodFSK ( uint8_t * dest
, size_t * size
, uint32_t * hi2
, uint32_t * hi
, uint32_t * lo
) {
1745 if ( justNoise ( dest
, * size
)) return - 1 ;
1747 size_t numStart
= 0 , size2
=* size
, startIdx
= 0 ;
1749 * size
= fskdemod ( dest
, size2
, 50 , 1 , 10 , 8 ); //fsk2a
1750 if (* size
< 96 * 2 ) return - 2 ;
1751 // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
1752 uint8_t preamble
[] = { 0 , 0 , 0 , 1 , 1 , 1 , 0 , 1 };
1753 // find bitstring in array
1754 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1755 if ( errChk
== 0 ) return - 3 ; //preamble not found
1757 numStart
= startIdx
+ sizeof ( preamble
);
1758 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
1759 for ( size_t idx
= numStart
; ( idx
- numStart
) < * size
- sizeof ( preamble
); idx
+= 2 ){
1760 if ( dest
[ idx
] == dest
[ idx
+ 1 ]){
1761 return - 4 ; //not manchester data
1763 * hi2
= (* hi2
<< 1 )|(* hi
>> 31 );
1764 * hi
= (* hi
<< 1 )|(* lo
>> 31 );
1765 //Then, shift in a 0 or one into low
1766 if ( dest
[ idx
] && ! dest
[ idx
+ 1 ]) // 1 0
1771 return ( int ) startIdx
;
1774 int IOdemodFSK ( uint8_t * dest
, size_t size
) {
1775 if ( justNoise ( dest
, size
)) return - 1 ;
1776 //make sure buffer has data
1777 if ( size
< 66 * 64 ) return - 2 ;
1779 size
= fskdemod ( dest
, size
, 64 , 1 , 10 , 8 ); // FSK2a RF/64
1780 if ( size
< 65 ) return - 3 ; //did we get a good demod?
1782 //0 10 20 30 40 50 60
1784 //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
1785 //-----------------------------------------------------------------------------
1786 //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
1788 //XSF(version)facility:codeone+codetwo
1790 size_t startIdx
= 0 ;
1791 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
1792 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), & size
, & startIdx
);
1793 if ( errChk
== 0 ) return - 4 ; //preamble not found
1795 if (! dest
[ startIdx
+ 8 ] && dest
[ startIdx
+ 17 ]== 1 && dest
[ startIdx
+ 26 ]== 1 && dest
[ startIdx
+ 35 ]== 1 && dest
[ startIdx
+ 44 ]== 1 && dest
[ startIdx
+ 53 ]== 1 ){
1796 //confirmed proper separator bits found
1797 //return start position
1798 return ( int ) startIdx
;
1803 // redesigned by marshmellow adjusted from existing decode functions
1804 // indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
1805 int indala26decode ( uint8_t * bitStream
, size_t * size
, uint8_t * invert
) {
1806 //26 bit 40134 format (don't know other formats)
1807 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 };
1808 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 };
1809 size_t startidx
= 0 ;
1810 if (! preambleSearch ( bitStream
, preamble
, sizeof ( preamble
), size
, & startidx
)){
1811 // if didn't find preamble try again inverting
1812 if (! preambleSearch ( bitStream
, preamble_i
, sizeof ( preamble_i
), size
, & startidx
)) return - 1 ;
1815 if (* size
!= 64 && * size
!= 224 ) return - 2 ;
1817 for ( size_t i
= startidx
; i
< * size
; i
++)
1820 return ( int ) startidx
;
1823 // loop to get raw paradox waveform then FSK demodulate the TAG ID from it
1824 int ParadoxdemodFSK ( uint8_t * dest
, size_t * size
, uint32_t * hi2
, uint32_t * hi
, uint32_t * lo
) {
1825 if ( justNoise ( dest
, * size
)) return - 1 ;
1827 size_t numStart
= 0 , size2
=* size
, startIdx
= 0 ;
1829 * size
= fskdemod ( dest
, size2
, 50 , 1 , 10 , 8 ); //fsk2a
1830 if (* size
< 96 ) return - 2 ;
1832 // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
1833 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 1 , 1 , 1 , 1 };
1835 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1836 if ( errChk
== 0 ) return - 3 ; //preamble not found
1838 numStart
= startIdx
+ sizeof ( preamble
);
1839 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
1840 for ( size_t idx
= numStart
; ( idx
- numStart
) < * size
- sizeof ( preamble
); idx
+= 2 ){
1841 if ( dest
[ idx
] == dest
[ idx
+ 1 ])
1842 return - 4 ; //not manchester data
1843 * hi2
= (* hi2
<< 1 )|(* hi
>> 31 );
1844 * hi
= (* hi
<< 1 )|(* lo
>> 31 );
1845 //Then, shift in a 0 or one into low
1846 if ( dest
[ idx
] && ! dest
[ idx
+ 1 ]) // 1 0
1851 return ( int ) startIdx
;
1854 // find presco preamble 0x10D in already demoded data
1855 int PrescoDemod ( uint8_t * dest
, size_t * size
) {
1856 //make sure buffer has data
1857 if (* size
< 64 * 2 ) return - 2 ;
1859 size_t startIdx
= 0 ;
1860 uint8_t preamble
[] = { 1 , 0 , 0 , 0 , 0 , 1 , 1 , 0 , 1 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1861 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1862 if ( errChk
== 0 ) return - 4 ; //preamble not found
1863 //return start position
1864 return ( int ) startIdx
;
1868 // FSK Demod then try to locate a Farpointe Data (pyramid) ID
1869 int PyramiddemodFSK ( uint8_t * dest
, size_t * size
) {
1870 //make sure buffer has data
1871 if (* size
< 128 * 50 ) return - 5 ;
1873 //test samples are not just noise
1874 if ( justNoise ( dest
, * size
)) return - 1 ;
1877 * size
= fskdemod ( dest
, * size
, 50 , 1 , 10 , 8 ); // fsk2a RF/50
1878 if (* size
< 128 ) return - 2 ; //did we get a good demod?
1880 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
1881 size_t startIdx
= 0 ;
1882 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1883 if ( errChk
== 0 ) return - 4 ; //preamble not found
1884 if (* size
!= 128 ) return - 3 ;
1885 return ( int ) startIdx
;
1889 // find viking preamble 0xF200 in already demoded data
1890 int VikingDemod_AM ( uint8_t * dest
, size_t * size
) {
1891 //make sure buffer has data
1892 if (* size
< 64 * 2 ) return - 2 ;
1894 size_t startIdx
= 0 ;
1895 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 };
1896 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1897 if ( errChk
== 0 ) return - 4 ; //preamble not found
1898 uint32_t checkCalc
= bytebits_to_byte ( dest
+ startIdx
, 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 8 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 16 , 8 )
1899 ^ bytebits_to_byte ( dest
+ startIdx
+ 24 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 32 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 40 , 8 )
1900 ^ bytebits_to_byte ( dest
+ startIdx
+ 48 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 56 , 8 );
1901 if ( checkCalc
!= 0xA8 ) return - 5 ;
1902 if (* size
!= 64 ) return - 6 ;
1903 //return start position
1904 return ( int ) startIdx
;
1908 // find Visa2000 preamble in already demoded data
1909 int Visa2kDemod_AM ( uint8_t * dest
, size_t * size
) {
1910 if (* size
< 96 ) return - 1 ; //make sure buffer has data
1911 size_t startIdx
= 0 ;
1912 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 };
1913 if ( preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
) == 0 )
1914 return - 2 ; //preamble not found
1915 if (* size
!= 96 ) return - 3 ; //wrong demoded size
1916 //return start position
1917 return ( int ) startIdx
;