]>
cvs.zerfleddert.de Git - proxmark3-svn/blob - common/lfdemod.c
74e3e6b64a0b0e0e35ecf8ca1f4b06904281a746
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 //**********************************************************************************************
42 #define LOWEST_DEFAULT_CLOCK 32
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
);
225 int getClosestClock ( int testclk
) {
226 uint8_t fndClk
[] = { 8 , 16 , 32 , 40 , 50 , 64 , 128 };
228 for ( uint8_t clkCnt
= 0 ; clkCnt
< 7 ; clkCnt
++)
229 if ( testclk
>= fndClk
[ clkCnt
]-( fndClk
[ clkCnt
]/ 8 ) && testclk
<= fndClk
[ clkCnt
]+ 1 )
230 return fndClk
[ clkCnt
];
235 void getNextLow ( uint8_t samples
[], size_t size
, int low
, size_t * i
) {
236 while (( samples
[* i
] > low
) && (* i
< size
))
240 void getNextHigh ( uint8_t samples
[], size_t size
, int high
, size_t * i
) {
241 while (( samples
[* i
] < high
) && (* i
< size
))
245 // load wave counters
246 bool loadWaveCounters ( uint8_t samples
[], size_t size
, int lowToLowWaveLen
[], int highToLowWaveLen
[], int * waveCnt
, int * skip
, int * minClk
, int * high
, int * low
) {
247 size_t i
= 0 , firstLow
, firstHigh
;
248 size_t testsize
= ( size
< 512 ) ? size
: 512 ;
250 if ( getHiLo ( samples
, testsize
, high
, low
, 80 , 80 ) == - 1 ) {
251 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: just noise detected - quitting" );
252 return false ; //just noise
255 // get to first full low to prime loop and skip incomplete first pulse
256 getNextHigh ( samples
, size
, * high
, & i
);
257 getNextLow ( samples
, size
, * low
, & i
);
260 // populate tmpbuff buffer with pulse lengths
262 // measure from low to low
264 //find first high point for this wave
265 getNextHigh ( samples
, size
, * high
, & i
);
268 getNextLow ( samples
, size
, * low
, & i
);
270 if (* waveCnt
>= ( size
/ LOWEST_DEFAULT_CLOCK
))
273 highToLowWaveLen
[* waveCnt
] = i
- firstHigh
; //first high to first low
274 lowToLowWaveLen
[* waveCnt
] = i
- firstLow
;
276 if ( i
- firstLow
< * minClk
&& i
< size
) {
277 * minClk
= i
- firstLow
;
284 //amplify based on ask edge detection - not accurate enough to use all the time
285 void askAmp ( uint8_t * BitStream
, size_t size
) {
287 for ( size_t i
= 1 ; i
< size
; i
++){
288 if ( BitStream
[ i
]- BitStream
[ i
- 1 ]>= 30 ) //large jump up
290 else if ( BitStream
[ i
- 1 ]- BitStream
[ i
]>= 20 ) //large jump down
293 BitStream
[ i
- 1 ] = Last
;
298 uint32_t manchesterEncode2Bytes ( uint16_t datain
) {
301 for ( uint8_t i
= 0 ; i
< 16 ; i
++) {
302 curBit
= ( datain
>> ( 15 - i
) & 1 );
303 output
|= ( 1 <<((( 15 - i
)* 2 )+ curBit
));
309 //encode binary data into binary manchester
310 //NOTE: BitStream must have double the size available in memory to do the swap
311 int ManchesterEncode ( uint8_t * BitStream
, size_t size
) {
312 size_t modIdx
= size
, i
= 0 ;
313 if ( size
> modIdx
) return - 1 ;
314 for ( size_t idx
= 0 ; idx
< size
; idx
++){
315 BitStream
[ idx
+ modIdx
++] = BitStream
[ idx
];
316 BitStream
[ idx
+ modIdx
++] = BitStream
[ idx
]^ 1 ;
318 for (; i
<( size
* 2 ); i
++){
319 BitStream
[ i
] = BitStream
[ i
+ size
];
325 // to detect a wave that has heavily clipped (clean) samples
326 uint8_t DetectCleanAskWave ( uint8_t dest
[], size_t size
, uint8_t high
, uint8_t low
) {
327 bool allArePeaks
= true ;
329 size_t loopEnd
= 512 + 160 ;
330 if ( loopEnd
> size
) loopEnd
= size
;
331 for ( size_t i
= 160 ; i
< loopEnd
; i
++){
332 if ( dest
[ i
]> low
&& dest
[ i
]< high
)
338 if ( cntPeaks
> 300 ) return true ;
343 //**********************************************************************************************
344 //-------------------Clock / Bitrate Detection Section------------------------------------------
345 //**********************************************************************************************
348 // to help detect clocks on heavily clipped samples
349 // based on count of low to low
350 int DetectStrongAskClock ( uint8_t dest
[], size_t size
, int high
, int low
, int * clock
) {
354 int shortestWaveIdx
= 0 ;
355 // get to first full low to prime loop and skip incomplete first pulse
356 getNextHigh ( dest
, size
, high
, & i
);
357 getNextLow ( dest
, size
, low
, & i
);
359 // loop through all samples
361 // measure from low to low
364 getNextHigh ( dest
, size
, high
, & i
);
365 getNextLow ( dest
, size
, low
, & i
);
366 //get minimum measured distance
367 if ( i
- startwave
< minClk
&& i
< size
) {
368 minClk
= i
- startwave
;
369 shortestWaveIdx
= startwave
;
373 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: DetectStrongAskClock smallest wave: %d" , minClk
);
374 * clock
= getClosestClock ( minClk
);
378 return shortestWaveIdx
;
382 // not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)
383 // maybe somehow adjust peak trimming value based on samples to fix?
384 // return start index of best starting position for that clock and return clock (by reference)
385 int DetectASKClock ( uint8_t dest
[], size_t size
, int * clock
, int maxErr
) {
387 uint8_t clk
[] = { 255 , 8 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 255 };
389 uint8_t loopCnt
= 255 ; //don't need to loop through entire array...
390 if ( size
<= loopCnt
+ 60 ) return - 1 ; //not enough samples
391 size
-= 60 ; //sometimes there is a strange end wave - filter out this....
392 //if we already have a valid clock
395 if ( clk
[ i
] == * clock
) clockFnd
= i
;
396 //clock found but continue to find best startpos
398 //get high and low peak
400 if ( getHiLo ( dest
, loopCnt
, & peak
, & low
, 75 , 75 ) < 1 ) return - 1 ;
402 //test for large clean peaks
404 if ( DetectCleanAskWave ( dest
, size
, peak
, low
)== 1 ){
405 int ans
= DetectStrongAskClock ( dest
, size
, peak
, low
, clock
);
406 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: detectaskclk Clean Ask Wave Detected: clk %i, ShortestWave: %i" , clock
, ans
);
408 return ans
; //return shortest wave start position
413 uint8_t clkCnt
, tol
= 0 ;
414 uint16_t bestErr
[]={ 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 };
415 uint8_t bestStart
[]={ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
417 size_t arrLoc
, loopEnd
;
425 //test each valid clock from smallest to greatest to see which lines up
426 for (; clkCnt
< clkEnd
; clkCnt
++){
427 if ( clk
[ clkCnt
] <= 32 ){
432 //if no errors allowed - keep start within the first clock
433 if (! maxErr
&& size
> clk
[ clkCnt
]* 2 + tol
&& clk
[ clkCnt
]< 128 ) loopCnt
= clk
[ clkCnt
]* 2 ;
434 bestErr
[ clkCnt
]= 1000 ;
435 //try lining up the peaks by moving starting point (try first few clocks)
436 for ( ii
= 0 ; ii
< loopCnt
; ii
++){
437 if ( dest
[ ii
] < peak
&& dest
[ ii
] > low
) continue ;
440 // now that we have the first one lined up test rest of wave array
441 loopEnd
= (( size
- ii
- tol
) / clk
[ clkCnt
]) - 1 ;
442 for ( i
= 0 ; i
< loopEnd
; ++ i
){
443 arrLoc
= ii
+ ( i
* clk
[ clkCnt
]);
444 if ( dest
[ arrLoc
] >= peak
|| dest
[ arrLoc
] <= low
){
445 } else if ( dest
[ arrLoc
- tol
] >= peak
|| dest
[ arrLoc
- tol
] <= low
){
446 } else if ( dest
[ arrLoc
+ tol
] >= peak
|| dest
[ arrLoc
+ tol
] <= low
){
447 } else { //error no peak detected
451 //if we found no errors then we can stop here and a low clock (common clocks)
452 // this is correct one - return this clock
453 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: clk %d, err %d, startpos %d, endpos %d" , clk
[ clkCnt
], errCnt
, ii
, i
);
454 if ( errCnt
== 0 && clkCnt
< 7 ) {
455 if (! clockFnd
) * clock
= clk
[ clkCnt
];
458 //if we found errors see if it is lowest so far and save it as best run
459 if ( errCnt
< bestErr
[ clkCnt
]){
460 bestErr
[ clkCnt
]= errCnt
;
461 bestStart
[ clkCnt
]= ii
;
467 for ( iii
= 1 ; iii
< clkEnd
; ++ iii
){
468 if ( bestErr
[ iii
] < bestErr
[ best
]){
469 if ( bestErr
[ iii
] == 0 ) bestErr
[ iii
]= 1 ;
470 // current best bit to error ratio vs new bit to error ratio
471 if ( ( size
/ clk
[ best
])/ bestErr
[ best
] < ( size
/ clk
[ iii
])/ bestErr
[ iii
] ){
475 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
]);
477 if (! clockFnd
) * clock
= clk
[ best
];
478 return bestStart
[ best
];
481 int DetectStrongNRZClk ( uint8_t * dest
, size_t size
, int peak
, int low
){
482 //find shortest transition from high to low
484 size_t transition1
= 0 ;
485 int lowestTransition
= 255 ;
486 bool lastWasHigh
= false ;
488 //find first valid beginning of a high or low wave
489 while (( dest
[ i
] >= peak
|| dest
[ i
] <= low
) && ( i
< size
))
491 while (( dest
[ i
] < peak
&& dest
[ i
] > low
) && ( i
< size
))
493 lastWasHigh
= ( dest
[ i
] >= peak
);
495 if ( i
== size
) return 0 ;
498 for (; i
< size
; i
++) {
499 if (( dest
[ i
] >= peak
&& ! lastWasHigh
) || ( dest
[ i
] <= low
&& lastWasHigh
)) {
500 lastWasHigh
= ( dest
[ i
] >= peak
);
501 if ( i
- transition1
< lowestTransition
) lowestTransition
= i
- transition1
;
505 if ( lowestTransition
== 255 ) lowestTransition
= 0 ;
506 if ( g_debugMode
== 2 ) prnt ( "DEBUG NRZ: detectstrongNRZclk smallest wave: %d" , lowestTransition
);
507 return lowestTransition
;
511 //detect nrz clock by reading #peaks vs no peaks(or errors)
512 int DetectNRZClock_ext ( uint8_t dest
[], size_t size
, int clock
, size_t * clockStartIdx
) {
514 uint8_t clk
[]={ 8 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 255 };
515 size_t loopCnt
= 4096 ; //don't need to loop through entire array...
516 if ( size
== 0 ) return 0 ;
517 if ( size
< loopCnt
) loopCnt
= size
- 20 ;
518 //if we already have a valid clock quit
520 if ( clk
[ i
] == clock
) return clock
;
522 //get high and low peak
524 if ( getHiLo ( dest
, loopCnt
, & peak
, & low
, 75 , 75 ) < 1 ) return 0 ;
526 int lowestTransition
= DetectStrongNRZClk ( dest
, size
- 20 , peak
, low
);
530 uint16_t smplCnt
= 0 ;
532 int16_t peaksdet
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
533 uint16_t maxPeak
= 255 ;
534 bool firstpeak
= false ;
535 //test for large clipped waves
536 for ( i
= 0 ; i
< loopCnt
; i
++){
537 if ( dest
[ i
] >= peak
|| dest
[ i
] <= low
){
538 if (! firstpeak
) continue ;
543 if ( maxPeak
> smplCnt
){
545 //prnt("maxPk: %d",maxPeak);
548 //prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt);
555 uint8_t ignoreCnt
= 0 ;
556 uint8_t ignoreWindow
= 4 ;
557 bool lastPeakHigh
= 0 ;
559 size_t bestStart
[]={ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
561 //test each valid clock from smallest to greatest to see which lines up
562 for ( clkCnt
= 0 ; clkCnt
< 8 ; ++ clkCnt
){
563 //ignore clocks smaller than smallest peak
564 if ( clk
[ clkCnt
] < maxPeak
- ( clk
[ clkCnt
]/ 4 )) continue ;
565 //try lining up the peaks by moving starting point (try first 256)
566 for ( ii
= 20 ; ii
< loopCnt
; ++ ii
){
567 if (( dest
[ ii
] >= peak
) || ( dest
[ ii
] <= low
)){
571 lastBit
= ii
- clk
[ clkCnt
];
572 //loop through to see if this start location works
573 for ( i
= ii
; i
< size
- 20 ; ++ i
) {
574 //if we are at a clock bit
575 if (( i
>= lastBit
+ clk
[ clkCnt
] - tol
) && ( i
<= lastBit
+ clk
[ clkCnt
] + tol
)) {
577 if ( dest
[ i
] >= peak
|| dest
[ i
] <= low
) {
578 //if same peak don't count it
579 if (( dest
[ i
] >= peak
&& ! lastPeakHigh
) || ( dest
[ i
] <= low
&& lastPeakHigh
)) {
582 lastPeakHigh
= ( dest
[ i
] >= peak
);
585 ignoreCnt
= ignoreWindow
;
586 lastBit
+= clk
[ clkCnt
];
587 } else if ( i
== lastBit
+ clk
[ clkCnt
] + tol
) {
588 lastBit
+= clk
[ clkCnt
];
590 //else if not a clock bit and no peaks
591 } else if ( dest
[ i
] < peak
&& dest
[ i
] > low
){
594 if ( errBitHigh
== true ) peakcnt
--;
599 // else if not a clock bit but we have a peak
600 } else if (( dest
[ i
]>= peak
|| dest
[ i
]<= low
) && (! bitHigh
)) {
601 //error bar found no clock...
605 if ( peakcnt
> peaksdet
[ clkCnt
]) {
606 bestStart
[ clkCnt
]= ii
;
607 peaksdet
[ clkCnt
]= peakcnt
;
614 for ( iii
= 7 ; iii
> 0 ; iii
--){
615 if (( peaksdet
[ iii
] >= ( peaksdet
[ best
]- 1 )) && ( peaksdet
[ iii
] <= peaksdet
[ best
]+ 1 ) && lowestTransition
) {
616 if ( clk
[ iii
] > ( lowestTransition
- ( clk
[ iii
]/ 8 )) && clk
[ iii
] < ( lowestTransition
+ ( clk
[ iii
]/ 8 ))) {
619 } else if ( peaksdet
[ iii
] > peaksdet
[ best
]){
622 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
);
624 * clockStartIdx
= bestStart
[ best
];
628 int DetectNRZClock ( uint8_t dest
[], size_t size
, int clock
) {
630 return DetectNRZClock_ext ( dest
, size
, clock
, & bestStart
);
634 //countFC is to detect the field clock lengths.
635 //counts and returns the 2 most common wave lengths
636 //mainly used for FSK field clock detection
637 uint16_t countFC ( uint8_t * BitStream
, size_t size
, uint8_t fskAdj
) {
638 uint8_t fcLens
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
639 uint16_t fcCnts
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
640 uint8_t fcLensFnd
= 0 ;
641 uint8_t lastFCcnt
= 0 ;
642 uint8_t fcCounter
= 0 ;
644 if ( size
< 180 ) return 0 ;
646 // prime i to first up transition
647 for ( i
= 160 ; i
< size
- 20 ; i
++)
648 if ( BitStream
[ i
] > BitStream
[ i
- 1 ] && BitStream
[ i
] >= BitStream
[ i
+ 1 ])
651 for (; i
< size
- 20 ; i
++){
652 if ( BitStream
[ i
] > BitStream
[ i
- 1 ] && BitStream
[ i
] >= BitStream
[ i
+ 1 ]){
656 //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8)
657 if ( lastFCcnt
== 5 && fcCounter
== 9 ) fcCounter
--;
658 //if fc=9 or 4 add one (for when we get a fc 9 instead of 10 or a 4 instead of a 5)
659 if (( fcCounter
== 9 ) || fcCounter
== 4 ) fcCounter
++;
660 // save last field clock count (fc/xx)
661 lastFCcnt
= fcCounter
;
663 // find which fcLens to save it to:
664 for ( int ii
= 0 ; ii
< 15 ; ii
++){
665 if ( fcLens
[ ii
]== fcCounter
){
671 if ( fcCounter
> 0 && fcLensFnd
< 15 ){
674 fcLens
[ fcLensFnd
++]= fcCounter
;
683 uint8_t best1
= 14 , best2
= 14 , best3
= 14 ;
685 // go through fclens and find which ones are bigest 2
686 for ( i
= 0 ; i
< 15 ; i
++){
687 // get the 3 best FC values
688 if ( fcCnts
[ i
]> maxCnt1
) {
693 } else if ( fcCnts
[ i
]> fcCnts
[ best2
]){
696 } else if ( fcCnts
[ i
]> fcCnts
[ best3
]){
699 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
]);
701 if ( fcLens
[ best1
]== 0 ) return 0 ;
702 uint8_t fcH
= 0 , fcL
= 0 ;
703 if ( fcLens
[ best1
]> fcLens
[ best2
]){
710 if (( size
- 180 )/ fcH
/ 3 > fcCnts
[ best1
]+ fcCnts
[ best2
]) {
711 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
]);
712 return 0 ; //lots of waves not psk or fsk
714 // TODO: take top 3 answers and compare to known Field clocks to get top 2
716 uint16_t fcs
= ((( uint16_t ) fcH
)<< 8 ) | fcL
;
717 if ( fskAdj
) return fcs
;
718 return fcLens
[ best1
];
722 //detect psk clock by reading each phase shift
723 // a phase shift is determined by measuring the sample length of each wave
724 int DetectPSKClock_ext ( uint8_t dest
[], size_t size
, int clock
, int * firstPhaseShift
) {
725 uint8_t clk
[]={ 255 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 255 }; //255 is not a valid clock
726 uint16_t loopCnt
= 4096 ; //don't need to loop through entire array...
727 if ( size
== 0 ) return 0 ;
728 if ( size
< loopCnt
) loopCnt
= size
- 20 ;
730 //if we already have a valid clock quit
733 if ( clk
[ i
] == clock
) return clock
;
735 size_t waveStart
= 0 , waveEnd
= 0 , firstFullWave
= 0 , lastClkBit
= 0 ;
736 uint8_t clkCnt
, fc
= 0 , fullWaveLen
= 0 , tol
= 1 ;
737 uint16_t peakcnt
= 0 , errCnt
= 0 , waveLenCnt
= 0 ;
738 uint16_t bestErr
[]={ 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 , 1000 };
739 uint16_t peaksdet
[]={ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
740 fc
= countFC ( dest
, size
, 0 );
741 if ( fc
!= 2 && fc
!= 4 && fc
!= 8 ) return - 1 ;
742 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: FC: %d" , fc
);
744 //find first full wave
745 for ( i
= 160 ; i
< loopCnt
; i
++){
746 if ( dest
[ i
] < dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
747 if ( waveStart
== 0 ) {
749 //prnt("DEBUG: waveStart: %d",waveStart);
752 //prnt("DEBUG: waveEnd: %d",waveEnd);
753 waveLenCnt
= waveEnd
- waveStart
;
754 if ( waveLenCnt
> fc
){
755 firstFullWave
= waveStart
;
756 fullWaveLen
= waveLenCnt
;
763 * firstPhaseShift
= firstFullWave
;
764 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: firstFullWave: %d, waveLen: %d" , firstFullWave
, fullWaveLen
);
765 //test each valid clock from greatest to smallest to see which lines up
766 for ( clkCnt
= 7 ; clkCnt
>= 1 ; clkCnt
--){
767 lastClkBit
= firstFullWave
; //set end of wave as clock align
771 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: clk: %d, lastClkBit: %d" , clk
[ clkCnt
], lastClkBit
);
773 for ( i
= firstFullWave
+ fullWaveLen
- 1 ; i
< loopCnt
- 2 ; i
++){
774 //top edge of wave = start of new wave
775 if ( dest
[ i
] < dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
776 if ( waveStart
== 0 ) {
781 waveLenCnt
= waveEnd
- waveStart
;
782 if ( waveLenCnt
> fc
){
783 //if this wave is a phase shift
784 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
);
785 if ( i
+ 1 >= lastClkBit
+ clk
[ clkCnt
] - tol
){ //should be a clock bit
787 lastClkBit
+= clk
[ clkCnt
];
788 } else if ( i
< lastClkBit
+ 8 ){
789 //noise after a phase shift - ignore
790 } else { //phase shift before supposed to based on clock
793 } else if ( i
+ 1 > lastClkBit
+ clk
[ clkCnt
] + tol
+ fc
){
794 lastClkBit
+= clk
[ clkCnt
]; //no phase shift but clock bit
803 if ( errCnt
<= bestErr
[ clkCnt
]) bestErr
[ clkCnt
]= errCnt
;
804 if ( peakcnt
> peaksdet
[ clkCnt
]) peaksdet
[ clkCnt
]= peakcnt
;
806 //all tested with errors
807 //return the highest clk with the most peaks found
809 for ( i
= 7 ; i
>= 1 ; i
--){
810 if ( peaksdet
[ i
] > peaksdet
[ best
]) {
813 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: Clk: %d, peaks: %d, errs: %d, bestClk: %d" , clk
[ i
], peaksdet
[ i
], bestErr
[ i
], clk
[ best
]);
818 int DetectPSKClock ( uint8_t dest
[], size_t size
, int clock
) {
819 int firstPhaseShift
= 0 ;
820 return DetectPSKClock_ext ( dest
, size
, clock
, & firstPhaseShift
);
824 //detects the bit clock for FSK given the high and low Field Clocks
825 uint8_t detectFSKClk_ext ( uint8_t * BitStream
, size_t size
, uint8_t fcHigh
, uint8_t fcLow
, int * firstClockEdge
) {
826 uint8_t clk
[] = { 8 , 16 , 32 , 40 , 50 , 64 , 100 , 128 , 0 };
827 uint16_t rfLens
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
828 uint8_t rfCnts
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
829 uint8_t rfLensFnd
= 0 ;
830 uint8_t lastFCcnt
= 0 ;
831 uint16_t fcCounter
= 0 ;
832 uint16_t rfCounter
= 0 ;
833 uint8_t firstBitFnd
= 0 ;
835 if ( size
== 0 ) return 0 ;
837 uint8_t fcTol
= (( fcHigh
* 100 - fcLow
* 100 )/ 2 + 50 )/ 100 ; //(uint8_t)(0.5+(float)(fcHigh-fcLow)/2);
842 //PrintAndLog("DEBUG: fcTol: %d",fcTol);
843 // prime i to first peak / up transition
844 for ( i
= 160 ; i
< size
- 20 ; i
++)
845 if ( BitStream
[ i
] > BitStream
[ i
- 1 ] && BitStream
[ i
]>= BitStream
[ i
+ 1 ])
848 for (; i
< size
- 20 ; i
++){
852 if ( BitStream
[ i
] <= BitStream
[ i
- 1 ] || BitStream
[ i
] < BitStream
[ i
+ 1 ])
855 // if we got less than the small fc + tolerance then set it to the small fc
856 // if it is inbetween set it to the last counter
857 if ( fcCounter
< fcHigh
&& fcCounter
> fcLow
)
858 fcCounter
= lastFCcnt
;
859 else if ( fcCounter
< fcLow
+ fcTol
)
861 else //set it to the large fc
864 //look for bit clock (rf/xx)
865 if (( fcCounter
< lastFCcnt
|| fcCounter
> lastFCcnt
)){
866 //not the same size as the last wave - start of new bit sequence
867 if ( firstBitFnd
> 1 ){ //skip first wave change - probably not a complete bit
868 for ( int ii
= 0 ; ii
< 15 ; ii
++){
869 if ( rfLens
[ ii
] >= ( rfCounter
- 4 ) && rfLens
[ ii
] <= ( rfCounter
+ 4 )){
875 if ( rfCounter
> 0 && rfLensFnd
< 15 ){
876 //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
878 rfLens
[ rfLensFnd
++] = rfCounter
;
889 uint8_t rfHighest
= 15 , rfHighest2
= 15 , rfHighest3
= 15 ;
891 for ( i
= 0 ; i
< 15 ; i
++){
892 //get highest 2 RF values (might need to get more values to compare or compare all?)
893 if ( rfCnts
[ i
]> rfCnts
[ rfHighest
]){
894 rfHighest3
= rfHighest2
;
895 rfHighest2
= rfHighest
;
897 } else if ( rfCnts
[ i
]> rfCnts
[ rfHighest2
]){
898 rfHighest3
= rfHighest2
;
900 } else if ( rfCnts
[ i
]> rfCnts
[ rfHighest3
]){
903 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: RF %d, cnts %d" , rfLens
[ i
], rfCnts
[ i
]);
905 // set allowed clock remainder tolerance to be 1 large field clock length+1
906 // we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off
907 uint8_t tol1
= fcHigh
+ 1 ;
909 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: most counted rf values: 1 %d, 2 %d, 3 %d" , rfLens
[ rfHighest
], rfLens
[ rfHighest2
], rfLens
[ rfHighest3
]);
911 // loop to find the highest clock that has a remainder less than the tolerance
912 // compare samples counted divided by
913 // test 128 down to 32 (shouldn't be possible to have fc/10 & fc/8 and rf/16 or less)
916 if ( rfLens
[ rfHighest
] % clk
[ ii
] < tol1
|| rfLens
[ rfHighest
] % clk
[ ii
] > clk
[ ii
]- tol1
){
917 if ( rfLens
[ rfHighest2
] % clk
[ ii
] < tol1
|| rfLens
[ rfHighest2
] % clk
[ ii
] > clk
[ ii
]- tol1
){
918 if ( rfLens
[ rfHighest3
] % clk
[ ii
] < tol1
|| rfLens
[ rfHighest3
] % clk
[ ii
] > clk
[ ii
]- tol1
){
919 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: clk %d divides into the 3 most rf values within tolerance" , clk
[ ii
]);
926 if ( ii
< 2 ) return 0 ; // oops we went too far
931 uint8_t detectFSKClk ( uint8_t * BitStream
, size_t size
, uint8_t fcHigh
, uint8_t fcLow
) {
932 int firstClockEdge
= 0 ;
933 return detectFSKClk_ext ( BitStream
, size
, fcHigh
, fcLow
, & firstClockEdge
);
936 //**********************************************************************************************
937 //--------------------Modulation Demods &/or Decoding Section-----------------------------------
938 //**********************************************************************************************
940 // 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...
941 bool findST ( int * stStopLoc
, int * stStartIdx
, int lowToLowWaveLen
[], int highToLowWaveLen
[], int clk
, int tol
, int buffSize
, size_t * i
) {
942 for (; * i
< buffSize
- 4 ; * i
+= 1 ) {
943 * 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...
944 if ( lowToLowWaveLen
[* i
] >= clk
* 1 - tol
&& lowToLowWaveLen
[* i
] <= ( clk
* 2 )+ tol
&& highToLowWaveLen
[* i
] < clk
+ tol
) { //1 to 2 clocks depending on 2 bits prior
945 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
946 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
947 if ( lowToLowWaveLen
[* i
+ 3 ] >= clk
* 1 - tol
&& lowToLowWaveLen
[* i
+ 3 ] <= clk
* 2 + tol
) { //1 to 2 clocks for end of ST + first bit
958 //attempt to identify a Sequence Terminator in ASK modulated raw wave
959 bool DetectST_ext ( uint8_t buffer
[], size_t * size
, int * foundclock
, size_t * ststart
, size_t * stend
) {
960 size_t bufsize
= * size
;
961 //need to loop through all samples and identify our clock, look for the ST pattern
964 int j
, high
, low
, skip
, start
, end
, minClk
= 255 ;
966 //probably should malloc... || test if memory is available ... handle device side? memory danger!!! [marshmellow]
967 int tmpbuff
[ bufsize
/ LOWEST_DEFAULT_CLOCK
]; // 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
968 int waveLen
[ bufsize
/ LOWEST_DEFAULT_CLOCK
]; // high to low wave count //if clock is larger then we waste memory in array size that is not needed...
969 //size_t testsize = (bufsize < 512) ? bufsize : 512;
972 memset ( tmpbuff
, 0 , sizeof ( tmpbuff
));
973 memset ( waveLen
, 0 , sizeof ( waveLen
));
975 if (! loadWaveCounters ( buffer
, bufsize
, tmpbuff
, waveLen
, & j
, & skip
, & minClk
, & high
, & low
)) return false ;
976 // set clock - might be able to get this externally and remove this work...
977 clk
= getClosestClock ( minClk
);
978 // clock not found - ERROR
980 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: clock not found - quitting" );
986 if (! findST (& start
, & skip
, tmpbuff
, waveLen
, clk
, tol
, j
, & i
)) {
987 // first ST not found - ERROR
988 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: first STT not found - quitting" );
991 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: first STT found at wave: %i, skip: %i, j=%i" , start
, skip
, j
);
993 if ( waveLen
[ i
+ 2 ] > clk
* 1 + tol
)
998 // skip over the remainder of ST
999 skip
+= clk
* 7 / 2 ; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point
1001 // now do it again to find the end
1005 if (! findST (& dummy1
, & end
, tmpbuff
, waveLen
, clk
, tol
, j
, & i
)) {
1006 //didn't find second ST - ERROR
1007 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: second STT not found - quitting" );
1011 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
);
1012 //now begin to trim out ST so we can use normal demod cmds
1014 size_t datalen
= end
- start
;
1015 // check validity of datalen (should be even clock increments) - use a tolerance of up to 1/8th a clock
1016 if ( clk
- ( datalen
% clk
) <= clk
/ 8 ) {
1017 // padd the amount off - could be problematic... but shouldn't happen often
1018 datalen
+= clk
- ( datalen
% clk
);
1019 } else if ( ( datalen
% clk
) <= clk
/ 8 ) {
1020 // padd the amount off - could be problematic... but shouldn't happen often
1021 datalen
-= datalen
% clk
;
1023 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting" , datalen
, clk
, datalen
% clk
);
1026 // if datalen is less than one t55xx block - ERROR
1027 if ( datalen
/ clk
< 8 * 4 ) {
1028 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: datalen is less than 1 full t55xx block - quitting" );
1031 size_t dataloc
= start
;
1032 if ( buffer
[ dataloc
-( clk
* 4 )-( clk
/ 8 )] <= low
&& buffer
[ dataloc
] <= low
&& buffer
[ dataloc
-( clk
* 4 )] >= high
) {
1033 //we have low drift (and a low just before the ST and a low just after the ST) - compensate by backing up the start
1034 for ( i
= 0 ; i
<= ( clk
/ 8 ); ++ i
) {
1035 if ( buffer
[ dataloc
- ( clk
* 4 ) - i
] <= low
) {
1044 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: Starting STT trim - start: %d, datalen: %d " , dataloc
, datalen
);
1045 bool firstrun
= true ;
1046 // warning - overwriting buffer given with raw wave data with ST removed...
1047 while ( dataloc
< bufsize
-( clk
/ 2 ) ) {
1048 //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)
1049 if ( buffer
[ dataloc
]< high
&& buffer
[ dataloc
]> low
&& buffer
[ dataloc
+ 3 ]< high
&& buffer
[ dataloc
+ 3 ]> low
) {
1050 for ( i
= 0 ; i
< clk
/ 2 - tol
; ++ i
) {
1051 buffer
[ dataloc
+ i
] = high
+ 5 ;
1053 } //test for single sample outlier (high between two lows) in the case of very strong waves
1054 if ( buffer
[ dataloc
] >= high
&& buffer
[ dataloc
+ 2 ] <= low
) {
1055 buffer
[ dataloc
] = buffer
[ dataloc
+ 2 ];
1056 buffer
[ dataloc
+ 1 ] = buffer
[ dataloc
+ 2 ];
1060 * ststart
= dataloc
-( clk
* 4 );
1063 for ( i
= 0 ; i
< datalen
; ++ i
) {
1064 if ( i
+ newloc
< bufsize
) {
1065 if ( i
+ newloc
< dataloc
)
1066 buffer
[ i
+ newloc
] = buffer
[ dataloc
];
1072 //skip next ST - we just assume it will be there from now on...
1073 if ( g_debugMode
== 2 ) prnt ( "DEBUG STT: skipping STT at %d to %d" , dataloc
, dataloc
+( clk
* 4 ));
1079 bool DetectST ( uint8_t buffer
[], size_t * size
, int * foundclock
) {
1080 size_t ststart
= 0 , stend
= 0 ;
1081 return DetectST_ext ( buffer
, size
, foundclock
, & ststart
, & stend
);
1085 //take 11 10 01 11 00 and make 01100 ... miller decoding
1086 //check for phase errors - should never have half a 1 or 0 by itself and should never exceed 1111 or 0000 in a row
1087 //decodes miller encoded binary
1088 //NOTE askrawdemod will NOT demod miller encoded ask unless the clock is manually set to 1/2 what it is detected as!
1089 int millerRawDecode ( uint8_t * BitStream
, size_t * size
, int invert
) {
1090 if (* size
< 16 ) return - 1 ;
1091 uint16_t MaxBits
= 512 , errCnt
= 0 ;
1093 uint8_t alignCnt
= 0 , curBit
= BitStream
[ 0 ], alignedIdx
= 0 ;
1094 uint8_t halfClkErr
= 0 ;
1095 //find alignment, needs 4 1s or 0s to properly align
1096 for ( i
= 1 ; i
< * size
- 1 ; i
++) {
1097 alignCnt
= ( BitStream
[ i
] == curBit
) ? alignCnt
+ 1 : 0 ;
1098 curBit
= BitStream
[ i
];
1099 if ( alignCnt
== 4 ) break ;
1101 // for now error if alignment not found. later add option to run it with multiple offsets...
1102 if ( alignCnt
!= 4 ) {
1103 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" );
1106 alignedIdx
= ( i
- 1 ) % 2 ;
1107 for ( i
= alignedIdx
; i
< * size
- 3 ; i
+= 2 ) {
1108 halfClkErr
= ( uint8_t )(( halfClkErr
<< 1 | BitStream
[ i
]) & 0xFF );
1109 if ( ( halfClkErr
& 0x7 ) == 5 || ( halfClkErr
& 0x7 ) == 2 || ( i
> 2 && ( halfClkErr
& 0x7 ) == 0 ) || ( halfClkErr
& 0x1F ) == 0x1F ) {
1111 BitStream
[ bitCnt
++] = 7 ;
1114 BitStream
[ bitCnt
++] = BitStream
[ i
] ^ BitStream
[ i
+ 1 ] ^ invert
;
1116 if ( bitCnt
> MaxBits
) break ;
1123 //take 01 or 10 = 1 and 11 or 00 = 0
1124 //check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010
1125 //decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding
1126 int BiphaseRawDecode ( uint8_t * BitStream
, size_t * size
, int offset
, int invert
) {
1127 uint16_t bitnum
= 0 ;
1128 uint16_t errCnt
= 0 ;
1130 uint16_t MaxBits
= 512 ;
1131 //if not enough samples - error
1132 if (* size
< 51 ) return - 1 ;
1133 //check for phase change faults - skip one sample if faulty
1134 uint8_t offsetA
= 1 , offsetB
= 1 ;
1136 if ( BitStream
[ i
+ 1 ]== BitStream
[ i
+ 2 ]) offsetA
= 0 ;
1137 if ( BitStream
[ i
+ 2 ]== BitStream
[ i
+ 3 ]) offsetB
= 0 ;
1139 if (! offsetA
&& offsetB
) offset
++;
1140 for ( i
= offset
; i
<* size
- 3 ; i
+= 2 ){
1141 //check for phase error
1142 if ( BitStream
[ i
+ 1 ]== BitStream
[ i
+ 2 ]) {
1143 BitStream
[ bitnum
++]= 7 ;
1146 if (( BitStream
[ i
]== 1 && BitStream
[ i
+ 1 ]== 0 ) || ( BitStream
[ i
]== 0 && BitStream
[ i
+ 1 ]== 1 )){
1147 BitStream
[ bitnum
++]= 1 ^ invert
;
1148 } else if (( BitStream
[ i
]== 0 && BitStream
[ i
+ 1 ]== 0 ) || ( BitStream
[ i
]== 1 && BitStream
[ i
+ 1 ]== 1 )){
1149 BitStream
[ bitnum
++]= invert
;
1151 BitStream
[ bitnum
++]= 7 ;
1154 if ( bitnum
> MaxBits
) break ;
1161 //take 10 and 01 and manchester decode
1162 //run through 2 times and take least errCnt
1163 int manrawdecode ( uint8_t * BitStream
, size_t * size
, uint8_t invert
, uint8_t * alignPos
) {
1164 uint16_t bitnum
= 0 , MaxBits
= 512 , errCnt
= 0 ;
1166 uint16_t bestErr
= 1000 , bestRun
= 0 ;
1167 if (* size
< 16 ) return - 1 ;
1168 //find correct start position [alignment]
1169 for ( ii
= 0 ; ii
< 2 ;++ ii
){
1170 for ( i
= ii
; i
<* size
- 3 ; i
+= 2 )
1171 if ( BitStream
[ i
]== BitStream
[ i
+ 1 ])
1174 if ( bestErr
> errCnt
){
1182 for ( i
= bestRun
; i
< * size
- 3 ; i
+= 2 ){
1183 if ( BitStream
[ i
] == 1 && ( BitStream
[ i
+ 1 ] == 0 )){
1184 BitStream
[ bitnum
++]= invert
;
1185 } else if (( BitStream
[ i
] == 0 ) && BitStream
[ i
+ 1 ] == 1 ){
1186 BitStream
[ bitnum
++]= invert
^ 1 ;
1188 BitStream
[ bitnum
++]= 7 ;
1190 if ( bitnum
> MaxBits
) break ;
1197 //demodulates strong heavily clipped samples
1198 int cleanAskRawDemod ( uint8_t * BinStream
, size_t * size
, int clk
, int invert
, int high
, int low
, int * startIdx
)
1201 size_t bitCnt
= 0 , smplCnt
= 1 , errCnt
= 0 ;
1202 bool waveHigh
= ( BinStream
[ 0 ] >= high
);
1203 for ( size_t i
= 1 ; i
< * size
; i
++){
1204 if ( BinStream
[ i
] >= high
&& waveHigh
){
1206 } else if ( BinStream
[ i
] <= low
&& ! waveHigh
){
1208 } else { //transition
1209 if (( BinStream
[ i
] >= high
&& ! waveHigh
) || ( BinStream
[ i
] <= low
&& waveHigh
)){
1210 if ( smplCnt
> clk
-( clk
/ 4 )- 1 ) { //full clock
1211 if ( smplCnt
> clk
+ ( clk
/ 4 )+ 1 ) { //too many samples
1213 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Modulation Error at: %u" , i
);
1214 BinStream
[ bitCnt
++] = 7 ;
1215 } else if ( waveHigh
) {
1216 BinStream
[ bitCnt
++] = invert
;
1217 BinStream
[ bitCnt
++] = invert
;
1218 } else if (! waveHigh
) {
1219 BinStream
[ bitCnt
++] = invert
^ 1 ;
1220 BinStream
[ bitCnt
++] = invert
^ 1 ;
1222 if (* startIdx
== 0 ) * startIdx
= i
- clk
;
1223 waveHigh
= ! waveHigh
;
1225 } else if ( smplCnt
> ( clk
/ 2 ) - ( clk
/ 4 )- 1 ) { //half clock
1227 BinStream
[ bitCnt
++] = invert
;
1228 } else if (! waveHigh
) {
1229 BinStream
[ bitCnt
++] = invert
^ 1 ;
1231 if (* startIdx
== 0 ) * startIdx
= i
-( clk
/ 2 );
1232 waveHigh
= ! waveHigh
;
1236 //transition bit oops
1238 } else { //haven't hit new high or new low yet
1248 //attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester
1249 int askdemod_ext ( uint8_t * BinStream
, size_t * size
, int * clk
, int * invert
, int maxErr
, uint8_t amp
, uint8_t askType
, int * startIdx
) {
1250 if (* size
== 0 ) return - 1 ;
1251 int start
= DetectASKClock ( BinStream
, * size
, clk
, maxErr
); //clock default
1252 if (* clk
== 0 || start
< 0 ) return - 3 ;
1253 if (* invert
!= 1 ) * invert
= 0 ;
1254 if ( amp
== 1 ) askAmp ( BinStream
, * size
);
1255 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: clk %d, beststart %d, amp %d" , * clk
, start
, amp
);
1257 //start pos from detect ask clock is 1/2 clock offset
1258 // NOTE: can be negative (demod assumes rest of wave was there)
1259 * startIdx
= start
- (* clk
/ 2 );
1260 uint8_t initLoopMax
= 255 ;
1261 if ( initLoopMax
> * size
) initLoopMax
= * size
;
1262 // Detect high and lows
1263 //25% clip in case highs and lows aren't clipped [marshmellow]
1265 if ( getHiLo ( BinStream
, initLoopMax
, & high
, & low
, 75 , 75 ) < 1 )
1266 return - 2 ; //just noise
1269 // if clean clipped waves detected run alternate demod
1270 if ( DetectCleanAskWave ( BinStream
, * size
, high
, low
)) {
1271 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Clean Wave Detected - using clean wave demod" );
1272 errCnt
= cleanAskRawDemod ( BinStream
, size
, * clk
, * invert
, high
, low
, startIdx
);
1273 if ( askType
) { //askman
1274 uint8_t alignPos
= 0 ;
1275 errCnt
= manrawdecode ( BinStream
, size
, 0 , & alignPos
);
1276 * startIdx
+= * clk
/ 2 * alignPos
;
1277 if ( g_debugMode
) prnt ( "DEBUG ASK CLEAN: startIdx %i, alignPos %u" , * startIdx
, alignPos
);
1283 if ( g_debugMode
) prnt ( "DEBUG ASK WEAK: startIdx %i" , * startIdx
);
1284 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Weak Wave Detected - using weak wave demod" );
1286 int lastBit
; //set first clock check - can go negative
1287 size_t i
, bitnum
= 0 ; //output counter
1289 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
1290 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
1291 size_t MaxBits
= 3072 ; //max bits to collect
1292 lastBit
= start
- * clk
;
1294 for ( i
= start
; i
< * size
; ++ i
) {
1295 if ( i
- lastBit
>= * clk
- tol
){
1296 if ( BinStream
[ i
] >= high
) {
1297 BinStream
[ bitnum
++] = * invert
;
1298 } else if ( BinStream
[ i
] <= low
) {
1299 BinStream
[ bitnum
++] = * invert
^ 1 ;
1300 } else if ( i
- lastBit
>= * clk
+ tol
) {
1302 if ( g_debugMode
== 2 ) prnt ( "DEBUG ASK: Modulation Error at: %u" , i
);
1303 BinStream
[ bitnum
++]= 7 ;
1306 } else { //in tolerance - looking for peak
1311 } else if ( i
- lastBit
>= (* clk
/ 2 - tol
) && ! midBit
&& ! askType
){
1312 if ( BinStream
[ i
] >= high
) {
1313 BinStream
[ bitnum
++] = * invert
;
1314 } else if ( BinStream
[ i
] <= low
) {
1315 BinStream
[ bitnum
++] = * invert
^ 1 ;
1316 } else if ( i
- lastBit
>= * clk
/ 2 + tol
) {
1317 BinStream
[ bitnum
] = BinStream
[ bitnum
- 1 ];
1319 } else { //in tolerance - looking for peak
1324 if ( bitnum
>= MaxBits
) break ;
1330 int askdemod ( uint8_t * BinStream
, size_t * size
, int * clk
, int * invert
, int maxErr
, uint8_t amp
, uint8_t askType
) {
1332 return askdemod_ext ( BinStream
, size
, clk
, invert
, maxErr
, amp
, askType
, & start
);
1335 // by marshmellow - demodulate NRZ wave - requires a read with strong signal
1336 // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
1337 int nrzRawDemod_ext ( uint8_t * dest
, size_t * size
, int * clk
, int * invert
, int * startIdx
) {
1338 if ( justNoise ( dest
, * size
)) return - 1 ;
1339 * clk
= DetectNRZClock ( dest
, * size
, * clk
);
1340 if (* clk
== 0 ) return - 2 ;
1341 size_t i
, gLen
= 4096 ;
1342 if ( gLen
>* size
) gLen
= * size
- 20 ;
1344 if ( getHiLo ( dest
, gLen
, & high
, & low
, 75 , 75 ) < 1 ) return - 3 ; //25% fuzz on high 25% fuzz on low
1347 //convert wave samples to 1's and 0's
1348 for ( i
= 20 ; i
< * size
- 20 ; i
++){
1349 if ( dest
[ i
] >= high
) bit
= 1 ;
1350 if ( dest
[ i
] <= low
) bit
= 0 ;
1353 //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit)
1356 for ( i
= 21 ; i
< * size
- 20 ; i
++) {
1357 //if transition detected or large number of same bits - store the passed bits
1358 if ( dest
[ i
] != dest
[ i
- 1 ] || ( i
- lastBit
) == ( 10 * * clk
)) {
1359 memset ( dest
+ numBits
, dest
[ i
- 1 ] ^ * invert
, ( i
- lastBit
+ (* clk
/ 4 )) / * clk
);
1360 numBits
+= ( i
- lastBit
+ (* clk
/ 4 )) / * clk
;
1362 * startIdx
= i
- ( numBits
* * clk
);
1363 if ( g_debugMode
== 2 ) prnt ( "DEBUG NRZ: startIdx %i" , * startIdx
);
1371 int nrzRawDemod ( uint8_t * dest
, size_t * size
, int * clk
, int * invert
) {
1373 return nrzRawDemod_ext ( dest
, size
, clk
, invert
, & startIdx
);
1376 //translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq])
1377 size_t fsk_wave_demod ( uint8_t * dest
, size_t size
, uint8_t fchigh
, uint8_t fclow
, int * startIdx
) {
1378 size_t last_transition
= 0 ;
1380 if ( fchigh
== 0 ) fchigh
= 10 ;
1381 if ( fclow
== 0 ) fclow
= 8 ;
1382 //set the threshold close to 0 (graph) or 128 std to avoid static
1383 uint8_t threshold_value
= 123 ;
1384 size_t preLastSample
= 0 ;
1385 size_t LastSample
= 0 ;
1386 size_t currSample
= 0 ;
1387 if ( size
< 1024 ) return 0 ; // not enough samples
1389 //find start of modulating data in trace
1390 idx
= findModStart ( dest
, size
, threshold_value
, fchigh
);
1391 // Need to threshold first sample
1392 if ( dest
[ idx
] < threshold_value
) dest
[ 0 ] = 0 ;
1395 last_transition
= idx
;
1398 // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
1399 // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere
1400 // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
1401 // (could also be fc/5 && fc/7 for fsk1 = 4-9)
1402 for (; idx
< size
; idx
++) {
1403 // threshold current value
1404 if ( dest
[ idx
] < threshold_value
) dest
[ idx
] = 0 ;
1407 // Check for 0->1 transition
1408 if ( dest
[ idx
- 1 ] < dest
[ idx
]) {
1409 preLastSample
= LastSample
;
1410 LastSample
= currSample
;
1411 currSample
= idx
- last_transition
;
1412 if ( currSample
< ( fclow
- 2 )) { //0-5 = garbage noise (or 0-3)
1413 //do nothing with extra garbage
1414 } else if ( currSample
< ( fchigh
- 1 )) { //6-8 = 8 sample waves (or 3-6 = 5)
1415 //correct previous 9 wave surrounded by 8 waves (or 6 surrounded by 5)
1416 if ( numBits
> 1 && LastSample
> ( fchigh
- 2 ) && ( preLastSample
< ( fchigh
- 1 ))){
1420 if ( numBits
> 0 && * startIdx
== 0 ) * startIdx
= idx
- fclow
;
1421 } else if ( currSample
> ( fchigh
+ 1 ) && numBits
< 3 ) { //12 + and first two bit = unusable garbage
1422 //do nothing with beginning garbage and reset.. should be rare..
1424 } 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)
1426 if ( numBits
> 0 && * startIdx
== 0 ) * startIdx
= idx
- fclow
;
1427 } else { //9+ = 10 sample waves (or 6+ = 7)
1429 if ( numBits
> 0 && * startIdx
== 0 ) * startIdx
= idx
- fchigh
;
1431 last_transition
= idx
;
1434 return numBits
; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
1437 //translate 11111100000 to 10
1438 //rfLen = clock, fchigh = larger field clock, fclow = smaller field clock
1439 size_t aggregate_bits ( uint8_t * dest
, size_t size
, uint8_t rfLen
, uint8_t invert
, uint8_t fchigh
, uint8_t fclow
, int * startIdx
) {
1440 uint8_t lastval
= dest
[ 0 ];
1444 for ( idx
= 1 ; idx
< size
; idx
++) {
1446 if ( dest
[ idx
]== lastval
) continue ; //skip until we hit a transition
1448 //find out how many bits (n) we collected (use 1/2 clk tolerance)
1449 //if lastval was 1, we have a 1->0 crossing
1450 if ( dest
[ idx
- 1 ]== 1 ) {
1451 n
= ( n
* fclow
+ rfLen
/ 2 ) / rfLen
;
1452 } else { // 0->1 crossing
1453 n
= ( n
* fchigh
+ rfLen
/ 2 ) / rfLen
;
1457 //first transition - save startidx
1459 if ( lastval
== 1 ) { //high to low
1460 * startIdx
+= ( fclow
* idx
) - ( n
* rfLen
);
1461 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: startIdx %i, fclow*idx %i, n*rflen %u" , * startIdx
, fclow
*( idx
), n
* rfLen
);
1463 * startIdx
+= ( fchigh
* idx
) - ( n
* rfLen
);
1464 if ( g_debugMode
== 2 ) prnt ( "DEBUG FSK: startIdx %i, fchigh*idx %i, n*rflen %u" , * startIdx
, fchigh
*( idx
), n
* rfLen
);
1468 //add to our destination the bits we collected
1469 memset ( dest
+ numBits
, dest
[ idx
- 1 ]^ invert
, n
);
1474 // if valid extra bits at the end were all the same frequency - add them in
1475 if ( n
> rfLen
/ fchigh
) {
1476 if ( dest
[ idx
- 2 ]== 1 ) {
1477 n
= ( n
* fclow
+ rfLen
/ 2 ) / rfLen
;
1479 n
= ( n
* fchigh
+ rfLen
/ 2 ) / rfLen
;
1481 memset ( dest
+ numBits
, dest
[ idx
- 1 ]^ invert
, n
);
1487 //by marshmellow (from holiman's base)
1488 // full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod)
1489 int fskdemod_ext ( uint8_t * dest
, size_t size
, uint8_t rfLen
, uint8_t invert
, uint8_t fchigh
, uint8_t fclow
, int * startIdx
) {
1491 size
= fsk_wave_demod ( dest
, size
, fchigh
, fclow
, startIdx
);
1492 size
= aggregate_bits ( dest
, size
, rfLen
, invert
, fchigh
, fclow
, startIdx
);
1496 int fskdemod ( uint8_t * dest
, size_t size
, uint8_t rfLen
, uint8_t invert
, uint8_t fchigh
, uint8_t fclow
) {
1498 return fskdemod_ext ( dest
, size
, rfLen
, invert
, fchigh
, fclow
, & startIdx
);
1502 // convert psk1 demod to psk2 demod
1503 // only transition waves are 1s
1504 void psk1TOpsk2 ( uint8_t * BitStream
, size_t size
) {
1506 uint8_t lastBit
= BitStream
[ 0 ];
1507 for (; i
< size
; i
++){
1508 if ( BitStream
[ i
]== 7 ){
1510 } else if ( lastBit
!= BitStream
[ i
]){
1511 lastBit
= BitStream
[ i
];
1521 // convert psk2 demod to psk1 demod
1522 // from only transition waves are 1s to phase shifts change bit
1523 void psk2TOpsk1 ( uint8_t * BitStream
, size_t size
) {
1525 for ( size_t i
= 0 ; i
< size
; i
++){
1526 if ( BitStream
[ i
]== 1 ){
1534 //by marshmellow - demodulate PSK1 wave
1535 //uses wave lengths (# Samples)
1536 int pskRawDemod_ext ( uint8_t dest
[], size_t * size
, int * clock
, int * invert
, int * startIdx
) {
1537 if ( size
== 0 ) return - 1 ;
1538 uint16_t loopCnt
= 4096 ; //don't need to loop through entire array...
1539 if (* size
< loopCnt
) loopCnt
= * size
;
1542 uint8_t curPhase
= * invert
;
1543 size_t i
= 0 , waveStart
= 1 , waveEnd
= 0 , firstFullWave
= 0 , lastClkBit
= 0 ;
1544 uint16_t fc
= 0 , fullWaveLen
= 0 , tol
= 1 ;
1545 uint16_t errCnt
= 0 , waveLenCnt
= 0 , errCnt2
= 0 ;
1546 fc
= countFC ( dest
, * size
, 1 );
1547 uint8_t fc2
= fc
>> 8 ;
1548 if ( fc2
== 10 ) return - 1 ; //fsk found - quit
1550 if ( fc
!= 2 && fc
!= 4 && fc
!= 8 ) return - 1 ;
1551 //PrintAndLog("DEBUG: FC: %d",fc);
1552 * clock
= DetectPSKClock ( dest
, * size
, * clock
);
1553 if (* clock
== 0 ) return - 1 ;
1555 //find start of modulating data in trace
1556 uint8_t threshold_value
= 123 ; //-5
1557 i
= findModStart ( dest
, * size
, threshold_value
, fc
);
1559 //find first phase shift
1560 int avgWaveVal
= 0 , lastAvgWaveVal
= 0 ;
1562 for (; i
< loopCnt
; i
++) {
1564 if ( dest
[ i
]+ fc
< dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
1566 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: waveEnd: %u, waveStart: %u" , waveEnd
, waveStart
);
1567 waveLenCnt
= waveEnd
- waveStart
;
1568 if ( waveLenCnt
> fc
&& waveStart
> fc
&& !( waveLenCnt
> fc
+ 3 )){ //not first peak and is a large wave but not out of whack
1569 lastAvgWaveVal
= avgWaveVal
/( waveLenCnt
);
1570 firstFullWave
= waveStart
;
1571 fullWaveLen
= waveLenCnt
;
1572 //if average wave value is > graph 0 then it is an up wave or a 1 (could cause inverting)
1573 if ( lastAvgWaveVal
> threshold_value
) curPhase
^= 1 ;
1580 avgWaveVal
+= dest
[ i
+ 2 ];
1582 if ( firstFullWave
== 0 ) {
1583 // no phase shift detected - could be all 1's or 0's - doesn't matter where we start
1584 // so skip a little to ensure we are past any Start Signal
1585 firstFullWave
= 160 ;
1586 memset ( dest
, curPhase
, firstFullWave
/ * clock
);
1588 memset ( dest
, curPhase
^ 1 , firstFullWave
/ * clock
);
1591 numBits
+= ( firstFullWave
/ * clock
);
1592 * startIdx
= firstFullWave
- (* clock
* numBits
)+ 2 ;
1593 //set start of wave as clock align
1594 lastClkBit
= firstFullWave
;
1595 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: firstFullWave: %u, waveLen: %u, startIdx %i" , firstFullWave
, fullWaveLen
, * startIdx
);
1596 if ( g_debugMode
== 2 ) prnt ( "DEBUG PSK: clk: %d, lastClkBit: %u, fc: %u" , * clock
, lastClkBit
,( unsigned int ) fc
);
1598 dest
[ numBits
++] = curPhase
; //set first read bit
1599 for ( i
= firstFullWave
+ fullWaveLen
- 1 ; i
< * size
- 3 ; i
++){
1600 //top edge of wave = start of new wave
1601 if ( dest
[ i
]+ fc
< dest
[ i
+ 1 ] && dest
[ i
+ 1 ] >= dest
[ i
+ 2 ]){
1602 if ( waveStart
== 0 ) {
1605 avgWaveVal
= dest
[ i
+ 1 ];
1608 waveLenCnt
= waveEnd
- waveStart
;
1609 lastAvgWaveVal
= avgWaveVal
/ waveLenCnt
;
1610 if ( waveLenCnt
> fc
){
1611 //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);
1612 //this wave is a phase shift
1613 //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc);
1614 if ( i
+ 1 >= lastClkBit
+ * clock
- tol
){ //should be a clock bit
1616 dest
[ numBits
++] = curPhase
;
1617 lastClkBit
+= * clock
;
1618 } else if ( i
< lastClkBit
+ 10 + fc
){
1619 //noise after a phase shift - ignore
1620 } else { //phase shift before supposed to based on clock
1622 dest
[ numBits
++] = 7 ;
1624 } else if ( i
+ 1 > lastClkBit
+ * clock
+ tol
+ fc
){
1625 lastClkBit
+= * clock
; //no phase shift but clock bit
1626 dest
[ numBits
++] = curPhase
;
1627 } else if ( waveLenCnt
< fc
- 1 ) { //wave is smaller than field clock (shouldn't happen often)
1629 if ( errCnt2
> 101 ) return errCnt2
;
1635 avgWaveVal
+= dest
[ i
+ 1 ];
1641 int pskRawDemod ( uint8_t dest
[], size_t * size
, int * clock
, int * invert
) {
1643 return pskRawDemod_ext ( dest
, size
, clock
, invert
, & startIdx
);
1646 //**********************************************************************************************
1647 //-----------------Tag format detection section-------------------------------------------------
1648 //**********************************************************************************************
1651 // FSK Demod then try to locate an AWID ID
1652 int AWIDdemodFSK ( uint8_t * dest
, size_t * size
) {
1653 //make sure buffer has enough data
1654 if (* size
< 96 * 50 ) return - 1 ;
1656 if ( justNoise ( dest
, * size
)) return - 2 ;
1659 * size
= fskdemod ( dest
, * size
, 50 , 1 , 10 , 8 ); // fsk2a RF/50
1660 if (* size
< 96 ) return - 3 ; //did we get a good demod?
1662 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
1663 size_t startIdx
= 0 ;
1664 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1665 if ( errChk
== 0 ) return - 4 ; //preamble not found
1666 if (* size
!= 96 ) return - 5 ;
1667 return ( int ) startIdx
;
1671 //takes 1s and 0s and searches for EM410x format - output EM ID
1672 uint8_t Em410xDecode ( uint8_t * BitStream
, size_t * size
, size_t * startIdx
, uint32_t * hi
, uint64_t * lo
)
1675 if (* size
< 64 ) return 0 ;
1676 if ( BitStream
[ 1 ]> 1 ) return 0 ; //allow only 1s and 0s
1678 // 111111111 bit pattern represent start of frame
1679 // include 0 in front to help get start pos
1680 uint8_t preamble
[] = { 0 , 1 , 1 , 1 , 1 , 1 , 1 , 1 , 1 , 1 };
1682 uint8_t FmtLen
= 10 ; // sets of 4 bits = end data
1684 errChk
= preambleSearch ( BitStream
, preamble
, sizeof ( preamble
), size
, startIdx
);
1685 if ( errChk
== 0 || (* size
!= 64 && * size
!= 128 ) ) return 0 ;
1686 if (* size
== 128 ) FmtLen
= 22 ; // 22 sets of 4 bits
1688 //skip last 4bit parity row for simplicity
1689 * size
= removeParity ( BitStream
, * startIdx
+ sizeof ( preamble
), 5 , 0 , FmtLen
* 5 );
1690 if (* size
== 40 ) { // std em410x format
1692 * lo
= (( uint64_t )( bytebits_to_byte ( BitStream
, 8 )) << 32 ) | ( bytebits_to_byte ( BitStream
+ 8 , 32 ));
1693 } else if (* size
== 88 ) { // long em format
1694 * hi
= ( bytebits_to_byte ( BitStream
, 24 ));
1695 * lo
= (( uint64_t )( bytebits_to_byte ( BitStream
+ 24 , 32 )) << 32 ) | ( bytebits_to_byte ( BitStream
+ 24 + 32 , 32 ));
1702 // Ask/Biphase Demod then try to locate an ISO 11784/85 ID
1703 // BitStream must contain previously askrawdemod and biphasedemoded data
1704 int FDXBdemodBI ( uint8_t * dest
, size_t * size
) {
1705 //make sure buffer has enough data
1706 if (* size
< 128 ) return - 1 ;
1708 size_t startIdx
= 0 ;
1709 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
1711 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1712 if ( errChk
== 0 ) return - 2 ; //preamble not found
1713 return ( int ) startIdx
;
1717 // demod gProxIIDemod
1718 // error returns as -x
1719 // success returns start position in BitStream
1720 // BitStream must contain previously askrawdemod and biphasedemoded data
1721 int gProxII_Demod ( uint8_t BitStream
[], size_t * size
) {
1723 uint8_t preamble
[] = { 1 , 1 , 1 , 1 , 1 , 0 };
1725 uint8_t errChk
= preambleSearch ( BitStream
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1726 if ( errChk
== 0 ) return - 3 ; //preamble not found
1727 if (* size
!= 96 ) return - 2 ; //should have found 96 bits
1728 //check first 6 spacer bits to verify format
1729 if (! BitStream
[ startIdx
+ 5 ] && ! BitStream
[ startIdx
+ 10 ] && ! BitStream
[ startIdx
+ 15 ] && ! BitStream
[ startIdx
+ 20 ] && ! BitStream
[ startIdx
+ 25 ] && ! BitStream
[ startIdx
+ 30 ]){
1730 //confirmed proper separator bits found
1731 //return start position
1732 return ( int ) startIdx
;
1734 return - 5 ; //spacer bits not found - not a valid gproxII
1737 // loop to get raw HID waveform then FSK demodulate the TAG ID from it
1738 int HIDdemodFSK ( uint8_t * dest
, size_t * size
, uint32_t * hi2
, uint32_t * hi
, uint32_t * lo
) {
1739 if ( justNoise ( dest
, * size
)) return - 1 ;
1741 size_t numStart
= 0 , size2
=* size
, startIdx
= 0 ;
1743 * size
= fskdemod ( dest
, size2
, 50 , 1 , 10 , 8 ); //fsk2a
1744 if (* size
< 96 * 2 ) return - 2 ;
1745 // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
1746 uint8_t preamble
[] = { 0 , 0 , 0 , 1 , 1 , 1 , 0 , 1 };
1747 // find bitstring in array
1748 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1749 if ( errChk
== 0 ) return - 3 ; //preamble not found
1751 numStart
= startIdx
+ sizeof ( preamble
);
1752 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
1753 for ( size_t idx
= numStart
; ( idx
- numStart
) < * size
- sizeof ( preamble
); idx
+= 2 ){
1754 if ( dest
[ idx
] == dest
[ idx
+ 1 ]){
1755 return - 4 ; //not manchester data
1757 * hi2
= (* hi2
<< 1 )|(* hi
>> 31 );
1758 * hi
= (* hi
<< 1 )|(* lo
>> 31 );
1759 //Then, shift in a 0 or one into low
1760 if ( dest
[ idx
] && ! dest
[ idx
+ 1 ]) // 1 0
1765 return ( int ) startIdx
;
1768 int IOdemodFSK ( uint8_t * dest
, size_t size
) {
1769 if ( justNoise ( dest
, size
)) return - 1 ;
1770 //make sure buffer has data
1771 if ( size
< 66 * 64 ) return - 2 ;
1773 size
= fskdemod ( dest
, size
, 64 , 1 , 10 , 8 ); // FSK2a RF/64
1774 if ( size
< 65 ) return - 3 ; //did we get a good demod?
1776 //0 10 20 30 40 50 60
1778 //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
1779 //-----------------------------------------------------------------------------
1780 //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
1782 //XSF(version)facility:codeone+codetwo
1784 size_t startIdx
= 0 ;
1785 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
1786 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), & size
, & startIdx
);
1787 if ( errChk
== 0 ) return - 4 ; //preamble not found
1789 if (! dest
[ startIdx
+ 8 ] && dest
[ startIdx
+ 17 ]== 1 && dest
[ startIdx
+ 26 ]== 1 && dest
[ startIdx
+ 35 ]== 1 && dest
[ startIdx
+ 44 ]== 1 && dest
[ startIdx
+ 53 ]== 1 ){
1790 //confirmed proper separator bits found
1791 //return start position
1792 return ( int ) startIdx
;
1797 // redesigned by marshmellow adjusted from existing decode functions
1798 // indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
1799 int indala26decode ( uint8_t * bitStream
, size_t * size
, uint8_t * invert
) {
1800 //26 bit 40134 format (don't know other formats)
1801 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 };
1802 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 };
1803 size_t startidx
= 0 ;
1804 if (! preambleSearch ( bitStream
, preamble
, sizeof ( preamble
), size
, & startidx
)){
1805 // if didn't find preamble try again inverting
1806 if (! preambleSearch ( bitStream
, preamble_i
, sizeof ( preamble_i
), size
, & startidx
)) return - 1 ;
1809 if (* size
!= 64 && * size
!= 224 ) return - 2 ;
1811 for ( size_t i
= startidx
; i
< * size
; i
++)
1814 return ( int ) startidx
;
1817 // loop to get raw paradox waveform then FSK demodulate the TAG ID from it
1818 int ParadoxdemodFSK ( uint8_t * dest
, size_t * size
, uint32_t * hi2
, uint32_t * hi
, uint32_t * lo
) {
1819 if ( justNoise ( dest
, * size
)) return - 1 ;
1821 size_t numStart
= 0 , size2
=* size
, startIdx
= 0 ;
1823 * size
= fskdemod ( dest
, size2
, 50 , 1 , 10 , 8 ); //fsk2a
1824 if (* size
< 96 ) return - 2 ;
1826 // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
1827 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 1 , 1 , 1 , 1 };
1829 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1830 if ( errChk
== 0 ) return - 3 ; //preamble not found
1832 numStart
= startIdx
+ sizeof ( preamble
);
1833 // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
1834 for ( size_t idx
= numStart
; ( idx
- numStart
) < * size
- sizeof ( preamble
); idx
+= 2 ){
1835 if ( dest
[ idx
] == dest
[ idx
+ 1 ])
1836 return - 4 ; //not manchester data
1837 * hi2
= (* hi2
<< 1 )|(* hi
>> 31 );
1838 * hi
= (* hi
<< 1 )|(* lo
>> 31 );
1839 //Then, shift in a 0 or one into low
1840 if ( dest
[ idx
] && ! dest
[ idx
+ 1 ]) // 1 0
1845 return ( int ) startIdx
;
1848 // find presco preamble 0x10D in already demoded data
1849 int PrescoDemod ( uint8_t * dest
, size_t * size
) {
1850 //make sure buffer has data
1851 if (* size
< 64 * 2 ) return - 2 ;
1853 size_t startIdx
= 0 ;
1854 uint8_t preamble
[] = { 1 , 0 , 0 , 0 , 0 , 1 , 1 , 0 , 1 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
1855 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1856 if ( errChk
== 0 ) return - 4 ; //preamble not found
1857 //return start position
1858 return ( int ) startIdx
;
1862 // FSK Demod then try to locate a Farpointe Data (pyramid) ID
1863 int PyramiddemodFSK ( uint8_t * dest
, size_t * size
) {
1864 //make sure buffer has data
1865 if (* size
< 128 * 50 ) return - 5 ;
1867 //test samples are not just noise
1868 if ( justNoise ( dest
, * size
)) return - 1 ;
1871 * size
= fskdemod ( dest
, * size
, 50 , 1 , 10 , 8 ); // fsk2a RF/50
1872 if (* size
< 128 ) return - 2 ; //did we get a good demod?
1874 uint8_t preamble
[] = { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 1 };
1875 size_t startIdx
= 0 ;
1876 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1877 if ( errChk
== 0 ) return - 4 ; //preamble not found
1878 if (* size
!= 128 ) return - 3 ;
1879 return ( int ) startIdx
;
1883 // find viking preamble 0xF200 in already demoded data
1884 int VikingDemod_AM ( uint8_t * dest
, size_t * size
) {
1885 //make sure buffer has data
1886 if (* size
< 64 * 2 ) return - 2 ;
1888 size_t startIdx
= 0 ;
1889 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 };
1890 uint8_t errChk
= preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
);
1891 if ( errChk
== 0 ) return - 4 ; //preamble not found
1892 uint32_t checkCalc
= bytebits_to_byte ( dest
+ startIdx
, 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 8 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 16 , 8 )
1893 ^ bytebits_to_byte ( dest
+ startIdx
+ 24 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 32 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 40 , 8 )
1894 ^ bytebits_to_byte ( dest
+ startIdx
+ 48 , 8 ) ^ bytebits_to_byte ( dest
+ startIdx
+ 56 , 8 );
1895 if ( checkCalc
!= 0xA8 ) return - 5 ;
1896 if (* size
!= 64 ) return - 6 ;
1897 //return start position
1898 return ( int ) startIdx
;
1902 // find Visa2000 preamble in already demoded data
1903 int Visa2kDemod_AM ( uint8_t * dest
, size_t * size
) {
1904 if (* size
< 96 ) return - 1 ; //make sure buffer has data
1905 size_t startIdx
= 0 ;
1906 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 };
1907 if ( preambleSearch ( dest
, preamble
, sizeof ( preamble
), size
, & startIdx
) == 0 )
1908 return - 2 ; //preamble not found
1909 if (* size
!= 96 ) return - 3 ; //wrong demoded size
1910 //return start position
1911 return ( int ) startIdx
;