//---------------------------------Utilities Section--------------------------------------------
//**********************************************************************************************
#define LOWEST_DEFAULT_CLOCK 32
+#define FSK_PSK_THRESHOLD 123
//to allow debug print calls when used not on device
void dummy(char *fmt, ...){}
#ifndef ON_DEVICE
#endif
uint8_t justNoise(uint8_t *BitStream, size_t size) {
- static const uint8_t THRESHOLD = 123;
//test samples are not just noise
uint8_t justNoise1 = 1;
for(size_t idx=0; idx < size && justNoise1 ;idx++){
- justNoise1 = BitStream[idx] < THRESHOLD;
+ justNoise1 = BitStream[idx] < FSK_PSK_THRESHOLD;
}
return justNoise1;
}
if (BitStream[i] > *high) *high = BitStream[i];
if (BitStream[i] < *low) *low = BitStream[i];
}
- if (*high < 123) return -1; // just noise
+ if (*high < FSK_PSK_THRESHOLD) return -1; // just noise
*high = ((*high-128)*fuzzHi + 12800)/100;
*low = ((*low-128)*fuzzLo + 12800)/100;
return 1;
}
// find start of modulating data (for fsk and psk) in case of beginning noise or slow chip startup.
-size_t findModStart(uint8_t dest[], size_t size, uint8_t threshold_value, uint8_t expWaveSize) {
+size_t findModStart(uint8_t dest[], size_t size, uint8_t expWaveSize) {
size_t i = 0;
size_t waveSizeCnt = 0;
uint8_t thresholdCnt = 0;
- bool isAboveThreshold = dest[i++] >= threshold_value;
+ bool isAboveThreshold = dest[i++] >= FSK_PSK_THRESHOLD;
for (; i < size-20; i++ ) {
- if(dest[i] < threshold_value && isAboveThreshold) {
+ if(dest[i] < FSK_PSK_THRESHOLD && isAboveThreshold) {
thresholdCnt++;
if (thresholdCnt > 2 && waveSizeCnt < expWaveSize+1) break;
isAboveThreshold = false;
waveSizeCnt = 0;
- } else if (dest[i] >= threshold_value && !isAboveThreshold) {
+ } else if (dest[i] >= FSK_PSK_THRESHOLD && !isAboveThreshold) {
thresholdCnt++;
if (thresholdCnt > 2 && waveSizeCnt < expWaveSize+1) break;
isAboveThreshold = true;
//by marshmellow
//detect nrz clock by reading #peaks vs no peaks(or errors)
-int DetectNRZClock_ext(uint8_t dest[], size_t size, int clock, size_t *clockStartIdx) {
+int DetectNRZClock(uint8_t dest[], size_t size, int clock, size_t *clockStartIdx) {
size_t i=0;
uint8_t clk[]={8,16,32,40,50,64,100,128,255};
size_t loopCnt = 4096; //don't need to loop through entire array...
return clk[best];
}
-int DetectNRZClock(uint8_t dest[], size_t size, int clock) {
- size_t bestStart=0;
- return DetectNRZClock_ext(dest, size, clock, &bestStart);
-}
-
//by marshmellow
//countFC is to detect the field clock lengths.
//counts and returns the 2 most common wave lengths
// by marshmellow - demodulate NRZ wave - requires a read with strong signal
// peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
-int nrzRawDemod_ext(uint8_t *dest, size_t *size, int *clk, int *invert, int *startIdx) {
+int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert, int *startIdx) {
if (justNoise(dest, *size)) return -1;
- *clk = DetectNRZClock(dest, *size, *clk);
+ size_t clkStartIdx = 0;
+ *clk = DetectNRZClock(dest, *size, *clk, &clkStartIdx);
if (*clk==0) return -2;
size_t i, gLen = 4096;
if (gLen>*size) gLen = *size-20;
*size = numBits;
return 0;
}
-int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert) {
- int startIdx = 0;
- return nrzRawDemod_ext(dest, size, clk, invert, &startIdx);
-}
//translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq])
size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow, int *startIdx) {
if (fchigh==0) fchigh=10;
if (fclow==0) fclow=8;
//set the threshold close to 0 (graph) or 128 std to avoid static
- uint8_t threshold_value = 123;
size_t preLastSample = 0;
size_t LastSample = 0;
size_t currSample = 0;
if ( size < 1024 ) return 0; // not enough samples
//find start of modulating data in trace
- idx = findModStart(dest, size, threshold_value, fchigh);
+ idx = findModStart(dest, size, fchigh);
// Need to threshold first sample
- if(dest[idx] < threshold_value) dest[0] = 0;
+ if(dest[idx] < FSK_PSK_THRESHOLD) dest[0] = 0;
else dest[0] = 1;
last_transition = idx;
// (could also be fc/5 && fc/7 for fsk1 = 4-9)
for(; idx < size; idx++) {
// threshold current value
- if (dest[idx] < threshold_value) dest[idx] = 0;
+ if (dest[idx] < FSK_PSK_THRESHOLD) dest[idx] = 0;
else dest[idx] = 1;
// Check for 0->1 transition
return;
}
+size_t pskFindFirstPhaseShift(uint8_t samples[], size_t size, uint8_t *curPhase, size_t waveStart, uint16_t fc, uint16_t *fullWaveLen) {
+ uint16_t loopCnt = (size+3 < 4096) ? size : 4096; //don't need to loop through entire array...
+
+ uint16_t avgWaveVal=0, lastAvgWaveVal=0;
+ size_t i = waveStart, waveEnd, waveLenCnt, firstFullWave;
+ for (; i<loopCnt; i++) {
+ // find peak
+ if (samples[i]+fc < samples[i+1] && samples[i+1] >= samples[i+2]){
+ waveEnd = i+1;
+ if (g_debugMode == 2) prnt("DEBUG PSK: waveEnd: %u, waveStart: %u", waveEnd, waveStart);
+ waveLenCnt = waveEnd-waveStart;
+ if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+8)){ //not first peak and is a large wave but not out of whack
+ lastAvgWaveVal = avgWaveVal/(waveLenCnt);
+ firstFullWave = waveStart;
+ *fullWaveLen = waveLenCnt;
+ //if average wave value is > graph 0 then it is an up wave or a 1 (could cause inverting)
+ if (lastAvgWaveVal > FSK_PSK_THRESHOLD) *curPhase ^= 1;
+ return firstFullWave;
+ }
+ waveStart = i+1;
+ avgWaveVal = 0;
+ }
+ avgWaveVal += samples[i+2];
+ }
+ return 0;
+}
+
//by marshmellow - demodulate PSK1 wave
//uses wave lengths (# Samples)
int pskRawDemod_ext(uint8_t dest[], size_t *size, int *clock, int *invert, int *startIdx) {
- if (size == 0) return -1;
- uint16_t loopCnt = 4096; //don't need to loop through entire array...
- if (*size<loopCnt) loopCnt = *size;
+ if (*size < 170) return -1;
- size_t numBits=0;
uint8_t curPhase = *invert;
- size_t i=0, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0;
- uint16_t fc=0, fullWaveLen=0, tol=1;
- uint16_t errCnt=0, waveLenCnt=0, errCnt2=0;
+ size_t i=0, numBits=0, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0;
+ uint16_t fc=0, fullWaveLen=0, waveLenCnt=0, avgWaveVal, tol=1;
+ uint16_t errCnt=0, errCnt2=0;
+
fc = countFC(dest, *size, 1);
- uint8_t fc2 = fc >> 8;
- if (fc2 == 10) return -1; //fsk found - quit
+ if ((fc >> 8) == 10) return -1; //fsk found - quit
fc = fc & 0xFF;
if (fc!=2 && fc!=4 && fc!=8) return -1;
- //PrintAndLog("DEBUG: FC: %d",fc);
*clock = DetectPSKClock(dest, *size, *clock);
if (*clock == 0) return -1;
//find start of modulating data in trace
- uint8_t threshold_value = 123; //-5
- i = findModStart(dest, *size, threshold_value, fc);
+ i = findModStart(dest, *size, fc);
//find first phase shift
- int avgWaveVal=0, lastAvgWaveVal=0;
- waveStart = i;
- for (; i<loopCnt; i++) {
- // find peak
- if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
- waveEnd = i+1;
- if (g_debugMode == 2) prnt("DEBUG PSK: waveEnd: %u, waveStart: %u",waveEnd, waveStart);
- waveLenCnt = waveEnd-waveStart;
- if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+3)){ //not first peak and is a large wave but not out of whack
- lastAvgWaveVal = avgWaveVal/(waveLenCnt);
- firstFullWave = waveStart;
- fullWaveLen=waveLenCnt;
- //if average wave value is > graph 0 then it is an up wave or a 1 (could cause inverting)
- if (lastAvgWaveVal > threshold_value) curPhase ^= 1;
- break;
- }
-
- waveStart = i+1;
- avgWaveVal = 0;
- }
- avgWaveVal += dest[i+2];
- }
+ firstFullWave = pskFindFirstPhaseShift(dest, *size, &curPhase, i, fc, &fullWaveLen);
if (firstFullWave == 0) {
// no phase shift detected - could be all 1's or 0's - doesn't matter where we start
// so skip a little to ensure we are past any Start Signal
} else { //waveEnd
waveEnd = i+1;
waveLenCnt = waveEnd-waveStart;
- lastAvgWaveVal = avgWaveVal/waveLenCnt;
if (waveLenCnt > fc){
- //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);
//this wave is a phase shift
//PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc);
if (i+1 >= lastClkBit + *clock - tol){ //should be a clock bit
extern uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low);
extern uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow);
extern uint8_t detectFSKClk_ext(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow, int *firstClockEdge);
-extern int DetectNRZClock(uint8_t dest[], size_t size, int clock);
-extern int DetectNRZClock_ext(uint8_t dest[], size_t size, int clock, size_t *clockStartIdx);
+extern int DetectNRZClock(uint8_t dest[], size_t size, int clock, size_t *clockStartIdx);
extern int DetectPSKClock(uint8_t dest[], size_t size, int clock);
extern int DetectPSKClock_ext(uint8_t dest[], size_t size, int clock, int *firstPhaseShift);
extern int DetectStrongAskClock(uint8_t dest[], size_t size, int high, int low, int *clock);
extern uint32_t manchesterEncode2Bytes(uint16_t datain);
extern int ManchesterEncode(uint8_t *BitStream, size_t size);
extern int manrawdecode(uint8_t *BitStream, size_t *size, uint8_t invert, uint8_t *alignPos);
-extern int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert);
-extern int nrzRawDemod_ext(uint8_t *dest, size_t *size, int *clk, int *invert, int *startIdx);
+extern int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert, int *startIdx);
extern uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType);
extern uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx);
extern bool preambleSearchEx(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx, bool findone);
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