X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/ae6ead3dc84acd074be24c0da5efd94ea7a0b225..refs/pull/44/head:/common/lfdemod.c diff --git a/common/lfdemod.c b/common/lfdemod.c index 11ad1403..062818ef 100644 --- a/common/lfdemod.c +++ b/common/lfdemod.c @@ -19,21 +19,9 @@ uint64_t Em410xDecode(uint8_t *BitStream, size_t size) //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future // otherwise could be a void with no arguments //set defaults - int high=0, low=128; uint64_t lo=0; - uint32_t i = 0; - uint32_t initLoopMax = 65; - if (initLoopMax>size) initLoopMax=size; - - for (;i < initLoopMax; ++i) //65 samples should be plenty to find high and low values - { - if (BitStream[i] > high) - high = BitStream[i]; - else if (BitStream[i] < low) - low = BitStream[i]; - } - if (((high !=1)||(low !=0))){ //allow only 1s and 0s + if (BitStream[10]>1){ //allow only 1s and 0s // PrintAndLog("no data found"); return 0; } @@ -51,9 +39,9 @@ uint64_t Em410xDecode(uint8_t *BitStream, size_t size) idx+=9; for (i=0; i<10;i++){ for(ii=0; ii<5; ++ii){ - parityTest += BitStream[(i*5)+ii+idx]; + parityTest ^= BitStream[(i*5)+ii+idx]; } - if (parityTest== ((parityTest>>1)<<1)){ + if (!parityTest){ parityTest=0; for (ii=0; ii<4;++ii){ lo=(lo<<1LL)|(BitStream[(i*5)+ii+idx]); @@ -63,7 +51,7 @@ uint64_t Em410xDecode(uint8_t *BitStream, size_t size) //PrintAndLog("DEBUG: EM parity failed parity val: %d, i:%d, ii:%d,idx:%d, Buffer: %d%d%d%d%d",parityTest,i,ii,idx,BitStream[idx+ii+(i*5)-5],BitStream[idx+ii+(i*5)-4],BitStream[idx+ii+(i*5)-3],BitStream[idx+ii+(i*5)-2],BitStream[idx+ii+(i*5)-1]); parityTest=0; idx-=8; - if (resetCnt>5)return 0; + if (resetCnt>5)return 0; //try 5 times resetCnt++; goto restart;//continue; } @@ -84,7 +72,7 @@ uint64_t Em410xDecode(uint8_t *BitStream, size_t size) int askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert) { int i; - int high = 0, low = 128; + int high = 0, low = 255; *clk=DetectASKClock(BinStream, *size, *clk); //clock default if (*clk<8) *clk =64; @@ -100,7 +88,7 @@ int askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert) else if (BinStream[i] < low) low = BinStream[i]; } - if ((high < 158) ){ //throw away static + if ((high < 129) ){ //throw away static (anything < 1 graph) //PrintAndLog("no data found"); return -2; } @@ -283,7 +271,7 @@ int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert) { uint32_t i; // int invert=0; //invert default - int high = 0, low = 128; + int high = 0, low = 255; *clk=DetectASKClock(BinStream, *size, *clk); //clock default uint8_t BitStream[502] = {0}; @@ -300,7 +288,8 @@ int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert) else if (BinStream[i] < low) low = BinStream[i]; } - if ((high < 134)){ //throw away static high has to be more than 6 on graph. noise <= -10 here + if ((high < 129)){ //throw away static high has to be more than 0 on graph. + //noise <= -10 here // PrintAndLog("no data found"); return -2; } @@ -410,8 +399,8 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow //uint32_t maxVal=0; if (fchigh==0) fchigh=10; if (fclow==0) fclow=8; - //set the threshold close to 0 (graph) to avoid static - uint8_t threshold_value = 134; //(uint8_t)(((maxVal-128)*.75)+128); + //set the threshold close to 0 (graph) or 128 std to avoid static + uint8_t threshold_value = 123; // sync to first lo-hi transition, and threshold @@ -471,7 +460,7 @@ size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t maxCons if ( dest[idx-1]==1 ) { n=myround2((float)(n+1)/((float)(rfLen)/(float)fclow)); } else {// 0->1 crossing - n=myround2((float)(n+1)/((float)(rfLen-2)/(float)fchigh)); //-2 for fudge factor + n=myround2((float)(n+1)/((float)(rfLen-1)/(float)fchigh)); //-1 for fudge factor } if (n == 0) n = 1; @@ -563,7 +552,7 @@ uint32_t bytebits_to_byte(uint8_t* src, size_t numbits) int IOdemodFSK(uint8_t *dest, size_t size) { - static const uint8_t THRESHOLD = 134; + static const uint8_t THRESHOLD = 129; uint32_t idx=0; //make sure buffer has data if (size < 66) return -1; @@ -607,7 +596,7 @@ int DetectASKClock(uint8_t dest[], size_t size, int clock) { int i=0; int peak=0; - int low=128; + int low=255; int clk[]={16,32,40,50,64,100,128,256}; int loopCnt = 256; //don't need to loop through entire array... if (size 1280) gLen=1280; // get high @@ -889,7 +877,7 @@ int pskNRZrawDemod(uint8_t *dest, size_t *size, int *clk, int *invert) int lastBit = 0; //set first clock check uint32_t bitnum = 0; //output counter 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 - if (*clk==32)tol=2; //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely + if (*clk==32) tol = 2; //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely uint32_t iii = 0; uint8_t errCnt =0; uint32_t bestStart = *size;