From 2147c307785639944f4843d7cf0d245778532ecf Mon Sep 17 00:00:00 2001 From: marshmellow42 Date: Mon, 16 Mar 2015 08:39:18 -0400 Subject: [PATCH] FIX EM Error missed two files for last push.. sorry --- common/lfdemod.c | 79 +++++++++++++++++++++++++++++++++++++++++++----- common/lfdemod.h | 3 +- 2 files changed, 73 insertions(+), 9 deletions(-) diff --git a/common/lfdemod.c b/common/lfdemod.c index 0a81c6b8..46ac4924 100644 --- a/common/lfdemod.c +++ b/common/lfdemod.c @@ -55,7 +55,7 @@ uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType) } //by marshmellow -//search for given preamble in given BitStream and return startIndex and length +//search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx) { uint8_t foundCnt=0; @@ -78,7 +78,7 @@ uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_ //by marshmellow //takes 1s and 0s and searches for EM410x format - output EM ID -uint64_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx) +uint64_t Em410xDecodeOld(uint8_t *BitStream, size_t *size, size_t *startIdx) { //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 @@ -120,6 +120,52 @@ uint64_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx) return 0; } +//by marshmellow +//takes 1s and 0s and searches for EM410x format - output EM ID +uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo) +{ + //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 + uint32_t i = 0; + if (BitStream[1]>1){ //allow only 1s and 0s + // PrintAndLog("no data found"); + return 0; + } + // 111111111 bit pattern represent start of frame + uint8_t preamble[] = {1,1,1,1,1,1,1,1,1}; + uint32_t idx = 0; + uint32_t parityBits = 0; + uint8_t errChk = 0; + uint8_t FmtLen = 10; + *startIdx = 0; + for (uint8_t extraBitChk=0; extraBitChk<5; extraBitChk++){ + errChk = preambleSearch(BitStream+extraBitChk+*startIdx, preamble, sizeof(preamble), size, startIdx); + if (errChk == 0) return 0; + if (*size>64) FmtLen = 22; + idx = *startIdx + 9; + for (i=0; i> 63); + *lo = (*lo << 1) | (BitStream[(i*5)+ii+idx]); + } + } + if (errChk != 0) return 1; + //skip last 5 bit parity test for simplicity. + // *size = 64 | 128; + } + return 0; +} + //by marshmellow //takes 3 arguments - clock, invert, maxErr as integers //attempts to demodulate ask while decoding manchester @@ -151,6 +197,8 @@ int askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int max int iii = 0; uint32_t gLen = *size; if (gLen > 3000) gLen=3000; + //if 0 errors allowed then only try first 2 clock cycles as we want a low tolerance + if (!maxErr) gLen=*clk*2; uint8_t errCnt =0; uint16_t MaxBits = 500; uint32_t bestStart = *size; @@ -305,16 +353,29 @@ int manrawdecode(uint8_t * BitStream, size_t *size) } //by marshmellow -//take 01 or 10 = 0 and 11 or 00 = 1 +//take 01 or 10 = 1 and 11 or 00 = 0 +//check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010 int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert) { uint16_t bitnum=0; uint32_t errCnt =0; - uint32_t i; - uint16_t MaxBits=500; - i=offset; - if (size == 0) return -1; - for (;i<*size-2; i+=2){ + size_t i=offset; + uint16_t MaxBits=512; + //if not enough samples - error + if (*size < 51) return -1; + //check for phase change faults - skip one sample if faulty + uint8_t offsetA = 1, offsetB = 1; + for (; i<48; i+=2){ + if (BitStream[i+1]==BitStream[i+2]) offsetA=0; + if (BitStream[i+2]==BitStream[i+3]) offsetB=0; + } + if (!offsetA && offsetB) offset++; + for (i=offset; i<*size-3; i+=2){ + //check for phase error + if (i<*size-3 && BitStream[i+1]==BitStream[i+2]) { + BitStream[bitnum++]=77; + errCnt++; + } if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){ BitStream[bitnum++]=1^invert; } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){ @@ -381,6 +442,8 @@ int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int max uint32_t iii = 0; uint32_t gLen = *size; if (gLen > 500) gLen=500; + //if 0 errors allowed then only try first 2 clock cycles as we want a low tolerance + if (!maxErr) gLen=*clk*2; uint8_t errCnt =0; uint32_t bestStart = *size; uint32_t bestErrCnt = maxErr; //(*size/1000); diff --git a/common/lfdemod.h b/common/lfdemod.h index 23525a48..8e10a7df 100644 --- a/common/lfdemod.h +++ b/common/lfdemod.h @@ -17,7 +17,8 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr); int askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr); -uint64_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx); +uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo); +//uint64_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx); int ManchesterEncode(uint8_t *BitStream, size_t size); int manrawdecode(uint8_t *BitStream, size_t *size); int BiphaseRawDecode(uint8_t * BitStream, size_t *size, int offset, int invert); -- 2.39.2