X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/fd1d30cb76a384adc8176df1f0f35658c091d96c..66837a0302678f4c5036b9c6a607731b9a8460de:/common/lfdemod.c diff --git a/common/lfdemod.c b/common/lfdemod.c index aa37bb9e..f5a0310e 100644 --- a/common/lfdemod.c +++ b/common/lfdemod.c @@ -282,6 +282,16 @@ int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert) return bestErr; } +uint32_t manchesterEncode2Bytes(uint16_t datain) { + uint32_t output = 0; + uint8_t curBit = 0; + for (uint8_t i=0; i<16; i++) { + curBit = (datain >> (15-i) & 1); + output |= (1<<(((15-i)*2)+curBit)); + } + return output; +} + //by marshmellow //encode binary data into binary manchester int ManchesterEncode(uint8_t *BitStream, size_t size) @@ -369,7 +379,9 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow 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; // sync to first lo-hi transition, and threshold // Need to threshold first sample @@ -389,13 +401,22 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow // Check for 0->1 transition if (dest[idx-1] < dest[idx]) { // 0 -> 1 transition - if ((idx-last_transition)<(fclow-2)){ //0-5 = garbage noise + preLastSample = LastSample; + LastSample = currSample; + currSample = idx-last_transition; + if (currSample < (fclow-2)){ //0-5 = garbage noise //do nothing with extra garbage - } else if ((idx-last_transition) < (fchigh-1)) { //6-8 = 8 waves + } else if (currSample < (fchigh-1)) { //6-8 = 8 sample waves + if (LastSample > (fchigh-2) && preLastSample < (fchigh-1)){ + dest[numBits-1]=1; //correct last 9 wave surrounded by 8 waves + } dest[numBits++]=1; - } else if ((idx-last_transition) > (fchigh+1) && !numBits) { //12 + and first bit = garbage + + } else if (currSample > (fchigh+1) && !numBits) { //12 + and first bit = garbage //do nothing with beginning garbage - } else { //9+ = 10 waves + } else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's + dest[numBits++]=1; + } else { //9+ = 10 sample waves dest[numBits++]=0; } last_transition = idx; @@ -580,7 +601,7 @@ int IOdemodFSK(uint8_t *dest, size_t size) // by marshmellow // takes a array of binary values, start position, length of bits per parity (includes parity bit), -// Parity Type (1 for odd; 0 for even; 2 for just drop it), and binary Length (length to run) +// Parity Type (1 for odd; 0 for even; 2 Always 1's), and binary Length (length to run) size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen) { uint32_t parityWd = 0; @@ -590,10 +611,12 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p parityWd = (parityWd << 1) | BitStream[startIdx+word+bit]; BitStream[j++] = (BitStream[startIdx+word+bit]); } - j--; + j--; // overwrite parity with next data // if parity fails then return 0 - if (pType != 2) { - if (parityTest(parityWd, pLen, pType) == 0) return -1; + if (pType == 2) { // then marker bit which should be a 1 + if (!BitStream[j]) return 0; + } else { + if (parityTest(parityWd, pLen, pType) == 0) return 0; } bitCnt+=(pLen-1); parityWd = 0; @@ -605,7 +628,7 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p // Ask/Biphase Demod then try to locate an ISO 11784/85 ID // BitStream must contain previously askrawdemod and biphasedemoded data -int ISO11784demodBI(uint8_t *dest, size_t *size) +int FDXBdemodBI(uint8_t *dest, size_t *size) { //make sure buffer has enough data if (*size < 128) return -1;