X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/a3abb028978d98bf28676d3b4a98083db3b2912a..f1b74c30899b5c1ce916f2a5c42d679e61aaa5ac:/common/lfdemod.c?ds=sidebyside

diff --git a/common/lfdemod.c b/common/lfdemod.c
index 7d40d22e..3b9402cc 100644
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -369,7 +369,9 @@ 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 +391,22 @@ 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;
@@ -526,7 +537,7 @@ int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, ui
 	return (int)startIdx;
 }
 
-uint32_t bytebits_to_byte(uint8_t* src, size_t numbits)
+uint32_t bytebits_to_byte(uint8_t *src, size_t numbits)
 {
 	uint32_t num = 0;
 	for(int i = 0 ; i < numbits ; i++)
@@ -537,6 +548,17 @@ uint32_t bytebits_to_byte(uint8_t* src, size_t numbits)
 	return num;
 }
 
+//least significant bit first
+uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits)
+{
+	uint32_t num = 0;
+	for(int i = 0 ; i < numbits ; i++)
+	{
+		num = (num << 1) | *(src + (numbits-(i+1)));
+	}
+	return num;
+}
+
 int IOdemodFSK(uint8_t *dest, size_t size)
 {
 	if (justNoise(dest, size)) return -1;
@@ -569,7 +591,7 @@ 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), 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;
@@ -579,9 +601,13 @@ 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 (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;
 	}
@@ -590,6 +616,21 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p
 	return bitCnt;
 }
 
+// Ask/Biphase Demod then try to locate an ISO 11784/85 ID
+// BitStream must contain previously askrawdemod and biphasedemoded data
+int FDXBdemodBI(uint8_t *dest, size_t *size)
+{
+	//make sure buffer has enough data
+	if (*size < 128) return -1;
+
+	size_t startIdx = 0;
+	uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,1};
+
+	uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+	if (errChk == 0) return -2; //preamble not found
+	return (int)startIdx;
+}
+
 // by marshmellow
 // FSK Demod then try to locate an AWID ID
 int AWIDdemodFSK(uint8_t *dest, size_t *size)