X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/7fa7e812fc913e391ada3008db059bb4393b4804..3e134b4c20a5528b8264cd87d3fdebd0b2df6fd9:/common/lfdemod.c

diff --git a/common/lfdemod.c b/common/lfdemod.c
index cb3e9f0b..8b31f1a4 100644
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -259,13 +259,15 @@ int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int
 //by marshmellow
 void askAmp(uint8_t *BitStream, size_t size)
 {
-	for(size_t i = 1; i<size; i++){
-		if (BitStream[i]-BitStream[i-1]>=30) //large jump up
-			BitStream[i]=255;
-		else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down
-			BitStream[i]=0;
+	uint8_t last = 128;
+	for(size_t i = 1; i < size; ++i){
+		if (BitStream[i]-BitStream[i-1] >= 30) //large jump up
+			last = 255;
+		else if(BitStream[i-1] - BitStream[i] >= 20) //large jump down
+			last = 0;
+		
+		BitStream[i] = last;
 	}
-	return;
 }
 
 //by marshmellow
@@ -679,10 +681,15 @@ int VikingDemod_AM(uint8_t *dest, size_t *size) {
 	uint8_t preamble[] = {1,1,1,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
 	uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
 	if (errChk == 0) return -4; //preamble not found
-	uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^ bytebits_to_byte(dest+startIdx+8,8) ^ bytebits_to_byte(dest+startIdx+16,8)
-	    ^ bytebits_to_byte(dest+startIdx+24,8) ^ bytebits_to_byte(dest+startIdx+32,8) ^ bytebits_to_byte(dest+startIdx+40,8) 
-	    ^ bytebits_to_byte(dest+startIdx+48,8) ^ bytebits_to_byte(dest+startIdx+56,8);
-	if ( checkCalc != 0xA8 ) return -5;
+	uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^ 
+						 bytebits_to_byte(dest+startIdx+8,8) ^ 
+						 bytebits_to_byte(dest+startIdx+16,8) ^ 
+						 bytebits_to_byte(dest+startIdx+24,8) ^ 
+						 bytebits_to_byte(dest+startIdx+32,8) ^ 
+						 bytebits_to_byte(dest+startIdx+40,8) ^ 
+						 bytebits_to_byte(dest+startIdx+48,8) ^ 
+						 bytebits_to_byte(dest+startIdx+56,8);
+	if ( checkCalc != 0xA8 ) return -5;	
 	if (*size != 64) return -6;
 	//return start position
 	return (int) startIdx;
@@ -759,6 +766,19 @@ int PyramiddemodFSK(uint8_t *dest, size_t *size)
 	return (int)startIdx;
 }
 
+// find nedap preamble in already demoded data
+int NedapDemod(uint8_t *dest, size_t *size) {
+	//make sure buffer has data
+	if (*size < 128) return -3;
+
+	size_t startIdx = 0;
+	//uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,0,0,0,1};
+	uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,0};
+	uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+	if (errChk == 0) return -4; //preamble not found
+	return (int) startIdx;
+}
+
 // by marshmellow
 // to detect a wave that has heavily clipped (clean) samples
 uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low)