X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/66837a0302678f4c5036b9c6a607731b9a8460de..db8296025f78251ffa2c28d6fe995bbb0a386c77:/armsrc/lfsampling.c?ds=sidebyside

diff --git a/armsrc/lfsampling.c b/armsrc/lfsampling.c
index 4a968776..7c541282 100644
--- a/armsrc/lfsampling.c
+++ b/armsrc/lfsampling.c
@@ -255,7 +255,7 @@ uint32_t SnoopLF()
 **/
 void doT55x7Acquisition(size_t sample_size) {
 
-	#define T55xx_READ_UPPER_THRESHOLD 128+40  // 50
+	#define T55xx_READ_UPPER_THRESHOLD 128+40  // 40 grph
 	#define T55xx_READ_TOL   5
 
 	uint8_t *dest = BigBuf_get_addr();
@@ -264,13 +264,11 @@ void doT55x7Acquisition(size_t sample_size) {
 	if ( bufsize > sample_size )
 		bufsize = sample_size;
 
-	//memset(dest, 0, bufsize);
-		
 	uint16_t i = 0;
 	bool startFound = false;
 	bool highFound = false;
 	uint8_t curSample = 0;
-	uint8_t firstSample = 0;
+	uint8_t lastSample = 0;
 	uint16_t skipCnt = 0;
 	while(!BUTTON_PRESS() && skipCnt<1000) {
 		WDT_HIT();
@@ -282,25 +280,26 @@ void doT55x7Acquisition(size_t sample_size) {
 			curSample = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
 			LED_D_OFF();
 
-			// find first high sample
+			// skip until the first high sample above threshold
 			if (!startFound && curSample > T55xx_READ_UPPER_THRESHOLD) {
-				if (curSample > firstSample) 
-					firstSample = curSample;
+				if (curSample > lastSample) 
+					lastSample = curSample;
 				highFound = true;
 			} else if (!highFound) {
 				skipCnt++;
 				continue;
 			}
-
-			// skip until samples begin to change
-			if (startFound || curSample < firstSample-T55xx_READ_TOL){
-				if (!startFound) 
-					dest[i++] = firstSample;
-				startFound = true;
+			// skip until first high samples begin to change
+			if (startFound || curSample < T55xx_READ_UPPER_THRESHOLD-T55xx_READ_TOL){
+				// if just found start - recover last sample
+				if (!startFound) {
+					dest[i++] = lastSample;
+					startFound = true;
+				}
+				// collect samples
 				dest[i++] = curSample;
 				if (i >= bufsize-1) break;
 			}
 		}
-		//skipCnt++;
 	}
 }