Merge pull request #143 from marshmellow42/master

[proxmark3-svn] / armsrc / lfsampling.c

diff --git a/armsrc/lfsampling.c b/armsrc/lfsampling.c
index 91572563ff1688e91e6b5d79eda2271ae1fa3491..115d4b18ffaba74ef9c5da113cabb5444679375b 100644 (file)
--- a/armsrc/lfsampling.c
+++ b/armsrc/lfsampling.c
@@ -253,20 +253,17 @@ uint32_t SnoopLF()
 * acquisition of T55x7 LF signal. Similart to other LF, but adjusted with @marshmellows thresholds
 * the data is collected in BigBuf.
 **/
-void doT55x7Acquisition(void){
+void doT55x7Acquisition(size_t sample_size) {
 
-       #define T55xx_SAMPLES_SIZE 12000 // 32 x 32 x 10  (32 bit times numofblock (7), times clock skip..)
-       #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();
        uint16_t bufsize = BigBuf_max_traceLen();
        
-       if ( bufsize > T55xx_SAMPLES_SIZE )
-               bufsize = T55xx_SAMPLES_SIZE;
+       if ( bufsize > sample_size )
+               bufsize = sample_size;
 
-       //memset(dest, 0, bufsize);
-               
        uint16_t i = 0;
        bool startFound = false;
        bool highFound = false;
@@ -283,7 +280,7 @@ void doT55x7Acquisition(void){
                        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;
@@ -293,15 +290,17 @@ void doT55x7Acquisition(void){
                                continue;
                        }
 
-                       // skip until samples begin to change
+                       // skip until first high samples begin to change
                        if (startFound || curSample < firstSample-T55xx_READ_TOL){
-                               if (!startFound) 
+                               // if just found start - recover last sample
+                               if (!startFound) {
                                        dest[i++] = firstSample;
-                               startFound = true;
+                                       startFound = true;
+                               }
+                               // collect samples
                                dest[i++] = curSample;
                                if (i >= bufsize-1) break;
                        }
                }
-               //skipCnt++;
        }
 }