lf t55xx and some lf demod fixes/adjustments

[proxmark3-svn] / armsrc / lfsampling.c

diff --git a/armsrc/lfsampling.c b/armsrc/lfsampling.c
index 6e78376986daa167079608c83b2189d4c528ea42..7c5412820b20ce065637c6af6d253345dba4ba5c 100644 (file)
--- a/armsrc/lfsampling.c
+++ b/armsrc/lfsampling.c
@@ -103,7 +103,6 @@ void LFSetupFPGAForADC(int divisor, bool lf_field)
        FpgaSetupSsc();
 }
 
-
 /**
  * Does the sample acquisition. If threshold is specified, the actual sampling
  * is not commenced until the threshold has been reached.
@@ -154,9 +153,6 @@ uint32_t DoAcquisition(uint8_t decimation, uint32_t bits_per_sample, bool averag
                        if ((trigger_threshold > 0) && (sample < (trigger_threshold+128)) && (sample > (128-trigger_threshold))) // 
                                continue;
                
-                       //if (trigger_threshold > 0 && sample < trigger_threshold) // 
-                               //continue;
-
                        trigger_threshold = 0;
                        sample_total_numbers++;
 
@@ -252,3 +248,58 @@ uint32_t SnoopLF()
 {
        return ReadLF(false, true);
 }
+
+/**
+* acquisition of T55x7 LF signal. Similart to other LF, but adjusted with @marshmellows thresholds
+* the data is collected in BigBuf.
+**/
+void doT55x7Acquisition(size_t sample_size) {
+
+       #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 > sample_size )
+               bufsize = sample_size;
+
+       uint16_t i = 0;
+       bool startFound = false;
+       bool highFound = false;
+       uint8_t curSample = 0;
+       uint8_t lastSample = 0;
+       uint16_t skipCnt = 0;
+       while(!BUTTON_PRESS() && skipCnt<1000) {
+               WDT_HIT();
+               if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
+                       AT91C_BASE_SSC->SSC_THR = 0x43;
+                       LED_D_ON();
+               }
+               if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
+                       curSample = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+                       LED_D_OFF();
+
+                       // skip until the first high sample above threshold
+                       if (!startFound && curSample > T55xx_READ_UPPER_THRESHOLD) {
+                               if (curSample > lastSample) 
+                                       lastSample = curSample;
+                               highFound = true;
+                       } else if (!highFound) {
+                               skipCnt++;
+                               continue;
+                       }
+                       // 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;
+                       }
+               }
+       }
+}