CHG: this timing should be quite good. needs to be verified.

[proxmark3-svn] / armsrc / legicrf.c

diff --git a/armsrc/legicrf.c b/armsrc/legicrf.c
index cdd5d08404748b11bae078f03d83ab393dbcf0b7..530970dee40ad1e96ea59ece4a9b6f25e9377a46 100644 (file)
--- a/armsrc/legicrf.c
+++ b/armsrc/legicrf.c
@@ -62,16 +62,16 @@ static void setup_timer(void) {
 //#define RWD_TIME_1 150     /* RWD_TIME_PAUSE off, 80us on = 100us */
 //#define RWD_TIME_0 90      /* RWD_TIME_PAUSE off, 40us on = 60us */
 //#define RWD_TIME_PAUSE 30  /* 20us */
+#define US_CALIBRATION 4
+#define        RWD_TIME_1 80-US_CALIBRATION            /* READER_TIME_PAUSE off, 80us on = 100us */
+#define RWD_TIME_0 40-US_CALIBRATION           /* READER_TIME_PAUSE off, 40us on = 60us */
+#define RWD_TIME_PAUSE 20-US_CALIBRATION       /* 20us */
 
-#define        RWD_TIME_1 80-4     /* READER_TIME_PAUSE off, 80us on = 100us */
-#define RWD_TIME_0 40-4      /* READER_TIME_PAUSE off, 40us on = 60us */
-#define RWD_TIME_PAUSE 20-4  /* 20us */
-
-#define TAG_BIT_PERIOD 100-8 // 100us for every bit
+#define TAG_BIT_PERIOD 100-US_CALIBRATION      // 100us for every bit
 
 #define RWD_TIME_FUZZ 20   /* rather generous 13us, since the peak detector + hysteresis fuzz quite a bit */
 
-#define TAG_TIME_WAIT 330  // 330us from READER frame end to TAG frame start, experimentally determined  (490)
+#define TAG_TIME_WAIT 330 - US_CALIBRATION // 330us from READER frame end to TAG frame start, experimentally determined  (490)
 #define RDW_TIME_WAIT 258  // 
 
 
@@ -278,17 +278,20 @@ static void frame_sendAsReader(uint32_t data, uint8_t bits){
  */
 static void frame_receiveAsReader(struct legic_frame * const f, uint8_t bits, uint8_t crypt) {
 
+       uint32_t starttime = GetCountUS();
+       
        frame_clean(f);
        
        uint8_t i = 0, edges = 0;       
        uint16_t lsfr = 0;
-       uint32_t the_bit = 1, next_bit_at, data;
+       uint32_t the_bit = 1, next_bit_at = 0, data;
        int old_level = 0, level = 0;
 
        if(bits > 32) bits = 32;
 
-       uint32_t starttime = GetCountUS();      
-
+       AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_DIN;
+       AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DIN;
+       
        // calibrate the prng.  
        legic_prng_forward(2);
        //CalibratePrng( starttime );
@@ -301,15 +304,12 @@ static void frame_receiveAsReader(struct legic_frame * const f, uint8_t bits, ui
 
        data = lsfr;
        
-       next_bit_at = GetCountUS() + TAG_BIT_PERIOD;
-       
        //FIXED time between sending frame and now listening frame. 330us
        uint32_t icetime = TAG_TIME_WAIT - ( GetCountUS() - stop_send_frame_us );
-       //
-       WAIT( icetime ); // 21.3us inc.
+       WAIT( icetime ); // 8-10us
         
-       AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_DIN;
-       AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DIN;
+       next_bit_at = GetCountUS();
+       next_bit_at += TAG_BIT_PERIOD;
        
        for( i = 0; i < bits; i++) {
                edges = 0;
@@ -336,6 +336,8 @@ static void frame_receiveAsReader(struct legic_frame * const f, uint8_t bits, ui
        f->bits = bits;
                
        // log
+       stop_send_frame_us = GetCountUS();
+       
        uint8_t cmdbytes[] = { 
                (data & 0xFF),
                (data >> 8) & 0xFF,
@@ -347,7 +349,7 @@ static void frame_receiveAsReader(struct legic_frame * const f, uint8_t bits, ui
                icetime & 0xff,
                (icetime >> 8) & 0xFF
        };
-       LogTrace(cmdbytes, sizeof(cmdbytes), starttime, GetCountUS(), NULL, FALSE);
+       LogTrace(cmdbytes, sizeof(cmdbytes), starttime, stop_send_frame_us, NULL, FALSE);
 
 }