CHG: `lf em` - added @marshmellow42 's changes

[proxmark3-svn] / armsrc / lfsampling.c

diff --git a/armsrc/lfsampling.c b/armsrc/lfsampling.c
index d726ba20c7c823fce1d25beb883cec7262cd308c..def7431ded510908bb3572da80fe486586031d65 100644 (file)
--- a/armsrc/lfsampling.c
+++ b/armsrc/lfsampling.c
@@ -8,18 +8,25 @@
 
 #include "lfsampling.h"
 
+/*
+Default LF config is set to:
+       decimation = 1  (we keep 1 out of 1 samples)
+       bits_per_sample = 8
+       averaging = YES
+       divisor = 95 (125khz)
+       trigger_threshold = 0
+       */
 sample_config config = { 1, 8, 1, 95, 0 } ;
 
 void printConfig() {
        Dbprintf("LF Sampling config: ");
-       Dbprintf("  [q] divisor:           %d ", config.divisor);
+       Dbprintf("  [q] divisor:           %d (%d KHz)", config.divisor, 12000 / (config.divisor+1));
        Dbprintf("  [b] bps:               %d ", config.bits_per_sample);
        Dbprintf("  [d] decimation:        %d ", config.decimation);
-       Dbprintf("  [a] averaging:         %d ", config.averaging);
+       Dbprintf("  [a] averaging:         %s ", (config.averaging) ? "Yes" : "No");
        Dbprintf("  [t] trigger threshold: %d ", config.trigger_threshold);
 }
 
-
 /**
  * Called from the USB-handler to set the sampling configuration
  * The sampling config is used for std reading and snooping.
@@ -34,12 +41,11 @@ void printConfig() {
 void setSamplingConfig(sample_config *sc) {
        if(sc->divisor != 0) config.divisor = sc->divisor;
        if(sc->bits_per_sample != 0) config.bits_per_sample = sc->bits_per_sample;
-       if(sc->decimation != 0) config.decimation = sc->decimation;
        if(sc->trigger_threshold != -1) config.trigger_threshold = sc->trigger_threshold;
-
+       
+       config.decimation = (sc->decimation != 0) ? sc->decimation : 1;
        config.averaging = sc->averaging;
        if(config.bits_per_sample > 8)  config.bits_per_sample = 8;
-       if(config.decimation < 1)       config.decimation = 1;
 
        printConfig();
 }
@@ -304,4 +310,122 @@ void doT55x7Acquisition(size_t sample_size) {
                }
        }
 }
-                       
\ No newline at end of file
+/**
+* acquisition of Cotag LF signal. Similart to other LF,  since the Cotag has such long datarate RF/384
+* and is Manchester?,  we directly gather the manchester data into bigbuff
+**/
+
+#define COTAG_T1 384
+#define COTAG_T2 (COTAG_T1>>1)
+#define COTAG_ONE_THRESHOLD 128+30
+#define COTAG_ZERO_THRESHOLD 128-30
+void doCotagAcquisition(size_t sample_size) {
+
+       uint8_t *dest = BigBuf_get_addr();
+       uint16_t bufsize = BigBuf_max_traceLen();
+       
+       if ( bufsize > sample_size )
+               bufsize = sample_size;
+
+       dest[0] = 0;    
+       uint8_t sample = 0, firsthigh = 0, firstlow = 0; 
+       uint16_t i = 0;
+
+       while (!BUTTON_PRESS() && !usb_poll_validate_length() && (i < bufsize) ) {
+               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) {
+                       sample = (uint8_t)AT91C_BASE_SSC->SSC_RHR;      
+                       LED_D_OFF();
+               
+                       // find first peak
+                       if ( !firsthigh ) {
+                               if (sample < COTAG_ONE_THRESHOLD) 
+                                       continue;
+                               firsthigh = 1;
+                       }
+                       if ( !firstlow ){
+                               if (sample > COTAG_ZERO_THRESHOLD )
+                                       continue;
+                               firstlow = 1;
+                       }
+
+                       ++i;                    
+       
+                       if ( sample > COTAG_ONE_THRESHOLD)
+                               dest[i] = 255;
+                       else if ( sample < COTAG_ZERO_THRESHOLD) 
+                               dest[i] = 0;
+                       else 
+                               dest[i] = dest[i-1];                    
+               }
+       }
+}
+
+uint32_t doCotagAcquisitionManchester() {
+
+       uint8_t *dest = BigBuf_get_addr();
+       uint16_t bufsize = BigBuf_max_traceLen();
+       
+       if ( bufsize > COTAG_BITS )
+               bufsize = COTAG_BITS;
+
+       dest[0] = 0;    
+       uint8_t sample = 0, firsthigh = 0, firstlow = 0; 
+       uint16_t sample_counter = 0, period = 0;
+       uint8_t curr = 0, prev = 0;
+
+       while (!BUTTON_PRESS() && !usb_poll_validate_length() && (sample_counter < bufsize) ) {
+               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) {
+                       sample = (uint8_t)AT91C_BASE_SSC->SSC_RHR;      
+                       LED_D_OFF();
+               
+                       // find first peak
+                       if ( !firsthigh ) {
+                               if (sample < COTAG_ONE_THRESHOLD) 
+                                       continue;
+                               firsthigh = 1;
+                       }
+                       
+                       if ( !firstlow ){
+                               if (sample > COTAG_ZERO_THRESHOLD )
+                                       continue;
+                               firstlow = 1;
+                       }
+                                               
+                       // set sample 255, 0,  or previous                      
+                       if ( sample > COTAG_ONE_THRESHOLD){
+                               prev = curr;
+                               curr = 1;
+                       }
+                       else if ( sample < COTAG_ZERO_THRESHOLD) {
+                               prev = curr;
+                               curr = 0;
+                       }
+                       else {
+                               curr = prev;
+                       }                       
+
+                       // full T1 periods, 
+                       if ( period > 0 ) {
+                               --period;
+                               continue;
+                       }
+                                               
+                       dest[sample_counter] = curr;
+                       ++sample_counter;
+                       period = COTAG_T1;
+               }
+       }
+       return sample_counter;
+}
\ No newline at end of file