#include "string.h"
#include "lfdemod.h"
+uint8_t decimation = 1;
+uint8_t bits_per_sample = 8;
+bool averaging = 1;
+
+typedef struct {
+ uint8_t * buffer;
+ uint32_t numbits;
+ uint32_t position;
+} BitstreamOut;
/**
-* Does the sample acquisition. If threshold is specified, the actual sampling
-* is not commenced until the threshold has been reached.
-* @param trigger_threshold - the threshold
-* @param silent - is true, now outputs are made. If false, dbprints the status
-*/
-void DoAcquisition125k_internal(int trigger_threshold,bool silent)
+ * @brief Pushes bit onto the stream
+ * @param stream
+ * @param bit
+ */
+void pushBit( BitstreamOut* stream, uint8_t bit)
{
- uint8_t *dest = (uint8_t *)BigBuf;
- int n = sizeof(BigBuf);
- int i;
-
- memset(dest, 0, n);
- i = 0;
- for(;;) {
- 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) {
- dest[i] = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
- LED_D_OFF();
- if (trigger_threshold != -1 && dest[i] < trigger_threshold)
- continue;
- else
- trigger_threshold = -1;
- if (++i >= n) break;
- }
- }
- if(!silent)
- {
- Dbprintf("buffer samples: %02x %02x %02x %02x %02x %02x %02x %02x ...",
- dest[0], dest[1], dest[2], dest[3], dest[4], dest[5], dest[6], dest[7]);
+ int bytepos = stream->position >> 3; // divide by 8
+ int bitpos = stream->position & 7;
+ *(stream->buffer+bytepos) |= (bit > 0) << (7 - bitpos);
+ stream->position++;
+ stream->numbits++;
+}
- }
+/**
+ * Does the sample acquisition. If threshold is specified, the actual sampling
+ * is not commenced until the threshold has been reached.
+ * This method implements decimation and quantization in order to
+ * be able to provide longer sample traces.
+ * Uses the following global settings:
+ * - decimation - how much should the signal be decimated. A decimation of N means we keep 1 in N samples, etc.
+ * - bits_per_sample - bits per sample. Max 8, min 1 bit per sample.
+ * - averaging If set to true, decimation will use averaging, so that if e.g. decimation is 3, the sample
+ * value that will be used is the average value of the three samples.
+ *
+ * @param trigger_threshold - a threshold. The sampling won't commence until this threshold has been reached. Set
+ * to -1 to ignore threshold.
+ * @param silent - is true, now outputs are made. If false, dbprints the status
+ * @return the number of bits occupied by the samples.
+ */
+uint32_t DoAcquisition125k_internal(int trigger_threshold,bool silent)
+{
+ //.
+ uint8_t *dest = (uint8_t *)BigBuf;
+ int bufsize = BIGBUF_SIZE;
+ memset(dest, 0, bufsize);
+
+ if(bits_per_sample < 1) bits_per_sample = 1;
+ if(bits_per_sample > 8) bits_per_sample = 8;
+
+ if(decimation < 1) decimation = 1;
+
+ // Use a bit stream to handle the output
+ BitstreamOut data = { dest , 0, 0};
+ int sample_counter = 0;
+ uint8_t sample = 0;
+ //If we want to do averaging
+ uint32_t sample_sum =0 ;
+ uint32_t sample_total_numbers =0 ;
+ uint32_t sample_total_saved =0 ;
+
+ while(!BUTTON_PRESS()) {
+ 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();
+ if (trigger_threshold != -1 && sample < trigger_threshold)
+ continue;
+
+ trigger_threshold = -1;
+ sample_total_numbers++;
+
+ if(averaging)
+ {
+ sample_sum += sample;
+ }
+ //Check decimation
+ if(decimation > 1)
+ {
+ sample_counter++;
+ if(sample_counter < decimation) continue;
+ sample_counter = 0;
+ }
+ //Averaging
+ if(averaging && decimation > 1) {
+ sample = sample_sum / decimation;
+ sample_sum =0;
+ }
+ //Store the sample
+ sample_total_saved ++;
+ if(bits_per_sample == 8){
+ dest[sample_total_saved-1] = sample;
+ data.numbits = sample_total_saved << 3;//Get the return value correct
+ if(sample_total_saved >= bufsize) break;
+ }
+ else{
+ pushBit(&data, sample & 0x80);
+ if(bits_per_sample > 1) pushBit(&data, sample & 0x40);
+ if(bits_per_sample > 2) pushBit(&data, sample & 0x20);
+ if(bits_per_sample > 3) pushBit(&data, sample & 0x10);
+ if(bits_per_sample > 4) pushBit(&data, sample & 0x08);
+ if(bits_per_sample > 5) pushBit(&data, sample & 0x04);
+ if(bits_per_sample > 6) pushBit(&data, sample & 0x02);
+ //Not needed, 8bps is covered above
+ //if(bits_per_sample > 7) pushBit(&data, sample & 0x01);
+ if((data.numbits >> 3) +1 >= bufsize) break;
+ }
+ }
+ }
+
+ if(!silent)
+ {
+ Dbprintf("Done, saved %d out of %d seen samples at %d bits/sample",sample_total_saved, sample_total_numbers,bits_per_sample);
+ Dbprintf("buffer samples: %02x %02x %02x %02x %02x %02x %02x %02x ...",
+ dest[0], dest[1], dest[2], dest[3], dest[4], dest[5], dest[6], dest[7]);
+ }
+ return data.numbits;
}
/**
* Perform sample aquisition.
/**
* Initializes the FPGA, and acquires the samples.
**/
-void AcquireRawAdcSamples125k(int divisor)
+void AcquireRawAdcSamples125k(int divisor,int arg1, int arg2)
{
- LFSetupFPGAForADC(divisor, true);
- // Now call the acquisition routine
- DoAcquisition125k_internal(-1,false);
+ if (arg1 != 0)
+ {
+ averaging = (arg1 & 0x80) != 0;
+ bits_per_sample = (arg1 & 0x0F);
+ }
+ if(arg2 != 0)
+ {
+ decimation = arg2;
+ }
+
+ Dbprintf("Sampling config: ");
+ Dbprintf(" divisor: %d ", divisor);
+ Dbprintf(" bps: %d ", bits_per_sample);
+ Dbprintf(" decimation: %d ", decimation);
+ Dbprintf(" averaging: %d ", averaging);
+
+ LFSetupFPGAForADC(divisor, true);
+ // Now call the acquisition routine
+ DoAcquisition125k_internal(-1,false);
}
/**
* Initializes the FPGA for snoop-mode, and acquires the samples.
int lmin=128, lmax=128;
uint8_t dir;
- AcquireRawAdcSamples125k(0);
+ AcquireRawAdcSamples125k(0,0,0);
lmin = 64;
lmax = 192;
projects / proxmark3-svn / blobdiff