#include "string.h"
#include "iso14443crc.h"
#include "common.h"
-#define RECEIVE_SAMPLES_TIMEOUT 800000
+#define RECEIVE_SAMPLES_TIMEOUT 600000
#define ISO14443B_DMA_BUFFER_SIZE 256
ToSendStuffBit(0);
ToSendStuffBit(0);
}
- for(i = 0; i < 10; i++) {
+ for(i = 0; i < 2; i++) {
ToSendStuffBit(1);
ToSendStuffBit(1);
ToSendStuffBit(1);
* false if we are still waiting for some more
*
*/
+ #define abs(x) ( ((x)<0) ? -(x) : (x) )
static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq)
{
- int v;
- int ai, aq;
+ int v = 0;
+ int ai = abs(ci);
+ int aq = abs(cq);
+ int halfci = (ai >> 1);
+ int halfcq = (aq >> 1);
// The soft decision on the bit uses an estimate of just the
// quadrant of the reference angle, not the exact angle.
#define MAKE_SOFT_DECISION() { \
- v = (Demod.sumI > 0) ? ci : -ci;\
+ if(Demod.sumI > 0) { \
+ v = ci; \
+ } else { \
+ v = -ci; \
+ } \
if(Demod.sumQ > 0) { \
v += cq; \
} else { \
#define SUBCARRIER_DETECT_THRESHOLD 8
-// Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by abs(ci) + abs(cq)
-/* #define CHECK_FOR_SUBCARRIER() { \
- v = ci; \
- if(v < 0) v = -v; \
- if(cq > 0) { \
- v += cq; \
- } else { \
- v -= cq; \
- } \
- }
- */
-
// Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by max(abs(ci),abs(cq)) + 1/2*min(abs(ci),abs(cq)))
#define CHECK_FOR_SUBCARRIER() { \
- ai = (abs(ci) >> 1); \
- aq = (abs(cq) >> 1); \
- v = MAX(abs(ci), abs(cq)) + MIN(ai, aq); \
+ v = MAX(ai, aq) + MIN(halfci, halfcq); \
}
break;
case DEMOD_PHASE_REF_TRAINING:
- if(Demod.posCount < 10*2) {
+ if(Demod.posCount < 8) {
+ //if(Demod.posCount < 10*2) {
CHECK_FOR_SUBCARRIER();
if (v > SUBCARRIER_DETECT_THRESHOLD) {
// set the reference phase (will code a logic '1') by averaging over 32 1/fs.
case DEMOD_AWAITING_FALLING_EDGE_OF_SOF:
MAKE_SOFT_DECISION();
//Dbprintf("ICE: %d %d %d %d %d", v, Demod.sumI, Demod.sumQ, ci, cq );
- if(v < 0) { // logic '0' detected
+ if(v <= 0) { // logic '0' detected
Demod.state = DEMOD_GOT_FALLING_EDGE_OF_SOF;
Demod.posCount = 0; // start of SOF sequence
} else {
}
lastRxCounter -= 2;
if(lastRxCounter <= 0) {
- lastRxCounter += ISO14443B_DMA_BUFFER_SIZE;
+ lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
}
samples += 2;
// Signal field is on with the appropriate LED
LED_D_ON();
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD);
+
+ //SpinDelay(100);
// Start the timer
//StartCountSspClk();