Tooltron

#include <string.h>

#include <stdint.h>

#include <util/delay.h>

#include "rfid.h"

#include "serial.h"

#define RFID_OK 1

static uint8_t read_cmd[] = {'!', 'R', 'W', 1, 32};

static int serno_idx;

static char n_failures;

static uint8_t serno[RFID_SERNO_SIZE];

static void zero_serno() {

  int i;

  for (i = 0; i < RFID_SERNO_SIZE; i++) {

    serno[i] = 0;

  }

}

void rfid_init() {

  serial_init();

}

static void restart_read() {

  serno_idx = -1;

  serial_write(read_cmd, sizeof(read_cmd));

}

void rfid_start_read() {

  n_failures = 0;

  restart_read();

}

char rfid_poll() {

  int c;

  while ((c = serial_read()) >= 0) {

    if (serno_idx < 0) {

      if (c != RFID_OK) {

        n_failures++;

        if (n_failures >= RFID_N_FAILURES) {

          zero_serno();

          return 1;

        } else {

          restart_read();

          return 0;

        }

      }

    } else {

      serno[serno_idx] = c;

    }

    serno_idx++;

    if (serno_idx >= RFID_SERNO_SIZE) {

      return 1;

    }

  }

  return 0;

}

void rfid_get_serno(uint8_t *buf) {

  memcpy(buf, serno, sizeof(serno));

}