Ejemplo n.º 1
0
void main(void) {
	// one wire bus
	struct soft_ow sow_ctx;

	// temperature reading
	uint16_t temperature = 0x00;
	
	// configure the bus
	sow_ctx.conf = SOFT_OW_CONF_MAKE(OW_POWER_PARASITE, OW_SINGLEDROP);
	sow_ctx.bus.port = &OW_PORT;
	sow_ctx.bus.pin = OW_PIN;

	// initialize one-wire
	sow_init(&sow_ctx);

	// perform HW init 12 bit resolution
	ds18b20_write_rom(&sow_ctx, NULL, 0x00, 0x00, 0x03, 0x00);

	// execution loop
	for (;;) {

		// start conversion
		ds18b20_start_conversion(&sow_ctx, NULL);

		// wait for the conversion to finnish
		_delay_ms(800);

		// read the temperature
		ds18b20_read_scratchpad(&sow_ctx, 
			NULL, 
			(uint8_t *)&temperature, 2);

	}
}
Ejemplo n.º 2
0
/*---------------------------------------------------------------------------*/
PROCESS_THREAD(ds18b20_poll_process, ev, data)
{
  static struct etimer et;
  static uint8_t scratchpad[DS18B20_SCRATCHPAD_SIZE];
  static ow_rom_code_t id;

  PROCESS_BEGIN();

  printf("\nDS18B20 test\n");

  printf("VSEC ON\n");
  power_control_vsec_set(1);

  /* initialize the DS18B20 hardware */
  printf("Initialize 1-wire\n");
  ow_init();
  printf("1-wire READ ROM\n");
  id = ow_read_rom();
  printf("Initialize DS18B20\n");
  ds18b20_init();
  printf("DS18B20 init done\n");

  /* Poll at 1Hz */
  etimer_set(&et, CLOCK_SECOND);

  while(1) {
    PROCESS_WAIT_EVENT_UNTIL(etimer_expired(&et));

    /* Reset the etimer to trig again */
    etimer_reset(&et);

    ds18b20_read_scratchpad(id, scratchpad);
    ds18b20_convert_temperature(id);
  }

  PROCESS_END();
}
Ejemplo n.º 3
0
void ds18b20_write_rom(volatile struct soft_ow *a_bus, ow_romcode_t *a_romcode, uint8_t a_th, uint8_t a_tl, uint8_t a_res, uint8_t a_force) {
	uint8_t tmp[5] = { 0x00 };
	
	if (NULL == a_romcode || 
			OW_SINGLEDROP == SOFT_OW_TOPOLOGY_GET(a_bus->conf)) {

		if (!a_force) {
			// first read ROM and check if the configuration register 
			// is not already set to the requested value
			ds18b20_read_scratchpad(a_bus, a_romcode, tmp, sizeof(tmp));
		}

		// build the configuration value
		tmp[0] = a_th;
		tmp[1] = a_tl;
		tmp[2] = ((a_res & 0x03) << 5) | 0x1f;

		// write only if configuration register differs or force has been
		// requested
		if (tmp[4] != tmp[2] || a_force) {
			sow_reset(a_bus);

			sow_write_byte(a_bus, OWN_SKIP_ROM);
			sow_write_byte(a_bus, DS18B20_CMD_WRITE_SP);

			// save to eeprom
			for (uint8_t len = 0; len < 3; len++)
				sow_write_byte(a_bus, tmp[len]);

			// persistently store in rom
			sow_reset(a_bus);
			sow_write_byte(a_bus, OWN_SKIP_ROM);
			sow_write_byte(a_bus, DS18B20_CMD_COPY_SP);
		}		
	}
}