/*
 * An interface to the TI TMP102 temperature sensor
 * 12 bit temperature reading, 0.5 deg. Celsius accuracy
 * -----------------------------------------------------------------
 *
 * Author  : Hedde Bosman (heddebosman@incas3.eu)
 */

#include "contiki.h"
#include "lib/sensors.h"
#include "dev/tmp102-sensor.h"

#ifndef bool
#define bool uint8_t
#endif

#ifndef false
#define false 0
#endif

#ifndef true
#define true 1
#endif


static void set_configuration(uint8_t rate, bool precision) {
	uint8_t tx_buf[] = {TMP102_REGISTER_CONFIGURATION, 
						0,
						(precision ? TMP102_CONF_EXTENDED_MODE : 0) | ((rate << 6) & TMP102_CONF_CONVERSION_RATE)
						};

	i2c_transmitinit(TMP102_ADDR, 3, tx_buf);
}

/*---------------------------------------------------------------------------*/
static int value(int type) {
	uint8_t reg = TMP102_REGISTER_TEMPERATURE;
	uint8_t temp[2];
	int16_t temperature = 0;
	
	/* transmit the register to start reading from */
	i2c_transmitinit(TMP102_ADDR, 1, &reg);
	while (!i2c_transferred()); // wait for data to arrive

	/* receive the data */
	i2c_receiveinit(TMP102_ADDR, 2, temp);
	while (!i2c_transferred()); // wait for data to arrive
	
	// 12 bit normal mode
	temperature = ((temp[0] <<8) | (temp[1])) >> 4; // lsb

	// 13 bit extended mode
	//temperature = ((temp[0] <<8) | (temp[1])) >> 3; // lsb

	temperature = (100*temperature)/16; // in 100th of degrees
	
	return temperature;
}
/*---------------------------------------------------------------------------*/
static int status(int type) {
	switch (type) {
		case SENSORS_ACTIVE:
		case SENSORS_READY:
			return 1; // fix?
			break;
	}
	return 0;
}
/*---------------------------------------------------------------------------*/
static int configure(int type, int c) {
	switch (type) {
		case SENSORS_ACTIVE:
			if (c) {
				// set active
				set_configuration(1, false); // every 1 second, 12bit precision
			} else {
				// set inactive
			}
			return 1;
	}
	return 0;
}


/*---------------------------------------------------------------------------*/
SENSORS_SENSOR(tmp102_sensor, "Temperature", value, configure, status); // register the functions