contiki/platform/zoul/dev/tmp102.c
2016-08-24 16:34:02 +02:00

75 lines
2.7 KiB
C

/*
* Copyright (c) 2015, Zolertia - http://www.zolertia.com
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
/*---------------------------------------------------------------------------*/
/**
* \addtogroup zoul-tmp102-sensor
* @{
*
* \file
* Driver for the TMP102 temperature sensor
*/
/*---------------------------------------------------------------------------*/
#include <stdio.h>
#include "contiki.h"
#include "dev/i2c.h"
#include "tmp102.h"
void
tmp102_init(void)
{
i2c_init(I2C_SDA_PORT, I2C_SDA_PIN, I2C_SCL_PORT, I2C_SCL_PIN, I2C_SCL_NORMAL_BUS_SPEED);
}
/*---------------------------------------------------------------------------*/
uint8_t
tmp102_read(uint16_t *data)
{
uint8_t buf[2];
uint16_t temp;
/* Write to the temperature register to trigger a reading */
if(i2c_single_send(TMP102_ADDR, TMP102_TEMP) == I2C_MASTER_ERR_NONE) {
/* Read two bytes only */
if(i2c_burst_receive(TMP102_ADDR, buf, 2) == I2C_MASTER_ERR_NONE) {
/* 12-bit value, TMP102 SBOS397F Table 8-9 */
temp = (buf[0] << 4) + (buf[1] >> 4);
if(temp > 2047) {
temp -= (1 << 12);
}
temp *= 0.625;
*data = temp;
return I2C_MASTER_ERR_NONE;
}
}
return i2c_master_error();
}
/*---------------------------------------------------------------------------*/
/** @} */