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/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
2011 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS/RT is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* TMP75 is most simple I2C device in our case. It is already useful with
* default settings after powerup.
* You only must read 2 sequential bytes from it.
*/
#include <stdlib.h>
#include "ch.h"
#include "hal.h"
#include "tmp75.h"
/* input buffer */
static uint8_t tmp75_rx_data[TMP75_RX_DEPTH];
/* temperature value */
static int16_t temperature = 0;
static i2cflags_t errors = 0;
#define tmp75_addr 0b1001000
/* This is main function. */
void request_temperature(void){
int16_t t_int = 0, t_frac = 0;
msg_t status = RDY_OK;
systime_t tmo = MS2ST(4);
i2cAcquireBus(&I2CD1);
status = i2cMasterReceiveTimeout(&I2CD1, tmp75_addr, tmp75_rx_data, 2, tmo);
i2cReleaseBus(&I2CD1);
if (status != RDY_OK){
errors = i2cGetErrors(&I2CD1);
}
t_int = tmp75_rx_data[0] * 100;
t_frac = (tmp75_rx_data[1] * 100) >> 8;
temperature = t_int + t_frac;
}
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