contiki/platform/mbxxx/dev/temperature-sensor.c

114 lines
3.6 KiB
C

/*
* Copyright (c) 2010, STMicroelectronics.
* 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. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*
* This file is part of the Contiki OS
*
*/
/*---------------------------------------------------------------------------*/
/**
* \file
* Temperature sensor.
* \author
* Salvatore Pitrulli <salvopitru@users.sourceforge.net>
*/
/*---------------------------------------------------------------------------*/
/**
* NOTE:
* For the temperature measurement, the ADC extended range mode is needed;
* but this is inaccurate due to the high voltage mode bug of the general purpose ADC
* (see STM32W108 errata).
*/
#include PLATFORM_HEADER
#include BOARD_HEADER
#include "hal/error.h"
#include "hal/hal.h"
#include "micro/adc.h"
#include "dev/temperature-sensor.h"
/*---------------------------------------------------------------------------*/
static void
init(void)
{
halGpioConfig(TEMPERATURE_SENSOR_GPIO,GPIOCFG_ANALOG);
halInternalInitAdc();
halAdcSetRange(TRUE);
}
/*---------------------------------------------------------------------------*/
static int
value(int type)
{
static int16u ADCvalue;
static int16s volts;
halStartAdcConversion(ADC_USER_APP, ADC_REF_INT, ADC_SOURCE(halGetADCChannelFromGPIO(TEMPERATURE_SENSOR_GPIO),ADC_MUX_VREF2), ADC_CONVERSION_TIME_US_4096);
halReadAdcBlocking(ADC_USER_APP, &ADCvalue); // This blocks for a while, about 4ms.
// 100 uVolts
volts = halConvertValueToVolts(ADCvalue);
//return ((18641 - (int32s)volts)*100)/1171; // +- 0.23 degC in the range (-10;65) degC
return ((18663 - (int32s)volts)*100)/1169; // +- 0.004 degC in the range (20;30) degC
}
/*---------------------------------------------------------------------------*/
static int
configure(int type, int value)
{
switch(type){
case SENSORS_HW_INIT:
init();
return 1;
case SENSORS_ACTIVE:
return 1;
}
return 0;
}
/*---------------------------------------------------------------------------*/
static int
status(int type)
{
switch(type) {
case SENSORS_READY:
return 1;
}
return 0;
}
/*---------------------------------------------------------------------------*/
SENSORS_SENSOR(temperature_sensor, TEMPERATURE_SENSOR,
value, configure, status);