osd-contiki/platform/cc2530dk/dev/adc-sensor.c

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/*
* Copyright (c) 2011, George Oikonomou - <oikonomou@users.sourceforge.net>
* 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.
*
* This file is part of the Contiki operating system.
*/
/**
* \file
* ADC sensor module for TI SmartRF05EB devices.
*
* \author
* George Oikonomou - <oikonomou@users.sourceforge.net>
*/
#include "sfr-bits.h"
#include "cc253x.h"
#include "adc-sensor.h"
#if ADC_SENSOR_ON
/*---------------------------------------------------------------------------*/
static int
value(int type)
{
uint16_t reading;
/*
* For single-shot AD conversions, we may only write to ADCCON3[3:0] once
* (This write triggers the conversion). We thus use the variable 'command'
* to store intermediate steps (reference, decimation rate, input channel)
*/
uint8_t command;
/* 1.25V ref, max decimation rate */
command = ADCCON3_EDIV1 | ADCCON3_EDIV0;
/* Clear the Interrupt Flag */
ADCIF = 0;
/* Depending on the desired reading, append the input bits to 'command' and
* enable the corresponding input channel in ADCCFG if necessary */
switch(type) {
#if TEMP_SENSOR_ON
case ADC_SENSOR_TYPE_TEMP:
command |= ADCCON3_ECH3 | ADCCON3_ECH2 | ADCCON3_ECH1;
break;
#endif
#if VDD_SENSOR_ON
case ADC_SENSOR_TYPE_VDD:
command |= ADCCON3_ECH3 | ADCCON3_ECH2 | ADCCON3_ECH1 | ADCCON3_ECH0;
break;
#endif
default:
/* If the sensor is not present or disabled in conf, return -1 */
return -1;
}
/* Writing in bits 3:0 of ADCCON3 will trigger a single conversion */
ADCCON3 = command;
/*
* When the conversion is complete, the ADC interrupt flag is set. We don't
* use an ISR here, we just wait on the flag and clear it afterwards.
*/
while(!ADCIF);
/* Clear the Interrupt Flag */
ADCIF = 0;
reading = ADCL;
reading |= (((uint8_t) ADCH) << 8);
/* 12-bit decimation rate: 4 LS bits are noise */
reading >>= 4;
return reading;
}
/*---------------------------------------------------------------------------*/
static int
status(int type)
{
return 1;
}
/*---------------------------------------------------------------------------*/
static int
configure(int type, int value)
{
switch(type) {
case SENSORS_HW_INIT:
#if TEMP_SENSOR_ON
/* Connect temperature sensor to the SoC */
ATEST = 1;
TR0 = 1;
#endif
APCFG = 0; /* Disables Input Channels */
break;
}
return 1;
}
/*---------------------------------------------------------------------------*/
SENSORS_SENSOR(adc_sensor, ADC_SENSOR, value, configure, status);
#endif /* ADC_SENSOR_ON */