mirror of
https://github.com/oliverschmidt/contiki.git
synced 2024-11-19 03:05:14 +00:00
67bf9ec10e
- Removed some DOS EOLs - Changed some tabs to spaces - Removed some trailing whitespaces Closes #6
77 lines
2.9 KiB
C
77 lines
2.9 KiB
C
/*
|
|
* Copyright (c) 2010, University of Colombo School of Computing
|
|
* 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.
|
|
*
|
|
*/
|
|
|
|
#include <avr/io.h>
|
|
#include "dev/adc.h"
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
void
|
|
adc_init()
|
|
{
|
|
ADMUX = 0;
|
|
/* AVCC with external capacitor at AREF pin. */
|
|
ADMUX |= _BV(REFS0);
|
|
/* Disable ADC interrupts. */
|
|
ADCSRA &= ~( _BV(ADIE) | _BV(ADIF) );
|
|
/* Set ADC prescaler to 64 and clear interrupt flag. */
|
|
ADCSRA |= _BV(ADPS2) | _BV(ADPS1) | _BV(ADIE);
|
|
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
/* Poll based approach. The interrupt based adc is currently not used.
|
|
The ADC result is right adjusted. First 8 bits(from left) are in ADCL and
|
|
other two bits are in ADCH. See Atmega128 datasheet page 228. */
|
|
uint16_t
|
|
get_adc(int channel)
|
|
{
|
|
uint16_t reading;
|
|
|
|
ADMUX |= (channel & 0x1F);
|
|
|
|
/* Disable ADC interrupts. */
|
|
ADCSRA &= ~_BV(ADIE);
|
|
/* Clear previous interrupts. */
|
|
ADCSRA |= _BV(ADIF);
|
|
/* Enable ADC and start conversion. */
|
|
ADCSRA |= _BV(ADEN) | _BV(ADSC);
|
|
/* Wait until conversion is completed. */
|
|
while ( ADCSRA & _BV(ADSC) );
|
|
/* Get first 8 bits. */
|
|
reading = ADCL;
|
|
/* Get last two bits. */
|
|
reading |= (ADCH & 3) << 8;
|
|
/* Disable ADC. */
|
|
ADCSRA &= ~_BV(ADEN);
|
|
return reading;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|