/*
* Copyright (c) 2012, BinaryLabs.
* 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.
*
* @(#)$Id: adc.c,v 1.1 2010/08/25 19:34:06 nifi Exp $
*/

/**
* \file
* ADC file for Atmega128rfa1.
* \author
* Paulo Louro <paulolouro@binarylabs.dk>
*/

#include "adc.h"

static uint8_t analog_reference = ADC_DEFAULT;

/*
 * For arduino interface for setting external reference voltage
 * Note that applying an external voltage *and* then setting the analog
 * reference to something internal will short the internal and the
 * external reference voltage and most likely destroy the processor.
 */
void analogReference(uint8_t mode)
{
    analog_reference = mode;
}

int readADC(uint8_t pin)
{
  int result = 0;

  adc_setup (analog_reference, pin);
  result = adc_read ();
  adc_fin ();
  return result;
}

/**
* \return Internal temperature in 0.01C, e.g. 25C is 2500
*/
int readInternalTemp(void)
{
  int reading = 0;

  ADCSRB |= _BV(MUX5);
  ADMUX = _BV(REFS1) | _BV(REFS0) | 0b1001 ;
  ADCSRA = _BV(ADEN) | _BV(ADPS0) | _BV(ADPS2) ;

  ADCSRA |= 1 << ADSC;
  loop_until_bit_is_clear(ADCSRA,ADSC);
  reading = ADC;

  ADCSRB=0; //disable ADC, need to write B first for MUX5 bit
  ADCSRA=0; //disable ADC
  ADMUX=0; //turn off internal vref

  return reading * 113 - 27280;
}