adc.h

Go to the documentation of this file.

/*
 * Copyright (c) 2012, TU Braunschweig.
 * 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 driver definitions
 * \author
 *      Ulf Kulau <kulau@ibr.cs.tu-bs.de>
 */

/**
 * \addtogroup inga_sensors_driver
 * @{
 */

/**
 * \defgroup adc_driver Analog Digital Converter (internal ADC)
 *
 * <p>The ATmega1284p has 8 ADC-channels. You can run the ADC in
 *    different modes like just "single coversion", "free running" or
 *    "auto triggered" by timer or interrupts. Moreover it is possible
 *    to get differential values of two ADC-channels (with or without
 *    a gain factor)</p>
 * @{
 *
 */

#ifndef ADCCTR_H_
#define ADCCTR_H_

#include <avr/io.h>


/********************************************************************
 * ADC mode:
 ********************************************************************/
/**
 * \name ADC modes
 * @{ */
/*!
 * mode: ADC Single Conversion
 * \note The ADC will make just one conversion cycle (normal use)
 */
#define ADC_SINGLE_CONVERSION   0xFF
/*!
 * mode: ADC Free Running Mode
 * \note The ADC runs all the time. An interrupt occurs whenever one ADC cycle
 * will finish
 */
#define ADC_FREE_RUNNING                0x00
/*!
 * mode: ADC Analog Comparator
 * \note Sets the ADC to comparator mode.
 */
#define ADC_ANALOG_COMPARATOR   (1 << ADTS0)
/*!
 * mode: External Interrupt Trigger
 * \note Enables the auto trigger mode. The ADC will start a conversion, whenever
 * changes on external interrupt will occur.
 */
#define ADC_EXT_INTERRUPT               (1 << ADTS1)
/*!
 * mode: Timer0 Compare Flag Trigger
 * \note Enables the auto trigger mode. The ADC will start a conversion, whenever
 * Timer0 Compare Flag is set.
 */
#define ADC_TIMER0_COMP_FLAG    ((1 << ADTS1) | (1 << ADTS0))
/*!
 * mode: Timer0 Compare Flag Trigger
 * \note Enables the auto trigger mode. The ADC will start a conversion, whenever
 * Timer0 overflow occurs.
 */
#define ADC_TIMER0_OVERFLOW             (1 << ADTS2)
/*!
 * mode: Timer1 Compare Flag Trigger
 * \note Enables the auto trigger mode. The ADC will start a conversion, whenever
 * Timer0 Compare Flag is set.
 */
#define ADC_TIMER1_COMP_FLAG    ((1 << ADTS2) | (1 << ADTS0))
/*!
 * mode: Timer1 Compare Flag Trigger
 * \note Enables the auto trigger mode. The ADC will start a conversion, whenever
 * Timer0 overflow occurs.
 */
#define ADC_TIMER1_OVERFLOW             ((1 << ADTS2) | (1 << ADTS1))
/*!
 * mode: Timer1 Compare Flag Trigger
 * \note Enables the auto trigger mode. The ADC will start a conversion, whenever
 * Timer0 Capture Flag is set.
 */
#define ADC_TIMER1_CAPTURE              ((1 << ADTS2) | (1 << ADTS1) | (1 << ADTS0))
/** @} */

/********************************************************************
 * ADC reference voltage source:
 ********************************************************************/

/**
 * \name ADC reference voltage sources
 * @{ */
/*!
 * ref: External Reference Voltage (Aref)
 * \note The ADC reference voltage is provided by the external reference pin Aref
 */
#define ADC_REF_AREF                    0
/*!
 * ref: Supply Voltage Reference (AVcc)
 * \note The ADC reference voltage is provided by the supply voltage.
 */
#define ADC_REF_AVCC                    (1 << REFS0)
/*!
 * ref: Internal 1.1V Reference
 * \note The ADC reference voltage is provided by internal 1.1V
 */
#define ADC_REF_1100MV_INT      (1 << REFS1)
/*!
 * ref: Internal 2.56V Reference
 * \note The ADC reference voltage is provided by internal 2.56V
 */
#define ADC_REF_2560MV_INT      ((1 << REFS1)| (1 << REFS0))
/** @} */


/**
 * \name ADMUX - ADC Multiplexer Selection Register
 * \{ */
#define ADC_CHANNEL_0                   0x00
#define ADC_CHANNEL_1                   0x01
#define ADC_CHANNEL_2                   0x02
#define ADC_CHANNEL_3                   0x03
#define ADC_CHANNEL_4                   0x04
#define ADC_CHANNEL_5                   0x05
#define ADC_CHANNEL_6                   0x06
#define ADC_CHANNEL_7                   0x07

#define ADC_DIFF_ADC0_ADC0_10X  0x08
#define ADC_DIFF_ADC1_ADC0_10X  0x09
#define ADC_DIFF_ADC0_ADC0_200X 0x0A
#define ADC_DIFF_ADC1_ADC0_200X 0x0B
#define ADC_DIFF_ADC2_ADC2_10X  0x0C
#define ADC_DIFF_ADC3_ADC2_10X  0x0D
#define ADC_DIFF_ADC2_ADC2_200X 0x0E
#define ADC_DIFF_ADC3_ADC2_200X 0x0F
#define ADC_DIFF_ADC0_ADC1_1X   0x10
#define ADC_DIFF_ADC1_ADC1_1X   0x11
#define ADC_DIFF_ADC2_ADC1_1X   0x12
#define ADC_DIFF_ADC3_ADC1_1X   0x13
#define ADC_DIFF_ADC4_ADC1_1X   0x14
#define ADC_DIFF_ADC5_ADC1_1X   0x15
#define ADC_DIFF_ADC6_ADC1_1X   0x16
#define ADC_DIFF_ADC7_ADC1_1X   0x17
#define ADC_DIFF_ADC0_ADC2_1X   0x18
#define ADC_DIFF_ADC1_ADC2_1X   0x19
#define ADC_DIFF_ADC2_ADC2_1X   0x1A
#define ADC_DIFF_ADC3_ADC2_1X   0x1B
#define ADC_DIFF_ADC4_ADC2_1X   0x1C
/** \} */

/*
 * ADCSRA - ADC control and status register A
 * \cond
 */
#define ADC_ENABLE                              (1 << ADEN)

#define ADC_START                               (1 << ADSC)
#define ADC_STOP                                0x00

#define ADC_LEFT_ADJUSTED               (1 << ADLAR)
#define ADC_RIGHT_ADJUSTED      (0 << ADLAR)

#define ADC_TRIGGER_ENABLE              (1 << ADATE)
#define ADC_TRIGGER_DISABLE             (0 << ADATE)

#define ADC_INTERRUPT_ENABLE    (1 << ADIE)
#define ADC_INTERRUPT_DISABLE   (0 << ADIE)

#define ADC_PRESCALE_2                  (1 << ADPS0)
#define ADC_PRESCALE_4                  (1 << ADPS1)
#define ADC_PRESCALE_8                  ((1 << ADPS0) | (1 << ADPS1))
#define ADC_PRESCALE_16                 (1 << ADPS2)
#define ADC_PRESCALE_32                 ((1 << ADPS2) | (1 << ADPS0))
#define ADC_PRESCALE_64                 ((1 << ADPS2) | (1 << ADPS1))   /*choose this for F_CPU = 8MHZ*/
#define ADC_PRESCALE_128                ((1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0))
/*
 * \endcond
 */


/**
 * \brief      Initialize the ADC module
 *
 * \note This routine performes a pre-check whether the AREF pin
 * is connected. It aborts initialization if AREF pin is connected but 
 * internal reference is chosen.
 *
 * \param mode Select an ADC mode like single conversion or free running, etc.
 * \param ref  The ADC reference voltage source.
 * \retval 0 succeeded
 * \retval 1 failed
 *
 */
void adc_init(uint8_t mode, uint8_t ref);

/**
 * \brief      This function returns the ADC data register
 *             value. Use adc_set_mux to preselect the ADC-channel
 *             or differential input.
 *
 * \return     The ADC-value of preselected mux
 *
 */
uint16_t adc_get_value(void);

/**
 * \brief      This function returns the ADC data register
 *             value of the given ADC channel.
 *
 * \param chn  The ADC channel (ADC0 ... ADC7)
 *
 * \return     The ADC-value
 *
 *                         This function is more efficient for the single
 *                         conversion mode. Just select the ADC channel (or
 *                         differential settings) and get the result.
 */
uint16_t adc_get_value_from(uint8_t chn);

/**
 * \brief      With this function you can set the ADX multiplexer.
 *                         Here you select the ADC channel or choose differential
 *             value between two ADC-channels with or without gain.
 *
 * \param mux  Select single ADC channel (ADC_CHANNEL_0 ... ADC_CHANNEL_7)
 *             or differential input of various ADC-channels with or
 *             without gain
 *
 */
void adc_set_mux(uint8_t mux);

/**
 * \brief      This function stops all running ADC
 *
 */
void adc_deinit(void);

/** @} */
/** @} */

#endif /* ADCCTR_H_ */