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/*! \file a2d.h \brief Analog-to-Digital converter function library. */
//*****************************************************************************
//
// File Name : 'a2d.h'
// Title : Analog-to-digital converter functions
// Author : Pascal Stang - Copyright (C) 2002
// Created : 4/08/2002
// Revised : 4/30/2002
// Version : 1.1
// Target MCU : Atmel AVR series
// Editor Tabs : 4
//
// This code is distributed under the GNU Public License
// which can be found at http://www.gnu.org/licenses/gpl.txt
//
/// \ingroup driver_avr
/// \defgroup a2d A/D Converter Function Library (a2d.c)
/// \code #include "a2d.h" \endcode
/// \par Overview
/// This library provides an easy interface to the analog-to-digital
/// converter available on many AVR processors. Updated to support
/// the ATmega128.
//
//****************************************************************************
//@{
#ifndef A2D_H
#define A2D_H
// defines
// A2D clock prescaler select
// *selects how much the CPU clock frequency is divided
// to create the A2D clock frequency
// *lower division ratios make conversion go faster
// *higher division ratios make conversions more accurate
#define ADC_PRESCALE_DIV2 0x00 ///< 0x01,0x00 -> CPU clk/2
#define ADC_PRESCALE_DIV4 0x02 ///< 0x02 -> CPU clk/4
#define ADC_PRESCALE_DIV8 0x03 ///< 0x03 -> CPU clk/8
#define ADC_PRESCALE_DIV16 0x04 ///< 0x04 -> CPU clk/16
#define ADC_PRESCALE_DIV32 0x05 ///< 0x05 -> CPU clk/32
#define ADC_PRESCALE_DIV64 0x06 ///< 0x06 -> CPU clk/64
#define ADC_PRESCALE_DIV128 0x07 ///< 0x07 -> CPU clk/128
// default value
#define ADC_PRESCALE ADC_PRESCALE_DIV64
// do not change the mask value
#define ADC_PRESCALE_MASK 0x07
// A2D voltage reference select
// *this determines what is used as the
// full-scale voltage point for A2D conversions
#define ADC_REFERENCE_AREF 0x00 ///< 0x00 -> AREF pin, internal VREF turned off
#define ADC_REFERENCE_AVCC 0x01 ///< 0x01 -> AVCC pin, internal VREF turned off
#define ADC_REFERENCE_RSVD 0x02 ///< 0x02 -> Reserved
#define ADC_REFERENCE_256V 0x03 ///< 0x03 -> Internal 2.56V VREF
// default value
#define ADC_REFERENCE ADC_REFERENCE_AVCC
// do not change the mask value
#define ADC_REFERENCE_MASK 0xC0
// bit mask for A2D channel multiplexer
#define ADC_MUX_MASK 0x1F
// channel defines (for reference and use in code)
// these channels supported by all AVRs with A2D
#define ADC_CH_ADC0 0x00
#define ADC_CH_ADC1 0x01
#define ADC_CH_ADC2 0x02
#define ADC_CH_ADC3 0x03
#define ADC_CH_ADC4 0x04
#define ADC_CH_ADC5 0x05
#define ADC_CH_ADC6 0x06
#define ADC_CH_ADC7 0x07
#define ADC_CH_122V 0x1E ///< 1.22V voltage reference
#define ADC_CH_AGND 0x1F ///< AGND
// these channels supported only in ATmega128
// differential with gain
#define ADC_CH_0_0_DIFF10X 0x08
#define ADC_CH_1_0_DIFF10X 0x09
#define ADC_CH_0_0_DIFF200X 0x0A
#define ADC_CH_1_0_DIFF200X 0x0B
#define ADC_CH_2_2_DIFF10X 0x0C
#define ADC_CH_3_2_DIFF10X 0x0D
#define ADC_CH_2_2_DIFF200X 0x0E
#define ADC_CH_3_2_DIFF200X 0x0F
// differential
#define ADC_CH_0_1_DIFF1X 0x10
#define ADC_CH_1_1_DIFF1X 0x11
#define ADC_CH_2_1_DIFF1X 0x12
#define ADC_CH_3_1_DIFF1X 0x13
#define ADC_CH_4_1_DIFF1X 0x14
#define ADC_CH_5_1_DIFF1X 0x15
#define ADC_CH_6_1_DIFF1X 0x16
#define ADC_CH_7_1_DIFF1X 0x17
#define ADC_CH_0_2_DIFF1X 0x18
#define ADC_CH_1_2_DIFF1X 0x19
#define ADC_CH_2_2_DIFF1X 0x1A
#define ADC_CH_3_2_DIFF1X 0x1B
#define ADC_CH_4_2_DIFF1X 0x1C
#define ADC_CH_5_2_DIFF1X 0x1D
// compatibility for new Mega processors
// ADCSR hack apparently no longer necessary in new AVR-GCC
#ifdef ADCSRA
#ifndef ADCSR
#define ADCSR ADCSRA
#endif
#endif
#ifdef ADATE
#define ADFR ADATE
#endif
// function prototypes
//! Initializes the A/D converter.
/// Turns ADC on and prepares it for use.
void a2dInit(void);
//! Turn off A/D converter
void a2dOff(void);
//! Sets the division ratio of the A/D converter clock.
/// This function is automatically called from a2dInit()
/// with a default value.
void a2dSetPrescaler(unsigned char prescale);
//! Configures which voltage reference the A/D converter uses.
/// This function is automatically called from a2dInit()
/// with a default value.
void a2dSetReference(unsigned char ref);
//! sets the a2d input channel
void a2dSetChannel(unsigned char ch);
//! start a conversion on the current a2d input channel
void a2dStartConvert(void);
//! return TRUE if conversion is complete
uint8_t a2dIsComplete(void);
//! Starts a conversion on A/D channel# ch,
/// returns the 10-bit value of the conversion when it is finished.
unsigned short a2dConvert10bit(unsigned char ch);
//! Starts a conversion on A/D channel# ch,
/// returns the 8-bit value of the conversion when it is finished.
unsigned char a2dConvert8bit(unsigned char ch);
#endif
//@}
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