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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

u08 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

//@}