A/D Converter Function Library (a2d.c)
[Drivers (for AVR peripherals)]

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Detailed Description

 #include "a2d.h" 

Overview

This library provides an easy interface to the analog-to-digital converter available on many AVR processors. Updated to support the ATmega128.

Defines
#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
#define	ADC_PRESCALE   ADC_PRESCALE_DIV64
#define	ADC_PRESCALE_MASK   0x07
#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
#define	ADC_REFERENCE   ADC_REFERENCE_AVCC
#define	ADC_REFERENCE_MASK   0xC0
#define	ADC_MUX_MASK   0x1F
#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.
#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
#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
Functions
void	a2dInit (void)
void	a2dOff (void)
	Turn off A/D converter.
void	a2dSetPrescaler (unsigned char prescale)
void	a2dSetReference (unsigned char ref)
void	a2dSetChannel (unsigned char ch)
	sets the a2d input channel
void	a2dStartConvert (void)
	start a conversion on the current a2d input channel
u08	a2dIsComplete (void)
	return TRUE if conversion is complete
unsigned short	a2dConvert10bit (unsigned char ch)
unsigned char	a2dConvert8bit (unsigned char ch)

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Function Documentation

unsigned short a2dConvert10bit (  unsigned char  ch  )

Starts a conversion on A/D channel# ch, returns the 10-bit value of the conversion when it is finished. Definition at line 87 of file a2d.c.

unsigned char a2dConvert8bit (  unsigned char  ch  )

Starts a conversion on A/D channel# ch, returns the 8-bit value of the conversion when it is finished. Definition at line 103 of file a2d.c.

void a2dInit (  void   )

Initializes the A/D converter. Turns ADC on and prepares it for use. Definition at line 33 of file a2d.c.

void a2dSetPrescaler (  unsigned char  prescale  )

Sets the division ratio of the A/D converter clock. This function is automatically called from a2dInit() with a default value. Definition at line 55 of file a2d.c.

void a2dSetReference (  unsigned char  ref  )

Configures which voltage reference the A/D converter uses. This function is automatically called from a2dInit() with a default value. Definition at line 61 of file a2d.c.

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