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142 lines
4.5 KiB
C
Executable File
142 lines
4.5 KiB
C
Executable File
/*! \file a2d.h \brief Analog-to-Digital converter function library. */
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//*****************************************************************************
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//
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// File Name : 'a2d.h'
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// Title : Analog-to-digital converter functions
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// Author : Pascal Stang - Copyright (C) 2002
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// Created : 4/08/2002
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// Revised : 4/30/2002
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// Version : 1.1
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// Target MCU : Atmel AVR series
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// Editor Tabs : 4
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//
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// This code is distributed under the GNU Public License
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// which can be found at http://www.gnu.org/licenses/gpl.txt
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//
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//*****************************************************************************
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#ifndef A2D_H
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#define A2D_H
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// defines
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// A2D clock prescaler select
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// *selects how much the CPU clock frequency is divided
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// to create the A2D clock frequency
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// *lower division ratios make conversion go faster
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// *higher division ratios make conversions more accurate
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#define ADC_PRESCALE_DIV2 0x00 ///< 0x01,0x00 -> CPU clk/2
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#define ADC_PRESCALE_DIV4 0x02 ///< 0x02 -> CPU clk/4
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#define ADC_PRESCALE_DIV8 0x03 ///< 0x03 -> CPU clk/8
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#define ADC_PRESCALE_DIV16 0x04 ///< 0x04 -> CPU clk/16
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#define ADC_PRESCALE_DIV32 0x05 ///< 0x05 -> CPU clk/32
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#define ADC_PRESCALE_DIV64 0x06 ///< 0x06 -> CPU clk/64
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#define ADC_PRESCALE_DIV128 0x07 ///< 0x07 -> CPU clk/128
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// default value
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#define ADC_PRESCALE ADC_PRESCALE_DIV64
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// do not change the mask value
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#define ADC_PRESCALE_MASK 0x07
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// A2D voltage reference select
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// *this determines what is used as the
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// full-scale voltage point for A2D conversions
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#define ADC_REFERENCE_AREF 0x00 ///< 0x00 -> AREF pin, internal VREF turned off
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#define ADC_REFERENCE_AVCC 0x01 ///< 0x01 -> AVCC pin, internal VREF turned off
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#define ADC_REFERENCE_RSVD 0x02 ///< 0x02 -> Reserved
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#define ADC_REFERENCE_256V 0x03 ///< 0x03 -> Internal 2.56V VREF
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// default value
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#define ADC_REFERENCE ADC_REFERENCE_AVCC
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// do not change the mask value
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#define ADC_REFERENCE_MASK 0xC0
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// bit mask for A2D channel multiplexer
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#define ADC_MUX_MASK 0x1F
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// channel defines (for reference and use in code)
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// these channels supported by all AVRs with A2D
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#define ADC_CH_ADC0 0x00
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#define ADC_CH_ADC1 0x01
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#define ADC_CH_ADC2 0x02
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#define ADC_CH_ADC3 0x03
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#define ADC_CH_ADC4 0x04
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#define ADC_CH_ADC5 0x05
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#define ADC_CH_ADC6 0x06
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#define ADC_CH_ADC7 0x07
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#define ADC_CH_122V 0x1E ///< 1.22V voltage reference
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#define ADC_CH_AGND 0x1F ///< AGND
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// these channels supported only in ATmega128
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// differential with gain
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#define ADC_CH_0_0_DIFF10X 0x08
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#define ADC_CH_1_0_DIFF10X 0x09
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#define ADC_CH_0_0_DIFF200X 0x0A
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#define ADC_CH_1_0_DIFF200X 0x0B
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#define ADC_CH_2_2_DIFF10X 0x0C
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#define ADC_CH_3_2_DIFF10X 0x0D
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#define ADC_CH_2_2_DIFF200X 0x0E
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#define ADC_CH_3_2_DIFF200X 0x0F
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// differential
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#define ADC_CH_0_1_DIFF1X 0x10
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#define ADC_CH_1_1_DIFF1X 0x11
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#define ADC_CH_2_1_DIFF1X 0x12
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#define ADC_CH_3_1_DIFF1X 0x13
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#define ADC_CH_4_1_DIFF1X 0x14
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#define ADC_CH_5_1_DIFF1X 0x15
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#define ADC_CH_6_1_DIFF1X 0x16
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#define ADC_CH_7_1_DIFF1X 0x17
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#define ADC_CH_0_2_DIFF1X 0x18
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#define ADC_CH_1_2_DIFF1X 0x19
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#define ADC_CH_2_2_DIFF1X 0x1A
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#define ADC_CH_3_2_DIFF1X 0x1B
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#define ADC_CH_4_2_DIFF1X 0x1C
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#define ADC_CH_5_2_DIFF1X 0x1D
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// compatibility for new Mega processors
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// ADCSR hack apparently no longer necessary in new AVR-GCC
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#ifdef ADCSRA
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#ifndef ADCSR
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#define ADCSR ADCSRA
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#endif
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#endif
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#ifdef ADATE
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#define ADFR ADATE
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#endif
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// function prototypes
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//! Initializes the A/D converter
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// (turns ADC on and prepares it for use)
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void a2dInit(void);
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//! Turn off A/D converter
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void a2dOff(void);
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//! sets the division ratio of the A/D converter clock
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// this function is automatically called from a2dInit()
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// with a default value
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void a2dSetPrescaler(unsigned char prescale);
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//! configures which voltage reference the A/D converter uses
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// this function is automatically called from a2dInit()
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// with a default value
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void a2dSetReference(unsigned char ref);
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//! sets the a2d input channel
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void a2dSetChannel(unsigned char ch);
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//! start a conversion on the current a2d input channel
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void a2dStartConvert(void);
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//! return TRUE if conversion is complete
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u08 a2dIsComplete(void);
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//! starts a conversion on A/D channel# ch,
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// returns the 10-bit value of the conversion when it is finished
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unsigned short a2dConvert10bit(unsigned char ch);
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//! starts a conversion on A/D channel# ch,
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// returns the 8-bit value of the conversion when it is finished
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unsigned char a2dConvert8bit(unsigned char ch);
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#endif
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