0,0 → 1,115 |
/*! \file a2d.c \brief Analog-to-Digital converter function library. */ |
//***************************************************************************** |
// |
// File Name : 'a2d.c' |
// Title : Analog-to-digital converter functions |
// Author : Pascal Stang - Copyright (C) 2002 |
// Created : 2002-04-08 |
// Revised : 2002-09-30 |
// 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 |
// |
//***************************************************************************** |
|
#include <avr/io.h> |
#include <avr/interrupt.h> |
|
#include "global.h" |
#include "a2d.h" |
|
// global variables |
|
//! Software flag used to indicate when |
/// the a2d conversion is complete. |
volatile unsigned char a2dCompleteFlag; |
|
// functions |
|
// initialize a2d converter |
void a2dInit(void) |
{ |
sbi(ADCSR, ADEN); // enable ADC (turn on ADC power) |
cbi(ADCSR, ADFR); // default to single sample convert mode |
a2dSetPrescaler(ADC_PRESCALE); // set default prescaler |
a2dSetReference(ADC_REFERENCE); // set default reference |
cbi(ADMUX, ADLAR); // set to right-adjusted result |
|
sbi(ADCSR, ADIE); // enable ADC interrupts |
|
a2dCompleteFlag = FALSE; // clear conversion complete flag |
sei(); // turn on interrupts (if not already on) |
} |
|
// turn off a2d converter |
void a2dOff(void) |
{ |
cbi(ADCSR, ADIE); // disable ADC interrupts |
cbi(ADCSR, ADEN); // disable ADC (turn off ADC power) |
} |
|
// configure A2D converter clock division (prescaling) |
void a2dSetPrescaler(unsigned char prescale) |
{ |
outb(ADCSR, ((inb(ADCSR) & ~ADC_PRESCALE_MASK) | prescale)); |
} |
|
// configure A2D converter voltage reference |
void a2dSetReference(unsigned char ref) |
{ |
outb(ADMUX, ((inb(ADMUX) & ~ADC_REFERENCE_MASK) | (ref<<6))); |
} |
|
// sets the a2d input channel |
void a2dSetChannel(unsigned char ch) |
{ |
outb(ADMUX, (inb(ADMUX) & ~ADC_MUX_MASK) | (ch & ADC_MUX_MASK)); // set channel |
} |
|
// start a conversion on the current a2d input channel |
void a2dStartConvert(void) |
{ |
sbi(ADCSR, ADIF); // clear hardware "conversion complete" flag |
sbi(ADCSR, ADSC); // start conversion |
} |
|
// return TRUE if conversion is complete |
u08 a2dIsComplete(void) |
{ |
return bit_is_set(ADCSR, ADSC); |
} |
|
// Perform a 10-bit conversion |
// starts conversion, waits until conversion is done, and returns result |
unsigned short a2dConvert10bit(unsigned char ch) |
{ |
a2dCompleteFlag = FALSE; // clear conversion complete flag |
outb(ADMUX, (inb(ADMUX) & ~ADC_MUX_MASK) | (ch & ADC_MUX_MASK)); // set channel |
sbi(ADCSR, ADIF); // clear hardware "conversion complete" flag |
sbi(ADCSR, ADSC); // start conversion |
//while(!a2dCompleteFlag); // wait until conversion complete |
//while( bit_is_clear(ADCSR, ADIF) ); // wait until conversion complete |
while( bit_is_set(ADCSR, ADSC) ); // wait until conversion complete |
|
// CAUTION: MUST READ ADCL BEFORE ADCH!!! |
return (inb(ADCL) | (inb(ADCH)<<8)); // read ADC (full 10 bits); |
} |
|
// Perform a 8-bit conversion. |
// starts conversion, waits until conversion is done, and returns result |
unsigned char a2dConvert8bit(unsigned char ch) |
{ |
// do 10-bit conversion and return highest 8 bits |
return a2dConvert10bit(ch)>>2; // return ADC MSB byte |
} |
|
//! Interrupt handler for ADC complete interrupt. |
SIGNAL(SIG_ADC) |
{ |
// set the a2d conversion flag to indicate "complete" |
a2dCompleteFlag = TRUE; |
} |
|
Property changes: |
Added: svn:executable |
+* |
\ No newline at end of property |