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/*********************************************************************
xBoard(TM) v2.0 Sample Programs
------------------------------------
Description : Demonstrate the use of ADC interfacing functions.
Author : Avinash Gupta
Web : www.eXtremeElectronics.co.in
Copyright 2008-2010 eXtreme Electronics, India
**********************************************************************/
#include <avr/io.h>
#include <util/delay.h>
#include "lcd.h"
void InitADC()
{
ADMUX=(1<<REFS0); // For Aref=AVcc;
ADCSRA=(1<<ADEN)|(1<<ADPS2)|(1<<ADPS1)|(1<<ADPS0); //Rrescalar div factor =128
}
uint16_t ReadADC(uint8_t ch)
{
//Select ADC Channel ch must be 0-7
ch=ch&0b00000111;
ADMUX|=ch;
//Start Single conversion
ADCSRA|=(1<<ADSC);
//Wait for conversion to complete
while(!(ADCSRA & (1<<ADIF)));
//Clear ADIF by writing one to it
//Note you may be wondering why we have write one to clear it
//This is standard way of clearing bits in io as said in datasheets.
//The code writes '1' but it result in setting bit to '0' !!!
ADCSRA|=(1<<ADIF);
return(ADC);
}
void Wait()
{
uint8_t i;
for(i=0;i<20;i++)
_delay_loop_2(0);
}
void main()
{
uint16_t adc_result;
//Wait for LCD to Startup
_delay_loop_2(0);
//Initialize LCD
LCDInit(LS_BLINK|LS_ULINE);
LCDClear();
//Initialize ADC
InitADC();
//Put some intro text into LCD
LCDWriteString("ADC Test");
LCDWriteStringXY(0,1,"ADC=");
while(1)
{
adc_result=ReadADC(0); // Read Analog value from channel-0
LCDWriteIntXY(4,1,adc_result,4); //Print the value in 4th column second line
Wait();
}
}
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