ADC with AVR

ADC: Analog to digital Converter:

 In ATMEGA16/32, PORTA contains the ADC pins. Some other features of the ADC are as follows:

• 8 channel implies that there are 8 ADC pins are multiplexed together. You can easily see that these pins are located across PORTA (PA0…PA7).
• 10 bit resolution implies that there are 2^10 = 1024 steps (as described below).

• ADC Registers – ADMUX, ADCSRA, ADCH, ADCL. 

1) ADMUX Register:

Program on ADC potentiometer:

First Method:

#include<avr/io.h>

#include<util/delay.h>

#include<stdio.h>

unsigned long int temp;

char res[4];

void datta(unsigned char a)

{

PORTD=a;

PORTB=0x05;

_delay_ms(30);

PORTB=0x01;

}

void command(unsigned char s)

{

PORTD=s;

PORTB=0x04;

_delay_ms(30);

PORTB=0x00;

}

void init()

{

command(0x38);

_delay_ms(100);

command(0x01);

_delay_ms(100);

command(0x0E);

_delay_ms(100);

command(0x80);

_delay_ms(100);

}

void stringg(unsigned char *p)

{

while(*p!='\0')

{

datta(*p);

p++;

}

}

void main()

{

unsigned int x;

ADMUX=0x40;

DDRD=0xFF;

DDRB=0xFF;

init();

while(1)

{

ADCSRA=((1<<ADEN)|(1<<ADSC)|(1<<ADIF));

while((ADCSRA&(1<<ADIF))==0);

temp=ADC;

sprintf(res,"%d",temp/10);

stringg(res);

_delay_ms(1000);

command(0x01);

_delay_ms(100);

}

}

Simulation for  Program:

Second Method:

#include<avr/io.h>
#include<util/delay.h>


void datta(unsigned char a)
{
PORTD=a;
PORTB=0x05;
_delay_ms(30);
PORTB=0x01;
}
void command(unsigned char s)
{
PORTD=s;
PORTB=0x04;
_delay_ms(30);
PORTB=0x00;
}
void init()
{
command(0x38);
_delay_ms(100);
command(0x01);
_delay_ms(100);
command(0x0E);
_delay_ms(100);
command(0x80);
_delay_ms(100);
}
void stringg(unsigned char *p)
{
while(*p!='\0')
{
datta(*p);
p++;
}
}
void num(unsigned int i)
{
int j=1,k,l;
k=i;
while(k>=9)
{
j=j*10;
k=k/10;
}
while(j>=1)
{
l=i/j;
i=i%j;
j=j/10;
datta(l+48);
}
}


void main()
{
unsigned int x;
ADMUX=0x40;
DDRD=0xFF;
DDRB=0xFF;
init();
while(1)
{
ADCSRA=((1<<ADEN)|(1<<ADSC)|(1<<ADIF));
while((ADCSRA&(1<<ADIF))==0);
x=ADC;
num(x);
_delay_ms(1000);
command(0x01);
_delay_ms(100);
}
}

Simulation for  Program:

Program on ADC (temperature Sensor):

First Method:

#include<avr/io.h>

#include<util/delay.h>

#include<stdio.h>

unsigned long int temp;

char res[4];

void datta(unsigned char a)

{

PORTD=a;

PORTB=0x05;

_delay_ms(30);

PORTB=0x01;

}

void command(unsigned char s)

{

PORTD=s;

PORTB=0x04;

_delay_ms(30);

PORTB=0x00;

}

void init()

{

command(0x38);

_delay_ms(100);

command(0x01);

_delay_ms(100);

command(0x0E);

_delay_ms(100);

command(0x80);

_delay_ms(100);

}

void stringg(unsigned char *p)

{

while(*p!='\0')

{

datta(*p);

p++;

}

}

void main()

{

unsigned int x;

ADMUX=0x40;

DDRD=0xFF;

DDRB=0xFF;

init();

while(1)

{

ADCSRA=((1<<ADEN)|(1<<ADSC)|(1<<ADIF));

while((ADCSRA&(1<<ADIF))==0);

temp=ADC;

sprintf(res,"%d",temp/2);

stringg(res);

_delay_ms(1000);

command(0x01);

_delay_ms(100);

}

}

Simulation for  Program:

Second Method:

#include<avr/io.h>

#include<util/delay.h>

#include"lcd_header.h"

void datta(unsigned char a)

{

PORTD=a;

PORTB=0x05;

_delay_ms(30);

PORTB=0x01;

}

void command(unsigned char s)

{

PORTD=s;

PORTB=0x04;

_delay_ms(30);

PORTB=0x00;

}

void init()

{

command(0x38);

_delay_ms(100);

command(0x01);

_delay_ms(100);

command(0x0E);

_delay_ms(100);

command(0x80);

_delay_ms(100);

}

void stringg(unsigned char *p)

{

while(*p!='\0')

{

datta(*p);

p++;

}

}

void num(unsigned int i)

{

int j=1,k,l;

k=i;

while(k>=9)

{

j=j*10;

k=k/10;

}

while(j>=1)

{

l=i/j;

i=i%j;

j=j/10;

datta(l+48);

}

}

void main()

{

unsigned int x;

ADMUX=0x40;

DDRD=0xFF;

DDRB=0xFF;

init();

while(1)

{

ADCSRA=0xE7;

while((ADCSRA&(1<<ADIF))==0);

x=ADC/2;

num(x);

_delay_ms(1000);

command(0x01);

_delay_ms(100);

}

}

Simulation for  Program: