#include <avr/io.h>
#include <stdio.h>
#include <avr/interrupt.h>
#include <util/delay.h>
//system clock @1MHz
#define F_CPU 1000000
//Global variable
int adc_result[3]={0,0,0};//for storing the adc out put
uint8_t ch=0;
/* PORT INIT */
void port_init (void)
{
//set portB.1 as output drive for relay
DDRB |=(1<<PB1);
PORTB&=~(1<<PB1);
//set portC0-4 as input and enable the pull up resistor
DDRC &=~((1<<PC0)|(1<<PC1)|(1<<PC2)|(1<<PC3)|(1<<PC4));// ADC i/p R,B,Y & Gnd, neutral
PORTC |=((1<<PC0)|(1<<PC1)|(1<<PC2)|(1<<PC3)|(1<<PC4));
//set up port D 0-3 as output
DDRD &=~((1<<PD0)|(1<<PD1)|(1<<PD2)|(1<<PD3));//o/p led for R,B,Y and GLP
}
void init_adc(void)
{
// Set ADC prescaler to 8 - 125KHz sample rate @ 1MHz
ADCSRA |= ((1 << ADPS1) | (1 << ADPS0));
// Enable ADC Interrupt
ADCSRA |= (1 << ADIE);
// Enable ADC
ADCSRA |= (1 << ADEN);
// Enable Global Interrupts
sei();
ADCSRA |= (1<<ADSC);
}
/* Interrupt service routine for Analog comparator*/
ISR(ANA_COMP)
{
}
/* Interrupt service routines */
ISR(ADC_vect)
{
//delay for discarding first conversion result
//_delay_ms(10);
//Read the adc result
switch(ch)
{
case 0:
{
adc_result[0]=ADCW;
if(adc_result[0]>823) //checking for vge >265V
{
do
{
PORTD|=(1<<PD0);//glow the led corresponding to signal 1
_delay_ms(3);
//Start next conversion with same channel
ADCSRA |= (1<<ADSC);
//wait for coversion to be completed
while (!(ADCSRA & (1<<ADIF)));
adc_result[0]=ADCW;
if(adc_result[0]>837) //checking for vge >270V
{
do
{
ADCSRA |= (1<<ADSC);
//wait for coversion to be completed
while (!(ADCSRA & (1<<ADIF)));
adc_result[0]=ADCW;
PORTB|=(1<<PB1);// o/p drive ON if the state at adc0 exist for a particular time
}while (adc_result[0]<823);//do until the vge reduced to 265V
}
}while(adc_result[0]>823);
PORTD&=~(1<<PD0);//off the led corresponding to signal 1
PORTB&=~(1<<PB1);// o/p drive off for ON the relay
}
else if (adc_result[0]<713)//checking for vge <230V
{
do
{
PORTD|=(1<<PD3);//glow the led corresponding to UV indication
ADCSRA |= (1<<ADSC);
//wait for coversion to be completed
while (!(ADCSRA & (1<<ADIF)));
adc_result[0]=ADCW;
}while(adc_result[0]<713);//do until vge >230V
PORTD&=~(1<<PD3);//off the led corresponding to UV indication
}
else
{
if(ch<3)
{
ch++;//change adc channel
ADMUX=ch;
}
}
break;
}
case 1:
{
adc_result[1]=ADCW;
if(adc_result[1]>823)//checking for vge >265V
{
do
{
PORTD|=(1<<PD1);//glow the led corresponding to signal 2
//Start next conversion with same channel
_delay_ms(3);
ADCSRA |= (1<<ADSC);
//wait for coversion to be completed
while (!(ADCSRA & (1<<ADIF)));
adc_result[0]=ADCW;
if(adc_result[0]>837) //checking for vge >270V
{
do
{
ADCSRA |= (1<<ADSC);
//wait for coversion to be completed
while (!(ADCSRA & (1<<ADIF)));
adc_result[0]=ADCW;
PORTB|=(1<<PB1);// o/p drive if the state at adc1 exist for a particular time
}while (adc_result[1]>862);
}
}while(adc_result[1]>823);
PORTD|=(1<<PD1);//off the led corresponding to signal 2
PORTB&=~(1<<PB1);// o/p drive off for ON the relay
}
else if(adc_result[1]<713)//checking for vge <230V
{
do
{
PORTD|=(1<<PD3);//glow the led corresponding to UV indication
ADCSRA |= (1<<ADSC);
//wait for coversion to be completed
while (!(ADCSRA & (1<<ADIF)));
adc_result[0]=ADCW;
}while(adc_result[0]<713);//do until vge >230V
PORTD&=~(1<<PD3);//off the led corresponding to UV indication
}
else
{
if(ch<3)
{
ch++;
ADMUX=ch;
}
}
break;
}
case 2:
{
adc_result[2]=ADCW;
//Start next conversion
ADCSRA |= (1<<ADSC);
if(adc_result[2]>862)//checking for vge >265V
{
do
{
PORTD|=(1<<PD2);//glow the led corresponding to signal 3
//Start next conversion with same channel
_delay_ms(3);
ADCSRA |= (1<<ADSC);
//wait for coversion to be completed
while (!(ADCSRA & (1<<ADIF)));
adc_result[0]=ADCW;
if(adc_result[2]>837) //checking for vge >270V
{
do
{
ADCSRA |= (1<<ADSC);
//wait for coversion to be completed
while (!(ADCSRA & (1<<ADIF)));
adc_result[0]=ADCW;
PORTB|=(1<<PB1);// o/p drive if the state at adc2 exist for a particular time
}while (adc_result[2]<862);
}
}while(adc_result[2]<862);
PORTD|=(1<<PD2);//glow the led corresponding to signal 3
PORTB&=~(1<<PB1);// o/p drive off for ON the relay
}
else if(adc_result[2]<713)//checking for vge <230V
{
do
{
PORTD|=(1<<PD3);//glow the led corresponding to UV indication
ADCSRA |= (1<<ADSC);
//wait for coversion to be completed
while (!(ADCSRA & (1<<ADIF)));
adc_result[0]=ADCW;
}while(adc_result[0]<713);
PORTD&=~(1<<PD3);//off the led corresponding to UV indication
}
else
{
if(ch<3)
{
ch++;
ADMUX=ch;
}
}
break;
}
// GLP
case 3:
{
adc_result[3]=ADCW;
ADMUX=0x04;//select adc 4
//Start next conversion
ADCSRA |= (1<<ADSC);
//wait for coversion to be completed
while (!(ADCSRA & (1<<ADIF)));
adc_result[4]=ADCW;
if((adc_result[3]-adc_result[4])>31)
{
PORTD|=(1<<PD3);//ON the led corresponding to GLP indication
do
{
ADMUX=0x03;//select adc 3
//Start next conversion
ADCSRA |= (1<<ADSC);
//wait for coversion to be completed
while (!(ADCSRA & (1<<ADIF)));
adc_result[3]=ADCW;
ADMUX=0x04;//select adc 4
//Start next conversion
ADCSRA |= (1<<ADSC);
//wait for coversion to be completed
while (!(ADCSRA & (1<<ADIF)));
adc_result[4]=ADCW;
if((adc_result[3]-adc_result[4])>38)
{
PORTB|=(1<<PB1);// o/p drive
}
}while((adc_result[3]-adc_result[4])>31);
PORTD&=~(1<<PD3);//OFF the led corresponding to GLP indication
PORTB&=~(1<<PB1);// off the o/p drive
}
}
}
int main(void)
{
port_init();
//discarding the first adc result
ADCSRA |= (1<<ADSC);
//wait for coversion to be completed
while (!(ADCSRA & (1<<ADIF)));
ADMUX=ch;
// Loop Forever
while(1)
{
init_adc();
}
}
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