Project 1 - Controlling a DC motor using PWM and monitoring its Running status

#include <avr/io.h>
#define F_CPU 16000000L
#include <util/delay.h>
#include "interrupt.h"
#define lcdport PORTB
#define rs_high PORTD |=(1<<0);
#define rs_low PORTD &=~(1<<0);
#define en_high PORTD |=(1<<1);
#define en_low PORTD &=~(1<<1);

int a;
void lcd_command(unsigned char cmd);
void lcd_data(unsigned char data);
void lcd_init();
void cursorps(char x,char y);
void lcd_out(char x, char y, char *str);

int main(void)
{
DDRB =0xff;
DDRD |=(1<<5);
DDRC |=(1<<0);
DDRC |=(1<<1);
sei();
GICR=(1<<7)|(1<<6);
PORTD=(1<<2)|(1<<3);
lcd_init();
TCCR1A=0x81;
TCCR1B=0x01;
TCNT1L=0;
TCNT1H=0;
while(1)
{
if(a==1)
{
lcd_out(1,1,"motor clockwise");
OCR1AL=0x3F;
}
else
{
OCR1AL=0x7F;
lcd_out(1,1,"motor anticlockwise");
}
}
}

ISR(INT0_vect)
{
PORTC |=(1<<0);
PORTC &=~(1<<1);
a=1;
lcd_cmd(0x01);_delay_ms(5);
}
ISR(INT1_vect)
{
PORTC |=(1<<1);
PORTC &=~(1<<0);
a=2;
lcd_cmd(0x01);_delay_ms(5);
}

void lcd_cmd(unsigned char cmd)
{
lcdport=cmd;
rs_low;
en_low;
_delay_ms(1);
en_high;
}
void lcd_data(unsigned char data)
{
lcdport=data;
rs_high;
en_low;
_delay_ms(1);
en_high;
}
void lcd_init()
{
lcd_cmd(0x38);_delay_ms(5);
lcd_cmd(0x02);_delay_ms(5);
lcd_cmd(0x01);_delay_ms(5);
lcd_cmd(0x0c);_delay_ms(5);
lcd_cmd(0x06);_delay_ms(5);
lcd_cmd(0x80);_delay_ms(5);
lcd_cmd(0xc0);_delay_ms(5);
}
void cursorps(char x,char y)
{
if(x<1||x>2)||(y<1||y>16)
{
x=1;
y=1;
}
if(x==1)
lcd_cmd(0x7F+y);
else
lcd_cmd(0xbf+y);
}
void lcd_out(char x,char y,char *str)
{
cursorps(x,y);
while(*str)
{
lcd_data(*str);
str++;
}
}