Customer Project – LCD Clock

#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/wdt.h>
#include <stdio.h>
#include <util/delay.h>
#include <stdlib.h>
#include <avr/hd44780.h>
 
unsigned char sec=0;
unsigned char min=0;
unsigned char hour=0;
ISR(SIG_OUTPUT_COMPARE1A)
{
sec=sec+4;
if(sec>59){min++;sec=0;};
if(min>59){min=0;hour++;};
if(hour>23){hour=0;};
return; 
}
void ioinit (void)
{
   DDRC  = 0b11001111; //1 = output, 0 = input
   PORTC = 0b00110000; //Enable pin 5 and 4 internal pullup
}
 
#define HOU() (bit_is_clear(PINC,4))
#define MIN() (bit_is_clear(PINC,5))
int main(void)
{
TIMSK1 = _BV(OCIE1A); // Enable Interrupt Timer/Counter 1, Output Compare A
TCCR1B = _BV(CS12) | _BV(WGM12); // Clock/256, 0.000256 secs per tick, Mode=CTC
OCR1A = 15625; // SIG_COMPARE1A triggered every 4 seconds
sei();
ioinit();
lcd_init();
while(1)
{
if(MIN())
{
min++; // Button for minute increase has been pressed
sec=0;
if(min>59){min=0;}
Delay_ms(100); // Not too fast on the button, increase to slow it down
}
if(HOU())
{
hour++; // Button for hour increase has been pressed
sec=0;
if(hour>24){hour=0;}
Delay_ms(100); // Not too fast on the button, increase to slow it down
}
char buffer[16];
sprintf(buffer,"%2d : %2d . %2d",hour,min,sec); // Just an example of a working format
lcd_goto(0);
lcd_puts(buffer);
Delay_ms(1);
}
}