52 lines
1.1 KiB
C
52 lines
1.1 KiB
C
/*
|
|
* Control PB5 with the two buttons. One button disables, the other enables.
|
|
* The board uses interrupts for this. PB5 will quickly oscilate between on and
|
|
* off to make cool sounds with a summer.
|
|
*/
|
|
#define F_CPU 16000000UL
|
|
#define __AVR_ATmega328P__
|
|
#include <util/delay.h>
|
|
#include <avr/interrupt.h>
|
|
#include <avr/io.h>
|
|
|
|
int beep = 0;
|
|
int sound = 0;
|
|
|
|
// code for INT0
|
|
ISR(INT0_vect) { beep = 1; }
|
|
|
|
// code for INT1
|
|
ISR(INT1_vect) { beep = 0; PORTB &= ~(1 << PORTB5); sound = 0;}
|
|
|
|
int main(void) {
|
|
|
|
DDRB = 0xff; // write to B
|
|
DDRD = 0; // read from D
|
|
|
|
PORTD |= (1 << PORTD2) | (1 << PORTD3); // pull up D2 and D3
|
|
|
|
PORTB = 0;
|
|
|
|
// enable external interruprs
|
|
EIMSK |= (1 << INT0);
|
|
EIMSK |= (1 << INT1);
|
|
|
|
// trigger when anything changes
|
|
EICRA |= (1 << ISC00); // for INT0
|
|
EICRA |= (1 << ISC10); // for INT1
|
|
|
|
sei(); // interrupt magic macro
|
|
while (1) {
|
|
if (beep) {
|
|
PORTB |= (1 << PORTB5);
|
|
_delay_us(sound);
|
|
PORTB &= ~(1 << PORTB5);
|
|
_delay_us(sound);
|
|
sound++;
|
|
if (sound > 1000) {
|
|
sound = 0;
|
|
}
|
|
}
|
|
}
|
|
}
|