roboforum.ru

#include <avr/pgmspace.h>
#include <avr/interrupt.h>

unsigned int    sound = 0;
unsigned char   *data;

#define DIV_0           ((0 << CS22) | (0 << CS21) | (1 << CS20))
#define DIV_8           ((0 << CS22) | (1 << CS21) | (0 << CS20))
#define DIV_64          ((0 << CS22) | (1 << CS21) | (1 << CS20))
#define DIV_256         ((1 << CS22) | (0 << CS21) | (0 << CS20))
#define DIV_1024        ((1 << CS22) | (0 << CS21) | (1 << CS20))

ISR(SIG_OUTPUT_COMPARE3A) {
    sei();

    if (sound) {
        if (sound--) {
            OCR1B = pgm_read_byte(data++);
        } else {
            TCCR1A = 0;
            TCCR1B = 0;
            TCCR3B = 0;
            DDRE &= ~(1 << PE2);
        }
    }
    TCNT3 = 0;
}

void SoundPlay(unsigned char* wave, unsigned int wave_size) {
    if (!sound) {
        data = wave;
        sound = wave_size;

        /* PWM 8bit, 32kHz */

        DDRE |= (1 << PE2);
        TCCR1A = (1 << WGM10) | (1 << COM1B1);
        TCCR1B = (1 << WGM12) | DIV_0;

        /* Change samples timer - 8kHz */

        TCCR3A = 0;
        TCCR3B = DIV_8;
        OCR3A = 125;
        ETIMSK |= (1 << OCIE3A);
        TCNT3 = 0;
    }
}