#include <avr/io.h>
 
void pwm_init() {
    // Setăm pinul OC1A (de ex. pinul digital 9 pe Arduino UNO) ca output
    DDRB |= (1 << PB1);
 
    // Setăm Timer1 în mod Fast PWM, cu TOP în ICR1
    TCCR1A = (1 << COM1A1) | (1 << WGM11);  // Clear OC1A on compare match
    TCCR1B = (1 << WGM13) | (1 << WGM12) | (1 << CS10);  // No prescaler
 
    // Frecvență PWM = f_clk / (TOP + 1)
    // Pentru f_clk = 16 MHz și perioadă de 250 µs => f = 4 kHz
    // => TOP = (16,000,000 * 0.00025) - 1 = 3999
    ICR1 = 3999;
 
    // Duty cycle de 25% => OCR1A = 25% din 3999 = 1000
    OCR1A = 1000;
}
 
int main(void) {
    pwm_init();
    while (1) {
        // PWM este generat automat de hardware, nu e nevoie de cod suplimentar
    }
}
 

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