#include <avr/io.h>
#include <util/delay.h>

void setup_pwm() {
    // Set PB1 (OC1A) and PB2 (OC1B) as outputs
    DDRB |= (1 << PB5) | (1 << PB6);

    // Configure Timer1 for Fast PWM mode
    TCCR1A |= (1 << COM1A1) | (1 << COM1B1) | (1 << WGM10); // Fast PWM, non-inverted
    TCCR1B |= (1 << WGM12) | (1 << CS11);   // Prescaler = 8
}

int main() {
    setup_pwm(); // Initialize PWM
    
    while (1) {
        // Gradually increase brightness on OC1A and decrease on OC1B
        for (uint8_t duty = 0; duty <= 255; duty++) {
            OCR1A = duty;         // Set duty cycle for LED1
            OCR1B = 255 - duty;   // Set duty cycle for LED2 (opposite)
            _delay_ms(50);        // Delay to visualize the change
        }

        // Gradually decrease brightness on OC1A and increase on OC1B
        for (uint8_t duty = 255; duty > 0; duty--) {
            OCR1A = duty;         // Set duty cycle for LED1
            OCR1B = 255 - duty;   // Set duty cycle for LED2 (opposite)
            _delay_ms(50);        // Delay to visualize the change
        }
    }

    return 0;
}