void timerSetup() {
    // Configure Timer1 for Fast PWM mode, non-inverted, 8-bit resolution
    TCCR1A = (1 << WGM10) |(1<<COM1A0)|(1 << COM1A1)|(1<<WGM11);  // Fast PWM 10 BIT, non-inverted mode
    TCCR1B = (1 << WGM12)  | (1 << CS11) |(1<<CS10);  // Prescaler = 64
    
    ICR1 = 1023; // FREQUENCY 250HZ  
    OCR1A= 300;  //INITIAL dutyCycle
    
}

void setup() {
    // Set PORTB pin 1 (OC1A) as output for PWM
    DDRB |= (1 << PB1);

    // Initialize Serial communication
    Serial.begin(9600);

    // Setup the timer
    timerSetup();

    // Configure ADC
    ADMUX = 0x00;  // Use ADC0, Vref = AVcc
    ADCSRB = 0x00;  // Free-running mode
    ADCSRA |= (1 << ADEN) | (1 << ADATE) | (1 << ADIE) | (1 << ADPS2);

    // Start the first ADC conversion
    ADCSRA |= (1 << ADSC);
}

void loop() {
    // Main loop remains empty; all work is done in interrupts
}

ISR(ADC_vect) {
    // Read the ADC value and update the PWM duty cycle
     
    OCR1A = ADC;  // dutycycle value equals provided by adc
    Serial.println(ADC);
     
    ADCSRA |= (1 << ADSC);  // WORKING WHEN MANUALLY START
}