سلام دوست عزیز. برای گرفتن فرکانس های بالا باید مستقیما از پایه های تایمر استفاده کنید.

void setup() { // Set up Timer1 to generate a 4 MHz square wave on pin 9 (OC1A) // Clear Timer1 control registers TCCR1A = 0; TCCR1B = 0; // Set Timer1 to CTC (Clear Timer on Compare Match) mode TCCR1B |= (1 << WGM12); // Set the compare value for 4 MHz // The formula is: OCR1A = (F_CPU / (2 * desired_frequency)) – 1 // For 4 MHz: OCR1A = (16,000,000 / (2 * 4,000,000)) – 1 = 1 OCR1A = 1; // Set the Timer1 prescaler to 1 (no prescaling) TCCR1B |= (1 << CS10); // Enable the Timer1 compare match A interrupt (optional, if you need it) // TIMSK1 |= (1 << OCIE1A); // Set pin 9 (OC1A) as output pinMode(9, OUTPUT);}

void loop() { // The main loop doesn’t need to do anything since the timer is handling the signal generation}