85. Timer Calculations

Amy has generated a PWM signal to control the LED brightness. What will be the PWM signal frequency after executing the following code?

Given: CPU clock frequency is 16MHz

Code

#define LED_PIN 3

void setup() {
  pinMode(LED_PIN, OUTPUT);
  
  // Configure Timer2 for Fast PWM, Non-Inverting Mode with 1024 Prescaler, clear OC2B on compare match
  TCCR2A = (1 << WGM21) | (1 << WGM20) | (1 << COM2B1);
  TCCR2B = (1 << WGM22) | (1 << CS22) | (1 << CS21) | (1 << CS20);

  OCR2A = 77;  // Set the TOP value for the timer (frequency control)
}

void loop() {
  // Gradually increasing PWM
  for (int duty = 0; duty <= 77; duty++) {
    OCR2B = duty;  // Set the current duty cycle
    delay(10);
  }

  // Gradually decreasing PWM
  for (int duty = 77; duty >= 0; duty--) {
    OCR2B = duty;  // Set the current duty cycle
    delay(10);
  }
}