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

unsigned int top = 100;

void setup() {
  // add external voltage (Javascript) with name "pin n" to access output pins
  pinMode(9, OUTPUT);
  pinMode(6, INPUT);

  // Clear interrupts
  cli();
  // Reset TCCR1B from Arduino meddeling
  TCCR1B = 0;
  // Set fast PWM Mode with Top value as a frequency controller
  TCCR1A |= (1 << WGM10) | (1 << WGM11);
  TCCR1B |= (1 << WGM12) | (1 << WGM13);
  // Set toggle on compare match
  TCCR1A |= (1 << COM1A0);
  // Set TOP value which will reflect period length between 0 to 65536
  OCR1A = 200;
  // Set prescaler to 1 and start PWM
  TCCR1B |= (1 << CS10);
  // Enable global interrupts
  cli();
}

void loop() {
  while (1) {
    int v_out;
    v_out = digitalRead(6);
    delay (1);
  }
}