byte servoPin = 5;
byte buttonPin = 14;
bool oneSide = false;

void setup() {
  Serial.begin(9600);

  pinMode(servoPin, OUTPUT);
  digitalWrite(servoPin, LOW);
}

void loop() {
  Serial.print("one side...");
  oneSide = !oneSide;

  if(oneSide)
  {
    sideA();
  }else{
    sideB();
  }
  
  //changing this delay will change the effective frequency of the metronome.
  delay(600);
}

void sideA(){
  for(int i = 0; i < 35; i++){
    digitalWrite(servoPin, HIGH);
    delayMicroseconds(1000);    //position
    digitalWrite(servoPin, LOW);
    delayMicroseconds(18100);   //balance of 20000 cycle
  }
  Serial.println("one side");
}


void sideB(){
  for(int i = 0; i < 35; i++){
    digitalWrite(servoPin, HIGH);
    delayMicroseconds(2000);    //position
    digitalWrite(servoPin, LOW);
    delayMicroseconds(1800);   //balance of 20000 cycle
  }
  Serial.println("other side");
}