Ultrasonic pest repeller

ultrasonic_pest_repeller.ino

int speaker = 0; // speaker pin (pwm)
long int pick_freq = 22000;

int duration = 100; // ms to play tone

int led = 13; // led operating status pin


void setup() {
  pinMode(speaker, OUTPUT);
  Serial.begin(9600);
  Serial.println("ATMEGA BOOTING...");
}

void loop() {
  pick_freq = random(22000, 64000);
  duration = random(100, 3000);
  digitalWrite(led, HIGH);   // turn the LED on (HIGH is the voltage level)
  Serial.print("Tone: Freq: "); Serial.print(pick_freq); Serial.print(" / Duration: "); Serial.println(duration);

  tone(speaker, pick_freq);
  delay(duration);
  noTone(speaker);

  digitalWrite(led, LOW);   // turn the LED off (LOW is the voltage level)
  delay(duration * 0.1);
}