Generates a square wave of the specified frequency (and 50% duty cycle) on a pin. A duration can be specified, otherwise the wave continues until a call to noTone(). The pin can be connected to a piezo buzzer or other speaker to play tones.

Only one tone can be generated at a time. If a tone is already playing on a different pin, the call to tone() will have no effect. If the tone is playing on the same pin, the call will set its frequency.

NOTE: if you want to play different pitches on multiple pins, you need to call noTone() on one pin before calling tone() on the next pin.


tone(pin, frequency)
tone(pin, frequency, duration)


pin: the pin on which to generate the tone
frequency: the frequency of the tone in hertz – unsigned int
duration: the duration of the tone in milliseconds (optional) – unsigned long




tone() employs the PWM timer of pin 32; so to avoid conflicts, tone() and analogWrite(32) cannot be called at the same time. In addition, tone() should also not be used with the MsTimer2 and IRremote libraries at the same time.

See also

Tutorial: Tone
Tutorial: Pitch follower
Tutorial: Simple Keyboard
Tutorial: multiple tones

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The text of the 86Duino reference is a modification of the Arduino reference, and is licensed under a Creative Commons Attribution-ShareAlike 3.0 License. Code samples in the reference are released into the public domain.