Advanced I/O

1. tone()

1.1. Description

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.

1.2. Syntax

tone(pin, frequency)

tone(pin, frequency, duration)

1.3. Parameters

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

1.4. Returns

Nothing

1.5. Notes and Warnings

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.

2. noTone()

2.1. Description

Stops the generation of a square wave triggered by tone(). Has no effect if no tone is being generated.

2.2. Syntax

noTone(pin)

2.3. Parameters

pin: the pin on which to stop generating the tone

2.4. Returns

Nothing

2.5. Notes and Warnings

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.