on Event

Run some code when a pin is pulsed high (true) or low (false) or rising or falling on the edge.

pins.A0.onEvent(PinEvent.PulseHigh, () => {})

A pulse is a change of voltage at the input of a digital pin. This might happen if a switch connected to the pin is pressed or a sensor attached to the pin wants to give a signal. A pulse is an action of changing voltage from high to low, or from low to high. The input to a pin is normally made to stay at either a high or low voltage when it isn’t pulsed (its unsignalled state). You can decide what input value to keep the pin at is when it’s not pulsed. You do this by giving it a pull direction with ||pins:set pull||.

Your code is inside an event block that starts when the input voltage at the pin changes. You give the pulse direction you want the code to run for. Make the value for pulse be high if you want the code to start when the pin changes from a low voltage to a high voltage. Use low for pulse if you want your code to run when the voltage at the pin goes from high to low.

Parameters

• event: the pulse value to run code for, either high (true) or low (false).
• body: the code to run when the pin is pulsed.

Example

When pin D4 is pulsed low, run code that flashes an LED connected to pin D13 .

pins.D4.setPull(PinPullMode.PullUp)

pins.D4.onEvent(PinEvent.PulseLow, () => {
    pins.D13.digitalWrite(true)
    pause(250)
    pins.D13.digitalWrite(false)
})

See also

pulse in, set pull