Crate debounced_pin

A platform-agnostic debounce library.

This library provides an update() method to debounce a pin.

Implements approach 1 from here (archived 2018-09-03).

It also adds a wrapper for an InputPin that debounces it’s is_high() and is_low() methods.

Implementation

The InputPin wrapper checks only the debounced state. It does not poll the pin and drives the debouncing poll implementation forward. To do this, you have to call update(). At best call it every 1ms in an ISR.

Example

For examples check the examples directory in the repository.

use debounced_pin::prelude::*;
use debounced_pin::ActiveHigh;

// This is up to the implementation details of the embedded_hal you are using.
let pin: InputPin = hal_function_which_returns_input_pin();

let pin = DebouncedInputPin::new(pin, ActiveHigh);

loop {
    match pin.update()? {
        // Pin is not active.
        DebounceState::NotActive => break,
        // Pin was reset or is not active in general.
        DebounceState::Reset => break,
        // Pin is active but still debouncing.
        DebounceState::Debouncing => continue,
        // Pin is active and debounced.
        DebounceState::Active => break,
    }
    // Wait to poll again in 1ms. Also hardware specific.
    wait(1.ms());
}

// If the debounce state is DebounceState::Active
// this returns true and the code gets executed,
// else this false.
if pin.is_high()? {
    // Do something with it
    break;
}

Modules

prelude

Import the needed types and traits to use the update() method.

Structs

ActiveHigh

Unit struct for active-high pins.

ActiveLow

Unit struct for active-low pins.

DebouncedInputPin

A debounced input pin.

Enums

DebounceState

The debounce state of the update() method.

Traits

Debounce

Debounce Trait which provides an update() method which debounces the pin.