Button

Digital

input

Medium RAM

0.1.0

#Description

Buttons are the very basic inputs used everywhere. They can function as input at your keyboard, start element from your coffee machine or even as touch sensor at your door.

#Links

Open Wiki for Grove Component Get the Grove Component

#Units

State

#Functions

#JavaScript / Node.js

@blokdots/components on npm ↗

ClassButtonextends ComponentBase

Base class for button and switch components with software debouncing and hold detection.

#Constructor options

Option	Type	Required	Description
`invert`	`boolean`	optional	—
`isPullup`	`boolean`	optional	—
`isPulldown`	`boolean`	optional	—
`holdTime`	`number`	optional	—
`pin`	`number \| DigitalPin`	required	—

#Events

Event	Parameters	Description
`change`	`value: number`	—
`down`	`—`	—
`press`	`—`	—
`up`	`—`	—
`release`	`—`	—
`held`	`—`	—

#Methods

updateOptions(options: { invert?: boolean })

Update runtime options such as invert direction.

get isPressed→ boolean

Check if the button is currently pressed

get value→ number | undefinedfrom ComponentBase

Get the current value of the component.

#Example

JavaScript

import { Board, Button } from "@blokdots/components";

const board = new Board("/dev/ttyACM0");
await board.open();

const button = new Button({ board, pin: "D5", isPullup: false, isPulldown: false, holdTime: 1000 });

button.on("change", (value) => {
  console.log("Button changed:", value);
});

See the Button reference for the full API including all methods and events.

#C++ (Arduino)

ClassButton

#Setup

C++

#include "blokdots.h"

Button myComponent(eventBus, 5, MY_EVENT, MY_EVENT);

#Constructor

Button(bus, pin, evtDown, evtUp, pullup, debounceMs, invert, sampleIntervalMs)

Parameter	Type	Default
`bus`	`EventBus`	required
`pin`	`uint8_t`	required
`evtDown`	`uint8_t`	required
`evtUp`	`uint8_t`	required
`pullup`	`bool`	`true`
`debounceMs`	`uint32_t`	`30`
`invert`	`bool`	`false`
`sampleIntervalMs`	`uint16_t`	`2`

#Methods

isPressed()→ bool

emittedValue()→ int

onHold(holdMs, cb, ctx)→ int

Returns slot index, or -1 if full.

Parameter	Type	Default
`holdMs`	`uint32_t`	required
`cb`	`EventBus::Handler`	required
`ctx`	`void`	`nullptr`

setHoldMs(slot, ms)

Optional: update hold time later

Parameter	Type	Default
`slot`	`int`	required
`ms`	`uint32_t`	required

begin()

See the Button reference for the full API.