Touch Button

Digital

input

Medium RAM

0.1.1

#Description

The touch sensor is basically the same as a button, except that it only reacts to capacitive contact from your skin, similar to the screen of a smartphone.

#Links

Open Wiki for Grove Component Get the Grove Component

#Aliases

Capacitive Touch Sensor

#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.