Buttons

Buttons are crucial components in the world of embedded systems. They provide an intuitive means of input, allowing users to interact with hardware and trigger specific functions or commands.

What is a button?

A button, in the context of electronics and human-machine interfaces, refers to a component or control mechanism that can be pressed or activated to initiate a specific action or command. Buttons are ubiquitous and can be found in a wide range of devices, from simple household appliances to complex industrial machines.

In embedded systems, buttons are typically interfaced with microcontrollers, which are programmable devices that control the operation of the hardware. When a button is pressed, it sends a signal to the microcontroller, which can then respond in a variety of ways—lighting up an LED, for instance, or triggering a buzzer.

Button Types

Buttons come in various forms and types, each designed for specific applications and functionalities. Here are some common types of buttons -

Push Button or Tactile Button

The most basic type of button.

Momentary action, meaning it only remains active as long as it's pressed.

Commonly used in doorbells, calculators, and various electronic devices.

Provides tactile feedback when pressed, often in the form of a "click" feel. Commonly used in electronic devices, keypads, and interfaces where a tactile response is desired.

Toggle Button

Maintains its state after being pressed until it's pressed again.

Used in interfaces where a user might want to turn a feature on or off with a single button.

Radio Button

Named after the physical buttons on old radios where only one button could be pressed at a time.

n user interfaces, allow users to select one option from a set.

Latching Button

Remains in its actuated state until pressed again.

Unlike a standard push button, which is momentary, a latching button will "latch" in either the on or off position.

Emergency Stop (E-Stop) Button

Used in industrial and machinery applications.

Designed to halt operations immediately for safety purposes. Often has a distinct red color.

Footswitch

Designed to be operated by foot.

Commonly used in medical equipment, industrial machinery, and guitar effect pedals.

Capacitive Button

Uses changes in capacitance (caused by a human finger) to detect when it's pressed.

Often found on modern touchscreens and devices where physical movement of the button is not required.

Piezo Button

Uses a piezoelectric effect to function.

Does not have moving parts and is often more durable and resistant to environmental factors.

Rotary Button (or Rotary Encoder)

Can be turned to different positions.

Often used in volume controls or as a method of selecting different options.

Joystick Button

Combines the functionality of a button with the movement capabilities of a joystick.

Commonly used in gaming controllers.

Touchpad/Button Combination

Combines a touchpad (for directional controls) with a central button.

Seen in some older laptop models and certain remote controls.