7 Best Functions of the Membrane Keypad Arduino

27 Dec, 2021

By hqt

What is the membrane keypad, Arduino?

The membrane keypad Arduino is a high-quality keypad suitable for the most diverse projects with microcontrollers. Moreover, it features a simple design and a fine finish, with all its soft and resistant keys for easy handling.

The communication uses only 8 pins for 16 keys. Similarly, it makes installation and development easier, in addition, on the back. There is an adhesive for fixing to a smooth surface. Its ribbon cable is more practical both aesthetically and functionally.

Membrane Keypad Arduino

Developing useful applications for your day today

The project that below involves the operation of the 4×4 Matrix Keypad with Arduino, together with the development platform. The membrane keypad Arduino will be connected to the Arduino, where it will read the pressed key and send the character to the serial port.

From this project, you can be developing countless useful applications for your day-to-day, whatever your need or idea.

Video 4×4 Matrix Keypad Project with Arduino

Products Common in the Project

  1. Matrix Keypad;
  2. Arduino Uno R3;
  3. Jumper Kit.

Keypad Communication Protocol

The Arduino Matrix Keypad works with the Multiplexed scanning method, that is, the microcontroller sequences the channels to see which key presses. The keys connect as shown in the image below, that is, columns and rows.

The multiplexing system is a basic system that works as follows:

 The Arduino defines that all columns are output, and the lines are input. If any button presses, the microcontroller instantly changes the inputs by outputs.

And again checks which button was pressed, so by joining the two pieces of information we will have the location of the pressed button by the coordinates of the rows by the columns.

Arduino Matrix Keypad Project Assembly

For the perfect functioning of the project, the connections must come correctly, following the connections as shown in the image below. For connection of the Arduino with the membrane keypad Arduino, male jumpers can be common, specially colored, to avoid incorrect connection.

Arduino Matrix Keypad Project Schematic

Code Operation:

The code of the 4×4 Matrix Keypad Project with Arduino has the function of waiting for a key to press. And when it occurs, it will display the pressed character on the screen, through the serial port.

The keypad is one of the most important parts of the Arduino, as it is an information input device.

Its design comes mainly on the keypads that typewriters had. Like typewriters, on an Arduino keypad each of the keys has a different function and that when pressed sends an order to run.

Definition of Arduino keypad

The membrane keypad Arduino is an information input device to the Arduino that allows you to interact and enter data quickly in the Arduino.

History of the Arduino keypad

According to history, the Arduino keypad is based on the keypad common in ancient typewriters; These machines appears in the mid-nineteenth century and arose out of the need to give a more formal style to writing.

Membrane Keypad Arduino 2022

The first Arduino keypads as such appeared in the early 70s, although previously arduinos common something similar teletype and that serves to give orders. The first keypads were quite heavy, but over time they to become small and sometimes already integrated as in the case of laptops or invisible as in the case of smartphones.

Arduino membrane keypad Arduino functions

These are the functions of the membrane keypad Arduino:

  • Open specific applications
  • Also, Enter text in some programs such as word processors
  • Moreover, Accept or enter
  • Furthermore, Move in different directions
  • In addition, Insert special symbols
  • Moreover, Perform combinations of two or more keys
  • Other special functions such as screen copying, shutting down or hibernating the Arduino, and executing special functions (function keys), among others.

Membrane keypad Arduino types

We can classify keypads in different ways, here are some of them.

According to their physical form

  • Ergonomic keypad: provide greater user comfort
  • Multimedia keypad: they have special keys that are common for email, internet or music player use
  • On-screen keypad: these are virtual keypads that appear on the screen and that the user can use using the mouse.
  • Projection keypads: the same size as a standard membrane keypad Arduino but use lasers. It is connecting via USB, Bluetooth, or Wi-Fi
  • Braille keypad: common by blind people

We can distinguish several parts of a keypad, depending on the function performed by the keys that are by the way groups, the most important are the following:

membrane keypad Arduino Function keys

This part is located at the top. They are keys that have a special function and that, in general, each program or software assigns them a different function within it. However, we can say that the F1 key is generally always common to get help.

Numeric keypad

It is a part of the keypad in which we only find numbers and mathematical symbols, it is common to perform calculations.

Alphanumeric membrane keypad Arduino

It is the main part of the membrane keypad Arduino, it is in the center, and we find the letters of the alphabet, numbers, and symbols.

Edit keys

They allow us to work in the edition of text documents, with these keys we can move between lines, paragraphs, or pages.

Arrow keys

They are the arrows that allow us to move in the direction they indicate.

Special or system membrane keypad Arduino

They are the other keys that perform other functions such as obtaining contextual menus, system menu, ctrl, alt, shift, change upper / lower case, escape, tab, etc.


From this simple test, we learn the basic operation that the 4×4 Matrix membrane keypad Arduino with Arduino presents, in addition to being a high-quality device, having a different and very thin design, facilitating its use in electric locks, access control, safes, electronic scales, among others.

The function of keypad is quite important in every electronic device. This brings positivity and faith on our range of membrane products. If you are looking for a reliable partner to extend your electronics business, you can contact us.

We shall deliver highest quality products.


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