How to Interface Keypad 4x4 (2D) With Arduino

This tutorial is going to teach you some basics on using Keypad 4x4 on Arduino.

Description:

This keypad consists of 4 rows x 4 columns of buttons. It is ultra-thin that it provides an useful human interface component for microcontroller projects. Convenient adhesive backing provides a simple way to mount the keypad in a variety of applications, such as menu selection, security systems, data entry for embedded systems and so on.

Specifications:

• Maximum rating: 24VDC, 30mA
• Interface: 8-pin access to 4x4 matrix
• Operating temperature: 32ᵒF to 122ᵒF (0ᵒC to 50ᵒC)
• Dimension: Keypad (69mm x 76mm), Cable (20mm x 87mm)

To get the results, please download the sample source code attached below and upload it into Arduino.

Method One:

1. Download the library from this link: http://playground.arduino.cc/uploads/Code/keypad.z... or you can directly download the zip file attached below.

2. Go to the location of the downloaded file and unzip it.

3. Next, move the unzipped file to the library folder of your Arduino software.

4. Quit your currently-opened Arduino software (if you are running it at the moment)

5. Open your Arduino software once again. Now you should be able to use your keypad library.

Method Two (Only applicable to Arduino IDE 1.6.2 or above):

1. Go to the menu of your Arduino software, then Sketch>Include Library>Manage Libraries...

2. Next, search for Keypad.

3. For a short while, the relevant result is displayed. Select the "Keypad" library and choose Install.

4. Quit your currently-opened Arduino software (if you are running it at the moment).

5. Open your Arduino software once again. Now you should be able to use your keypad library.

*Note that to understand the programming language used in keypad library and to know better their functions, you may kindly refer to this website: http://playground.arduino.cc/code/keypad

The picture above shows the button being pressed randomly and the corresponding number or symbol or alphabet is being displayed on the Serial Monitor.