Description:

This 2×2 matrix keypad module serves as a convenient input device for various projects. It features four tactile buttons arranged in a 2×2 grid, providing four distinct input values.

The module is a non-encoded matrix, meaning it requires external logic to interpret key presses. It utilizes a 4×4 matrix configuration, with rows controlled by pins R1 and R2, and columns controlled by pins L1 and L2. Each key press is detected as a unique combination of row and column signals.

The module incorporates durable microswitch buttons for reliable and responsive key presses. It includes four 3mm (M3) mounting holes for secure attachment to your project enclosure. Clear pin designations are printed on the PCB for easy wiring.

Specifications:

• Pin Spacing:2.54mm
• Switch Type:Momentary
• Length:32mm

Features:

• 22 matrix keypad module with 4 buttons
• Small in size and hence Save space
• More convenient to use
• Expanded development application modules for single-chip
• With 4 keys and 4 pins

How it Works:

• First test whether any key is pressed down. Connect power to rows, so they are High level. Then set all the rows R1-R2 as Low and then detect the status of the columns. Any column of Low indicates there is key pressing and that the key is among the 4 keys of the column. If all columns are High, it means no key is pressed down. Next, locate the key. Since the column in which the pressed key lies is identified, knowing the line would finalize the testing. Thus, set the rows as Low in turns until any is unveiled accordingly other rows will still be High.
• Now the row can be identified. Detect the status of each column in turns. The column tested Low is the one intersecting with the line their cross point is just the key pressed.

Package Included:

1 x 2×2 Keypad Matrix 4-Button Keypad Module