2 x 2 Matrix 4 Push Button Keyboard Module

PRODUCT DESCRIPTION

The 2×2 Matrix Keypad Module is commonly used as an input device in various projects. It features a compact layout with 4 keys, providing a simple method for entering data. The module operates as a non-encoded matrix keypad, with 14 keys connected in parallel. The rows and columns are controlled via external pins—R1 and R2 control the rows, while L1 and L2 control the columns.

This module uses microswitch buttons for reliable input, and it includes four 3mm (M3) mounting holes for easy installation. Pin designations are clearly labeled on the PCB for straightforward connection. The module’s pinout is arranged such that two pins function as the ‘x’ coordinates and the other two as the ‘y’ coordinates. It comes with pre-soldered pin headers that are rotated 90 degrees for convenient integration into your project.

How it Works:

To test if a key is pressed on the 2×2 matrix keypad, follow these steps:

1. Power the Rows: Begin by setting the rows (R1 and R2) to a high level (High).
2. Set Rows Low: Then, sequentially set each row (R1, R2) to a low level (Low) one at a time.
3. Check Columns: While each row is low, check the status of the columns (L1, L2).
– If any column reads low, it indicates that a key is being pressed, and the key belongs to the corresponding column.
– If all columns read high, no key is pressed.

4. Identify the Row: Once the column with the pressed key is identified, set the rows to low one by one to determine which row corresponds to the pressed key. Other rows will remain high during this process.

5. Pinpoint the Key: Once the correct row is identified, check the status of the columns again. The column that is low at the intersection of the identified row is the key that has been pressed.

By following this process, you can accurately detect which key is pressed on the matrix keypad.

Features: