4×4 Matrix 16 Push Button Keyboard Module

The 4 x 4 matrix keypad serves as an input device commonly used in projects, offering a total of 16 keys for inputting values. It functions as a matrix non-encoded keypad, with 16 keys arranged in parallel. Each row and column of keys are connected through external pins, with pins labeled as R1-R4 controlling the rows and L1-L4 controlling the columns.

This keypad module comprises microswitch buttons and includes four 3mm (M3) mounting holes for easy installation. The pin designations are clearly indicated on the PCB. Four pins are allocated as ‘x’ coordinates and the other four as ‘y’ coordinates. The module comes with soldered pin headers already attached, rotated 90 degrees for convenience.

Here’s how it operates:
1. Initially, check if any key is pressed. Apply power to the rows, setting them to a high level.
2. Set all rows (R1-R4) to low and then examine the status of the columns. A low status in any column indicates a pressed key within that column. If all columns are high, no key is pressed.
3. Identify the pressed key by determining the row. Set the rows as low one by one until the pressed row is detected, with the other rows remaining high.
4. Once the row is identified, check the status of each column individually. The column with a low status indicates the intersecting point with the row, identifying the pressed key.

Package Includes:

1 x 4×4 Matrix 16 Push Button Keyboard Module