Adafruit
3x4 Phone-style Matrix Keypad
This phone-style 3×4 matrix keypad features 12 buttons (0–9, *, #) with telephone-layout lettering printed on the keys. It uses a matrix scanning arrangement...
This phone-style 3×4 matrix keypad features 12 buttons (0–9, *, #) with telephone-layout lettering printed on the keys. It uses a matrix scanning arrangement requiring only 7 microcontroller pins (3 columns + 4 rows) to read all 12 keys.
The keypad comes with 7 or 8 header pins pre-soldered for easy breadboard use. Starting from the left, the first three pins are columns, followed by the four row pins. If an 8th pin is present, it is unused and can be left disconnected.
Key Features
- Phone-Style Layout – Letters and numbers printed on keys, just like a telephone
- 12-Key Matrix – Standard 3×4 arrangement (0–9, *, #)
- Pre-Soldered Headers – Ready for breadboard use out of the box
- Sturdy Plastic Construction – Rigid body with durable plastic buttons
- 7-Pin Interface – Matrix scanning with 3 columns + 4 rows
Pin Order
From left to right: COL1, COL2, COL3, ROW1, ROW2, ROW3, ROW4. An 8th pin (if present) is unused.
Ideal For
- Telephone and dialler projects
- Security keypads and access control
- Menu navigation interfaces
- Arduino and microcontroller input
Package Contents
- 1× 3×4 phone-style matrix keypad (with pre-soldered headers)
Jargon buster
Plain-language definitions for the technical terms used above.
- Headers
- Rows of metal pins used to plug a module into a breadboard or connect it with jumper wires. Pre-soldered headers make the module easier to use straight away without needing to solder the pins yourself.
- microcontroller
- A microcontroller is a small computer on a chip that runs your program and controls connected inputs and outputs. For this product, it is the part that reads buttons and sensors, drives the display and speaker, and communicates over Bluetooth.
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