Radio Shack 12 Key Matrix Number Pad/ Keypad For Arduino/ (Model: PTT-12KPM)

Add numeric input capability to your Arduino or microcontroller projects with this 12 Key Matrix Number Pad/Keypad (PTT-12KPM), a reliable and easy-to-integrate input solution perfect for DIY electronics, security systems, calculator projects, and embedded applications. This professional-grade membrane keypad features a familiar telephone-style layout with numbers 0-9 plus asterisk (*) and pound (#) symbols.

The matrix-style wiring design uses just 7 pins (4 rows + 3 columns) to read all 12 keys, significantly reducing the number of microcontroller I/O pins required compared to direct-wired buttons. This efficient design makes it ideal for projects where pin count is limited. The keypad includes pre-attached header pins, allowing for easy connection to breadboards, development boards, or custom circuits without soldering.

Technical Specifications:

• 12 keys: 0-9, *, # in telephone layout
• Matrix configuration: 4x3 (4 rows, 3 columns)
• Interface: 7-pin header (pre-attached)
• Membrane construction for long life
• Tactile feedback on key press
• Operating voltage: 5V (compatible with most microcontrollers)
• Compact dimensions for easy project integration
• Compatible with Arduino, Raspberry Pi, ESP32, and more
• Includes header pins for breadboard connection

Ideal for Arduino enthusiasts, electronics students, makers, and engineers creating projects that require numeric input. Common applications include security keypads, calculator interfaces, menu navigation systems, and access control projects. The keypad works seamlessly with readily available Arduino libraries, making programming simple even for beginners.