4PCS 3x4 Matrix Keypad 12 Keyboard Module for Microcontroller (12Key) What this product is Set of four identical keypad modules, each with 12 keys arranged in a 3 by 4 matrix. Designed as an external input board for microcontroller projects. Key benefits Reduced wiring and GPIO usage: matrix layout lets you read 12 keys using a few digital lines, simplifying wiring and freeing pins for other functions. Fast integration: plug a module into a breadboard or wire directly to your development board and use standard matrix scanning code to read key presses. Reliable user input: tactile keycaps provide consistent, repeatable presses for numeric entry, menus, and command input. Multiple units included: four identical modules provide spare parts, allow multiple input stations, or let you prototype several designs in parallel. Important attributes Function: 12key numeric and function input in a standard 3x4 matrix configuration for scanning by microcontrollers. Compatibility: suitable for use with Arduino, Raspberry Pi, ESP32, PIC, AVR, and other microcontroller development boards that support matrix keypad scanning or GPIO polling. Size and form factor: compact, lowprofile keypad modules that fit into typical project enclosures and prototyping setups. Material and build: PCBmounted keys with plastic keycaps designed for routine use in electronics projects. Performance: responsive key detection for reliable user interaction in control panels, menus, or numeric input tasks. Typical applications Access and control panels: enter numeric codes or select options for DIY security, automation, or access projects. Embedded device interfaces: add keypad input to microcontroller projects for menu navigation, parameter entry, or simple calculators. Prototyping and education: useful for learning matrix scanning, building multiple test rigs, or supplying input for robotics and control experiments. What you get Four 3x4 matrix keypad modules (12Key each), ready to wire into your microcontroller project. Notes for use These are matrix keypads and require simple scanning code or a keypad library on your microcontroller to detect individual key presses. They are intended as external input modules for development and prototyping.