4×4, 16button layout: Expands your I/O options with a compact keypad module that provides 16 discrete inputs on a single board for menus, numeric entry, command shortcuts, and more. Designed for singlechip microcontrollers: Built as an external keyboard module specifically to interface with microcontroller projects, making it easy to add tactile input without redesigning your PCB. Simple integration and reliable input: The matrix arrangement reduces required I/O lines and simplifies scanning in firmware, so you can implement responsive key reading with minimal code. Versatile application: Use it as a numeric keypad, menu navigator, or control panel input across a wide range of microcontrollerbased projects. Key benefits — why you need it Adds functionality quickly: Gives your project a readymade input surface so you can focus on firmware and features rather than custom keypad hardware. Saves I/O and development time: The matrix design minimizes pin usage and is compatible with common microcontroller scanning routines. Practical and flexible: Works as an external keyboard module that complements singlechip microcontrollers for testing, prototyping, and finished builds. Typical use scenarios Prototype control panels: Add keypad input for prototypes or small control systems where a compact numeric/command interface is required. Access or PIN entry: Implement simple security or authentication interfaces (PINs, codes) for locks, safes, or restricted functions. Menu and parameter entry: Use for navigating ondevice menus, entering setpoints, or controlling robot/automation functions in microcontroller projects. Compatibility and function notes Interface: 4×4 matrix keypad providing 16 keys on a single module. Target use: External keyboard module intended for use with singlechip microcontrollers; designed to be scanned and handled in standard microcontroller firmware. Form factor: Compact 16key module that plugs into or mounts near your microcontroller system for immediate input capability. This keypad module provides a straightforward, loweffort way to add reliable, multikey input to microcontroller projects and external applications where a compact, programmable keyboard is needed.