4×4 Keypad Membrane

🔹 4×4 Membrane Matrix Keypad – 16-Key, Thin, Flexible, Adhesive Backing

This 4×4 membrane matrix keypad is a slim, durable input device featuring 16 tactile keys arranged in a standard 4×4 matrix layout (0-9, A-D, *, #). With a flexible construction and adhesive backing, it’s ideal for embedded systems, access control, security panels, and custom user interface projects requiring alphanumeric input.

✅ Specifications:

• Key Configuration: 4 Rows x 4 Columns (16 Keys)

• Key Layout: 1, 2, 3, A, 4, 5, 6, B, 7, 8, 9, C, *, 0, #, D

• Key Type: Membrane / Tactile dome (audible click)

• Contact Rating: 10mA @ 12V DC (max)

• Contact Resistance: <100Ω (initial)

• Insulation Resistance: >100MΩ @ 100V DC

• Operating Life: >1 million cycles per key

• Actuation Force: 150g – 250g (typical)

• Travel Distance: 0.2mm – 0.3mm (typical)

• Interface: 8-pin Berg strip (female) / 8-pin male header (varies)

• Cable Length: ~60mm – 80mm (from keypad to connector)

• Backing: 3M adhesive (peel-and-stick)

• Material: Polyester overlay, silver circuit traces

• Operating Temperature: -20°C to +60°C

• Dimensions (Keypad): ~77mm x 77mm (typical)

📦 Features:
✔️ Ultra-thin, lightweight design
✔️ Low profile – mounts easily behind panels
✔️ Self-adhesive backing for quick installation
✔️ Sealed surface – resistant to dust and moisture
✔️ Audible tactile feedback
✔️ Low power consumption
✔️ 16 keys for alphanumeric input
✔️ Standard matrix layout simplifies programming
✔️ Compatible with Arduino Keypad library

📦 Applications:
✔️ Arduino, ESP32, Raspberry Pi projects
✔️ Access control and security systems
✔️ Door entry keypads
✔️ Industrial control panels
✔️ Embedded system user interfaces
✔️ DIY electronics projects
✔️ Time clocks and attendance systems
✔️ Home automation control panels
✔️ Educational microcontroller kits
✔️ Calculator and data entry projects

🔧 Arduino / Microcontroller Wiring:

• Connect rows (pins 1-4) to digital output pins (e.g., 2,3,4,5)

• Connect columns (pins 5-8) to digital input pins with internal pull-ups (e.g., 6,7,8,9)

• Use Arduino Keypad library for easy scanning:

⚠️ Important Notes:

• Matrix scanning required. Keypresses are detected by scanning rows and columns; cannot be read as individual digital inputs without a matrix scanning routine.

• Pull-up resistors. Enable internal pull-ups on column pins or use external 10kΩ resistors.

• Debouncing. Add software debouncing (typically 10-50ms) for reliable key detection.

• Adhesive mounting. Clean surface thoroughly before applying adhesive backing.

• Current limit. Do not exceed contact rating (10mA) to avoid damaging membrane traces.