4x4 Matrix Keypad – 16 Key Membrane Keypad for Arduino & ESP32
4x4 Matrix Keypad – 16 Key Membrane for Arduino & ESP32
This 4x4 matrix membrane keypad provides 16 tactile buttons in a compact, flexible layout ideal for numeric input, password systems, and menu navigation in Arduino, ESP32, and Raspberry Pi projects.
Key Specifications
| Key Count | 16 |
|---|---|
| Matrix Layout | 4 Rows × 4 Columns |
| Switch Type | Membrane (conductive rubber) |
| Contact Rating | 12V DC, 20mA |
| Connector | 8-pin 2.54mm female header |
| Cable Length | ~85 mm |
| Dimensions | 69 mm × 77 mm |
What You Can Build With This
- Digital Door Lock: Create a simple password‑protected lock using a servo motor and the Keypad library on Arduino Uno.
- Wi‑Fi Smart Lock: Build an IoT entry system with ESP32 that sends OTPs to a phone or logs access to the cloud.
- Retro Game Console Controller: Use a Raspberry Pi to map keypad buttons as game controls for retro emulators like RetroPie.
- Password Security System: A CBSE Class 12 practical project demonstrating matrix scanning and digital I/O with status LEDs and a buzzer.
- Multi‑factor Authentication System: Combine the keypad with RFID and a database on Raspberry Pi for a college Smart India Hackathon project.
Compatibility
| Platform | Compatible | Connection | Library / Method |
|---|---|---|---|
| Arduino Uno R3 | Yes | 8 digital pins (4 rows, 4 cols) | Keypad.h |
| Arduino Nano | Yes | 8 digital pins | Keypad.h |
| Arduino Mega 2560 | Yes | 8 digital pins | Keypad.h |
| ESP8266 NodeMCU | Yes | 8 GPIO pins | Keypad library (Arduino ESP8266) |
| ESP32 Dev Board | Yes | 8 GPIO pins | Keypad library (Arduino ESP32) |
| Raspberry Pi Pico | Yes | 8 GPIO pins | MicroPython or pico‑keypad library |
| Raspberry Pi 4 / 5 | Yes | 8 GPIO pins (pull‑ups in software) | RPi.GPIO or pad4pi |
Wiring and Interface Notes
Connect the 8‑pin female header directly to any 8 digital GPIOs on your microcontroller; the internal pull‑up resistors of the MCU are sufficient. The Keypad library for Arduino or the pad4pi module for Raspberry Pi handles matrix scanning automatically—no external components needed. Since the keypad is a passive switch matrix, voltage levels are not an issue, but ensure your GPIOs are configured as inputs with pull‑ups to avoid floating lines.
Frequently Asked Questions
Do I need any resistors or external pull‑ups to use this keypad?
No external resistors are required. The standard Keypad library for Arduino and similar platforms uses the microcontroller’s built‑in pull‑up resistors on the input pins, so wiring is plug‑and‑play.
Can the keypad be used outdoors or in a wet environment?
The membrane surface offers some moisture resistance but is not fully waterproof. For outdoor projects, house the keypad in an appropriate enclosure to protect the connector and backside from humidity.
What you can build with this
Shipping Information
- Prepaid Orders: ₹75 for orders up to ₹999, FREE shipping above ₹999
- COD Orders: ₹125 shipping + ₹50 COD fee = ₹175 total
- Delivery Timeline: Dispatch in 1-2 days, delivery in 2-7 days depending on location
Returns & Warranty
- 7-Day Return: Manufacturing defects only (approval required)
- Warranty: 7 days from delivery
- Non-Returnable: Batteries, consumables, cut wires, clearance items