Membrane 1×4 Matrix Keypad
Membrane 1×4 Matrix Keypad
Membrane 1×4 Matrix Keypad
Membrane 1×4 Matrix Keypad

Membrane 1×4 Matrix Keypad

Keypads
SWK205
Part.No: 0259
€2.00
In Stock
Immediate Dispatch
Membrane 1×4 Matrix Keypad with FPC circuit — 4 independent keys, adhesive backing, compatible with Arduino, ESP32, Raspberry Pi. Pad size: 68×20mm, total length: 107mm.

 

The Membrane 1×4 Matrix Keypad is a compact, flexible input device featuring 4 buttons arranged in a single row. Thanks to its ultra-thin membrane construction and self-adhesive backing, it integrates seamlessly into enclosures, panels, and DIY project housings. Each button is independently wired via a flexible printed circuit (FPC), making it extremely simple to interface with any microcontroller — no complex matrix scanning code is required. It is an ideal choice for makers, students, and engineers who need a reliable, low-profile user input solution for prototyping or finished products.

Key Features

  • 4 Independent Keys via FPC Circuit: Each button has its own dedicated line — no matrix scanning algorithm needed, unlike larger keypads. Simplifies firmware significantly.
  • Self-Adhesive Backing: Peel-and-stick mounting on any flat surface. No screws or brackets needed — ideal for clean enclosure integration.
  • Ultra-Thin Membrane Construction: Flexible polyester top layer keeps the profile minimal. Fits in tight spaces where mechanical buttons cannot.
  • Wide Voltage Compatibility (3.3V – 5V logic): Works with both 3.3V and 5V microcontroller GPIO pins. No level-shifting required for most common platforms.
  • FPC (Flexible Printed Circuit) Interface: Professional, stable electrical connections with consistent actuation. Reliable performance over repeated key presses.
  • Compact Dimensions — 68×20mm Pad: Small footprint fits even the most space-constrained projects. Perfect for handheld devices, remote controls, and panels.

Pinout & Wiring

The keypad exposes 4 signal pins (one per button) via the FPC connector. Each pin corresponds directly to one key. Wiring is straightforward — connect each signal pin to a digital GPIO input on your microcontroller and enable the internal pull-up resistor (or use an external 10kΩ pull-up). Pressing a key pulls the corresponding pin LOW.

PinSymbolDescription
1K1Button 1 signal output — active LOW when pressed
2K2Button 2 signal output — active LOW when pressed
3K3Button 3 signal output — active LOW when pressed
4K4Button 4 signal output — active LOW when pressed

Wiring note: Connect each signal pin (K1–K4) to a digital input pin on your Arduino (e.g., D2–D5). Enable INPUT_PULLUP in your sketch. No common GND or VCC pin is required on the keypad itself — the buttons act as simple normally-open switches connecting the signal line to GND when pressed.

Compatibility

  • Arduino UNO / Nano / Mega: Fully compatible — 5V GPIO with INPUT_PULLUP, direct connection to digital pins.
  • ESP32 / ESP8266: Compatible — 3.3V GPIO, use internal or external pull-up resistors.
  • Raspberry Pi (all models): Compatible — 3.3V GPIO, use RPi.GPIO or gpiozero with pull-up enabled.
  • STM32 / Other 3.3V MCUs: Compatible — works with any 3.3V–5V digital GPIO input.

Typical Applications

  • Menu navigation in DIY embedded systems and custom UI panels
  • 4-function selection in Arduino-based control projects
  • Access control or simple PIN entry (combined with a display)
  • Prototyping user interfaces on a breadboard or perfboard
  • Remote control buttons for IoT devices (ESP32 / ESP8266 projects)
  • Educational electronics labs — teaching GPIO and debounce techniques

Technical Specifications

Interface / ProtocolDirect GPIO (Digital I/O) — 4 independent signal lines
Operating Voltage (Logic)3.3V – 5V DC
Max Voltage per Button24V DC
Max Current per Button30 mA
Operating Temperature0°C to 50°C
Number of Keys4 (1×4 layout)
Circuit TypeFPC (Flexible Printed Circuit)
Pad Size68 × 20 mm
Total Length (with cable)107 mm
MountingSelf-adhesive backing
MPNN/A

Frequently Asked Questions

Q: Does this keypad require matrix scanning code like a 4×4 keypad?
A: No. Unlike larger matrix keypads, this 1×4 model wires each button independently to its own signal pin. You simply read 4 separate GPIO pins — no row/column scanning or Keypad library needed. This makes the code much simpler: just use digitalRead() on each pin with INPUT_PULLUP enabled.

Q: How do I mount the keypad securely?
A: The keypad has a self-adhesive backing — peel off the protective paper and press firmly onto any clean, flat surface. It adheres well to plastic, metal, and acrylic panels and maintains a low profile due to its thin membrane construction.

Package Contents: 1× Membrane 1×4 Matrix Keypad with FPC cable

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