{"product_id":"lonely-binary-2-pack-4x4-matrix-keypad-with-i2c-adapter-for-arduino-id","title":"2-Pack 4x4 Matrix Keypad with I2C Adapter","description":"\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e8 GPIO PINS DOWN TO 2\u003c\/strong\u003e SIX PINS BACK ON EVERY BUILD: A 4x4 matrix keypad wired directly takes eight GPIO pins. Through the adapter it needs two — SDA and SCL. The six pins you get back stay free for displays, SD cards, servos and sensors, and other I2C devices can share the same two wires.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRIGID HOUSING, INDIVIDUAL KEYS\u003c\/strong\u003e BUILT FOR REPEATED PRESSES: Molded ABS frame with 16 separately raised keys on a PCB — 0-9, A-D, star and hash. 160-180g actuation force and under 100 ohm contact resistance give a firm, repeatable press rather than a soft membrane feel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNO JUMPER WIRES BETWEEN THEM\u003c\/strong\u003e FACTORY PRE-SOLDERED HEADER: The 2.54mm 8-pin header arrives already soldered to the keypad and plugs straight into the adapter socket. Four wires — GND, VCC, SDA, SCL — go to your board. Runs on 3.3V or 5V logic, so no level shifter is needed.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTWO IN THE PACK\u003c\/strong\u003e ONE TO BUILD WITH, ONE IN RESERVE: Two complete keypad-and-adapter pairs, so a second project or a spare is already covered. Both adapters ship at address 0x20 and work independently on separate boards straight away.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOPTIONAL: BOTH ON ONE BUS\u003c\/strong\u003e A0\/A1\/A2 ADDRESS PADS: To run both keypads on a single board, bridge the A0 solder pad on one adapter to move it to 0x21. This step needs a soldering iron. The pads cover eight addresses, 0x20 to 0x27. Compatible with Arduino IDE, ESP32-S3 and Raspberry Pi boards; the open-source I2CKeyPad library is in the Arduino Library Manager.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003ctable\u003e\n\u003ctr\u003e\n\u003cth\u003eBrand\u003c\/th\u003e\n\u003ctd\u003eLONELY BINARY\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eCompatible Devices\u003c\/th\u003e\n\u003ctd\u003eArduino Uno, Arduino Mega, Arduino Nano, ESP32-S3 development boards, ESP32, ESP8266, Raspberry Pi (4B, 3B+, Zero, Pico), STM32 boards, MicroPython-compatible boards, I2C-enabled microcontrollers, embedded systems and IoT development platforms\nArduino Uno, Arduino Mega, Arduino Nano, ESP32-S3 development boards, ESP32, ESP8266, Raspberry Pi (4B, 3B+, Zero, Pico), STM32 boards, MicroPython-compatible boards, I2C-enabled microcontrollers, embedded sy… See more\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eConnectivity Technology\u003c\/th\u003e\n\u003ctd\u003eI2C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eKeyboard Description\u003c\/th\u003e\n\u003ctd\u003eMembrane\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eRecommended Uses For Product\u003c\/th\u003e\n\u003ctd\u003eArduino projects, ESP32-S3 development, Raspberry Pi interfaces, IoT automation projects, smart home control panels, DIY electronics prototyping, embedded systems development, robotics control input, microcontroller-based interfaces, sensor control systems, breadboard prototyping setups, Home security systems, electronic door locks, keypad entry systems, alarm control panels, access control systems, password input devices, PIN-based access systems, digital safes, vending machines, attendance systems, electronic voting systems, Industrial control panels, automation interfaces, menu navigation systems, interactive user input systems, custom control consoles, data entry panels, user authentication systems, prototype hardware interfaces, lab testing setups, engineering training projects, STEM education kits, classroom electronics learning, maker projects, hobby electronics projects\nArduino projects, ESP32-S3 development, Raspberry Pi interfaces, IoT automation projects, smart home control panels, DIY electronics prototyping, embedded systems development, robotics control input, microcontroller-bas… See more\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eSpecial Feature\u003c\/th\u003e\n\u003ctd\u003eBuilt-in I2C interface simplifies wiring and reduces pin usage to just SDA and SCL. Includes a dual keypad set (2-pack), ideal for multi-device or expandable projects., Compact and lightweight design with breadboard-compatible headers for easy soldering and quick setup. Supports both 3.3V and 5V systems with stable, noise-resistant signal performance. Plug-and-play compatibility with widely available libraries, perfect for Arduino, ESP32, Raspberry Pi, and other IoT or embedded applications., Designed to save GPIO pins while supporting multiple devices on the same I2C bus. Durable membrane keys provide long lifespan with responsive tactile feedback and low contact resistance (\u0026lt;100Ω).\nBuilt-in I2C interface simplifies wiring and reduces pin usage to just SDA and SCL. Includes a dual keypad set (2-pack), ideal for multi-device or expandable projects., Compact and lightweight design with breadboard-compatible head… See more\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eStyle\u003c\/th\u003e\n\u003ctd\u003eDual 4x4 I2C Matrix Keypad (Heavy Duty, 2-Pack)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eProduct Dimensions\u003c\/th\u003e\n\u003ctd\u003e2.72\"L x 2.72\"W x 0.38\"H\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003eFlexible Membrane (PET) with PCB and Electronic Components\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eIncluded Components\u003c\/th\u003e\n\u003ctd\u003e2x Lonely Binary Heavy Duty 4x4 Matrix Keypad, 2x Lonely Binary I2C Adapters\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e","brand":"Lonely Binary","offers":[{"title":"Default Title","offer_id":48884154499229,"sku":"B0G6YRQJ5F","price":27.71,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0331\/9994\/7908\/files\/51vWdpxj65L.jpg?v=1788828913","url":"https:\/\/lonelybinary.com\/products\/lonely-binary-2-pack-4x4-matrix-keypad-with-i2c-adapter-for-arduino-id","provider":"Lonely Binary","version":"1.0","type":"link"}