{"product_id":"4x5-matrix-20-key-membrane-keypad-for-arduino","title":"4x5 Matrix 20-Key Membrane Keypad for Arduino","description":"\u003ch1\u003e4x5 Matrix 20-Key Membrane Keypad for Arduino\u003c\/h1\u003e\u003cp\u003eThis is a 4x5 matrix membrane keypad with 20 keys, ideal for user input in Arduino and microcontroller projects. It uses a flexible membrane construction with conductive traces, providing a lightweight, water-resistant input solution. Commonly used in security panels, numeric entry, and menu navigation, it simplifies projects requiring multiple buttons without occupying many I\/O pins.\u003c\/p\u003e\u003ch2\u003eKey Specifications\u003c\/h2\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eKey Matrix\u003c\/td\u003e\n\u003ctd\u003e4 rows × 5 columns\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTotal Keys\u003c\/td\u003e\n\u003ctd\u003e20\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Voltage\u003c\/td\u003e\n\u003ctd\u003e3.3V – 5.5V DC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePin Count\u003c\/td\u003e\n\u003ctd\u003e9-pin male header (2.54mm pitch)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e67mm × 76mm × 1mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCable Length\u003c\/td\u003e\n\u003ctd\u003e80mm flexible ribbon\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch2\u003eWhat You Can Build With This\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/products\/kit-servo-door-lock\"\u003ePassword-protected door lock system\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003eArduino calculator with LCD display\u003c\/li\u003e\n\u003cli\u003eMenu navigation for LCD-based projects\u003c\/li\u003e\n\u003cli\u003eSecurity alarm keypad (arming\/disarming)\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eCompatibility\u003c\/h2\u003e\u003cp\u003eWorks with Arduino Uno, Nano, Mega, ESP32, ESP8266, and any board with 9 digital I\/O pins. 3.3V logic tolerant. Commonly paired with the Arduino Keypad library and character LCD displays for interactive projects.\u003c\/p\u003e\u003ch2\u003eWiring Notes\u003c\/h2\u003e\u003cp\u003eConnect the 9-pin header to digital I\/O pins. For standard Keypad library usage, connect rows 0-3 to pins 5-2 and columns 0-4 to pins 9-5 (order flexible). Enable internal pull-ups on row pins; no external resistors needed. Avoid exceeding 5V on I\/O pins.\u003c\/p\u003e\u003ch2\u003eWhy Buy from Compoden\u003c\/h2\u003e\u003cp\u003eEvery component is sourced from verified suppliers and tested for compatibility before listing. We've spent 10 years building projects for makers, schools, and institutions across India. Ships from Bengaluru in 3-5 days. If defective on arrival, replace within 7 days.\u003c\/p\u003e\u003cdetails\u003e\u003csummary\u003eIs this compatible with Arduino Uno?\u003c\/summary\u003e\u003cp\u003eYes, it works perfectly with Arduino Uno using the Keypad library. Connect any 9 digital pins and configure the library accordingly.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eDoes this keypad have tactile feedback?\u003c\/summary\u003e\u003cp\u003eNo, it's a membrane keypad with a smooth, flat surface. Presses require light pressure but no click. It's quiet and durable.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003eHow do I connect it to fewer pins?\u003c\/summary\u003e\u003cp\u003eUse a PCF8574 I2C backpack module to reduce pin count to 2 (SDA\/SCL). Libraries like Keypad_I2C support this.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdiv class=\"compoden-handoff\" style=\"margin-top:24px;padding:16px;background:#f0f4ff;border-left:4px solid #2B4D8F;border-radius:4px;\"\u003e\n  \u003cp style=\"margin:0 0 6px 0;font-weight:600;color:#1A3560;\"\u003e📦 Free Setup Handoff Document Included\u003c\/p\u003e\n  \u003cp style=\"margin:0;font-size:0.95em;color:#333;\"\u003eEvery Compoden order includes a free setup handoff document — step-by-step instructions to get your component working within minutes. Download it via QR code on your package. The handoff document is also trained to help you troubleshoot the majority of problems.\u003c\/p\u003e\n\u003c\/div\u003e\n","brand":"Compoden","offers":[{"title":"Default Title","offer_id":53444946493805,"sku":"CDN-0057","price":75.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0999\/3997\/5533\/files\/image_1_37089503-b7d0-4250-b191-4761c162df3b.jpg?v=1781512128","url":"https:\/\/compoden.com\/products\/4x5-matrix-20-key-membrane-keypad-for-arduino","provider":"Compoden","version":"1.0","type":"link"}