{"product_id":"mpr121-capacitive-touch-sensor-module-12-key-i2c-3-3v-5v-arduino","title":"MPR121 Capacitive Touch Sensor Module — 12-Key, I²C, 3.3V\/5V, Arduino","description":"\u003ch2\u003eMPR121 Capacitive Touch Sensor Module — 12-Key, I²C, Arduino\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eMPR121 capacitive touch sensor module\u003c\/strong\u003e detects touch on up to 12 independent electrode inputs using Freescale's MPR121 proximity capacitive touch controller — reporting touch\/release events via I²C with an interrupt (IRQ) output for efficient MCU polling. No mechanical switches required — any conductive surface (copper pad, wire, foil, fruit) connected to an electrode input becomes a touch sensor. Widely used for touch keyboards, touch buttons, and human-machine interface (HMI) projects with Arduino and Raspberry Pi.\u003c\/p\u003e\n\n\u003ch3\u003eModule Specifications\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eIC:\u003c\/strong\u003e MPR121 (NXP\/Freescale)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTouch Channels:\u003c\/strong\u003e 12 independent capacitive inputs (ELE0–ELE11)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eInterface:\u003c\/strong\u003e I²C (address selectable: 0x5A–0x5D via ADDR pin)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSupply Voltage:\u003c\/strong\u003e 3.3V (on-board regulator for 5V input)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eInterrupt:\u003c\/strong\u003e IRQ pin (active LOW on touch\/release event)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSensitivity:\u003c\/strong\u003e Adjustable via touch\/release threshold registers\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAuto-calibration:\u003c\/strong\u003e Built-in baseline tracking\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eArduino Wiring\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eVCC → 3.3V | GND → GND | SDA → A4 | SCL → A5 | IRQ → D2\u003c\/li\u003e\n  \u003cli\u003eUse Adafruit MPR121 library from Arduino Library Manager\u003c\/li\u003e\n  \u003cli\u003eConnect electrodes (wires, copper pads, or conductive objects) to ELE0–ELE11\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTypical Applications\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e12-key capacitive touch keyboard\u003c\/li\u003e\n  \u003cli\u003eTouch-sensitive control panel\u003c\/li\u003e\n  \u003cli\u003eMusical instrument touch controller (Theremin-style)\u003c\/li\u003e\n  \u003cli\u003eFruit piano (banana, orange as touch electrodes)\u003c\/li\u003e\n  \u003cli\u003eProximity sensor (detect hand approach without contact)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eMPR121 capacitive touch module — 12-key, I²C, IRQ, auto-calibration for Arduino touch keyboard, HMI, and capacitive sensing projects.\u003c\/p\u003e","brand":"Keszoox","offers":[{"title":"Default Title","offer_id":46991447884011,"sku":"\u003cnone\u003e","price":8.04,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0677\/1005\/8731\/files\/mpr121-capacitive-touch-sensor-module-multi-key.webp?v=1761804681","url":"https:\/\/keszoox.com\/products\/mpr121-capacitive-touch-sensor-module-12-key-i2c-3-3v-5v-arduino","provider":"Keszoox","version":"1.0","type":"link"}