MPR121 Capacitive Touch Sensor Module

MPR121 Capacitive Touch Sensor Module is a 12-key touch sensing interface based on the MPR121 IC by NXP. It provides a reliable and efficient way to detect human touch through capacitive sensing, ideal for interactive electronics projects and embedded systems.

Key Features of MPR121 Capacitive Touch Sensor:

• • 12 Touch Inputs: Supports up to 12 independent capacitive keys.
  • I2C Interface: Simple 2-wire communication with address selectability.
  • Interrupt Output: Alert pin for touch detection without constant polling.
  • Touch & Release Thresholds: Programmable via software.
  • LED Indicators: Visual feedback for touch status on most modules.
  • Low Power Mode: Sleep and standby features for battery-powered applications.

Technical Specifications of MPR121 Touch Module:

• • Operating Voltage: 2.5V to 3.6V (typically powered via 3.3V regulator onboard)
  • Communication: I2C (7-bit address range 0x5A – 0x5D)
  • Touch Inputs: 12 (Electrodes 0 to 11)
  • Interrupt Pin: Active-low output to signal touch event
  • Touch Sensitivity: Software adjustable
  • Response Time: Typically <1ms after a touch event
  • PCB Dimensions: Approx. 36mm x 20mm
  • IC Package: MPR121 in QFN-20

Mechanical Characteristics of MPR121 Module:

• • Board Type: Breakout module
  • Mounting Holes: Present on most versions
  • Connector Type: Male header pins (straight or right-angle)
  • Weight: ~5 grams

Wiring and Pinout for MPR121:

• • VCC: Power input (typically 3.3V)
  • GND: Ground
  • SCL: I2C Clock Line
  • SDA: I2C Data Line
  • IRQ: Interrupt Output (Active LOW)
  • ADD: Address Select Input (High/Low to set I2C address)
  • ELE0 – ELE11: Touch Input Pins

Applications of MPR121 Capacitive Touch Sensor Module:

• • Interactive Interfaces: Keypads, sliders, and custom touch inputs
  • DIY Electronics: Arduino, ESP32, Raspberry Pi projects
  • Wearable Devices: Low-power touch sensing for embedded gadgets
  • Home Automation: Touch panels for light switches and controls
  • Art Installations: Touch-triggered sound, lights, and media

Equivalent Models:

• • Adafruit MPR121 Breakout: High-quality equivalent with extra features.
  • SparkFun MPR121 Breakout: Fully compatible breakout board with robust design.

Datasheet:

• • Download NXP MPR121 Datasheet

Keywords for MPR121 Capacitive Touch Module:

• • MPR121 Touch Sensor
  • 12 Channel Capacitive Keypad
  • I2C Touch Interface Module
  • Arduino Capacitive Sensor
  • Capacitive Touch Breakout Board

Package Includes:

• • 1x MPR121 Capacitive Touch Sensor Module