The Adafruit MPR121 Gator Breakout adds 12 capacitive touch inputs to any microcontroller project — no soldering required. With large alligator/croc-clip friendly pads and STEMMA QT / Qwiic connectors, simply clip conductive materials to the pads and plug into your board's I2C port.

The MPR121 handles all capacitive touch filtering and threshold detection internally over I2C, making it far simpler than reading analog inputs directly. Two selectable I2C addresses (via the ADDR solder jumper) allow up to 24 touch pads on a single bus. The breakout includes a 3.3 V regulator and level shifting for compatibility with both 3.3 V and 5 V systems, plus an IRQ LED that blinks on touch detection for easy debugging.

Key Features

• 12 Capacitive Touch Channels – Each with its own large gator-clip pad
• MPR121 Touch Controller – Built-in filtering and configurable sensitivity
• I2C Interface – 2 selectable addresses for up to 24 pads on one bus
• STEMMA QT / Qwiic Connectors – Solderless I2C connection (cable not included)
• 3.3 V and 5 V Compatible – On-board regulator and level shifting
• IRQ LED Indicator – Blinks when a touch is detected
• No Soldering Required – Clip conductive materials directly to the oversized pads

Ideal For

• Interactive art and music installations
• Custom touch-sensitive controllers and keyboards
• Educational projects exploring capacitive sensing
• Costume and wearable touch interfaces

Package Contents

• 1× Adafruit MPR121 12-Key Capacitive Touch Gator Breakout (assembled)

Resources

• STEMMA QT Overview
• MPR121 Touch Sensor Tutorial