Adafruit 12-Key Capacitive Touch Sensor Breakout - MPR121 (STEMMA QT)

Add touch sensitivity to your next project with the 12-Channel Capacitive Touch Sensor Breakout Board, featuring the MPR121 chip. This compact sensor can handle up to 12 individual touchpads, making it perfect for projects that require multiple touch inputs, such as interactive controls or custom touch interfaces.

The MPR121 operates via I2C communication, making it compatible with almost any microcontroller. You can choose one of four addresses using the ADDR pin, allowing you to connect up to 48 capacitive touchpads on a single I2C bus. The chip does all the hard work of capacitive sensing, including filtering, so it's much easier to use than analog inputs. Plus, it can be configured for different levels of sensitivity to match your needs.

To make using this chip easier, we've placed the MPR121 on a breakout board, and added essential components like a 3V regulator and I2C level shifting, ensuring compatibility with both 3V and 5V microcontrollers, like Arduino. An LED indicator on the IRQ line blinks whenever a touch is detected, helping with debugging and ensuring you know when the sensor is activated.

Key Features:

• Handles up to 12 capacitive touchpads (expandable to 48 with multiple boards)
• I2C interface for easy integration with microcontrollers (supports addresses 0x5A, 0x5B, 0x5C, or 0x5D)
• Built-in filtering for easy touch sensing (configurable sensitivity)
• 3V-only chip, with integrated 3V regulator and I2C level shifting
• LED indicator to signal touch detection (useful for debugging)
• Comes with fully assembled breakout board and a stick of 0.1" header for breadboard use

Easy Setup:

• Connect the board to any microcontroller (Arduino, CircuitPython, or other I2C-based systems).
• Our Arduino library and tutorial make it easy to get started, and the code is easily ported to other microcontrollers.
• The STEMMA QT connectors make wiring even simpler, offering plug-and-play compatibility with SparkFun qwiic cables. No soldering required for I2C and power connections!

Technical Details:

• I2C 7-bit address: 0x5A (can be changed to 0x5B, 0x5C, or 0x5D)
• Breakout board includes: MPR121 chip, 3V regulator, level-shifting circuitry, and IRQ LED
• Compatible with 3V to 5V systems
• Dimensions: Small form factor for easy integration into various projects
• Datasheets, PCB files, and Fritzing objects are available in the tutorial

Revision History:

• November 22, 2022: PCB updated with Adafruit Pinguin for better silkscreen clarity. You may receive either the new or older version.
• January 21, 2021: Updated to STEMMA QT standard for easy connections with STEMMA QT cables.

With this 12-channel capacitive touch sensor breakout board, you can easily add touch functionality to your next microcontroller project—whether you're building a custom touchpad interface, interactive buttons, or more!