# Adafruit MPR121 12-Key Capacitive Touch Sensor Gator Breakout - STEMMA QT / Qwiic

**Type:** Product page · **SKU:** ADA4830 · **Brand:** [Adafruit](https://core-electronics.com.au/brands/adafruit-australia)
**Page:** https://core-electronics.com.au/adafruit-mpr121-12-key-capacitive-touch-sensor-gator-breakout-stemma-qt-qwiic.html ([markdown](https://core-electronics.com.au/adafruit-mpr121-12-key-capacitive-touch-sensor-gator-breakout-stemma-qt-qwiic.html.md))

Add lots of touch sensors to your next microcontroller project with this easy-to-use 12-channel capacitive touch sensor breakout board, starring the MPR121. This chip can handle up to 12 individual touchpads with plug-and-play STEMMA QT connector and large alligator/croc-clip friendly pads, its a no-solder solution to capacitive touch sensing.

## Pricing

- **Price:** $13.25 (inc GST) — $12.05 AUD, exc GST
- **Quantity discounts:** 10+ $11.68 (exc GST) · 50+ $11.45 (exc GST)

## Availability & dispatch

- In stock, ships same business day if ordered before 2PM (Australia/Sydney).
- We can dispatch 1 today, and up to 2 more in 8–12 days.

## Description

Add lots of touch sensors to your next microcontroller project with this easy-to-use 12-channel capacitive touch sensor breakout board, starring the MPR121. This chip can handle up to 12 individual touchpads with plug-and-play STEMMA QT connector and large alligator/croc-clip friendly pads, its a no-solder solution to capacitive touch sensing.

The MPR121 has support for reading data over I2C, which can be implemented with nearly any microcontroller. You can select one of 2 addresses with the ADDR pin (solder it close for the alternative address), for a total of 24 capacitive touch pads on one I2C 2-wire bus. Using this chip is a lot easier than doing the capacitive sensing with analog inputs: it handles all the filtering for you and can be configured for more/less sensitivity.

This sensor comes as a tiny hard-to-solder chip so they put it onto a breakout board for you. Since it's a 3V-only chip, Adafruit added a 3V regulator and I2C level shifting so it's safe to use with any 3V or 5V microcontroller/processor like Arduino. Adafruit even added an LED onto the IRQ line so it will blink when touches are detected, making debugging by sight a bit easier on you.

Comes with a fully assembled board. For contacts, we suggest using copper foil, [metallic nylon](https://core-electronics.com.au/nylon-fabric-squares-with-conductive-adhesive-10cm-x-10cm-3-pack.html), or [pyralux](https://core-electronics.com.au/flex-pcb-material-pyralux-6-by-6-square-ac-352500ey.html), then [connect up any alligator clip](https://core-electronics.com.au/search/?q=alligator) from the conductive material to one of the big pads on the breakout.

To make using it as easy as possible, we’ve put the MPR121 on a breakout PCB in our Stemma QT form factor with a sprinkle of support circuitry to give you options when testing. You can either use a breadboard or the **SparkFun qwiic** compatible **STEMMA QT** connectors, and compatibility with 5V voltage levels as commonly found on [Arduinos](https://core-electronics.com.au/arduino.html), as well as 3.3V logic used by many other boards like the Raspberry Pi or Adafruit's Feathers. QT Cable is not included**, but Adafruit have a variety in the shop for quick plug-and-play support.

Getting started is a breeze with Adafruit's Arduino and CircuitPython/Python libraries and tutorials. You'll be up and running in a few minutes, and if you are using another microcontroller, it's easy to port Adafruit's code.

[Of course, Adafruit wouldn't leave you with a datasheet and a "good luck!" - Adafruit wrote a detailed tutorial showing how to wire up the sensor, use it with an Arduino, and example code that g](https://learn.adafruit.com/adafruit-mpr121-12-key-capacitive-touch-sensor-breakout-tutorial)ets the sensor logging data and detecting your touch!

**Technical Details**

- Product Dimensions: 51.0mm x 25.2mm x 4.5mm / 2.0" x 1.0" x 0.2"

## Images

- [Product image 1](https://core-electronics.com.au/media/catalog/product/4/8/4830-00.jpg)