Grove - I2C Touch Sensor


3.3V 5.0V I2C

The I2C Touch Sensor is based on the Proximity Capacitive Touch Sensor Controller from FreeScale - MPR121. It detects the touch or proximity of human fingers. This sensor includes a Touch Sensor controller and 4 finger feelers. One can insert the connectors of feelers into base of Sensor controller, and start sensing the touch.


Parameter Value/Range
Operating voltage 3~5.5V
Standby Mode Current 2μA
Touch Channels 12 (Including 4 with Touch feelers)
Communicating Protocol I2C
I2C Address 0x5A - 0x5D

Platforms Supported

Hardware Overview

There are 12 electrodes CH0-CH11. CH0-CH3 are connected to 4 Touch feelers.

The CH4-CH11 are for customer expanding the function. If you need more, you can make the feelers by yourself.

The wires of feelers are twisted to reduce the impact of environment. The black(ground) wire can be cut off if high sensitivity is needed.

The INT pin has to be led out if customers want to use the interrupt pin of MPR121.

Getting Started

Grove - Help

Following documents help in getting the user started with Grove.


Since each electrode needs to be auto-configured by the MPR121 during power up and there is no power reset on the touch sensor controller, everytime you insert or remove a feeler, you need to reset the power of Seeeduino.

The feelers can also feel the human being fingers with something between, that’s to say, you do not need to touch the feelers with your fingers indeed.

With a paperboard about 3 mm thick, the feeler can feel the touch of fingers, makes it a good solution for many applications.


ArduinoWioBeagleBoneRaspberry PiLinkIt ONE


The platforms mentioned above as supported is/are an indication of the module's hardware or theoritical compatibility. We only provide software library or code examples for Arduino platform in most cases. It is not possible to provide software library / demo code for all possible MCU platforms. Hence, users have to write their own software library.

Help us make it better

Thank you for choosing Seeed. A couple of months ago we initiated a project to improve our documentation system. What you are looking at now is the first edition of the new documentation system. Comparing to the old one, here is the progresses that we made:

  • Replaced the old documentation system with a new one that was developed from Mkdocs, a more widely used and cooler tool to develop documentation system.
  • Integrated the documentation system with our official website, now you can go to Bazaar and other section like Forum and Community more conveniently.
  • Reviewed and rewrote documents for hundreds of products for the system’s first edition, and will continue migrate documents from old wiki to the new one.

An easy-to-use instruction is as important as the product itself. We are expecting this new system will improve your experience when using Seeed’s products. However since this is the first edition, there are still many things need to improve, if you have any suggestions or findings, you are most welcome to submit the amended version as our contributor or give us suggestions in the survey below, Please don’t forget to leave your email address so that we can reply.

Happy hacking