Touch Shield for Arduino

Introduction

The MPR121 IC is a great way to build simple capacitive touch interfaces, and now it's even easier to incorporate into your Arduino projects with the touch shield. The touch shield has 9 capacitive touch pads, with headers for the remaining 3 electrode connections. With this shield you can have a total of 12 touch sensitive buttons. An on-board logic level converter allows it to work with 5V and 3.3V Arduino boards. Simply solder on some header pins and stack it on to your Arduino for a convenient input device. Check below for some example code to get you started.

Below photos are for shield without headers:

Schematic

• Schematics

Usage

Test Report

This board use the MPR121 as the main IC,This IC can connect 12 pads,8 of the 12 pads can be usd as the second functions(driving the leds),The supply voltage vary from 1.71v to 3.6v. The circuit can be as low as 29uA at the sampling rate of 16ms,The IC communicatie with the MCU Through interrupt or I2C.

We used 9 pads on our board as input,This board can be placed on the arduino board conveniently.

Programming

instructions

This board use the 3.3v voltage of the arduino board,it communicate with the arduino board through I2C,the voltage of the MCU’s IO is 5V, in order to compatible with the Tocuth shield board voltage , the board used 2 MOS FET to solve the problems.

• SDA------A4
• SCK------A5
• interrupt------D2

test procedure

software platform: arduino

test code:see the attachment

code procedure:

init the I2C

init MPR121

enable the interrupt

handle the interrupt process,send the data through UART

notice: The interrupt handle function cannot work with the condition more than two key push down at the same time.

after the initialize

The interrupt function send the data to the PC when the key is pressed

FAQ

Please list your question here:

Support

If you have questions or other better design ideas, you can go to our forum to discuss or creat a ticket for your issue at linksprite support.

Resources

• Sample Code

How to buy

Here to buy Touch Shield for Arduino on store

See Also

Other related products and resources.

Licensing

This documentation is licensed under the Creative Commons Attribution-ShareAlike License 3.0 Source code and libraries are licensed under GPL/LGPL, see source code files for details.