The mTouch Capacitive Sensing Library is a software library that can be loaded by the MPLAB® Code Configurator (MCC). Please refer to the MCC installation instructions.
The mTouch library is included in the MCC installation, but it is always a good idea to check the latest version of the library in the Current Download section of the MCC website, because the mTouch library may be released independently of of the MCC release. The release note associated with the library provides part support list, change log, etc.
If a newer version is found on the website, download the library file and unzip the .jar file, and then open up the Options windows of the MPLAB X IDE, as shown in the figure.
Click the Add Library button, and select the unzipped .jar file.
After adding the library file, restart the MPLAB X IDE.