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Ensure that you have read the following articles:
Setting up the submodule
A submodule is more than just a regular folder, it also acts as a repo that you can push, create branches, and more just as any other repository.
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Follow the Using this repository section from the USVT-KicadLibraries repo readme on how to add the symbol libraries to your project
Currently, the readme uses "common" as the name of the submodule, but that'll change depending on what you name it. By default, it is named the name of the repo (UTSVT-KiCADLibraries).
To set up your footprints enter the PCB editor and follow the same steps. This time use the .pretty folders (folders that contain all our footprints) instead of the .sym files
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