GroundStudio boards
In Arduino IDE "File->Preferences->Aditional Boards Manager URLs:" add: https://raw.githubusercontent.com/GroundStudio/Boards/master/package_groundstudio_index.json
GroundStudio boards
In Arduino IDE "File->Preferences->Aditional Boards Manager URLs:" add: https://raw.githubusercontent.com/GroundStudio/Boards/master/package_groundstudio_index.json