This code repository no longer maintain. New code repository is here: LKxPro marlin1.1.9 update and modification will going on new repository.
This firmware was mdified by Longer3D. It was based on Marlin 1.1.9 and applies to U20_Pro and U30_Pro. Marlin1.1.9 LGT0.3.X supports the U30 Pro printer by default. If you are using U20 Pro,you need unremark "U20_Pro" in Configuration.h.