epaper tag firmware, BLE MCU is FR8010
+ unpack `lib.zip` to current directionary.
+ open `ARM Keil`, click 'Project' in toolbar and select 'Open Project...'
+ select project file `ble_4_2_app.uvprojx`.
+ also supoort `Eclipse` as C editor, import `\EpaperTag\epaper` into your workspace.