For those looking for an easy build pre loaded hardware kit, then check out the new case design:  https://www.thingiverse.com/thing:4538747
This is a station box designed for the Wemos D1 Mini and the standard 0.96" 128x64 OLED display.  Get creative with Arduino code or load some of the awesome Wemos applications out there.
The Wemos D1 mini will slide in and is held in place by the back plate.  The display will need to be glued in with a dab of glue on each corner.
Code and Project:
You can monitor your 3D Printer's OctoPrint Server using a Wemos D1 Mini ESP8266 and a I2C SSD1306 OLED Display over a wifi connection.  The 3D Printing files (STL) are freely available.  The source code link down below.  (Note: some have reported that it works out of the box with AstroPrint as well.)
Features:
Displays the print status from OctoPrint Server
Estimated time remaining
Time Printing
Percentage complete
Progress bar
Bed and Tool Temperature
Screen turns off when printer is turned off or disconnected
Screen turns on…