This battery powered device uses an ESP32-WROOM-32D to retrieve values from Openhab 3 (over http) and display them on an OLED SSD1306 display. It uses one button for navigation and the other to turn a "thing" on and off.
There is no PCB board, because all components are wired directly together.
Unfortunately, the code is highly customized to my environment and to my needs, but some lines can probably be reused.