Safety

The device is intended for use in living areas, in particular bedrooms.
It should not be exposed to increased humidity (e.g. in bathrooms), direct sunlight or mechanical stress such as shocks, etc.
There are no dangerous voltages in the housing. The Arduino is supplied via USB cable.
The power bank at the other end of the USB cable is supplied by a 5-volt switching power supply, which in turn is plugged into a socket (230 volts/50 hertz in Germany). Only this part carries mains voltage.
It must be ensured that both the power supply and the power bank remain free of dust and objects (blankets, soft toys, magazines, etc.) that could impede heat dissipation. Otherwise there is a risk of fire!