The OctoPrint 3D Printer management tool provides an API, which allows access to data like
"ExpectedTimeRemaining" or "Printer Status".
This API is used to control an LED Strip (mounted on our 3D Printer) to display different colours depending on the printer status.
This repository also includes a simple effect script.
If the API functionality wants to be used, then OctoPrint has to be configured first.
The tutorial and curcuit to control the LED strip with a raspberry pi can be found here.