Which LED-ring is compatible?
Any ring using WS2812B LEDs (or compatible) will do. To avoid problems with the calibration we suggest using the FabScanPi LED-board.
If you choose to use an alternate light ring then consider that this is an addressable light and the code running on the Pi-Hat is configured for 12 LEDs. If you have more than 12 LED then only the first 12 will illuminate. Note that with the WS2812B, you can run the data line in paralell to multiple LED strips (mind the power consumption). many of the avaliable light rings are 24 LED. You can wire these to work by cutting the data connection between lights 12 and 13, and running a jumper from the data (DI) at LED 1 to the data (DI) at LED13. The photo shows where I scraped the paint around the dataline, and then once isolated, I used an exacto to cut thru the copper trace. after the mod clean and check to make sure there is no continuity between the cut traces, and that nothing is shorted to ground or +5v (copper areas above and below trace in photo.