Post your open source Singleboard Computer, and include information for others to follow along.
The requirement is the system must use a microcontroller and display of some kind. These definitions can be flexible, and can include platforms such as Raspberry Pi and a simple led matrix.
In general however, the concept of “less is more” applies to the ethos of Singleboard. The essence of the design is build a fully functioning computer, on a single pcb with only one chip, display and it’s prehiperals.
Singleboard is ultimately yours however! If you see a processor or display time that you would like to see listed (very likely!) please make a post requesting it be added.