If I understand correctly, you build the firmware yourself and then ran the demo program.
The demo programs work with the precompiled firmware linked in the GitHub repositry.
It uses an older LVGL version (v. 8.3) and an older version of mpy.
Try flashing it and run the demo script again.
To kdschlosser and de-dh:
Apologies for my delay in replying.
I think I have gone as far as I can on this post. From what I see in other posts by yourselves and others, the process of setting up LVGL to run with micropython is a work in progress. I have decide to wait until it is completed, and meanwhile I’ll write upython code for the CYD without using LVGL.
All the same, many thanks for your help – I have learnt a lot about running a virtual Linux distribution on Windows, which could be very useful for other projects.
Ken.