I have just got a Tufty 2040 and have moved over some code that was running correctly on a a Display Pack 2 and a 2.8 inch Waveshare screen but have come across a few issues…
When using any pen type other than RGB332 the screen corrupts when rotated 90 or 270 degrees:
I believe the parallel connection might not be your problem. I’ve come across similar types of occurrences, where RGB332 is the solution. That and not using pure white in certain scenarios.
Here is a link on one of the discussions (thanks to the testing by the participants)
As for your comment about the backlight…
Yes, I’ve noticed that as well. Anything less then 0.4 (or more exact 0.39 [that is what the output of the reading shows) it goes black. - Hence why I’ve added code to stop there, if I want the lowest dimmed screen.
I actually logged that issue on GitHub after I saw a similar issue posted in the circuitpython repo by someone trying to do a Tufty build and did a bit more testing.