To achieve 0% brightness, I needed another PIO line. I was able to save this by adding an additional state machine. The PIO program now uses four. With this version, I have gone through all the variants (1SM, 2SM, 3SM, and now 4SM).
I found another error during testing. With the bitmaps, exceeding the maximum Y position was not intercepted. This occurred in connection with vertical text.

Hub75_4SmDemo.zip

Albert