Hello,

I bought a CXY card, and all worked great, but after a firmware update MARLIN, I ended up with a display as we see on the attached image, I tested different firmware and I always have the same result and I can not find any solution. Every two seconds there is a refresh but it's never correct.

Is a display speed problem? I do not know where to find.

your googlefoo is very weak

[github.com]

Yes!
i find another solution

put to comment the line #pragma GCC optimize (3) in ultracd_st7920_u8glib_rrd.h

Like :

#pragma GCC optimize (3)

to

//#pragma GCC optimize (3)

Edited 2 time(s). Last edit at 10/24/2018 06:22AM by jiefel.

#define ST7920_DELAY_3 DELAY_NS(300)