pixelation on full-graphic-discount display

I have gone through all (most?) of the suggestions to eliminate the pixelation shifts that I see on my display, with some improvement but no complete fix. The attached video snippet shows the issue. Running the latest bug-fix version of Marlin on a reprap machine and a Melzi board. All works well on a srd lcd display. Anyone have a proven remedy? Thanks.

I'm having a similar issue. My display has worked fine for the past few years, upgrading from Marlin 1.1.6, 1.1.8, and finally 1.1.9. I had always used my laptop to do upgrades and to make changes to the firmware settings, but I grew tired of having to disconnect the laptop and plug in a USB cable to the RAMPS board. Since I usually have a Raspberry Pi connected to the RAMPS board (running Octoprint) I installed the Arduino IDE on it, and tested to insure it could upload the Marlin firmware. Immediately thereafter, the display looks pixelated like in the picture you provided. I re-uploaded, using my laptop, but the pixelation problem persists. Have you found any solution, yet? I've ordered a replacement display, but I'd like to get this one working again for use in another printer.

There seem to be fast and slow version of this lcd

if you have a slow one you get this corruption.

here is the standard answer, have you tried this?


The only adjustment I know of for the glcd in Marlin is timings

In configuration.h add these to override the defaults.

#define ST7920_DELAY_1 DELAY_NS(0)
#define ST7920_DELAY_2 DELAY_NS(0)
#define ST7920_DELAY_3 DELAY_NS(63) // these are the default values for a 16mhz processor (ie a mega2560)

For every bit that is sent the delays are added as follows.
set the clock pin low and wait delay_1
set the data pin and wait delay_2
set the clock pin high and wait delay_3

You need to adjust these values upwards to suit your display.

many have found that changing delay 3 to 125 works for them. but it depends on your LCD.
ie add #define ST7920_DELAY_3 DELAY_NS(125) to your configuration.h

SOLVED...

I found this on the Marlin github forum:

larsnordstrom commented on Oct 4, 2018 •

Ok, then you need to add a condition to ultralcd_st7920_u8glib_rrd.h
locate line 56 and make sure it reads:

#elif MB(MINIRAMBO) || MB(EINSY_RAMBO)

Since my board is an MKS GEN (v1.4), I also had to add info for my board, so mine looks like this:

#elif MB(MINIRAMBO) || MB(EINSY_RAMBO) || MB(MKS_GEN_13)

This fixed this issue for me.