teeminus

When using the emulated_st7920 Klipper display driver, you could try different bus speeds.

'spi_speed', see https://www.klipper3d.org/Config_Reference.html?h=spi_speed#common-spi-settings The default value is 1MHz, minimal value is 100kHz.

Maybe the issue is caused by crosstalk on the mainboard.

Have tried the original BTT firmware lately? Maybe the original firmware works better 🤷‍♂️

That really sounds like voodoo as there were only minor changes which have nothing to do with the SPI interface...

@pixeldoc2000 Very interesting discovery. Could be indeed some kind of ground loop. Or some interferences coupling into the display. Or some difference of potential between the frame and the ground...

@hapklaar Did you encounter the issue again or is 1.3.1 still working fine?

Hi, this firmware is based on a pretty old version of the original BTT firmware. Therefore, the new displays are not supported. To make this firmware work with new displays...

> as an optional feature sure, no hard opinion Same

There is no difference.