How to connect a 12864 screen to a SKR-RRF-E3

Overview

The information here is aimed at connecting a stock ender 3 12864 display but it can also be applied to other 12864 displays (as long as they are ST7567 or ST7920 based).

Wiring

The ender 3 stock display can be connected directly to the EXP header of the SKR-RRF-E3. No modifications are required.

Board.txt modifications

The following lines should be added to the board.txt file.

lcd.encoderPinA=B.2
lcd.encoderPinB=E.7
lcd.encoderPinSw=E.9
lcd.lcdCSPin=B.1
lcd.spiChannel=4
SPI4.pins={ E.10, NoPin, E.11 }
lcd.lcdBeepPin = E.8

Config.g changes

Add the following line to the end of your config.g

M918 P1 E4 F100000

Menu files must be uploaded to allow the display to generate the correct information. This can be done in two ways. First, obtain the recommended menu files from here

Method 1

Extract the contents of the zip file you downloaded above and place them in a folder called “menu” on the SD card of the SKR-RRF-E3.

Method 2

Activate the display using the config.g changes above.
A side menu called “Display” should appear in DWC. Navigate to it and upload the zip file.

Troubleshooting

If the screen is showing artifacts/random characters on the screen, the following may improve/eliminate the issue

  • Lower the SPI frequency by half. This is the F value in M918.
  • Reduce the length of the cable between the screen and the board.
  • Ensure that the cable between the screen and the board is routed away from other cables, especially motor cables.
  • Add a ferrite ring to the cable between the screen and the board.
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