The information here is aimed at connecting a RepRap 12864 display but it can also be applied to other 12864 displays (as long as they are ST7567 or ST7920 based).
Add the following lines to the board.txt file
lcd.encoderPinA=BTN_EN2 lcd.encoderPinB=BTN_EN1 lcd.encoderPinSw=BTN_ENC lcd.lcdCSPin=LCD_RS lcd.spiChannel=3
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 - WiFi Mode only
Extract the contents of the zip file you downloaded above and place them in a folder called “Menu” on the SD card of the GTR.
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.
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.