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=PB_2
lcd.encoderPinB=PE_7
lcd.encoderPinSw=PE_9
lcd.lcdCSPin=PB_1
lcd.spiChannel=4
SPI4.pins={ PE_10, NoPin, PE_11 }
lcd.lcdBeepPin = PE_8

Config.g changes

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

M918 P1 E4 F100000

Wiring

The Fysetc Mini12864 RGB Panel v2.1 can be connected directly to the EXP header of the Fly-E3-Pro using custom wiring.
Use the table below as a guide.

Pin Name BTT E3 RRF Pin location Mini 12864 Pin Location
5V EXP1 Pin 1 - 5V EXP1 Pin 1 - VCC
GND EXP1 Pin 2 - GND EXP1 Pin 2 - GND
LCD Reset TFT Pin 3 - TX1 (PA_9) EXP1 Pin 6 - LCD RST
lcd.encoderPinA=PE_10 EXP1 Pin 5 - PE10 EXP2 Pin 8 - BTN EN1
lcd.encoderPinB=PE_11 EXP1 Pin 3 - PE11 EXP2 Pin 6 - BTN EN2
lcd.encoderPinSw=PE_9 EXP1 Pin 9 - PE9 EXP1 Pin 9 - BTN_ENC
lcd.lcdCSPin=PB_1 EXP1 Pin 4 - PB1 EXP1 Pin 8 - LCD CS
SPI4.pins={ PB_2, NoPin, PE_7 } EXP1 Pin 6 - PB2, EXP1 Pin 8 - PE7 EXP2 Pin 8 - SCK , EXP2 Pin 5 - MOSI
lcd.lcdDCPin = PE_8 EXP1 Pin 10 - PE8 EXP1 Pin 7 - LCD A0
led.neopixelPin=PB_7 Neopixel Pin 2 - PB7 EXP1 Pin 5 - RED
Mainboard Reset EXP1 Pin 7 - RST EXP2 Pin 3 - RST (optional)

Board.txt modifications

Add the following lines to the board.txt file

lcd.encoderPinA=PE_10
lcd.encoderPinB=PE_11
lcd.encoderPinSw=PE_9
lcd.lcdCSPin=PB_1
lcd.spiChannel=4
SPI4.pins={ PB_2, NoPin, PE_7 }
lcd.lcdDCPin = PE_8
led.neopixelPin=PB_7

Config.g

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

M98 P"screen.g"

Add a file in your sys folder called screen.g and add the following contents

; ST7567 Init for FYSETC Mini12864 Panel V2.1

; Turn off backlight
m150 X2 R0 U0 B0 S3 F0
; Configure reset pin
M950 P1 C"TX1" 
; hardware reset of LCD
M42 P1 S0
G4 P500
M42 P1 S1
; Turn display on
M918 P2 C30 F1000000 E4
; Fade in backlight
while iterations < 256
    m150 X2 R255 U255 B255 P{iterations} S1 F0
    G4 P20
; flash Button 3 times
while iterations < 3
    m150 X2 R255 U255 B255 P255 S1 F1
    m150 X2 R0 U255 B0 P255 S2 F0
    G4 P250
    m150 X2 R255 U255 B255 P255 S1 F1
    m150 X2 R0 U255 B0 P0 S2 F0
    G4 P250
; Display "ready" button state  
m150 X2 R255 U255 B255 P255 S1 F1
m150 X2 R255 U0 B0 P255 S2 F0

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 SKR-RRF-E3.

Method 2

Activate the display using the config.g changes above.
On the “System” tab, above the list of files, is a dropdown menu that defaults to “System Directory”. Select this and change it to “Menu Directory”.

Dropdown Menu
Dropdown Menu

Then upload the menu 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.
Tags: