How to wire up the Display

On the SKR E3-DIP V1.1 and the E3 V1.2 you can use a 10 pin flat ribbon cable to connect to the DIY display. 

Both controller boards will use hardware I2C to communicate with the display.

On the SKR E3 V2.0 and the E3 V3.0 you need to make a special cable to connect to the DIY display because the pinout on the controller board is different. 

Please notice: Only the E3 V3.0 uses hardware I2C (I2C2 in this case), whereas the E3 V2.0 needs software I2C for the communication.

On the SKR E3-DIP V1.1 and the E3 V1.2 you need a 4 wire cable to connect to the display. The Reset signal of the display is optional and can be omitted.

Both controller boards will use hardware I2C to communicate with the display.

On the SKR E3 V2.0 and the E3 V3.0 you also need a 4 wire cable to connect to the display but the pinout on the controller board is different.

Please notice: Only the E3 V3.0 uses hardware I2C (I2C2 in this case), whereas the E3 V2.0 needs software I2C for the communication.

For these displays you'll need a cable which connects the EXP1 and the SPI1 header of the SKR E3 to the display.

This wiring scheme belongs to those displays known as DOG-LCD, EA DOGL or Mini 12864 and which operate on a 4-Wire hardware connection.

Be careful when wiring it all up. Accidentally swapped cables may lead to a damaged controller board, display or both. Just follow the names and the colors to get it right.

Before you start wiring up, make sure you have understood which pin on either side is which. 

In the firmware, comment all of the USE_xxx_DISPLAY definitions. The compiler will then use the default configuration.

Also: Please make sure you have at least firmware version 2.15 downloaded before compiling.

For these displays you may use the configuration shown above, since those display modules come with three display connectors (EXP1, EXP2 and EXP3).

If you're going for the EXP3 solution, you have two operational mode options:

• using software SPI

• using hardware SPI

Software SPI is the easiest to set up, since it requires only a 10 pin flat ribbon cable which connects directly and usually comes with your display. Though, since it's software SPI it's pretty slow when drawing on the screen.

Using hardware SPI speeds up drawing quite a bit but you'll need a custom cable as shown in the picture to the left. I'd recommend using Dupont wires / headers for this task since they're pretty easy to assemble. You'll need two 5x2 headers, one 2x3 header and ten Dupont female/female wires, 100-150 mm in length.

In the firmware, un-comment the USE_CREALITY_DISPLAY definition and, in case you're going for the hardware SPI, the CREALITY_HW_SPI as well. 

Please notice: The BTT TFT will work only in Marlin Mode (a.k.a. LCD12864 Emulation Mode). In the settings menu of the display, you'll find an entry which tells the display in which mode to start up. This can also be achieved by editing the config.ini file, which is part of the BTT TFT firmware. 

Also: The BTT TFT display modules won't be able to deliver a decent encoder button signal on EXP3, unless you manually remove the resistor (R7) sitting in between the ENCBTN pin and the button pin on the encoder itself (i.e. 2.4" display) or by cutting the trace that goes from the encoders button pin to the MCU and re-wiring it to the ENCBTN signal (i.e. 3.5" display).
However, using the original splitter cable (EXP1 on board to EXP1/2 on display) is supposed to work with the latest release of the display firmware.

In either case, be aware that doing so will void your warranty for the display!

For the new SKR E3 V3.0, please notice that the SPI1 connector not only has more pins but also a different pinout, as shown in the picture.

Keep in mind: For this controller board you'll need SMuFF firmware version 3.0 or newer!

On a side note: This board also comes with the option of using fast software SPI. In this case, you'll only need a 10 pin flat ribbon cable going from EXP1 on the controller board to EXP3 on the display. See down below.

The easiest way to connect such a display is by enabling the USE_FAST_SW_SPI option along with the USE_CREALITY_DISPLAY option in platformio.ini.

In this case you'll only need the 10 pin flat ribbon cable, that usually ships with the display, and connect it to the EXP1 header on the board to the EXP3 header on the display.

Although Fast Software SPI is a bit slower than hardware SPI, it's barely noticeable and reduces the effort when handling the display.

For these displays you may have to use another custom made cable because of the different signal pins on EXP1 and EXP2. This configuration is also meant to be used using hardware SPI.

To go for that option, you have to create a cable with the corresponding wiring shown on the left. I'd recommend using Dupont wires / headers for this task since they're pretty easy to assemble. You'll need two 5x2 headers, one 2x3 header and ten Dupont female/female wires, 100-150 mm in length.

In the firmware, un-comment the USE_CREALITY_DISPLAY definition and CREALITY_HW_SPI as well. 

Please notice: The BTT TFT will work only in Marlin Mode (a.k.a. LCD12864 Emulation Mode). In the settings menu of the display, you'll find an entry which tells the display in which mode to start up. This can also be achieved by editing the config.ini file, which is part of the BTT TFT firmware.

Also: The BTT TFT display modules won't be able to deliver a decent encoder button signal  on EXP3, unless you manually remove the resistor (R7) sitting in between the ENCBTN pin and the button pin on the encoder itself (i.e. 2.4" display) or by cutting the trace that goes from the encoders button pin to the MCU and re-wiring it to the ENCBTN signal (i.e. 3.5" display).
However, using the original splitter cable (EXP1 on board to EXP1/2 on display) is supposed to work with the latest release of the display firmware.

In either case, be aware that doing so will void your warranty for the display!

For the new SKR E3 V3.0, please notice that the SPI1 connector not only has more pins but also a different pinout, as shown in the picture to the left.

Keep in mind: For this controller board you'll need SMuFF firmware version 3.0 or newer!

A word of warning: As maker Plumpkatt1 over on Discord has pointed out recently, there is this Melow FLY Mini Screen 1.0 circulating, which is supposed to be a FYSETC clone, but isn't. For one the connectors don't match the assignment shown down below, for the other bores and positions of the reset button and encoder aren't matching, which means: It will not fit the housing I've designed for the FYSETC 12864 display.
Hence, don't use this display!
You may have spotted the label on the box, which says: FOR GIFT.
I guess this means: Melow has figured the display has issues and took it off the shelf, but that's my assumption only!
Keep in mind: There might be a different version of this display, that meets the FYSETC specs, out there but we don't know for sure yet!

For this display you also have to have a custom made cable because of the different signal pins on EXP1 and EXP2. This configuration is also meant to be used using hardware SPI.

To go for this display option, you have to create a cable with the corresponding wiring shown on the left. I'd recommend using Dupont wires / headers for this task since they're pretty easy to assemble. You'll need two 5x2 headers, one 2x3 header, on 1x5 header and thirteen Dupont female/female wires, 100-200 mm in length.

In the firmware, un-comment the USE_MINI12864_PANEL_V21. 

Please notice: The FYSETC Mini Panel 12864 V2.0 won't work in this configuration because it'll need two additional wires to drive the RGB display background LED (GREEN/BLUE).
Also, this configuration will work only with the SMuFF firmware 2.26 and above.  

Also: This display additionally needs the LCD-RST signal, which in this case goes to pin 2 of the SWD connector (E3-DIP / V1.2 / V2.0) or pin 2 of the I/O connector respectively (E3 V3.0).

Without this signal it will refuse to display anything after a power cycle!

In case your controller is the new SKR E3 V3.0 (the latest version), please notice that the SPI connector not only has more pins but also a different pinout, as shown in the picture to the left.

Also, since this board has spare I/O pins (YAY!), the display Reset signal has moved to pin 1 of the I/O header and must not be omitted.

Keep in mind: For this controller board you'll need SMuFF firmware version 3.0 or newer!

If your controller is a SKR mini V1.1 (not the E3 version), you have to connect both, EXP1 and EXP2 using a 1:1 cable.

If you're doing this, please double check whether your cables are crimped correctly. In some cases they might be twisted and hence the display will not work or, if the supply pins don't match, the display might be destroyed!