EZBoard – Lite V1.X – BTT TFT35-E3 Wiring and Firmware Setup

DISCLAIMER

Before we start we want to note that during testing to get this LCD working with the EZBoard we had one instance where the BTT TFT LCD killed the CPU on the EZBoard. Our engineer has also had stability issues with the BTT TFT LCD itself and its firmware. This information is provided as customers have requested it.

Warnings about the BTT TFT LCDs

• If you choose to use any BTT TFT LCD with the EZBoard and a CPU failure occurs we will NOT cover it under our warranty. Use at your own risk.
• If you have questions about updating, using, modifying, or compiling for the BTT LCD you need to contact BTT support for help with their product.
• This information is provided as-is and we will not provide technical support for the BTT TFT LCDs.
• Do not use the BTT TFT LCDs with the EZBoard if you do not want to accept the risks (EZBoard damage) that could occur by attaching their product to ours.

Information about the BTT TFT LCDs

This guide is specifically written using their TFT35-E3 but may work on their other LCDs. One thing to note is that their pinouts for the TFT35-E3 are wrong. The TX and RX pin labels on their RS232 header are flipped. Just follow the connections shown below for the correct way to connect it.

These LCDs are what are known as “dual-mode”. This means they have a touch screen interface and the traditional 12864 type. The 12864 will work without connecting the serial connections shown below as it just emulates the stock Creality LCD screen. If you want to use the touch screen then you need to connect the serial connections as shown below and then update your EZBoard firmware.

All the touch screen interface does is send and receive GCode commands from the printer board to the screen. You will not have all settings available on the touch mode that will be available on the 12864 LCD mode. These screens offer a good compromise on features and usability by having both modes available on the same screen.

Refer to the BTT documentation on their LCD for using it or updating its firmware. The BTT TFT LCDs run their own firmware and they have their source code posted on their github.

Firmware Changes needed to run the LCD

There is a 2nd serial port on the Serial header (see bottom of this page) that can be used to communicate with the touch portion of the BTT TFT LCDs. This port uses the same baud rate as the USB port, which is set to 115200 by default. If you change your baud rate on the board firmware you will need to change the baudrate on the LCD itself in the touch mode.

1. Recommended – Update to Unified 2 version 2.16 or higher.
2. Firmware version older than 2.16 – Add #define SERIAL_PORT_2 0 to the Configuration.h file, recompile, and then update the firmware. 

Connecting the LCD to the EZBoard

The BTT TFT will need the EXP3 10-pin cable connected from the EZBoard LCD header to the EXP3 header on the BTT TFT. This will provide the “12864 LCD” mode that it has. This will also provide the 5V power for the LCD.

The last thing to connect is the serial data lines from the RS232 port on the BTT TFT to the Serial header on the EZBoard. You can use Male to Female Dupont jumpers to make the connection. See below for pictures of how we wired this up to the EZBoard