Most FDM 3D printers will use an open-source firmware, Marlin. Marlin firmware runs on the main board of the LCD 3D printer, manages all real-time activities of the machine, and coordinates all operations of heating devices, stepper motors, sensors, LCD displays, and other devices. Marlin’s control language is G-code. After the 3D model is created, it will generate a file in .gcode format through the slicing software. The .gcode file will be transparently transmitted to Marlin through a memory card or U disk. Marlin will parse the .gcode file to obtain G-code, and then use G-code to control heating. It also uses G-code language to communicate with LCD screens. The G-code language is published on the open-source website:
http://marlinfw.org/meta/gcode/ and will be updated as the 3D printer functions increase.

The Communication Between STONE TFT And Marlin

Marlin is a code written in C and C++. The translation code is added to Marlin so that after receiving the instruction at the beginning of A5 5A, it can translate into G-code language by itself, and then it can recognize it, and then convert the content that needs to be fed back to the LCD screen into Languages beginning with A5 5A are sent to the touch screen for communication interaction.
Recommended module
STWI070WT-01 7 inches TFT LCD screen module with resistive touch panel

Advantage Of STONE TFT Module  

Powerful and simple developing tools

By Using The TOOL GUI Design Software, You Can Easily Create An Interface For The LCD 3D Printer With:

•  Multiple customized interface images: You can storage over 10K interface images in the flash memory of STONE TFT LCD. This will support you to add as many pages or functions as you want for your 3D printer.
  •   Multiple touch control: The 3D printer requires a lot of touch control adjustment for the nozzle position, platform height, or temperature. You can create +/- adjustment, or slide adjustment with TOOL GUI design software, to control all the parameters and actions of the 3D printer.
  •   Audio video play: The STONE TFT module will provide the audio interface. You can storage the audio and video files in the flash memory, to play tutorial videos.
  •   Stability for long time working: The 3D printer mostly has very long time working situations. This requires stability to make sure the project is successful. If the printer is stuck during the printing, all the printed items will be useless.

STONE TFT LCD modules are using high-quality components and have high performance on anti-interference ability. This will make sure your big project success in longtime working.