The Application of DWIN LCMs on FDM 3D Printers

publisher: dwin  release date:19-10-12  view:4406

1. The firmware of Marlin and G-code

3D printers on the market are divided into two types: FDM (Fused Deposition Modeling) and SLA ((Stereo lithography Appearance). Among them, FDM technology is more mature, lower price, and the market share is higher. A desktop-level FDM printer can be purchased in China at the price up to 2,000 RMB.



1.1 Ultimaker latest FDM printers


One open source firmware most FDM printers use is ——Marlin. Marlin firmware runs on the 3D printer motherboard, manages all real-time activities of the machine, and coordinates all operations of the heating devices, stepping motors, sensors, LCDs and more. Marlin's control language is G-code. After the 3D model is created, the slice software will generate the file of G-code format. The file of G-code format is sent to Marlin through a memory card or U disc., Marlin will parse the G-code file to get G-code, then use it to control heaters, motors and other devices as well as communicate with LCD using G-code language. G-code language is published on open source websites : http://marlinfw.org/meta/gcode/ , and it is updated as the 3D printer features increase.


1.2 Examples of motion instructions

2. Communication Protocols of DWIN Screens

The communication protocols applied by DWIN screens is as follows:

Serial communication protocol(UART2)

System debug serial port UART2 mode is fixed to8N1, baud rate can be set, the data frame consists of 5 data blocks:


Turn on or off of CRC check is controlled by 0x2c.6 bit of the configuration file


UART2 debugging instructions are as follows:


3. Communication between Marlin and DWIN screens

DWIN screens cannot communicate with Marlin directly, because Marlin does not recognize the instructions starting with 5AA5, and the DWIN screen recognize the G-code language. But If you want to achieve consistent communication, there are two ways:

a. Analyze DWIN communication protocols through Marlin

Marlin code is written in C and C++, the developer can add translation code to Marlin so when it receives instructions starting with 5AA5, it can translate those instructions into G-code language to identify. Then it will convert the content that needs to be fed back to the screen into the instructions starting with 5AA5, and send it to the screen for communication interaction.

b. Parse G-code language through DWIN OS

DWIN smart screens have two serial ports. One serial port fixedly uses the DWIN communication protocols starting with 5AA5, and the other can send or receive as well as recognize other forms of communication protocols through DWINOS. So, DWINOS can be written in pseudo-assembly language and DWIN communication protocols can communicate with G-code on the screen, which enables screens to send commands in the G-code language and recognize correctly when receiving the G-code language.

If it is possible, you can also make a form that is more user-friendly:

In PC software DGUS, users can add basic touch control, put some basic G-code needed in Marlin firmware into the control, and a specific control corresponds to a specific G-code.

For example, the meaning of M105 in G-code is to get the current temperature. If we set corresponding basic touch in DGUS, then touch the area on the screen where the basic control is located. The screen will send M105 to the Marlin firmware, and the firmware then returns real-time temperature to the screen.

This is equivalent to no difficulty for developers.


4. High cost performance of DWIN smart screens

4.1 Simple development

Using DWIN innovative and intelligent GUI software DGUS_V7591, the UI project can be easily and conveniently created, new effects not currently available on 3D printers can be achieved either.


(1)Page sliding : Whether it is a resistive screen or a capacitive screen, as long as it is a touch screen, it can achieve the function of page sliding like a mobile phone effect. the area and the front and back pages as well as the sensitivity (contact time and sliding distance) of page sliding can all be adjusted in the interface design software DGUS_V7591. It is easy to understand, convenient and fast.


(2)Zone rolling : This feature is ideal to display the brand LOGO , and it is easy to achieve the effect of subtitle rolling. Scientific experiments have shown that dynamic interfaces are more attractive than static interfaces. So after the boot, if there is a cyclic rolling of letters or patterns on the static interface, the visual effect will definitely be better. The arrow in the lower right corner of the picture below  is set the effect of rolling to right circularly. (You can imagine the effect of the barrage here)


(3) Music playback: If this function is well used, it can make the whole equipment much better. First of all, it can come to a boot music, which lets the beautiful boot music guide users into the world of 3D printing. Then, you can set different sound effects on different buttons such as the wind, the rain, the bird call, just use your imagination to create your own world.


(4) Numeric keyboard: When setting precise values such as extrusion head temperature, hot bed temperature and printing speed, values’ span is too large and a long time will be taking if just use plus and minus signs. In this case, the keyboard function can be called.


The more similar the human-computer interaction interface is to the mobile phone interface, the faster the user gets started to use and the better the experience.

4.2 Cost advantage

DWIN technology began industrial chain integration a few years ago.


(1) The DWIN smart screen is driven by the T5L chip designed and developed by DWIN. The T5L chip is specially designed for product development of display + application, and the cost can be excellently controlled.

(2) The LCD screens used by DWIN is manufactured by DWIN independently, with double guarantee of quality and stability.

(3) DWIN 300 acres of science and technology park has opened TP lines to mass process touch screens.

DWIN technology has realized the integration of the entire industry chain from IC design, independent development and manufacture of core components or supplier resident support.

Comparison of.5 inch color touch screen prices: 





It can be seen that the price of the DWIN smart screens has absolute advantage in the market.

In my opinion, the biggest advantage of DWIN smart screens is still on the T5L chip. One key point Marlin widely spread in 3D printing industry is that it can run on 8-bit Atmel AVR MCU, which are inexpensive, therefore it is widely used. T5L chip is a dual-core standard 8051, and both cores are 200MHz. In future, users can also develop printing functions based on the 8051 without affecting customer's use of DGUS to develop the human-machine interface, because the GUI core and the OS core are independently operated. So, in such situation, the core part of 3D printing will be concentrated on the smart screen, which can further save hardware costs and simplify product structures.

Currently, advantages that DWIN smart screen’s application in the 3D printing industry is not only on the surface, but also potential advantages of planning execution if the market demand is large enough. Although the market for FDM printers is relatively mature, it is still constantly improving and innovating. In such an open source industry, everyone shares the core of technology. Then, how can the final product advantage be improved except the core technology? The most intuitive and direct contact between products and consumers should be human-computer interaction!

DWIN smart screens can indeed make a difference with similar products based on the core technology and price are on par of FDM printers. Waiting for the maturity of SLA technology is still a long time, that is to say, the market of FDM printers can also erupt during this period. It is very likely that DWIN LCMs are an important part of this explosion.



Author: Ren Yajing

Translator: Aaron Zu