4 Inch Serial Port Screen Overview
The ET040DH7272-DC is a 4-inch diagonal circular UART TFT display with a resolution of 720×720. It features a serial interface, TFT display mode, and a 101.5 mm active area within an outline of 123.0×12.0 mm. The display offers 500 cd/m² brightness, 80° viewing angles in all directions, supports capacitive touch, and operates from –20 °C to 70 °C.

4 Inch Serial Port Screen Product Parameters
Core processor: 600M SOC processor.
Operating system: No operating system, it can run after power on, startup time: about 1 second.
Protocol type: Default Dacai configuration instruction set, the host computer can be configured to run MODBUSRTU and XGUS protocols.
Scripting language: Version 5.3 LUA script, the screen can run logic, protocols and algorithm functions written by the user.
Size: 4.0 inches
Resolution:720x720
Installation direction: Supports 0, 90, 180 and 270 degree rotation installation display.
Storage space: 128Mbit
Font library: Built-in vector fonts, edge anti-aliasing processing, supports any size ASCII, GBK, GB2312, UNICODE (global language) font library, and can also customize any computer font display.
Image storage: Supports JPEG, PNG (semi-transparent/fully transparent) compression, and supports image storage of any size. It can store approximately 87 full-screen pictures in total (based on the size of 169KB/picture, BMP format is not recommended). Depending on the picture compression ratio, this value will fluctuate up and down.
Color: 65K colors, 16-bit RGB
Voltage:5-28V
Power consumption
Darkest backlight, no speaker: 0.8W;
The darkest backlight and speakers: 2.4W;
Brightest backlight, no speaker: 2.3W;
The brightest backlight and speakers: 4.8W.
Communication method: RS232/TTL (factory default 232 level, short J5 for TTL level).
Communication baud rate: 1200~921600bps, typical baud rate: 115200bps.
Communication connector specifications: FPC1.0-10P
Local download of pictures: SD card, serial port, U disk
Firmware local/remote upgrade: Insert SD card/U disk for local upgrade/support user motherboard remote serial port upgrade screen firmware.
U disk connector specifications: PH2.0-4P vertical.
Remote image upgrade: Support users to remotely use their own motherboard serial port to upgrade screen-related image projects, fonts, configuration files, etc.
Real-time clock: supports clock, timer, countdown and other functions.
Screen effective display area: φ101.5mm
Product size: φ123.0mmx12.0mm
Supporting host computer software: VisualTFT®
Audio playback: MP3 audio format (speaker 4Ω 2W, mono), shares storage space with pictures. If the sampling rate of mp3 format is 128kbps, it takes up 0.92MB/minute of storage.
Audio connector specifications: PH2.0-2P
Video playback: MP4 video format, sharing storage space with pictures. If a video file has a resolution of 800*600, a video bit rate of 3000Kbps, an audio bitrate of 166Kbps, and a frame rate of 25Hz, it will occupy 21.9MB/minute of storage.

Reliability parameters
Operating Temperature: 20~+70°C
Storage Temperature: 30~+80°C
ESD Test: IEC 61000-4-2 Air: ±10KV (no restart).
EFT Test:IEC61000-4-4 Standard 4 (Voltage: +4kV; Frequency: 5kHz; Duration: 120s); No restart, display abnormalities, touch abnormalities, etc.; Test functions are normal.
Radiated Radiation Test: EN55022 Class B,Test environment: three-meter dark wave chamber.

Core competitiveness of products
Learning cycle: 30 minutes to familiarize yourself with the development environment, 3 days to complete human-computer interaction design.
Program debugging: The host computer integrates a "virtual serial port screen," eliminating the need for hardware connection and allowing direct Keil debugging. IDE-bound debugging
Startup Time: Runs instantly upon power-up, eliminating system loading time
Configuration Controls: Features a variety of configuration controls, including multi-language controls, buttons, text, drop-down menus, progress bars, sliders, meters, animations, QR codes, curves, data loggers, circular progress bars, and sub-screen slide controls.
System Keyboard: Built-in virtual numeric and character keyboards, supporting Chinese and English input methods, and customizable keyboards.
Data Logging: Supports exporting data logger content to an SD card.
Layer Technology: Multiple display layers are built into the system for faster switching.
Multilingual Capability: Factory-preset up to 15 global languages, enabling one-click switching without the need for multiple UIs.
Logical Operation Processing: The host computer has an embedded LUA script parser, allowing users to customize complex logic relationships and protocols within the screen, meeting 99.9% of customer product requirements.
Remote Upgrade: Supports remote serial port upgrades of display firmware, project files, specified images, configuration files, and fonts.
Lifecycle: Utilizes a traditional, leading-edge processor, ensuring long-term supply.

4 Inch Serial Port Screen
Display Type: IPS LCD
Backlight: LED
Brightness (cd/m²): 500
Backlight Lifespan (hours): >20,000
Contrast Ratio: 1200:1
Viewing Angles (L/R/T): 80/80/80/80

Touch panel  (capacitance optional)
Touch type: capacitive touch screen (IC: GT911)
Capacitive screen touch mode: single point, sliding touch
Capacitive screen transmittance: more than 90%
Number of touches on the capacitive screen: The number of touches on the capacitive screen is theoretically unlimited, and the touch life is related to the working environment (dust, humidity).
Capacitive cover customization: The "glass cover + capacitive touch" integrated fitting service can be customized according to the user's drawing size.

Customized services
Customization Fees: For orders of 1,000 units, some customization fees may be waived.
Hardware Circuits: Customizable PCB size, circuit thickness, custom circuitry, military-grade temperature display, and more.
Software Customization: Customizable instructions or controls based on user needs, reducing development effort.
Design Services: Graphic design and product structure design services available.
Other: Customizable on demand to meet all user needs.

Installation diagram

Step 1: Make a hole in the casing and put the product in from the front;
Step 2: Tear off the adhesive tape;
Step 3: Embed the serial port screen into the customer cabinet and fix it with 3M adhesive;
Step 4: Installation completed.

PRODUCTION AND MANUFACTURING

Application Areas