
Serial HMI · LCD Module · OLED Display
21 Years Display Solutions Expert
Zhaoqing GPT LCM, a National High-Tech Enterprise. Specializing in serial HMI, TFT color LCD modules, and OLED display development. Covering 0.96" to 8" full range, serving medical, industrial, automotive, and smart home industries.
Product Center
From character LCD to color TFT, one-stop display solutions

Monochrome LCD Display Module
Segment, character dot matrix, graphic dot matrix; MCU parallel/SPI/IIC communication
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TFT Color LCD Display Module
2.8 to 8 inches, UART serial driven, Visual OCM UI design
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OLED Display Module
Self-emissive high contrast, 0.96–5.5 inch, COG package, -40°C wide temperature range
View All Models →Color Display Driver IC
TFT/OLED color display driver ICs with SPI/I2C/RGB interfaces for color LCD modules. Covering 0.96 to 10.1 inch TFT/OLED display driving solutions, widely used in industrial instruments, smart home, and medical devices.
View All Models →Segment LCD Driver Chip
Segment/character LCD driver ICs with low power consumption and high reliability for segment LCD displays. Supporting I2C/SPI/parallel interfaces, widely used in electricity meters, water meters, thermostats, and instrumentation.
View All Models →Hot Products
Market-proven, cost-effective display solutions
Why Choose GPT LCM
21 Years Expertise
Founded in 2003, one of the earliest Chinese LCD module manufacturers. OCMJ series patented products.
R&D Capability
LCD testing system invention patents, complete hardware & software in-house development.
Global Certification
Full range CE & RoHS EU certification. SMT/COB cleanroom manufacturing.
Trusted by Leaders
Long-term partners with Neusoft, Han's Laser, Huntkey, and Rede Intelligence.
Industry Solutions
Medical
High-reliability LCD display solutions for medical devices. CE/FDA compliant, wide temperature range, long-term supply guarantee.
Learn More →Industrial Control
Stable and reliable HMI display solutions for industrial control equipment. Wide temperature, high brightness, anti-vibration design.
Learn More →Monitoring Instruments
Low-power, high-contrast display solutions for monitoring instruments. Excellent readability, compact design.
Learn More →HMI Solutions
Color touch serial HMI solutions for human-machine interaction devices. Visual OCM UI design, rapid development.
Learn More →About GPT LCM
Zhaoqing GPT LCM Co., Ltd., a subsidiary of GPT Investment Group, is a National High-Tech Enterprise specializing in LCD display module R&D and manufacturing. With 21 years of industry experience, we provide display solutions for businesses worldwide.
In 2025, we moved into the GPT High-Tech Industrial Park, upgrading production capacity and manufacturing standards with SMT, COB cleanroom facilities and intelligent warehousing.
FAQ
Common questions about serial HMI, LCD module selection, and technical support
All GPT LCM serial HMI modules support UART (TTL level), RS232, and RS485 communication protocols.
Standard operating temperature is -20°C to +70°C. OLED series can reach -40°C to +70°C.
Contact us and our engineers will send the complete development package via email or WeChat.
No MOQ for samples. Production orders typically start from 100 units.
Serial HMI communicates via UART, making it platform-independent. It works with any MCU or development board.
Contact us with your requirements. Our engineers will recommend the most suitable model within 24 hours.
Serial HMI communicates via UART, requiring only 2 wires (TX/RX), making development simple. Parallel HMI requires many GPIO pins and complex timing control. Serial HMI is ideal for rapid development and resource-constrained MCUs.
UART (TTL) is for short-distance board-level communication (<1m). RS232 is for point-to-point within 15m with good noise immunity. RS485 supports up to 1200m and multi-device bus topology. All GPT LCM serial HMI support all three interfaces.
Choose TFT for industrial control and medical instruments (high brightness, long lifespan, lower cost). Choose OLED for wearables and premium instruments (high contrast, fast response, wide viewing angles). TFT covers 0.96"~8", OLED covers 0.42"~2.23".
Serial HMI uses standard UART, compatible with virtually all MCUs with serial ports. Common platforms include STM32, Arduino, ESP32, 8051, PIC, Raspberry Pi, and Pico. We provide sample code and technical support for all platforms.
All products are certified with CE, RoHS, and FCC. Some also have UL and medical device certifications. All comply with REACH. Certification reports available upon request.
5-step process: 1) Provide requirements (size/resolution/interface/housing) → 2) Feasibility evaluation and quote → 3) Mold/sample production after confirmation (2~4 weeks) → 4) Testing and acceptance → 5) Mass production. Standard products skip mold step with shorter lead time.
Standard products ship in 3~5 business days when in stock, MOQ 1 piece. Custom products: samples in 2~4 weeks, mass production in 4~6 weeks, MOQ varies by project. We support both small-batch fast delivery and large-volume stable supply.
Standard products: -20°C to +70°C (commercial grade). Industrial grade: -30°C to +80°C. OLED series: -40°C to +70°C. Industrial-grade products use wider temperature range LCD materials for outdoor and factory environments.
1.8 inch serial HMI: about 30~50mA (5V). 3.5 inch: about 80~120mA. 7 inch: about 200~350mA. Turning off backlight reduces power by over 60%. Detailed power specs available for all models.
Serial HMI supports image display, text, progress bars, sliders, buttons, charts, and animations. Supports BMP/JPG/PNG images, TrueType fonts, and multi-language (Chinese, English, Japanese, Korean, etc.). UI design via drag-and-drop software — no programming required.
Standard baud rate range: 1200~921600bps. Default: 9600bps or 115200bps. Recommended: 115200bps for optimal speed and stability. At high baud rates, use shielded cables and keep distance under 15m (UART).
Send ASCII or hex commands via serial port. For example, sending "t0.txt=\"Hello\"" displays "Hello" on the t0 control. Images are displayed by image ID. We provide complete command set manuals and sample code for all platforms.
Yes, we offer both resistive and capacitive touch options. Resistive touch supports single-point, lower cost, suitable for industrial use (operable with gloves). Capacitive touch supports multi-point, high sensitivity, ideal for consumer products. Touch events are reported via serial port coordinates.
Yes. We offer high-brightness (1000+ nits) outdoor-readable models, clearly visible in direct sunlight. Industrial grade operates at -30°C~+80°C, with optional IP65 waterproof rating. Suitable for outdoor EV chargers, agricultural equipment, and vehicle terminals.
TFT backlight lifespan: about 30,000~50,000 hours (3~6 years continuous). OLED: about 50,000~100,000 hours. Reducing brightness and avoiding static images extends lifespan.
GPT LCM has 21 years of display module R&D experience, certified as a National High-Tech Enterprise. Advantages: 1) Full range 0.96"~8"; 2) All three serial interfaces supported; 3) Free UI design software; 4) 24-hour tech support; 5) Small batch customization; 6) Fast delivery — standard products ship in 3~5 days.
Some high-end models support video playback via serial commands (AVI format). Resolution and frame rate depend on the specific model. Ideal for product demos and advertising.
Standard supply: 5V (USB or DC). Some models support 3.3V or 12V. Use a stable power supply with ripple under 50mV. Screens 7 inch and above should use dedicated power supply.
We use a free desktop UI design software for Windows. Features include drag-and-drop UI design, image/font import, widget configuration, simulator preview, and firmware upgrade. No programming required — design interfaces quickly.
Serial HMI does not have built-in WiFi/Bluetooth, but you can connect via an external MCU (e.g., ESP32) that handles WiFi/Bluetooth and communicates with the serial HMI via UART. We provide ESP32 + serial HMI networking reference designs.




