HOTHMI 2 inch HMI Display 240×320 UART interface

Product Introduction

HTM-H020A4-UART-A01 is a compact 2 inch HMI Display designed for embedded devices, industrial control terminals, instrumentation, and small human-machine interface equipment. It features a 2.0-inch TFT LCD with a resolution of 240 × 320 pixels, a Normally Black display mode, and approximately 60% NTSC color gamut. The display can be used for equipment status, parameter settings, operating data, menu interfaces, and graphical information.

This 2 inch HMI Display uses a UART (TTL) interface. The CN1 connector provides VDD, RESX, TXD, RXD, NC, and GND signals. For systems using an MCU as the main controller, display data and control commands can be transmitted through the serial interface, reducing the amount of low-level LCD driver development required on the main controller.

The 2 inch HMI Display operating temperature range is -20°C to +70°C, while the storage temperature range is -30°C to +80°C, making it suitable for general industrial and embedded equipment. With an LCM brightness of approximately 400±100 cd/m², the module meets the basic display requirements of indoor equipment and general industrial control interfaces. Compared with conventional displays that require the host processor to directly handle TFT RGB, MIPI, or LVDS signals, this 2 inch HMI Display is more suitable for control systems that already have UART communication capability.

The module also supports USB Type-C resource updating and provides 128M-Bit resource storage. This allows display resources or HMI interfaces to be updated during product development and maintenance, providing greater flexibility when modifying icons, menus, fonts, and other interface elements.

Product Specifications

Key Features

Compact 2.0-inch Size for Embedded Equipment

The 2 inch HMI Display uses a compact 2.0-inch screen size, making the module suitable for equipment with limited installation space. It can provide an independent graphical interface for handheld instruments, testing equipment, small controllers, and other products where panel space is limited.

UART (TTL) Interface for Simplified System Integration

The module uses a UART (TTL) interface, with TXD, RXD, VDD, GND, and RESX signals available through CN1. During system design, engineers do not need to route a complex high-speed LCD pixel bus directly between the MCU and display. Instead, the system can be integrated around serial communication, which simplifies the hardware interface between the controller and the 2 inch HMI Display.

USB Type-C Resource Updating

The 2 inch HMI Display supports resource updates through USB Type-C and provides 128M-Bit resource storage. For projects that require changes to icons, menus, fonts, or other HMI resources, the update process can be handled without repeatedly modifying the main MCU application, depending on the system architecture and HMI software configuration.

Integrated Fonts, Graphics and UI Controls

This 2 inch HMI display integrates multiple ASCII font sizes and supports GBK2312 and BIG5 font resources, as well as drawing functions for points, lines, rectangles, circles, strings, and BMP images. It also supports buttons, numeric and string controls, drop-down boxes, progress bars, waveform displays, and bitmap animations, providing flexible options for data input, monitoring, and interactive interface design.

Pin Description

CN1 is a 6-pin connector. Among these signals, TXD and RXD are used for UART serial communication, while VDD and GND provide power connections. RESX is used for display module reset control.

Product Applications

Industrial Controllers

The 2 inch HMI Display can be integrated into compact industrial controllers for displaying operating status, working modes, set values, alarm information, and real-time parameters. The UART interface allows communication with the MCU control board, making it suitable for controllers that require a graphical interface but do not have enough panel space for a larger display.

Measurement and Testing Instruments

In portable test equipment and measurement devices, the 240 × 320 resolution can be used to present measurement values, units, menus, and operating prompts. Engineers can arrange measured data, upper and lower limits, and equipment status within a single interface, making the display suitable for compact instruments with multiple operating parameters.

Compact Instrumentation

For space-constrained instrumentation, the 2.0-inch format occupies less front-panel space while providing a more flexible graphical interface than traditional numeric or segmented displays. It can be used for parameter configuration, operating-status monitoring, fault notifications, and other basic HMI functions.

Embedded Smart Devices

The 2 inch HMI Display is also suitable for embedded control terminals, smart electronic devices, and compact human-machine interface modules. For MCU-based platforms with an available UART interface, the module can function as an independent HMI unit, allowing the host controller to communicate with the display through serial commands.

Engineering FAQ of 2 inch HMI Display

Q1: How can UART communication between an HMI display and the main MCU be managed to improve system stability?

For MCU-based equipment, the display communication task can be separated from real-time control functions in the main application. Engineers can use a UART transmission queue, state machine, or independent communication task to manage display commands and prevent continuous display data processing from consuming excessive MCU resources.

The software should also handle communication timeouts, invalid commands, and display refresh states. The HTM-H020A4-UART-A01 provides TXD, RXD, and RESX signals, allowing the communication process and module reset control to be incorporated into the host software architecture.

Q2: What are the engineering advantages of a UART interface compared with directly driving a TFT display?

A UART-based architecture can reduce the amount of high-speed display signaling between the host MCU and the display module. Instead of directly processing pixel-level RGB data, the host mainly communicates with the HMI through serial commands and data.

For embedded equipment using an MCU with limited processing resources, this architecture can reduce the PCB routing associated with the display interface and simplify low-level display driver development. The available MCU resources can then be allocated to core functions such as equipment control, data acquisition, sensor processing, and external communication.

For compact embedded products that require a graphical interface without a complex display bus, the 2 inch HMI Display provides a practical UART-based integration approach.

From minor concept tweaks to full custom redesign & development, our engineering team offers end-to-end technical support. Feel free to contact us for custom display demands or technical issues during product selection.