1.54 inch High Brightness Square TFT SPI

I. Product Introduction

The 1.54 Inch High Brightness TFT Display color LCD module (Model: HTM-H015A2-SPI-V02) features a standard resolution of 240×3RGB×240. It employs the advanced ST7789 driver chip and full-viewing-angle technology, delivering vivid, sharp, and detailed image quality from any viewing angle. In terms of hardware interface and electrical performance, it supports an efficient 4-wire SPI serial interface, with an operating voltage VCI of 2.5V~3.3V, and the built-in drive circuit simplifies system design.

As a product that highlights High Brightness characteristics, its backlight drive, under constant current test conditions, achieves a surface luminance of up to 700 cd/m². This high brightness, combined with its advanced full-viewing-angle technology, ensures that the screen maintains excellent color reproduction and text readability even in strong indoor lighting or when viewed from wide angles, completely solving the common problems of traditional LCDs that wash out or become unreadable in bright light.

Additionally, this High Brightness module boasts outstanding environmental adaptability, with an operating temperature range of -20°C to +70°C and a storage temperature range of -30°C to +80°C. It strictly adheres to standard tolerances and precision structural design, making it an ideal display solution that integrates high performance, high brightness, and high reliability.

II. Product Highlights 

• High Brightness: With a high brightness of 700 cd/m², it far exceeds the common 200-300 cd/m² found in ordinary portable screens. Under constant current backlight drive conditions, it ensures that the UI remains clearly visible even under direct sunlight, making it a standard feature for outdoor devices.
• 1.54-inch full-viewing-angle experience: Utilizing full-viewing-angle polarizer technology, the image remains free from distortion, color shift, or inversion when viewed from top, bottom, left, or right, providing a perfect omnidirectional visual experience.
• High-speed 4-wire SPI serial interface: The 4-Line Serial Interface significantly saves MCU pin resources. Even low-end microcontrollers with limited computing power (such as STM32, ESP32, Arduino, etc.) can easily drive it and achieve smooth animation refresh.
• Mature and stable ST7789 dedicated driver (Reliable ST7789 Driver IC): Integrates an industry-benchmark control chip, with abundant open-source code and strong compatibility, greatly shortening the R&D cycle and time-to-market.
• Industrial-grade wide temperature design: Supports harsh operating environments from -20°C to +70°C, withstanding extreme cold and heat, fully meeting the stringent stability requirements of industrial handheld terminals, in-vehicle equipment, and outdoor IoT devices.

III. Pin Description and Interface Definition

The High Brightness TFT display module is connected via a highly reliable board-to-board or FPC connector, with the main interfaces divided into CN1 and CN2, which serve as mirror/multifunctional signal groups.

IV. Typical Product Applications

Leveraging its High Brightness, compact size, and wide temperature characteristics, the HTM-H015A2-SPI-V02 is widely used across numerous vertical industries:

• Smart wearables and healthcare devices (Smart Wearables & Healthcare): The 1.54-inch square form factor is an excellent fit for smartwatches, sports bands, portable oximeters, and portable ECG monitors. The high brightness allows users to check health data conveniently during outdoor activities.
• Industrial handheld terminals and instrumentation (Industrial Handheld Terminals & Instrumentation): Used in infrared thermometers, industrial inspection devices, rugged handheld PDAs, and high-precision power meters. The industrial-grade wide temperature range (-20°C~+70°C) ensures stable operation in harsh workshop and field conditions.
• Smart home and IoT control panels (Smart Home & IoT Control Panels): Can be embedded in smart thermostats, fingerprint lock displays, smart switch panels, and desktop mini weather stations. The full viewing angle ensures a perfect visual experience for family members viewing from different heights and angles.
• E-bike and automotive displays (E-bike & Automotive Displays): Serves as an auxiliary display for smart handlebar instruments on electric bicycles and motorcycles, showing speed, battery level, navigation arrows, and more.

V. Technical FAQ

Q1: What are the advantages of the 4-wire SPI interface (4-Line Serial Interface) compared to the MCU parallel interface? How does it save pins?

A1: Traditional parallel interfaces (such as 8080 8-bit/16-bit) require at least 8 to 16 data lines plus several control lines, consuming a total of 10 to 20 I/O pins on the MCU, which is a significant burden for microcontrollers with limited pins. In contrast, the 4-wire SPI interface used in this module requires only four core signal lines: CS (Chip Select), SCK (Clock), SDA (Data), and D/C (Data/Command Select) to complete all display control. While ensuring a sufficient refresh rate, it frees up a large number of pins for sensor acquisition, communication, or other peripheral controls in the system design.

Q2: How can I adjust the brightness of this High Brightness TFT screen through the pins?

A2: The module provides a BLEN (Backlight Enable) pin. In actual development, besides providing basic on/off high/low levels, the most recommended method is to connect a PWM (Pulse Width Modulation) signal from the MCU to the BLEN pin. By changing the duty cycle of the PWM signal, you can smoothly adjust the backlight current, achieving stepless brightness adjustment from 0% to 100%. This not only saves power automatically according to ambient light levels but also further extends the lifespan of the backlight.

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.