1.3 inch Square TFT LCD Display ST7789 SPI

I. Product Overview of Square TFT LCD Display

HOTHMI introduces a high-quality 1.3-inch Square TFT LCD Display module, featuring a standard 1:1 square active area that breaks the limitations of traditional rectangular screens in symmetrical UI design. Built around the industry-proven ST7789 high-speed driver IC and supporting a standard 4-wire serial SPI interface, this module ensures fast response while significantly saving MCU pin resources. With 240(RGB)×240 pixel resolution, a display area of 23.40×23.40 mm, and compact outline dimensions of just 30.00×36.00×2.13 mm, it perfectly fits space‑constrained portable handheld devices, smart wearables, and various IoT instruments.

The Square TFT LCD Display adopts normally black transmissive technology, delivers 50% color saturation and supports up to 16.7M rich colors, while the wide viewing angle performance combined with 300 cd/m² bright white backlight ensures clear, vivid, and layered images from all directions. Operating at 3.3V, the module offers excellent environmental tolerance with a working temperature range of -20℃ to 70℃ (storage from -30℃ to 80℃), making it a cost‑effective visual display solution for industrial equipment, security terminals, and maker DIY projects.

II. Core Hardware Highlights

• Perfect 1:1 Square Composition and Symmetrical Aesthetics
  As a typical Square TFT LCD Display, its 240×240 pixel ratio provides a perfectly symmetrical space. Compared to conventional rectangular screens, the square display fully fills the entire screen when showing circular progress bars, 3×3 menu grids, instrument pointers, or QR codes—leaving no side black bars and utilising 100% of the limited UI area.
• Outstanding 16.7M Colors and Full Viewing Angle Experience
  Built on normally black transmissive technology, this module benefits from excellent panel craftsmanship, achieving U80/D80/R80/L80 full viewing angles. Even when viewed from the side, top, or bottom, the image remains clear and vivid without color inversion or distortion, ideally suiting handheld and dynamic observation devices.
• Board‑Integrated Design and 8kV Strong ESD Protection
  Unlike fragile, hard‑to‑secure bare LCD FPCs, the HTM-H013A2-SPI-A01 comes with a sturdy PCB control board and pre‑reserved standard mounting holes (4‑φ2.30mm), greatly facilitating mass production assembly and prototyping. Meanwhile, the product supports up to 8kV ESD protection, resisting common electrostatic discharges during industrial manufacturing and daily handling, ensuring system stability in complex electromagnetic environments.
• 4‑Wire Serial SPI Interface for Ultra‑Simple Wiring
  The Square TFT LCD Display module uses a standard 4‑line SPI interface, requiring only SCLK, SDA, D/CX, CS, and a few other host I/O pins to drive full‑color images. The low pin count not only simplifies PCB routing and reduces multi‑layer board design costs but also leaves more precious MCU resources available for connecting other sensors or communication modules.

III. Pin Description

This Square TFT LCD Display base board features a classic 8‑pin header/connector interface. 

IV. Industry and Application Scenarios

Thanks to its compact industrial outline (30.00×36.00mm), excellent wide‑temperature tolerance (-20℃ to 70℃), and superior display quality, this 1.3‑inch Square TFT LCD Display is widely deployed in the following key areas:

• Industrial Automation and Smart Instrumentation – ideal for small printer panels, digital pressure gauges, thermostat interfaces, handheld industrial testers, portable oscilloscopes, and various environmental monitors.
• IoT Smart Home Devices – suitable for smart wall switch panels, secondary status screens for smart speakers, home air purifier control panels, or graphical interfaces for fingerprint smart locks.
• Portable Consumer Electronics and Education/Maker Projects – fully compatible with Arduino, STM32 core boards, Raspberry Pi, and other open‑source hardware ecosystems, making it a top choice for advanced hackers and university engineering competitions.
• Wearable Tech and Health Monitoring/Medical Devices – applicable to portable pulse oximeters, heart rate monitors, pedometers, or miniature handheld sports tracking terminals.

V. Technical Q&A 

Q1: This Square TFT LCD Display module operates at 3.3V. If my host MCU (e.g., traditional Arduino UNO with 5V logic) uses 5V logic levels, can I connect it directly?

A1: Absolutely not. The module’s typical operating voltage and logic level standard are both 3.3V. Directly connecting 5V GPIO signals (such as SCLK or SDA) to the screen will most likely overload and permanently damage the embedded ST7789 driver IC. When the host runs on 5V, you must place a level‑shifter chip (e.g., 74HC245 or a dedicated logic‑level converter module) between the host pins and the screen to safely isolate and step down the signals to 3.3V logic levels.