Introduction
This document provides the product specification for the LS028T22-S-V1, a 2.8-inch transmissive a-Si TFT-LCD module from LESSON Smart Display. Featuring a QVGA resolution of 240x320 pixels, 262 thousand colors, and a simple SPI interface, this module is designed as a cost-effective and easy-to-integrate display solution. Driven by the common ST7789P3 controller, it is well-suited for a wide range of embedded systems, consumer electronics, and industrial devices where a reliable, medium-sized graphical display is required.
Key Specifications
- Brand & Model: LESSON Smart Display LS028T22-S-V1
- Screen Size: 2.8 inches (diagonal)
- Active Area: 43.2 mm (H) × 57.6 mm (V)
- Driver IC: ST7789P3
- Display Technology: Transmissive type a-Si TFT-LCD
- Display Mode: Active matrix TFT, Transmissive type
- Module Type: COG + FPC + B/L
- Display Resolution: 240(RGB) × 320 pixels (QVGA)
- Display Colors: 262 Thousand Colors
- Module Outline Dimensions: 50.0 mm (H) × 69.2 mm (V) × 2.32 mm (D)
- Interface: SPI (4-line Serial Interface) (Pins: CS, SCL, SDA, RS, RESET)
- Input Data: SPI (as per Physical Features table)
- Viewing Direction (Grayscale Inversion): TN (Twisted Nematic)
- Supply Voltage (VCC): 2.4V to 3.3V (Typical: 2.75V)
- Operating Temperature: -20°C to +70°C
- Storage Temperature: -30°C to +80°C
- Backlight: 4-chip white LED in parallel (Drive condition: IF=80mA, Vf=3V Typ.)
- Contrast Ratio: 500:1 (Typical)
- Response Time (Tr+Tf): 16 ms (Typical)
- Transmittance: 6.4% (Typical)
General Description
The LS028T22-S-V1 is a practical and widely applicable display module. Its 2.8-inch size with QVGA resolution offers a good balance between display size and cost. The module is controlled by the ST7789P3 driver IC, which is accessed via a straightforward 4-line SPI interface (Chip Select CS, Serial Clock SCL, Serial Data SDA, Command/Data RS, and Reset). This interface minimizes the required MCU pins and simplifies firmware development.
The panel uses TN (Twisted Nematic) technology. The specification notes "TN" for grayscale inversion, indicating that the viewing angles are more limited compared to IPS panels, with typical optimal viewing direction being 12 o'clock. The optical characteristics include a typical contrast ratio of 500:1 and a fast typical response time of 16ms. The document provides detailed SPI timing characteristics for both write and read operations, including setup/hold times for control signals and clock parameters. A dedicated section details the reset timing requirements, specifying a minimum reset pulse width of 10µs and defining the behavior for pulses shorter than 5µs (rejected) or longer than 9µs (accepted). Mechanical notes include recommendations for bezel design and warnings to prevent the touch panel (if added) from contacting metal conductors.
Application Scenarios
This versatile SPI module fits numerous embedded and portable applications:
- Consumer Electronics: Portable media players, handheld games, smart home controllers.
- Industrial HMIs: Status and control interfaces for machinery, test equipment, and sensors.
- Point-of-Sale Systems: Display for small kiosks, payment terminals, or ticket machines.
- Automotive Aftermarket: Displays for car audio systems, reverse cameras, or gauges.
- IoT Devices: Status displays for environmental monitors, smart appliances, or network devices.
Conclusion
The LESSON Smart Display LS028T22-S-V1 is a reliable, cost-effective display solution that emphasizes ease of integration. Its use of the common ST7789P3 driver, simple SPI interface, clear documentation, and adequate performance makes it an excellent choice for a vast array of projects and products requiring a medium-sized graphical display without the need for wide viewing angles.
