1. Introduction
This manual provides detailed instructions for the Estardyn 2.25-inch TFT LCD module, featuring the ST7789 driver IC. This compact, full-view color display utilizes a 4-wire SPI interface, making it suitable for a wide range of embedded applications requiring a small, vibrant screen.
2. Specifications
The following table outlines the key technical specifications of the 2.25-inch TFT LCD module:
| Feature | Description |
|---|---|
| Model Number | 2.25 inch TFT |
| Type | TFT |
| Brand Name | Estardyn |
| Origin | Mainland China |
| Size | 2.25 inches |
| Resolution | 76*284 pixels |
| Display Mode | 76*284 |
| Driver IC | ST7789 |
| Interface | 4-wire SPI |
| Display Color | Colorful |
| Power Supply | 2.8V ~ 3.3V |
| Operating Temperature | -20°C ~ 70°C |
| Linking Method | COG (Chip-on-Glass) |
| Screen Size (mm) | 17.9 * 62.5 * 2.36 |
| Module Size (mm) | 21.08 * 73.15 * 3.56 |
| Display Size (mm) | 14.797 * 55.295 |
3. Setup and Pin Definition
The module communicates via a 4-wire SPI interface. Proper connection to your microcontroller is crucial for correct operation. Refer to the pin definition table and the module's physical layout for wiring.
3.1 Pin Definition Table
| PIN | SYMBOL | Description |
|---|---|---|
| 1 | GND | Ground connection |
| 2 | VCC | Power supply (2.8V - 3.3V) |
| 3 | SCL | SPI Clock Line |
| 4 | SDA | SPI Data Line |
| 5 | RST | Reset Pin (Active Low) |
| 6 | DC | Data/Command Selection (High for Data, Low for Command) |
| 7 | CS | Chip Select (Active Low) |
| 8 | BL | Backlight Control (Typically High for ON) |
3.2 Basic Wiring Diagram
Connect the module to your microcontroller as follows:
- VCC to 3.3V power supply.
- GND to Ground.
- SCL to your microcontroller's SPI Clock (SCK) pin.
- SDA to your microcontroller's SPI Data Out (MOSI) pin.
- RST to a GPIO pin on your microcontroller.
- DC to a GPIO pin on your microcontroller.
- CS to a GPIO pin on your microcontroller.
- BL to 3.3V for backlight ON, or a PWM-capable GPIO for brightness control.
Ensure all connections are secure and correctly oriented before applying power.
4. Operating Instructions
Operating the ST7789 display involves sending commands and data via the SPI interface. A typical operation sequence includes initialization, setting display parameters, and writing pixel data.
4.1 Initialization Sequence
After power-up, the display requires an initialization sequence to configure the ST7789 driver. This usually involves:
- Hardware Reset: Toggle the RST pin (low, then high).
- Software Reset: Send the software reset command (0x01).
- Sleep Out: Send the sleep out command (0x11).
- Color Mode: Set the pixel format (e.g., 16-bit or 18-bit color) using command 0x3A.
- Display On: Send the display on command (0x29).
- Other configurations: Set gamma, power control, etc., as per the ST7789 datasheet.
4.2 Displaying Graphics and Text
To display content, you typically follow these steps:
- Set Address Window: Define the rectangular area on the display where pixels will be written using commands 0x2A (Column Address Set) and 0x2B (Row Address Set).
- Write to GRAM: Send the Memory Write command (0x2C), then continuously send pixel data. Each pixel's color is typically represented by 2 bytes (16-bit color) or 3 bytes (18-bit color).
- Backlight Control: Ensure the BL pin is high to illuminate the display. For brightness control, use PWM on the BL pin if supported by your microcontroller.
5. Maintenance
To ensure the longevity and optimal performance of your LCD module, follow these maintenance guidelines:
- Handling: Always handle the module by its edges. Avoid touching the display surface or the flexible flat cable (FFC) directly.
- Static Discharge: LCD modules are sensitive to electrostatic discharge (ESD). Use appropriate ESD precautions (e.g., anti-static wrist strap, grounded workstation) when handling.
- Cleaning: If the display surface becomes dirty, gently wipe it with a soft, lint-free cloth moistened with isopropyl alcohol or a specialized LCD cleaning solution. Do not use abrasive cleaners, solvents, or excessive pressure.
- Storage: Store the module in its original packaging or an anti-static bag in a cool, dry place, away from direct sunlight and extreme temperatures.
- Power Supply: Ensure the power supply voltage is within the specified range (2.8V - 3.3V). Over-voltage can permanently damage the module.
6. Troubleshooting
If you encounter issues with your Estardyn 2.25-inch TFT LCD module, refer to the following troubleshooting tips:
6.1 No Display / Blank Screen
- Power Check: Verify that VCC and GND are correctly connected and receiving the specified voltage (2.8V - 3.3V).
- Backlight: Ensure the BL pin is connected and receiving power (typically 3.3V) to turn on the backlight.
- Connections: Double-check all SPI connections (SCL, SDA, CS, DC, RST) for continuity and correct pin assignment.
- Initialization Code: Review your microcontroller code for the correct ST7789 initialization sequence. Incorrect commands or timing can prevent the display from starting.
- Reset Pin: Ensure the RST pin is properly toggled during initialization.
6.2 Garbled or Incorrect Display
- SPI Mode: Confirm that your microcontroller's SPI settings (clock polarity, phase) match the requirements of the ST7789 driver.
- Data/Command Pin (DC): Ensure the DC pin is correctly switched between high (data) and low (command) when sending bytes.
- Data Format: Verify that pixel data is sent in the correct color format (e.g., 16-bit RGB565) and byte order.
- Address Window: Check if the column and row address set commands (0x2A, 0x2B) are correctly defining the display area.
- Timing: Ensure sufficient delays between commands if required by the ST7789 datasheet.
6.3 Backlight Not Working
- BL Pin Connection: Confirm the BL pin is connected to a power source (e.g., 3.3V) or a GPIO pin configured for output.
- Code Control: If using PWM for brightness, ensure your code is correctly generating the PWM signal.
7. User Tips
- Reference Datasheet: Always refer to the official ST7789 datasheet for the most accurate and detailed information on commands and registers.
- Community Resources: Many online communities and forums (e.g., Arduino, Raspberry Pi forums) have extensive resources and code examples for ST7789-based displays. Searching for "ST7789 Arduino library" or "ST7789 Raspberry Pi Python" can provide valuable starting points.
- Start Simple: Begin with basic initialization and displaying a single color or simple shape to confirm functionality before moving to complex graphics.
8. Warranty and Support
For any technical assistance or inquiries regarding the Estardyn 2.25-inch TFT LCD module, please contact your vendor or the Estardyn Flagship Store directly. Specific warranty terms may vary by region and retailer. Please retain your proof of purchase for warranty claims.
