2.4" TFT LCD Breakout with Touch - How it works
The 2.4" TFT LCD Breakout with Touch features a vibrant color display based on the ILI9341 driver, which communicates over a SPI interface and includes resistive touch capabilities. This module is ideal for visual interfaces in embedded projects, offering full color support and fast refresh rates.
Datasheets and References
ILI9341 Datasheet
Detailed register and graphics command set documentation
How the Display Works
The display is controlled by the ILI9341 driver chip using SPI commands. It supports:
- Drawing primitives (lines, rectangles, circles)
- Text rendering via GFX-compatible fonts
- Full-screen image rendering (bitmaps)
- Rotation and mirroring
All drawing operations are handled by sending SPI commands to the display.
Touchscreen Functionality
The display includes a 4-wire resistive touchscreen managed by the XPT2046 controller, which communicates via SPI.
When pressed, the touch panel generates analog voltage levels corresponding to X and Y coordinates. These are read by the XPT2046's internal ADC and transmitted as 12-bit values to the microcontroller.
- Touch interface: SPI
- Controller: XPT2046
- Output: Raw X, Y coordinates and pressure
Touch data must be read through the CST (chip select) pin using SPI. Make sure MISO (D0) is connected to your microcontroller to receive data.
Display Communication (SPI)
| Signal | Description |
|---|---|
CLK | SPI clock |
DI | MOSI (data to display) |
CSL | Chip Select for ILI9341 |
DC | Data/Command control |
RST | Optional hardware reset |
BL | Backlight power or PWM control |
Rendering Pipeline
- Microcontroller sends commands over SPI
- ILI9341 decodes instructions and modifies internal RAM
- Pixels are refreshed on screen accordingly
- For touch input, the appropriate controller returns X/Y data