1.3 inch IPS HD TFT ST7789 Drive IC 240*240 SPI

Product Overview

This display module offers excellent visual quality in a compact format, making it ideal for wearables, portable devices, and micro-controller projects (like those using Arduino or ESP32).

Key Components

Component	Specification	Description
Size	1.3 inches (Diagonal)	Compact size suitable for wearables and handheld devices.
Display Type	IPS TFT (In-Plane Switching Thin-Film Transistor)	Provides superior color accuracy and ultra-wide viewing angles compared to older TN (Twisted Nematic) TFT technology.
Resolution	$240 \times 240$	A high-definition (HD) square resolution for its small size, resulting in a crisp image and good pixel-per-inch (PPI) density.
Driver IC	ST7789	The integrated circuit is responsible for controlling the display’s pixels. It handles data processing, memory, and timing signals.
Interface	SPI (Serial Peripheral Interface)	The communication protocol used to send display data (commands and pixel data) to the driver IC.

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The ST7789 Driver IC

The ST7789 is a single-chip controller/driver for a 240 \times 320 dot graphic display, though it’s commonly used here to drive the 240 \times 240 display area.

• Function: It features an internal power supply circuit, oscillator, and a controller that manages the display’s source and gate drivers.
• Color Depth: The driver typically supports up to 262k colors (18-bit), though it is often used with 65K colors (16-bit) in microcontroller applications to save memory and processing time.
• Memory: The IC includes internal GRAM (Graphic RAM) where the pixel data is stored before being displayed.

SPI Communication Interface

The use of the SPI interface is a major advantage for small microcontrollers. SPI is a synchronous serial data link standard that operates in full duplex mode.

Common Pins

The module typically exposes 7 to 8 pins, which include power and the necessary SPI lines:

Pin Name	Full Name	Function	Note
VCC/VDD	Power Supply	Typically 3.3V (It’s essential to check the specific module’s datasheet).
GND	Ground	Ground connection.
SCK	Serial Clock	Clock signal line.	Required for data synchronization.
SDA/MOSI	Master Out Slave In	Data line from the microcontroller (Master) to the display (Slave).
RES	Reset	Used to hardware reset the ST7789 driver.	Needs to be toggled low briefly during initialization.
DC	Data/Command	Used to tell the driver IC whether the data being sent on SDA} is a Command (DC rightarrow LOW) or Pixel Data (DC rightarrow HIGH).
CS	Chip Select	Used to enable/disable the display module.	Usually held LOW if it’s the only SPI device.
BLK	Backlight Control	Controls the LED backlight (often active HIGH).	Can be connected to a PWM pin for brightness control.

Benefits of SPI

• High Speed: SPI can transmit data quickly, allowing for fast screen refreshes and smooth graphics.
• Low Pin Count: Uses fewer microcontroller pins (typically 4-5) compared to parallel interfaces, saving I/O for other sensors and functions.

Applications

This display is extremely popular in projects requiring a high-quality visual output in a small space:

• Wearable Devices: Smartwatches and fitness trackers.
• Portable Instruments: Small digital multimeters or logging devices.
• Embedded HMI (Human-Machine Interface): Status panels for home automation or industrial controllers.
• IoT Devices: Displaying sensor data, network status, or time.