Configures the maximum number of simultaneous touches supported (1 to 5).
The Goodix GT911 is a widely used capacitive touch screen controller found in thousands of consumer electronics, embedded systems, and DIY microcontroller projects. It communicates primarily over I2C and supports up to five simultaneous touch points.
Set this register to 0x01 after writing the configuration and checksum. This signals the IC to parse the new settings. 2. Real-Time Coordinate Registers (0x814E – 0x8177)
Here are some of the key registers in the GT911 register map:
Real-time touch data and command flags.
The Goodix GT911 is one of the most popular capacitive touch screen controllers used in embedded systems, DIY electronics, and consumer devices. It communicates primarily over the I2C interface, allowing microcontrollers like Arduino, ESP32, STM32, and Raspberry Pi to read touch coordinates and configure panel settings.
The Goodix GT911 is a widely adopted, high-performance capacitive touch controller engineered for a diverse range of interactive displays, from smartphones and tablets to industrial HMIs and smart home devices. Known for its robust 5-point multi-touch support, excellent sensitivity, and sophisticated noise immunity, mastering this IC is a valuable skill for any embedded engineer.
Gesture detection must be enabled in the configuration registers (bit field in 0x8130 ). By default, many GT911 units ship with gestures disabled to save power.
A typical driver for the GT911 follows a specific initialization and operation sequence: gt911 register map
Controls touch orientation, swapping X/Y axes, and mirroring options. Bit 3: Swap X and Y axes. Bit 2: Reverse X axis direction. Bit 1: Reverse Y axis direction.
To read real-time touch events, your microcontroller should poll these registers or trigger an interrupt when the GT911's INT pin pulls low. The Buffer Status Register (0x8140) This is the most critical register for data retrieval.
| Register Address | Section | Description | | --- | --- | --- | | 0x00-0x0F | Configuration | Touch sensitivity, debounce time, and gesture recognition settings | | 0x10-0x1F | Control | Power management, interrupt handling, and communication interface settings | | 0x20-0x3F | Status | Touch event detection, gesture recognition, and error flags | | 0x40-0x5F | Data | Touch coordinates, pressure, and gesture information | | 0x60-0xFF | Reserved | Reserved for future use or proprietary functions |
Defines the maximum vertical resolution (e.g., 480 pixels). Set this register to 0x01 after writing the
Enter Gesture mode (must be preceded by a write to 0x8046 ).
At the heart of integrating a GT911 lies a complete understanding of its —the memory-mapped control panel that dictates how the chip is configured and how its data is accessed. This guide provides a detailed exploration of the register map, its various sections, and the practical procedures required to breathe life into your touch interface.
When starting up, the RESET pin must be pulled low for at least 100μ s to ensure a proper reset of the GT911.
For low-power or simple UI applications, you can poll this register to detect gestures without parsing coordinates. Real-Time Coordinate Registers (0x814E – 0x8177) Here are