Gt911 — Register Map [patched]
Wait until the GT911 INT pin changes state (or manually poll if not using hardware interrupts). Read Status Register: Read register 0x814F .
The register map is organized into functional blocks ranging from real-time commands to coordinate data reporting. Register Range Description Access Type Command and Status Read/Write (R/W) 0x8047 – 0x80FF Configuration Data Read/Write (R/W) 0x8100 – 0x813F Coordinate Data Read-Only (R) 0x8140 – 0x814E Product ID and Information Read-Only (R) Key Register Descriptions 1. Command Register (0x8040)
For those unfamiliar with the GT911, the register map is a crucial component that defines the chip's configuration and behavior. It's essentially a table that maps addresses to specific functions, allowing the host processor to communicate with the chip. The GT911 register map is divided into several sections, including the configuration registers, data registers, and status registers.
— Status/interrupt register (1 byte):
int X = ( (regs[0x8012] & 0x0F) << 8 ) | regs[0x8011]; int Y = ( (regs[0x8014] & 0x0F) << 8 ) | regs[0x8013];
By manipulating the "Refresh Rate" and "Sleep" registers, a device can significantly extend battery life when the screen is idle. Conclusion
For low-power or simple UI applications, you can poll this register to detect gestures without parsing coordinates.
Read register 0x8140 to confirm product ID (should return ASCII bytes for "911").
The configuration zone dictates how the touch controller behaves, including resolution, touch thresholds, interrupt modes, and power management. Key Configuration Fields
Determines the sensitivity required to register a touch.
Enter Gesture mode (must be preceded by a write to 0x8046 ).
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 I2C and supports up to 5 simultaneous touch points.
: Start of the first touch point data (Point 1 X-coordinate low byte).
Contains the version number of the configuration file. The chip will reject configuration writes if this value is lower than or equal to the current version in its internal flash, unless forced.
If you read register 0x8000 and always get 0x00 , your I²C is working, but the GT911 is not initialized. Ensure you performed the hardware reset sequence correctly. Many libraries forget to pull before reset.
