Understanding the GT911 Register Map: A Guide for Developers
. Its memory space is logically divided into four primary functional blocks: Register Range Description Access Type 0x8040 – 0x8046 Command and Status Read/Write (R/W) 0x8047 – 0x80FF Device Configuration Read/Write (R/W) 0x8100 – 0x813F Coordinate Data (Touch Points) Read-Only (R) 0x8140 – 0x814E Product ID and Hardware Info Read-Only (R) 2. Core Functional Blocks Command & Status (0x8040 – 0x8046)
First, perform a dummy write of the 16-bit address you want to read from. Then, issue a restart condition and read the data. Auto-Increment:
Contains the touch point status and X/Y coordinates for up to 5 points. 3. Key Functional Registers Command Register (0x8040)
This discovery explained why some GT911 screens worked instantly with Arduino libraries and others failed silently—the developer was shouting at the wrong address.
Pro tip: After reading all touch points, always write 0x00 back to 0x8009. If you fail to do this, the GT911 will stop sending interrupts.
The Early Days
Applications of the GT911 Register Map
Understanding the GT911 Register Map: A Guide for Developers
. Its memory space is logically divided into four primary functional blocks: Register Range Description Access Type 0x8040 – 0x8046 Command and Status Read/Write (R/W) 0x8047 – 0x80FF Device Configuration Read/Write (R/W) 0x8100 – 0x813F Coordinate Data (Touch Points) Read-Only (R) 0x8140 – 0x814E Product ID and Hardware Info Read-Only (R) 2. Core Functional Blocks Command & Status (0x8040 – 0x8046)
First, perform a dummy write of the 16-bit address you want to read from. Then, issue a restart condition and read the data. Auto-Increment: gt911 register map
Contains the touch point status and X/Y coordinates for up to 5 points. 3. Key Functional Registers Command Register (0x8040)
This discovery explained why some GT911 screens worked instantly with Arduino libraries and others failed silently—the developer was shouting at the wrong address. Understanding the GT911 Register Map: A Guide for Developers
Pro tip: After reading all touch points, always write 0x00 back to 0x8009. If you fail to do this, the GT911 will stop sending interrupts.
The Early Days
Applications of the GT911 Register Map