0x8154 / 0x8155 : Continuous 16-bit point target sizing scale data.
Here are some key registers and their functions:
| Touch Point | Address Range | Register Name | | :--- | :--- | :--- | | | 0x8150 | Track ID (identifies a finger's movement across frames) | | | 0x8151 | X coordinate (Low Byte) | | | 0x8152 | X coordinate (High Byte) | | | 0x8153 | Y coordinate (Low Byte) | | | 0x8154 | Y coordinate (High Byte) | | | 0x8155 | Touch Size | | Touch 2 | 0x8156 to 0x815B | (Same structure as Touch 1) | | Touch 3 | 0x815C to 0x8161 | (Same structure) | | Touch 4 | 0x8162 to 0x8167 | (Same structure) | | Touch 5 | 0x8168 to 0x816D | (Same structure) | | Key | 0x817D | Touch Key Status |
| Address Range | Category | Access | Description | | :--- | :--- | :--- | :--- | | | Real-time Command | Write Only | Used to send commands to the chip for mode switching and control. | | 0x8047 - 0x80FF | Configuration Info | Read/Write | Contains device parameters like screen resolution, touch thresholds, and other settings. | | 0x814E - 0x817D | Coordinate Info | Read Only | Stores raw touch data for up to 5 points, including coordinates, size, and a touch key status register. | | 0xAB10 - 0xAB1F | HotKnot Status | Read (mostly) | Status registers for the HotKnot data exchange protocol. | | 0xAC90 - 0xAE10 | HotKnot Buffer | Read/Write | Data buffers for transmitting and receiving HotKnot frames. | gt911 register map
Check if is equal to 1 . If it is 0 , abort the read cycle.
The initialization process is critical for reliable operation and must include:
Determines the sensitivity required to trigger a "touch" event. 0x8154 / 0x8155 : Continuous 16-bit point target
Must be written with 0x01 after updating the configuration registers to signal the MCU to parse the new settings. 4. System Control & Command Registers (0x8040)
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Must be updated when configuration changes. | | 0x814E - 0x817D | Coordinate Info
Bitmask registers used to mirror or swap the X and Y axes, change interrupt trigger modes (rising/falling edge vs. low/high level), and toggle proximity sensing.
The HotKnot feature enables two GT911 chips to exchange data via capacitive coupling (by bringing two touchscreen-enabled devices together). These registers manage this process: