Component: Touch Screen (GT911) (Graphical Library)

Author	Matrix Ltd
Version	2.0
Category	Graphical Library

Touch Screen (GT911) component

Low level routines for controlling or interacting with the GT911 touch screen controller IC found on a lot of common capacitive touch screen products.

Version information

Library Version, Component Version, Date, Author, Info
6, 1.0, 26-07-24, BR, Removed ghost greay square connection line
7, 1.0, 29-08-24, BR, Fixed a problem where the I2C writes were corrupted
8, 1.0, 29-08-24, BR, Added Orientation support
9, 1.0, 29-08-24, BR, Improved Orientation support

Detailed description

No detailed description exists yet for this component

Examples

Macro reference

Initialise

	Initialise
Activates the SPI peripheral and claims control over the I/O pins. Returns 1 if device found and communicating.
- BOOL	Return

ReadCoord

	ReadCoord
Reads a coordinate returned from the Sample Sensor macro. Coordinate is scaled to the X/Y Pixel bounds specified.
- BYTE	Coordinate
0 = X, 1 = Y, 2 = PointSize, 3= TrackID
- BYTE	Index
Touch Index Range: 0 - 4
- UINT	Return

ReadXBytes

	ReadXBytes
Reads the specified number of bytes starting at the specified address
- UINT	Address

- BYTE	Data

- BYTE	NumBytes

- BOOL	Return

SampleSensor

	SampleSensor
Reads the touch controller and returns true if there is currently a touch in progress. The touch coordinates can be read using the ReadCoord macro. Return 0 = No Touch, 1 = Single touch detected, 2 = Two touch points detected
- BYTE	Return

SetOrientation

	SetOrientation
Allows the orientation to be overridden.
- BYTE	Orientation
Range: 0 - 3
- VOID	Return

WriteXBytes

	WriteXBytes
Writes the specified number of bytes starting at the specified address
- UINT	Address

- BYTE	Data

- BYTE	NumBytes

- VOID	Return

Property reference

	Properties
	LinkTo

	Bus Settings
	Channel
Channel selection
	Baud Select
Baud rate option selector
	Baud Rate
Baud rate to be used
	Stop Delay
On older microcontroller devices there is a potential for the I2C hardware channel to lock up if there is not a 10ms delay between an I2C stop event and the next I2C start event. Most modern microcontrollers will not have a problem so this property can be disabled to speed up the I2C communications.
	Device Address
The device address is set using the INT pin on power up. Low = 0x5D / High = 0x14
	Connections
	SDA
Pin used for SDA (data signal)
	SCL
Pin used for SCL (clock signal)
	Reset Pin
Pin used to reset the touch module
	INT Pin
Pin used to set the I2C address and check for new touch data.
	Configuration
	Analogue Mode

	X Pixel

	Y Pixel

	Flip X

	Flip Y

	Simulation
	Label
Label used to identify the component on the panel.
	Enable Interrupt

	Interrupt Macro
Macro called when the simulated display fires an interrupt.
	Simulate Comms
Allows the I2C communications to be simulated and piped through an API to real world hardware.