Matrix Orbital GTT70A - Manual (Page 9)

5 Command Summary
1.2 Interactive Input
Keypad
Unique values can be assigned for up to 25 keys. When a key event occurs it will be saved to a 20 key
buffer. Key events will generate a return message that can be transmitted immediately or polled by
toggling the auto transmit key press command. A sample return message is shown below.
Table 6: Example Keypad Response
Prefix Message ID Length Event Key ID
252 165 0 2 0 65
Key presses will have a message ID of 165, and a data length equal to the number of bytes currently in
the key buffer. Each key value will be preceded by an event byte as per the Keypad Event Types table.
Table 7: Keypad Event Types
Value 0 1 2
Event Press Release Repeat
Touch
Touch input * allows the screen to return various types of up, down and move messages depending on
the reporting style. Two distinct styles are available: region and coordinate. Both generate a return
message with an identification number of 135, followed by event information.
Table 8: Touch Event Types
Value 0 1 2
Event Down Up Move
In coordinate mode, the GTT will send an event type as listed above followed by signed short x and y
coordinates of the touch location.
Table 9: Example Co-ordinate Response
Prefix Message ID Length Event X Y
252 135 0 5 0 0 50 0 10
In region mode, rectangular buttons are defined on the screen. When touch activities occur within
regions, a visual update accompanies the event report listed in the Touch Event Types table. Events that
occur outside defined regions may be reported as Region 255, when reporting is turned on.
Table 10: Example Region Response
Prefix Message ID Length Event Region
252 135 0 2 0 5
*Note: P lease ensure your touch screen is calibrated correctly by locating a touchcal.dat file within the SYSTEM
folder of your SD Card. If necessary, calibration can be performed using the Calibrate Touch Screen command.