Matrix Orbital GLK24064-25 Legacy - Manual (Page 27)

GLK24064-25 rev. 06 27
7. Miscellaneous Commands
The commands listed in this chapter don't readily fit in any of the other categories, or are used in more than
one category. Before issuing commands to the GLK24064-25 please read sections 8.2 and 8.3.
7.1.1 Clear display (254 88)
This command clears the display and resets the text write position to the top left of the screen.
7.1.2 Set contrast (254 80 [contrast])
This command sets the display's contrast to [contrast], where [contrast] is a value between 0x00 and 0xFF
(between 0 and 255). Lower values cause "on" elements in the display area to appear lighter, while higher
values cause "on" elements to appear darker.
Lighting conditions will affect the actual value used for optimal viewing. Individual GLK24064-25 modules
will also differ slightly from each other in appearance. In addition, values for optimal viewing while the
GLK24064-25 backlight is on may differ from values used when backlight is off.
7.1.3 Set contrast and save (254 145 [contrast])
This command works in exactly the same way as the “Set Contrast” command. The only difference is it
saves the contrast value in the memory of the module, whereas, the previous command only changes the
value for the duration of use.
7.1.4 Backlight on (254 66 [minutes])
This command turns on the backlight for a time of [minutes] minutes. (this specifies how long the backlight
will remain on after receipt of the command). If [minutes] is zero (0), the backlight will remain on
indefinitely. Note: backlight is always on by default on power up.
7.1.5 Backlight off (254 70)
This command turns the backlight of the GLK24064-25 off.
7.1.6 General purpose output on (254 86)
This command turns on the General Purpose Output (see section 2.3 for a description of the GPO). In the
"on" state the GPO provides 5 volts at a maximum current of 20 mA to operate external devices.
7.1.7 General purpose output off (254 87)
This command turns the General Purpose Output (GPO) off.
7.1.8 Set I
2
C address 254 51 [address])
This command sets the I²C write address of the module. This value must be an even number and the read
address is one higher. For example if the I²C write address is set to 0x50, then the read address is 0x51. The
change in address is immediate. This address is 0x50 by default, and is reset temporarily back to that value
when the "Manual Over-ride" jumper is used on power up (see section 1.7).