Matrix Orbital LK202-25 Legacy - Manual (Page 21)

LK202-25 rev 3 21
6. 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 LK202-25 please read sections 7.2 and 7.3.
Some commands, marked with an (R), may be "remembered" to set new defaults that will be in effect each
time the unit is powered on. See section 6.1.1 for further information.
6.1 Command List
6.1.1 Remember (254 147 [0|1])
This command allows a number of settings, such as cursor state, backlight, etc. to automatically be stored
to non-volatile memory so they become new defaults. The command should only be used when required
for two reasons:
1. Writing to non-volatile memory is time consuming and slows down the operation of the display.
2. Non-volatile memory has a "write limit" and may only be changed approximately 100,000 times.
Commands which may be used with the "remember" function are marked with an "R" in the "default"
column in the command tables.
The example shows the procedure to set Auto scroll ON as the default condition. Commands are shown in
both decimal and hex in this example.
Decimal Hex Function
254 147 1 FE 93 01 Turn on "remember" function.
254 81 FE 51 Turn on auto scroll. Since "remember" is ON, this setting will be
saved in non-volatile memory.
254 147 0 FE 93 00 Turn off "remember" function.
Any number of commands may be entered between the "remember ON" and "remember OFF" commands,
and all settings will be memorized.
6.1.2 Clear display (254 88)
This command clears the display and resets the text insertion point to the top left of the screen.
6.1.3 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 LK202-25 modules
will also differ slightly from each other in appearance. In addition, values for optimal viewing while the
LK202-25 backlight is on may differ from values used when backlight is off.
6.1.4 Set contrast and save (254 145 [contrast])
This command works in exactly the same way as the “Set Contrast” command. The only difference is that
it saves the contrast value in the non-volatile memory of the module, whereas the previous command only
changes the value until the next power down.