633 Custom Characters

The Big Sorbo

New member
I have the Serial 633 and was wondering how I can make custom characters to send to the screen. I want to send play, stop, pause, etc. and it isn't for bootup. I know this has been discussed before but I couldn't find anything that was for the 633.

Thanks for any help that you can provide.
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USB LCD Displays - Graphic and Character LCDs with a Keypad

CF Tech

Thank you for your question.

Please consult the 633's data sheet:


Command 9 is used to set the special characters.

9: Set LCD Special Character Data

Sets the font definition for one of the special characters (CGRAM).

type = 9
valid data_length is 9
data[0] = index of special character that you would like to modify, 0-7 are valid
data[1-8] = bitmap of the new font for this character

Here is an example you can try in the packet debugger of 633_WinTest. First dsipaly a screen that will show the the special character:

Command 7
Special Char [\001]

Then set the special character's font:

Command 9

This will show a diagonal line from the upper right of the character cell, down and to the left until it "hits" the left of the cell, then continues down and to the right.