Matrix Orbital PK202-24-USB - Manual (Page 22)

3.3.7 Set Debounce Time (254 85 [time])(R)
This command sets the time between key press and key read. All key types with the exception of latched
piezo switches will ’bounce’ for a varying time depending on their physical characteristics. The default
debounce time for the module is about 52mS, which is adequate for most membrane keypads.
4 Bar Graphs and Special Characters
The display includes the ability to draw bar graphs (either horizontal or vertical) and allows users to
define up to eight special characters.
Eight characters (ASCII values 0x00 to 0x07) are set aside for use with bar graphs, user defined char-
acters, and big numbers. Since the same 8 characters are used for each function, the functions may not
be used simultaneously. The characters may be defined or redefined at any time by issuing the commands
shown in this section. Once defined, they may be used either by means of the bar graph commands, or by
simply issuing one of the ASCII values 0x00 to 0x07, which are not prefixed by the command byte, 254.
4.1 Command List
4.1.1 Initialize Wide Vertical Bar Graph (254 118)
This command defines the 8 special / user characters to be blocks suitable for use in drawing wide (5
pixel) vertical bar graphs. Any previously existing definitions will be lost. Once this command has been
issued, any number of vertical bar graphs may be drawn unless the characters are redefined by another
command.
4.1.2 Initialize Narrow Vertical Bar Graph (254 115)
This command defines the 8 special / user characters to be blocks suitable for use in drawing narrow (2
pixel) vertical bar graphs. Any previously existing definitions will be lost. Once this command has been
issued, any number of vertical bar graphs may be drawn unless the characters are redefined by another
command.
4.1.3 Draw Vertical Bar Graph (254 61 [column][height])
Draws a vertical bar graph in [column] having a height of [height] pixels. The height may range from
0 to 20 (0x00 to 0x14) pixels. The necessary characters must first be initialized by either of the commands
shown in section 4.1.1 or 4.1.2, which will determine the width of the bar graph. The graph may be erased
by drawing a bar graph of height=0 in the same column.
Matrix Orbital PK202-24-USB 18