Matrix Orbital PK202-24-USB - Manual (Page 25)

4.1.9 Draw Medium Digits (254 111 [row][column][digit])
Draws a medium digit in [row] and [column] using the specified [digit]. Medium digits occupy two
rows. When the [row] is specified to be “1”, the medium digit will be displayed correctly. When the [row]
is specified to be “2”, only the top part of the medium digit will be displayed. When [row] is specified to be
“0”, only the bottom part of the medium digit will be displayed.
5 Fan and GPO Commands
5.1 Display Return Protocol
To facilitate the reporting of information other than keypresses, the “Display return protocol”, (DRP)
was developed. This protocol allows the display to return arbitrary information back to the controller. This
protocol is used for reading fan speeds and retrieving 1-wire bus information. The basic structure of the
protocol is described in the Table below.
Table 9: Display Return Protocol
Offset
(Bytes)
Length
(Bytes)
Value Description
0 2 0x23 0x2A Preamble
2 1 Continued / Size
3 1 Packet Type
4 1–127 Packet Data
The first two bytes is the standard preamble to separate the protocol from returned keypresses. The next
byte is described in the Table below. The CONT flag specifies that the data will be continued in the next
DRP packet. The lower seven bits contains the size of the data section excluding the four byte header. The
type specifies what type of information is contained in the packet. Finally, the data returned is specific to the
packet type.
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