User manual

Microgate MicroGraph LED User Manual Page 54 of 88
3 TRANSMISSION PROTOCOL
Using 'Base Program' (see par. 2.2) it is possible to send commands to the display board or using
the serial port (set by default to 9600 baud, 8 bit, No parity, 1 stop bit) or a TCP/IP socket via
connected Ethernet or via WiFi (by default the Ethernet port listens to the IP address
192.168.0.123, port 21967, whereas the WiFi board listens to the IP address 192.168.0.124, port
21968).
All display boards of the MicroLED family use the same protocols of the MicroPIX family, more
specifically the original MicroTAB and the specialized MicroGRAPH protocol.
With the Test Protocol (ALPHA) (kept to ensure compatibility with older 'character' display boards
and all those devices using this protocol) elements are positioned by ROW and COLUMN, where
the row is identified by a character (from ‘A’ to ‘Q’, ‘ ‘ space = all) and the column by an integer
from 0 to 99.
Conventionally, in graphical and LED display boards, a column corresponds to the number of dots
(pixels or LEDs) composing the space character ' ' (ASCII 32, hex 20h) in the font set on the display
board. For example a column on the LED display boards set to the font 'medium proportional'
corresponds to 10 LEDs.
The font used to display information is the one set in the display board menu.
In the example below, the writing 'CIAO' in the font 'Medium' is positioned on row B, column 2
(the first column is zero) and the command to be given is the following:
Start Frame
Row
Command
Column
Data
End Frame
ESC
B
‘S’
02
'CIAO'
ETX + Chk
Row A
Row B
Col0 Col1 Col2 ...
Figure 31 - Writing positioning example with ALPHA protocol
It is clear that with this protocol positioning elements is discreted and not free for every single dot
(e.g. it is not possible to write in the center of the display board).