Matrix Orbital LK202-25 Legacy - Manual (Page 8)

NOTES
• The keypad connector must be wired with columns on one side and rows on the other
side of the center of the connector. If the keypad isn’t wired this way an adapter must
be made or the connector must be rewired to meet this requirement.
• The connector is reversible. Reversing the connector will not damage the keypad or
the display, but will however, change the ASCII character map.
3. Press a key on the keypad. An upper case ASCII character (A-Y) should appear on the PC screen.
Different keys should generate different characters.
To experiment, reverse the connector and see if it generates a more logical set of characters. Ultimately, the
program in the micro-controller will have to ‘map’ these characters to the ones marked on the keypad, which
will likely be different.
1.7 Manual Over-ride
Manual over-ride should only be required in one instance. If for some reason the module is set at a baud
rate which cannot be produced by the host system and all communication to the display is lost, then the user
should follow this simple procedure:
1. Load an appropriate test software that is located on the eCD (ex: displaytuner.exe)
2. Turn off the display.
3. Put a jumper on pins 5 and 6 of the keypad connector (C5 and R1).
4. Power up the display. The baud rate is now set to 19200 baud.
5. Remove the jumper and change the RS232 port settings to the desired baud rate. Refer to the "Set
RS-232 port speed" command for acceptable baud rates.
6. Use “Display Tuner” or any other available test software to check functionality of the unit.
Try turning the backlight off/on, turning the contrast up/down, etc.
7. Turn off the display.
8. Power up the display.
2 Connections
2.1 Connector Pinout
Refer to the diagram below for this section.
Matrix Orbital LK202-25 4