Matrix Orbital GLK12232-25-SM Legacy - Manual (Page 7)

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The keypad interface on the GLK12232-25-SM converts a row/column connection to an ASCII character.
By default, a keypress is transmitted as serial data immediately. Keypad buffering can be selected using the
appropriate commands.
1.7.1 Here's what to do:
1. Your PC should be running a terminal program, such as Hyperterm (as in the previous section).
2. With the GLK12232-25-SM connected to the PC, plug in your keypad. If your connector has fewer
pins than the one on the GLK12232-25-SM, center it as well as possible.
Note 1: The keypad connector must be wired with columns on one side and rows on the other side of
the center of the connector. If your keypad isn't wired this way you will need to make an adapter or
rewire the connector to meet this requirement.
Note 2: The connector is reversible. Reversing the connector will not damage the keypad or the
GLK12232-25-SM, but it will 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.
If you want to experiment, reverse the connector and see if it generates a more logical set of characters.
Ultimately, the program in your controller will have to "map" these characters to the ones marked on the
keypad, which will likely be different.
1.8 Manual Override
Manual override 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. Turn off the display
2. Put a jumper on pins 5 and 6 of the keypad connector (C5 and R1).
3. Power up the display. The baud rate is now set to 19,200.
4. Remove the jumper and change the RS-232 port settings to the desired baud rate.
5. Turn off the display.
6. Power up the display.
Refer to the “Set RS-232 Port Speed” command (section 7.1.10) for acceptable baud rates.
Note: This procedure does not change settings in the memory chip, it uses default settings stored in the main
processor. This allows the user to communicate with the display when all other communications are lost.
Once able to communicate with the display, the user may then change the default settings in the memory
chip.