Matrix Orbital LK202-24-USB - Manual (Page 7)

• Run a PC program such as Hyperterm to experiment with typing text. Make certain it’s configured to
use the correct port. Set the baud rate to 19,200 and turn flow control off.
Once this is complete, try typing some characters on the keyboard. The characters should now appear on the
display screen.
Alpha Demo, Display Tuner or MOGD are excellent for basic display tests.
1.6 Trying out a Keypad
Since a number of different keypad types can be connected to the display, the results may be a little
unpredictable. At this point the user should make certain the keypad and interface work, and possibly
generate an ASCII map for any programming needs.
The keypad interface on the display 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.
The keypad should be a matrix style or momentary switches. It is possible to simulate key strokes by
shorting out a row and a column pin.
1.6.1 Here’s what to do:
1. The PC should be running a terminal program, such as Hyperterm.
2. With the display connected to the PC, plug in the keypad. If the connector has fewer pins than the one
on the display, centre it as well as possible.
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 the user will
need to make an adapter or rewire the connector 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-X) should appear on the PC screen.
Different keys should generate different characters.
To experiment, reverse the connector to see if it generates a more logical set of characters. Ultimately the
program in the controller will have to ’map’ these characters to the ones marked on the keypad, which will
likely be different.
Matrix Orbital LK202-24-USB 3