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Gnd co l 1 r o w 1 gnd – Matrix Orbital GLK12232-25-SM Legacy User Manual

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6.1 General

The display keypad interface processes the keypad row / column matrix into a serial (RS-232 or I

2

C)

data byte stream. Aside from this processing, the keypad has no effect on the display. If it is necessary to

send keystrokes to the display, they must be routed through the micro-controller.

6.2 Connections

Figure 12: Keypad Connector

GND CO

L

1

R

O

W

1

GND

Figure 13: Keypad Connector

The connector is not ’keyed’ so the keypad will probably plug in either of two ways. The display will

not be damaged by reversing the connector. However, the keypad will generate a different ASCII character

mapping for each position. If the connector has fewer than 10 pins it should be centered on the display

connector.

The diagram shows the logical layout (row 1, column 1 in upper left). The connector for the keypad is a

10 pin 0.1" spacing male header. Pins 1 through 5 are columns and pins 6 through 10 are rows. The keypad

is scanned whenever a key is pressed; there is no continuous key scan. This means that key presses are dealt

with immediately without any appreciable latency. This also prevents electrical noise which is often caused

by continuous key scans.

NOTE Please note that keypads may be laid out in a different pattern. If this is the

case, the user will need to interpret the key codes differently. Also included are two extra

pins on each end of the connector to be used for ground strapping. This can be used

in conjuntion with your keypad if a ground strap connection is required or if a common

ground connection is needed.

Matrix Orbital

GLK12232-25-SM

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