13
4.3
Common Features
General Purpose Outputs
Figure 10: GPO Header
Table 6: GPO Pinout
Pin Function
1
GPO 1
2
GND
3
GPO 2
4
GND
A unique feature of the GLK12232-25 is the ability to control relays
*
and other external devices using
either one of two General Purpose Outputs. Each can source up to 20mA of current at five volts when
on or sink 20mA at zero volts when off. The straight, four pin header can be interfaced to a number of
female connectors to provide control to any peripheral devices required.
*Note:
If connecting a relay, be sure that it is fully clamped using a diode and capacitor in order to absorb any
electro-motive force (EMF) which will be generated.
Keypad Header
Figure 11: Keypad Header
Table 7: Keypad Pinout
Pin Function Pin
Function
1
Gnd
7
Column 1
2
Row 1
8
Column 2
3
Row 2
9
Column 3
4
Row 3
10
Column 4
5
Row 4
11
Column 5
6
Row 5
12
Gnd/Vcc
*
To facilitate user input, the GLK12232-25 provides a Keypad Interface Connector which allows a matrix
style keypad of up to twenty-five keys to be directly connected to the display module. Key presses are
generated when a short is detected between a row and a column. When a key press is generated, a
character specific to that key press is automatically sent on the Tx communication line. If a synchronous
read method is desired in serial mode
*
, the “Auto Transmit Keypress”
function can be turned off to
allow the key presses to remain in the buffer so that they may be polled. The character that is
associated with each key press may also be altered using the “Assign Key Codes” command. The straight
twelve pin header of the Keypad Interface Connector will interface to a variety of different devices
including the Matrix Orbital KPP4x4 keypad.
*Note:
In I
2
C mode, the “Auto Transmit Keypress” function should always be on, keypresses should not be polled.
**Note:
The Ground / +5V pin is toggled by the jumper above the right of the keypad connector. Jump pads 1 & 2
for GND or 2 & 3 for +5V.