2.2
Power/Data Connector
The Power/Data Connector provides a standard connector for powering the display module. The LK202-
25 requires five volts for the standard display module, between nine to fifteen for the wide voltage (V)
and between nine to thirty-five volts for the wide voltage with efficient power supply module (VPT). The
voltage is applied through pins one and four of the four pin Power/Data connector. Pins two and three are
reserved for serial transmission, using either the RS-232/TTL or the I
2
C protocol, depending on what has
been selected by the Protocol Select Jumpers. Pins two and three may be reversed by changing the Legacy
Connector Jumpers in order to be compatible with previous PCB revisions.
Pin
1
PWR
(See table 1)
Pin
2
Rx \ SCL (I
2
C clock)
Pin
3
Tx \ SDA (I
2
C data)
Pin
4
GND
Figure 16: Power Connector and Pin out
Table 1: Power Requirements
Standard
-V
-VPT
Supply Voltage
+5Vdc
±
0.25V
+9V to +15V
+9V to +35V
Supply Current
148 mA typical
Inrush
148 mA
WARNINGS
•
Do not apply any power with reversed polarization.
•
Do not apply any voltage other than the specified voltage.
2.3
Protocol Select Jumpers
The Protocol Select Jumpers, pictured below in
figure 17
, provide the means necessary to toggle the
display module between RS-232, TTL and I
2
C protocols. As a default, the jumpers are set to RS-232 mode
with solder jumps on the 232 jumpers. In order to place the display module in I
2
C mode you must first
remove the solder jumps from the 232 jumpers and then place them on the I2C jumpers. The display will
now be in I
2
C mode and have a default slave address of 0x50 unless it has been changed. Similarly, in order
to change the display to TTL mode, simply remove the zero ohm resistors from the 232 or I
2
C jumpers and
solder them to the TTL jumpers.
Matrix Orbital
LK202-25
10
electronic components distributor
