Matrix Orbital LK402-25 Legacy - Manual (Page 9)

2 Hardware Information
Refer to the following diagram for this chapter:
1 DB-9 Connector 5 Power / Data Connector
2 Power Through DB9 Jumper 6 Manual Override
3 GPOs 7 Protocol Select Jumpers
4 Keypad Interface 8 Optional Dallas One-Wire Bridge
Figure 8: LK402-25
2.1 DB-9 Connector
The LK402-25 provides a DB-9 Connector to readily interface with serial devices which use the EIA232
standard signal levels of ±12V to ±12V. It is also possible to communicate at TTL levels of 0 to +5V by
setting the Protocol Select Jumpers to TTL. As an added feature it is also possible to apply power through
pin 9 of the DB-9 Connector in order to reduce cable clutter. However, in order to accomplish this you must
set the Power Through DB-9 Jumper.
Pin 2 Tx \ SDA (I 2 C data)
Pin 3 Rx \ SCL (I 2 C clock)
Pin 5 GND
Pin 9 PWR (Must solder Power Through DB-
9 Jumper. See table 68 on page 49 for
power requirements.)
Figure 9: RS-232 Pin out
Matrix Orbital LK402-25 5