Using a GPS mouse as primary or backup GPS with the Brookhouse NMEA multiplexer.

It is now possible to plug a low-cost PS2 GPS directly into the Brookhouse multiplexer with the mini-Din plug. The GPS mouse can be used as the primary GPS, but it is also particularly suitable as a backup. 

In combination with the automatic backup switching feature of the brookhouse mux, this is a great way of ensuring uninterrupted lat/lon fixes in case the primary GPS fails, at very affordable cost. 
The PS2 connector is available as a low-cost option for all Brookhouse multiplexer models.

A GPS mouse is a small, selfcontained GPS receiver incl. antenna, without any switches, buttons or display. It has a fixed cable, for output of GPS NMEA sentences. The same cable is used to supply power. This type of compact GPS is designed primarily for use with a laptop or PDA.
Common models are:

1. The GPS USB mouse.
2. The GPS PS2 mouse.

The USB GPS mouse receives its power via the USB connector and can only be directly plugged into a (laptop) computer.

The PS2 GPS  is an  RS232 GPS, with a PS2 connector.  A more correct name would be “mini-DIN” connector. (DIN= Deutsche Industrie Norm). 5V power is received through one of the pins.

The problem with this type of GPS in marine navigation systems is that they receive their power (5V) via the same cable as they output NMEA data. It is therefore not possible to simply cut off the connector and insert the wires in the NMEA IN terminals of a multiplexer or other NMEA listener.  The extra 5V power supply made the use of these wonderful small and affordable GPS units often impractical in integrated marine navigation systems.

The Brookhouse NMEA multiplexer can  now be supplied with a female mini-Din connector which allows the PS2 GPS  to be directly plugged in. The multiplexer supplies the required 5V  power  via this connector. 


The GPS is internally connected to NMEA input port 3 of the multiplexer. The user can decide if the GPS mouse will be used as a backup GPS, by activation of the automatic backup switching feature in the setup menu, or as the primary GPS. 

This provides a  tidy and  very affordable GPS solution. The standard connector does not need to be cut off, no adapter cable is required, power supply is taken care of by the multiplexer. If a multiplexer with LCD is used, the lat/lon and other GPS data can be displayed, also if no computer is connected. 



Please be aware that not all pin-outs for PS2 GPSs  are the same. We use pinout as for the Haicom Hi-204III, see picture above. A connector with different pin-out can be supplied.  As the connector is internally wired to mux NMEA input port 3,  no other NMEA talker should be connected to this port. But a listener that only requires GPS data, such as a DSC radio, may be connected to input port 3 to share the GPS output with the multiplexer.