Time for (another) new GPS23/05/2008 at 7:32 pm | Posted in Uncategorized | Leave a comment
So it seems we’ve destroyed another (and our last) GM862-GPS unit which provides our GPS and GSM communications. The only GPS unit we have left is my handheld Garmin eTrex which I brought with me to use in the chase boat to see how far we were from waypoints. Fortunately I also brought the data cable and the eTrex can use NMEA 0183 the standardised protocol used by most GPS units. The bad news is that the GM862 didn’t actually use NMEA so we’ve got to rewrite some code, but one of our other boats does have an NMEA GPS so its just a matter of copying that code. As for mounting it, in order to get a GPS signal we’ve got to mount the eTrex outside the electronics box as there’s no external antenna support like the GM862 had. So this means drilling another hole in the electronics box to get the data cable through. We also have to power the eTrex from its internal AA batteries so we’ll have to keep an eye on them. Luckily the eTrex itself is waterproof so we don’t have to worry about any waterproofing for it.
The picture below shows the mess that the electronics box is now in. The yellow thing at the bottom is the eTrex.
A nice test sail in the very gentle evening wind.