C'est la Vie is a 1966 Charlie Morgan 34.

Her home port is Everglades City, FL. Our typical cruising area is Southwest Florida, the Florida Keys, the Southeastern Atlantic Seaboard, and the Bahamas. We are C'est la Vie's third owners and purchased her in 2005. We continue to maintain and update this classic vessel. Please post any questions or comments about C'est la Vie or our travels via the comment links below.

Saturday, May 29, 2010

tis the season...

With 6 coats of Bristol Finish applied to the gallows, generator box, and lazurette hatch, I moved on to the brightwork aboard C'est la Vie.  Tis the season to knock out refinishing the brightwork.
We have little wood topsides, but it feels expansive when driving a sheet of 220 grit sandpaper.  I did complete all the sanding & prep this afternoon, so barring any rain tonight or Sunday, we will be able to complete the refinishing tomorrow.

I spent some time this morning researching the various NMEA protocols and methods of linking electronics aboard the boat. The realization that our GPS, VHF, handheld VHF, & autopilot all speak NMEA0183 inspired the morning research.

I learned that NMEA0183 allows one device to be the "talker" and multiple other devices to "listen".  Thus with our system the GPS would be the talker and the two VHF's and the Autopilot would listen.

The newer NMEA2000 standard allows for each device to be both a talker and a listener.  Currently none of the systems on C'est la Vie are NMEA2000.

So back to the the task at hand... create a network where the GPS can talk while the VHFs & autopilot listen.   I believe that this could be achieved with a simple electrical bus, but my internet research lead me to the Actisense QNB-1 network block and we now are awaiting the shipment.

The ability of this block to host communications and act as the power supply/ground will allow us to simplify the wiring in our electrical panel and avoid numerous runs from electronics back to the panel.  Another great aspect of this block is that it is both NMEA0183 and NMEA2000 compliant.   So as we upgrade systems this block will not join the growing bin of obsolescent boat parts (note: the block can be either 0183 or 2000, but cannot host both systems simultaneously.)

Why does do our VHF Radios and Autopilot want to listen to the GPS? 

Both our fixed VHF - ICOM422 - and our handheld VHF - HX600 are DSC equipped.  This feature enables the VHF radios to broadcast a distress signal that identifies our vessel and it's current location - if the radio is linked to a GPS.

Connecting the GPS - Garmin492 - to our electric autopilot, a Raymarine ST1000+ , will allow the autopilot to steer to a waypoint selected on the GPS system.  In the past we used the GPS to identify a point to which we wish to travel, then we asked the GPS to give us a heading in degrees, then steered this heading, and then set the autopilot to the heading we were steering.  Allowing the GPS to talk to the Autopilot would eliminate many of these steps and hopefully make the system more accurate.

I'm guessing that a large portion of our blog followers are simply wishing that Anne and I would cast off already and start posting more images and narrative about our travels.  What is all this talk of NMEA and images of projects day after day after day.  I'm also growing weary of the projects and the price tags that come along with the projects.  Soon the day will come... at least that is my mantra while I sand the brightwork.

No comments:

Post a Comment