Sunday 26 October 2014

Pig Trough Again

Hi everyone,
This weekend the weather was good for another visit to Pig Trough anchorage at Garden Island.  We sailed over on Saturday in cloudy but rain-free conditions with a nice 10-12 knot westerly.  A single leg without having to tack.

Zen Again tracks - straight out, gybing back
We arrived at Pig Trough at about midday and spent a lazy afternoon aboard.  Played around with the new TV and Raspberry Pi computer.  The pi runs OpenCPN quite well, including plotting AIS targets as shown below.  It is a little slow zooming in and out but otherwise is perfectly fine.

OpenCPN showing AIS targets while running on Raspberry Pi
During the afternoon FSC yachts Aqua Vitae and Divided Sky arrived in the anchorage.  We had a very pleasant sundowner on Divided Sky.  There were a few light showers during the afternoon as a weak cold front came through but the anchorage was very well protected.

On Sunday morning the folks visited Zen Again for coffee.  It was a little damp outside occasionally but the weather was gradually improving.

We sailed back to FSC in the early afternoon, continuing to test OpenCPN on the pi.  No problems.  We sailed back under jib alone - just to be cruisy.  The boat was doing 3 to 4.5 knots under the No 2 yankee alone in 10-12 knots of breeze.  We gybed a couple of times to keep a good angle and to stay in deep water.

Twas a very pleasant weekend!

Saturday 18 October 2014

Super Cheap Cruising Chartplotter and Media Player

Hi everyone,
This week we became real cruisers - we installed a TV on Zen Again!  The TV was a gift from Alain from sv CG, who I helped with his VHF and HF radios recently.  He had installed a bigger TV on his yacht and the old one was surplus to his requirements but a perfect fit for ours.

We don't expect to use the unit for live TV anytime soon.  Rather we will use it as a media player and cheap chartplotter.  Both functions are in combination with the Raspberry Pi computer we have also installed and which runs the Linux version of the excellent and free chartplotter OpenCPN.

TV installed on the main bulkhead
The TV is installed on the main bulkhead in the saloon and the Raspberry Pi in a partitioned area in the chart table.  A USB hub connects WiFi adaptor, GPS, 1TB disk and (when necessary) keyboard/mouse to the computer.

The Raspberry Pi "Zenny"
(shown out of its normal home on the other side of the divider)
The Raspberry Pi computer originated in the UK where it was designed as a cheap computer for use in schools.  It has been wildly successful and is widely used by hobbyists.  Millions have been sold.  They cost less than $40 each!  Google it for more info.

OpenCPN runs a little slowly on the Raspberry Pi but so far it is managing OK and receiving GPS information from the GPS puck.  Next week I intend to try connecting the Pi to our AIS via WiFi so OpenCPN can also display AIS traffic.  One nice aspect of the system is that OpenCPN alarms sound through our stereo system, even in the middle of movies or music.  Good for anchor watch!

If tests go well I'll try installing our library of GoogleEarth "charts" on the USB disk to see how OpenCPN copes with them on the Pi.  That might be a little too compute-intensive for it!

Raspberry Pi running OpenCPN
 The parts cost of the system, which provides chartplotting and media playing is:

  • Raspberry Pi => $40
  • SD Card => $10 (holds operating system, applications and OpenCPN charts on the Pi)
  • USB power cable => $20
  • 12V to 5V converter => $30
  • HDMI cable => $20
  • USB Hub => $40
  • USB WiFi => $20
  • USB GPS => $60
  • 1TB USB disk => $90 (holds multimedia, books/manuals and GoogleEarth "charts")
  • Total Parts Cost => $330 (not including TV)

I'm certainly not suggesting a system like this could replace a mainstream marine chartplotter,  It is certainly a very cheap and completely independent backup system.