22 June 2011

iNavX on the iPad

I thought I'd share my experience with iNavX on iOS with you.

As most boaters with an iOS device I was quick to download the original Navionics programs. Although hefty downloads they work quite well. Scrolling and zooming is pretty smooth in the Navionics apps. They are a little unstable requiring an app restart now and then, but not very often.

When I learned that iNavX supported a TCP feed I rewired my AIS transceiver into my Linux box and had that start sending AIS and GPS data over TCP, and bought a license for iNavX and a set of (Navionics) charts. This works great, and I'm now able to see my navigation data and AIS targets on my iPad. This promotes the iPad from a good tool for situational awareness to a great one.

There are still a few issues that you should be aware of in case you're considering to use your iPad for full navigation duty, with any app. Depending on your use you may need a waterproof case and have a problem with sun viewability. Also, although iOS supports multi-tasking, it's too easy to accidentally stop an app. In general the large amount of memory that the navigation apps seem to use also makes for occasional crashes. Thus, keeping these apps running for hours on end is not how I personally see them at their best.

Also there is a bit of a downside to the way that iNavX works with charts. Although it is beautiful that you can buy charts online and then download these to the device, it looks as if the charts are stored as "disposable documents." When I upgraded my iPad from 4.3 to 4.3.3 I lost all my charts and had to download them again. As that didn't work at sea without internet I had to fall back to Navionics for a while. Next time I'll make sure I test my chart store after updating the device.

02 June 2011

L&S Ecopilot reduces autopilot current consumption

I just installed an Ecopilot device made by Lecomble et Schmitt from France. Let me tell you what this does and how much of a difference it makes to our power consumption.

Our autopilot uses a reversible pump that sends hydraulic fluid backwards and forwards through a rather stout cylinder. It has ample power to steer the boat, much more than I have certainly!

For those times when you do not want to steer by autopilot, or when it is off, a bypass is installed. Look at the photo on the right. The steering cylinder is at the very bottom of the picture. The black and black-and-orange hoses carry the hydraulic fluid from the pump (not depicted) to the cylinder. The bypass line is the shiny "inverse U" shaped pipe. At the rear you see a metal box with a plastic black blob attached to it with another smaller blob attached to it and a black cable sticking out. The metal box contains a hydraulic valve that is controlled by a solenoid (electromagnetic coil) in the bigger black box. Industry has, smartly, standardized the size of these solenoids and even the connectors.

The story of today is about replacing the smallest of the two black boxes. This is a replacement for the standard connector that attaches to the industry standard magnet. As you can see here it isn't much to look at. Instead of the normal connector which only contains a bit of plastic and some screws, this version contains a small electronic circuit that aims to reduce the power used by the magnet. The reasoning behind this product is that the current used by the solenoid to move the valve initially is much higher than the current required to keep the valve open. Since the standard coil is just a bit of wire it doesn't know how to do this. And that's where the Ecopilot comes in: it measures the current and reduces this to the point where the valve just stays open.


With my solenoid the power consumption went from 1.4 A @ 24 V to 0.3 A. That is a 1.1 A saving, and adds up to a 26,4 Ah savings per day (when sailing). So this € 110 device is a very worthwhile investment -- easily cheaper than adding another solar panel.

To find one on sale, search the internet for "ecopilot 2204028" for the 24V version and "ecopilot 2204027" for the 12V version. Note that most web stores selling this will be French. The one that I ordered from (www.tyboat.com) was very helpful but their online ordering process did not yet take into account any increase in shipping costs outside France... C'est la vie.