Systems – Electronics

NMEA Data Sharing Across Applications and Platforms

With a Maretron USB100 NMEA-0183 Gateway and an Actisense NGT-1 NMEA 2000 gateway I was struggling to get the NMEA data to all the applications on my PC, iPAD and iPhone. Many applications can not only connect to the an NMEA data source but also share the data on another TP Port or Virtual Com Port. Originally I was using a complicated stack of software all connected to each other to get data to some of the applications but couldn’t really use them all at once. More importantly which ever app I felt like using at the time might require starting up two applications!

Well in comes GPSGate Client ($40) which lets you connect to a data source and then share it with many other applications.

You can see in the graphic below that I’ve dedicated the Actisense Gateway to Coastal Explorer. GPSGate is then connected to the Maretron Gateway and then it is used to serve up the data to 7 other applications some on Windows and some on my WiFi iPad and iPhone.

Also of note is that my preferred iOS navigation application Navionics works fine on the iPhone since it has a built-in GPS, but on the WiFi iPad there’s no way to get the NMEA data into the application. I’ve contacted Navionics about this and we’ll see if they add the functionality.

NMEA Data Sharing

This is greatly simplified from the way I was doing it before and I’m very excited to not only have all this finally working but to have it working simply! $40 for GPSGate was worth every penny!

Still not done

When we were still on the dock at Shilshole we’d get asked all the time “when you going to be done?” And I’d always say, “never!” Well, in that spirit you should know that we’re not done yet!

Today I worked on adding six new switches to control some functions of the AIS and power on/off various components of what we call the NavSystem. The new switches will allow us to turn off the transmit portion of our AIS to save power or avoid being tracked by CB. The other switches will allow us to turn off the PC, WiFi Bridge, LAN/USB Hub, and the NMEA 2000 network (instruments). All of these things used to come on or off all at once, now we can more granularly control our power usage, which us very good thing!!


Maretron DST100 Installed

Maretron DST800 Transducer and fairing block

When we purchased the boat we had a non-working knot meter and a single function transducer with a display located only on an internal bulkhead in the aft cabin. The new gorgeously installed Maretron DST100 instrument will measure Depth, Speed and Temperature.

I just have to get a cable to hook it up to the NMEA 2000 network and we’re done!

Steve, a fellow burner and shipwright at Seaview, made that fairing block. It looks great and I’m sure will give us +.001 kts in boat speed. Winking smile

AIS is worth it !

This has been our first time out with AIS on the boat and I must say it is absolutely worth it. Being able to see exactly where that tug is headed and it’s speed is very useful. Even more useful is when you want to cutoff the shipping traffic separation lanes, you can “see” way up the sound and know whether or not a freighter or tug is coming around that next bend.

If you have been unsure about AIS… GET IT !

Our First Weather Fax

I’ve started devoted a little bit of time each night to playing around with our ICOM M710 SSB Radio. We’re sitting in the middle of a marina surrounded by aluminum masts so I assume reception or transmission is going to be greatly impaired. Thus far I’m focusing on what I can hear and then I’ll work up to transmitting.

With that in mind, two night ago I was tuning around to find some Shortwave broadcasts and was able to hear China and Cuba, not too shabby. Last night I use the GetFax module in Airmail to receive (or download you might say) our first weatherfax. Weatherfax will be critical to our onboard weather forecasts and route planning so it felt pretty good to see it work properly on the first try!

Here’s our first weatherfax image.

Our First WeatherFax

I’ll do a video podcast at some point of the image actually downloading its cool to watch, and it will be impressive to all my geek  friends to see just how SLOW it is. There’s no broadband at sea (well that we can afford).

12V DC Ship’s Computer by Aleutia

I just ordered the PC which will become the heart of our navigation systems–the Aleutia P1 Marine PC (@Aleutia).

I have probably spent 4 the equivalent of four full days mostly late at night looking into fanless PCs that either designed to be run on 12V DC power or happen to be powered as such but come with an AC-DC converter. PCs in that secondary category might work fine hooked directly up to the ship’s 12V power, but really should be run on a DC to DC regulator that essentially guarantees the PC is seeing 12V consistently or if it’s a 19V PC (lots of options out there for that) then it could handle that as well. I would look at the Carnetix Regulators if you decide to go that route.

I decided on the Aleutia because I felt it was the most hardware for the right price. I’m not saying it was the cheapest! However it is a very cable power sipping PC that can do the work I need. It also has the advantage of already being able to accept a wide input of DC power (6V-32V DC) which means I won’t need the regulator for the PC (I might still need one for a monitor TBD). Here’s a quick list of the specs of the unit I selected:


Processor Intel ATOM D510 1.66GHz (The lower power slower of the two choices)
RAM 4GB (Upgraded from 2GB)
System Cooling Fanless
Power Input 6V – 12V DC
Power Draw 19W * Let’s discuss this below
Solid State Drive (SSD HD) I will supply
OS I will supply
Bulkhead Mountable YES
Tested in Nigeria YES – No really…
Wi-Fi No * (Optional)
64Bit Yes


I didn’t include a Solid State Drive  because their options for SSD HD were limited and I can slide in a better larger drive than their choices.

I didn’t buy Windows 7 64 bit from them because I have a better deal than theirs.

I didn’t include Wi-Fi because this PC is going to be mounted less than a foot from the wireless access point. I will cable it directly instead.

As for the power draw, the PC is designed to be very efficient, but if I go buy a crappy SSD which is a power hog then this will all be for naught. When I select my SSD I need to be very conscious of that! Aleutia’s options were for a 32GB or a 64GB Corsair Nova SSD which draw 0.5W (0.04A @ 12VDC) at idle and 2.0W (0.16A @ 12VDC) max. If I bought Corsairs most high performance SSD it would draw 0.2A at idle 0.5A Max. Not as much as other things on the boat, but I want this PC to stay on 24×7 so I need to watch every little bit I can. I’ll probably go with the Corsair Force F120 120GB SSD because it is larger, has better perf and the same power draw as the NOVA series which Aleutia has spec’d and tested. I might be able to find an even more miserly SSD but I’ve not looked yet.

The next step is making a decision about the Monitor…. but that is another post for another day.

One more little thing to finish the electronics

Maretron FA-CF-90

This is a Maretron FA-CF-90, it is a field installable right angle connector and it’s what I need to finish the install of Maretron DSM250 the instrument display in my cockpit completing all the critical electronics systems.

NMEA 2000 connectors are keyed, which means when you’re mating this right angle to a device, the angle might end up pointing up, down, left, right; who knows. The field installable connector can be rotated as you assemble it (or that’s what support told me) so that YOU can choose which direction the cable leads off from the connector.

I still have two tank level meters to install and I want to upgrade the NMEA 0183 1980’s depth transducr  to a combo Depth, Speed, Temp instrument and NMEA 2000, but when this bad boy arrives and I get the cockpit display installed we’ll have reached a pretty major milestone and I will feel very cool!

God Speed USPS, bring my baby to me!!

RADAR Options Greatly Simplified

I think I should have be reincarnated as a search engine; I love to look things up. And in that vein I’ve ben doing all kinds of research on RADARs and PC Navigation Software packages and as a slight backup plan by looking into Chartplotters. That was a really open ended problem space and a tad frustrating to look at all that data and feature comparisons.

I was able to boil all that down pretty quickly since I’ve decided for sure to go the PC Software route with no chartplotter. Instead of a chartplotter I’ll use a Tablet PC and the Maretron DSM 250 instrument display in the cockpit.

When you look at RADARs they have two ways to connect:1) through a chartplotter and to a network or directly to a PC or 2) through a box that puts the RADAR data onto a network which the PC can plug into. This second mode is what I need, so that narrows it down to Koden’s RADARpc’s MDS-50R 18” radome and MDS-51R 24” radome and the Nobeltec IR2-4D 24” radome (seems their 2kW offering has been discontinued).

With Nobeltec you have the option of using Nobeltec Admiral or VNS navigation programs.

With the Koden RADARpc you have the option of using the following software packages:

Some general thoughts about these:

P-Sea is not a properly built or designed Windows 7 Application. The first thing they tell you to do before installing is to turn off some Windows 7 security features. I’m not willing to do that so I’m not going to be able to evaluate P-Sea.

iExpedition is apparently really cool, but I can’t find a reliable website that is clearly the development company that has contact information, support forums, all the things I’d expect for a quality software package. Maybe it exists and I can’t find it but without that I’m not even going to bother.

Now we’re down to RosePoint and Nobeltec. I have RosePoint and like it pretty well, they’re a local company which is nice. They’re also very responsive on their forums. I was very intrigued by the network and multi-PC capabilities of EuroNa’v’s SeaPro 3000, but it doesn’t support RADARChart overlay and that lead me to ask about Coastal Explorer’s plan for multiple PC scenarios which it turns out are the high priority for this year.

I don’t know much at all about Nobeltec, but I’m going to seek out a demo copy.

At any rate that was a long winded way of saying that I’ve narrowed down my RADAR to the Koden RADARpc MDS-51R, now I just need to look for the best price, possibly with a software package deal.

Thinking about AIS Integration

I’m starting to get back into the electronics projects one of which is the AIS solution.

What is AIS you ask?

Non Sailor Elevator Pitch: AIS is a radio based system that large vessels use to transmit information within their local area about who they are, where they are going, how fast and how to contact them. By receiving their signal and displaying it on your charts you can avoid hitting them which is the most important but not the only way in which you can use the information. For more go to Wikipedia’s article on AIS.

As a non-commercial vessel we’re not required to transmit our data so at a bare minimum we will have an AIS Receiver on board. I can’t see why we wouldn’t have a transponder (which can also transmit), but I’m leaving that option out there.

First thing to think about is how does all this fit together?

This is a logical diagram of the systems involved and how they link up.

The first thing to note is that the antennas are already in place. I have a dedicated Digital Antenna 222-VW VHF Antenna on my main masthead and a dedicated Digital Antenna 236-VW AIS Antenna on my mizzen masthead.

Secondly, I already have the NMEA 2000 network in place with both a NMEA 0183 and NMEA 2000 gateway to connect to the PC.

Integration Items for Discussion:

  • VHF
    The VHF may not happen. My version of the Icom m504 has no AIS capabilities. Icom tech support says there’s no upgrade. I just bought the VHF in April of 2009 so unless someone at Icom can hook me up with a trade-in or an upgrade to my unit I may just skip that part.
  • PC Navigation
    I’ve not picked my RADAR yet so I’ve not picked my Nav Software package, but all of the major vendors call out AIS support as you can see in my PC Navigation Software Comparison spreadsheet on SkyDrive.
  • Chartplotter
    Again, since I’ve not picked out my RADAR I’ve also not decided on my chartplotter. What chartplotter and what connection options they have is part of a new research project and the Marine Chartplotter Feature comparison spreadsheet which I worked on tonight. Seems like all the major players support similar AIS functionality.

Just a few thoughts I guess no real answers, but I hope you find it useful just the same.

Maretron DSM250 Display Standby Mode Workaround

After the first night of trying to sleep in the same cabin with the DSM 250 on “low” backlight lead to me turn it off at nights. But this isn’t so good because then the buffer of data is uses to charts graphs is lost.

Turns out you can do this, sort of. The Brightness button (the one that looks like a sun) and the three levels it cycles through are configurable. From any display screen press along:

  1. Enter (to get into the config menus)
  2. Select “Display Settings” and hit Enter.
  3. Select “Backlight” and hit Enter
    At this point you’ll see settings for Low, Medium and High.
  4. Change Low to 0% by selecting that line and hitting Enter.
    Then hit the down arrow till the value is Zero and hit Enter again.
  5. Hit Back until your back at a standard instrument screen.

From here tap the Brightness button.

One of your clicks should turn the screen off completely. It’s probably not off completely in the electrical sense, but it certainly is on low and it’s not emitting light so you can sleep soundly or just have the display be less intrusive.


I forgot to mention. While the display is dimmed to 0%, the DSM250 is still capturing data which means all the trend charts you want to see (like barometric pressure) will have historical data, instead of being blank like they would be if turned the display completely off.

A great workaround!