Monday, May 25, 2015

A very connected boat Part 2

This is what a Signal K system will typically look like on your boat. The boxes may well be different but the concept will not. This will be a beta site and I'm playing with ways to install the gear, make it unobtrusive, easy to access, and I'm documenting any issues along the way.

My mantra is it's better to be lucky than smart, although being both lucky and smart isn't a condition to be sneered at. The boat is a Searay 39 MY and in this case the lucky part of the equation is access is great. Below this panel is a large removable cabinet door where a couple of air conditioner units live. I can actually work myself into the void, sit upright and get at the back of the panel. It's also right next door to the new TV which made its installation easier. 

The things I'm looking at are wiring management, physical mounting constraints, packaging, securing the gear sufficiently enough to survive both a good rocking and rolling and easy day to day access to SD cards, idiot lights and power. Right now I'm using sticky pads and tie wraps for the wiring and good quality Velcro for the little server and Netgear router. I may well want to do some relocation in the future and I don't want to make holes until it becomes permanent. 

I'll start with the Raspberry Pi 2 model B. It may or may not end up as the overall preferred choice but it has many of the attributes needed to fill that role. This pint sized computer, like the Beaglebone Black and similar all have a lot of processing bang for a very small buck.

As an example this Pi 2 has a quad core ARM processor that runs at 700MHz, a gigabit of RAM memory, and supports up to a 32GB SD card along with four USB ports and more. The Beaglebone Black is no slouch either for a few dollars more. Just to provide some historical perspective my 4 function Bomar Brain pocket calculator cost me $150 dollars in 1972.

For the time being the Pi 2 will work fine for software testing and will talk to the Signal K Arduino yet to come with no problems. Others who are more technically nuanced than I will decide what the final recommendations for server hardware options are.

The Pi costs about $40 dollars plus shipping. The case and micro USB power cord were $10.00. My inside voice was yelling get the clear case Bill, it's cool. You can see the guts and everything inside it. My outside voice prevailed, and I settled for a dark brown case that blends well with the location it's going to live in. I am striving for hmmm...  the word tasteful comes to mind. I don't want a lot of clutter and it should be unobtrusive. I almost in an OCD way considered some cable change outs so they were all black.  As you can see I resisted this and just tried to be neat and tidy. I may change my mind about this yet. I did buckle and painted the shiny SS clam shell flat black. 

Likewise the same is true of the router. I wanted it to be elevated as much as practical with clean looking short as possible wiring. It should also be near the center of the vessel. It's just a bit aft of amidships and I have a strong WiFi signal from the swim platform to the forward V berth. I still have the change the password and that will get done this week. 

Power is required, both USB 5VDC for the server and 12VDC for the router. I had bought this dual 12/5VDC outlet but only recently installed it.

You have to be a bit careful when selecting the USB power/charger port. This one outputs 2.1 amps. It will be okay but to power all four of the Pi's USB ports 2.5 amps are needed.

When I installed the router earlier I used the original 12 volt outlet in the panel to power it. The coiled cable going to this outlet doesn't look as good as I would like it to. As a result I'm moving it to the other outlet with the USB charging ports. The install will look much cleaner.

I'm also going to remove the outlet's rubber caps. They aren't needed and get in the way. The spare USB charging port will be good for phones, tablets and ilk. To be honest I wasn't terribly impressed with the outlets price, power output and with the plastic locking nuts on the back side that don't leave much margin for hole cutting errors. I think a better and less expensive option can be found. It does look sharp though.

Here's is my initial summary. A Signal K system is easy to install, very DIY suitable and there is a lot of flexibility in how and where it can be done. The rough cost without the Rouge Wave portion (this isn't needed for a basic Signal K system) but including the wireless router was about $135.00. The labor time should be about three hours max or much less depending on how picky the installation requirements are. If it was less visible 1.5 hours would have done the trick. Add the gateway and you're ready to go forth into the connected world with your boat. Just fasten your seat belts first.

Next on the list is to add the Arduino with a case and connect it to the server. My immediate goals downstream are modest. I want to get the software into the server along with some logged data and try out a sample app. Later I want do something simple like using the Arduino to turn on a LED from an app to demonstrate IoT (Internet of Things) capability. I know my programming skills are very rusty, but with some WD40 squirted on them, and hopefully minor help from the group this will happen. What fun!

The Signal K forum is here. If you can help with the project, join. If you just want to watch join also. If you don't want to watch hoist the Signal K flag and show you too want to communicate and email me a pic. I'll post them all on a special page. 


  1. Hi Bill,

    I've recently begun tinkering around with Pi's/Arduinos. Was looking for a project to get back into tech and decided on a vessel monitor system for my boat. The system commercially available, while appearing to be fine products, seem very expensive for the limited capability they offer.

    Originally, it was going to be a simple is "my power on and is there water in the bilge" but as I did more research I was amazed at the number of low cost sensors available and I have expanded my plans to include many other parameters and controls.

    I've started test communications with Small Arduino's (Adafruit industry Trinket Pro) coupled with small ($7) 2.4GHz RF cards. My thinking was to distribute these low cost, low power modules around the vessel to gather/distribute analog/digital information. They would then pass it upstream to or take commands from a Pi that was Wifi or "cellularlly" connected to the cloud.

    Your signal K write-ups were timely ( and very good) as I was wondering how standard would evolve. Seems like the perfect platform for what I have in mind.

    My limiting item is time but I will continue to plug away. I look forward to following along with your progress.

    Tim C
    St Pete, FL

  2. Hi Tim and thanks. Arduinos speaking Signal K have been part of the project from the very beginning. They are an inexpensive way of bringing real world boat IoT functionality and specialized data acquisition into the Signal K server which can then move it into the cloud. Take a look at the Freeboard Project's Arduino Mega, Due and UDOO interface board.
    If you have questions join the Signal K forum:!forum/signalk

  3. Thanks Bill - I'll be traveling this week so will have plenty of time in airports to read.

    I like the little RF cards as they do not have the overhead (processing and power) of a full ethernet stack and can be placed in a very power efficient sleep state along with the Trinkets. Just haven't had time to get them on the boat to test in that environment.

    Know each boat is different so this is probably one of those "well Tim, there is an infinite number of combinations of systems" :>) but, in general, any idea if 2.4 GHz RF devices (similar to those used in wireless home phone handsets - this chip - 2.4GHz transceiver nRF24L01 from Nordic Semiconductor) would interfere or get interfered with by boat systems?

  4. Check out the Spark now renamed Particle and the $20 Photon board or the new Espruino Pico-both talk using Javascript.

    1. Thanks cdog, you can also add the the list the upcoming C.H.I.P that starts at $9.

      It's almost a case of too many options and which ones will survive and be adopted.

  5. Thanks Tim, the two big 2.5GHz interference problems on a typical boat are the microwave oven, and to some degree shortwave radios. However some 2.4GHZ devices can interfere with WiFi signals.


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