Building an Open Source Boat with Raspberry Pi & NMEA 2000 - Part IV | OpenPlotter, Signal K, KIP 

Great idea! Thank you!

Multiple redundancies is ideal.

@@CaymanIslandsCatWalks 100% especially when it comes to being out on the water. My parents are retired coast guard and I myself was a network engineer as a contractor for the USCG for a few years. Redundancy is critical to your safety :)

@@DeadlyDragon_ I wrote my comment before he said that he not even near a boat yet. Solid tips from you!

As an engineer how would you do the box? Sealed and no fans or the way I did it?

@@TheFloridaCaptain HEAT is the enemy of Pi's since the Pi 3. They get hot in a hurry and the CPU throttles it's top speed to cope, probably why you were crashing a lot? I've tried all sorts of bigger heatsinks so I can run faster than stock CPU clock speeds. I'd say the least painful route to get around being inside a sealed box is if you water-cooled the Pi with a small external radiator. There's several RU-vid videos that show how. The big problem I'd imagine is the Pi hat probably blocks off most easy access to the CPU to use bigger heatsinks or even run some heat pipes from the CPU outside the box to an external heatsink? If you modeled the design off of passive cooled PC towers you could put the whole thing in an aluminum box and run a copper tube from the CPU to the aluminum box, using it as a big heatsink. Just need CPU thermal grease or pads making good contact on each end of the tube. Could solder on little flat copper sheeting pads on at least the CPU side.

It will!

Help me understand. Vertical bus bars require less stripping of insulation how?

@@TheFloridaCaptain So they don't need to be vertical, but the open terminals need to face each other. this way the pos and neg can be inserted within a inch of each other...

I've been binge watching the series and that was the first thing that caught my eye. I'd go as far as to say skip usb/nvme and go with sata ssd. You'll hit a bottleneck with nvme drives. But any of those options will be better than sticking with the sd card

I appreciate these comments. I'm obviously in an ideal environment (house, with AC, etc). This will be in a pilothouse 50-60 ft boat. While it won't get wet, the rest of the environment will be hard on the electronics. So how does a SATA SSD connect to the Pi?

With a Pi 5, I would go for an nvme sad simply to reduce the requirement of a USB port. They make some super sleek nvme drives that attach to the bottom of the pi and avoiding much added thickness

Very interesting, thanks for sharing!

To my knowledge there are some enterprise SD cards which can take this amount of data being constantly transferred, but they are more expensive (~1,80€ per GB) and not avialable such a high capacity. So, if doable, an SSD is often the smarter choice.

Great idea. I have a bme280 laying around too.

Ha, I know the feeling. I like both (boating with projects) so long as its not unexpectedly upside down in an engine room underway!

It sure is! Thanks for the comment.

Thanks for sharing!

Although, I do wonder if I could do this with heat shrinks and no fans and thus, a truly sealed box

@@TheFloridaCaptain the Pis are low heat but depending on the application running on them they could require some cooling.

@TheFloridaCaptain With a sealed enclosure, technically adding a heatsink to the Pi will accelerate how fast the inside air of the enclosure heats up. Without a heatsink, the heat moves to the surrounding air inefficiently (air is a poor conductor of heat) and the heat will inefficiently move from the air, thru the enclosure inefficiently (plastics are almost as poor conductors of heat) to the outside air. Eventually the air temp inside the enclosure will reach an equilibrium as the air can only move a certain amount of heat and the enclosure can only dissipate a certain amount of heat in a given amount of time. If you add a heatsink to the Pi, you will increase the surface area the heat source has. Sure, the Pi's temperature will momentarily drop as the heatsink sinks the heat from the Pi to itself. But eventually the heatsink will have sunk as much heat as it can and the Pi's temperature will increase. Because you increase the surface area of the heat source, it can move it's heat to the surrounding air faster. If you have a fan on the heatsink, you will further increase the transfer rate of heat to the surrounding air. Air thermal conductivity ~0.025W/m*k ABS (enclosure material) ~0.130W/m*k Acrylic (presumably lid material) ~0.170W/m*k Aluminium 237W/m*k Steel ~45W/m*k Stainless (316) ~16W/m*k Then there's obviously the thickness of the material to consider to get a true idea of heat transfer but the above is just for reference. Feel free to geek out with formulas and calculations if you want. But what I'm thinking is.. With just the Pi, you're dealing with only a few funny little watts of heat. That's pretty insignificant. Place the heat producing components to the bottom of the enclosure so you utilize the natural convection currents to mix the air inside the enclosure. By the air mixing, you probably increase the heat flow from the inside of the enclosure to the outside. This way, the air isn't stagnant and just sit against the sides of the enclosure doing nothing. Warmer air at the top transfers it's heat to the enclosure and the enclosure to the outside air. The air get's a little colder and eventually sinks to the bottom. Not a very efficient process but it will move some heat. But the effect is very minor. Sure, hot air rises but even a wimpy fan will easily overpower the convection current. So the next step on the path of escalation is to add a fan blowing upwards to force the air to move and mix and help increase the heat transfer. Maybe place it on the inside edge of the enclosure. So it kind of creates a spin in the air.. If that is not enough, change the material of the enclosure to metal. And if we're being pedantic, the paint on steel enclosures surface will limit the transfer of heat (conductivity etc.) but the layer is thin and like I said above, you need to consider the thickness as well as the conductivity. The next step after that is to mount a heatsink to the inside surface of the metal enclosure and have a fan blow on it. Preferably with thermal paste or thermal glue/epoxy under the heatsink. Or a phase change thermal pad if you're fancy (Honeywell PTM7950). You might also look into conformal coating or maybe even encapsulating your electronics. To start you can search for "electrolube conformal coatings vs encapsulation". Or "parylene Best Conformal Coating for Moisture and Chemical Protection". Even if you have a sealed enclosure, conformal coating the boards probably doesn't hurt. Just make sure you've plugged in everything you intend to plug in before coating. Regarding fans, purchase high quality fans. Noctua is a popular choice. And if you end up with a bigger enclosure, their IndustrialPPC lineup (120mm/140mm) have fans with IP52 or IP67 rating. But all Noctua fans have a 6 year warranty. And their regular lineup has the same quality bearing as the industrial lineup. So if you don't need the IP rating or you need a smaller fan (40/60/80/92mm), look at the regular lineup. Maybe contact them and ask what they think about your use case. They have an awesome customer support. (perhaps even hint about this project, might get a care package) If noise is an issue, don't look at the voltage. At some point you replaced a 12V fan with a 5V one. Just because the voltage is lower doesn't mean it's any quieter. I would advise you to look in to PWM control (with a PWM fan) to adjust the speed. Or just lower the voltage of the fan to reduce the speed. There are potentiometer fan controllers around or you could just add a resistor in series with the fan to reduce the speed. You can calculate the value of the resistor with online calculators or just try what works. For example a 12V fan that draws 0.2A and you want to it to only spin at 7V, something in the neighbourhood of 40-45ohms should get you there. If you can't make it (PWM control) happen with the Pi, look for a small control board to do that. Search for something like "dc 12v pwm fan temperature control". I have a little control board like that, which cost 2€, in my AV cabinet controlling a 12V computer fan acting as an exhaust. Annoying board to configure with it's single button interface and the manual is really not helpful but in the end it was worth it. Other variants of the board do have dip switches though if you prefer that. Or you could buy a fan that already has temperature control. For example the TC lineup from Artic, the smallest fan is 80mm. Around 500rpm until 32*C and ramps to 2000rpm at 38*C so pretty aggressive curve but you don't need to configure anything. They have a long 6 year warranty as well.

I think this is a good idea (and also moving to Pi 5).

I’m working on buying a 20 year old twin diesel Pilothouse. So someday, I’m probably dealing with your exact situation. Stay tuned!

I think about the fans and holes a lot. I’ll likely experiment with heat sinks before an actual install.

@@TheFloridaCaptain I agree with all the above. Micro Sd cards fail way too often for this application. Don't use ventilators to avoid water ingress. Try the biggest heatsink you can get instead. Think about how you bring cables into your boxes. Never from the top and always use cable glands. Think about a robust power supply. On the barges I work on we use 12 Volt DC screens and 12V DC Windows pc's for the software. I'm not sure what the Raspberry Pi is doing there to be honest. Convert a small windows pc to linux and add a IO card and you can drop the RPI altogether. It's the weak link in your system. Just my 3 cents.

Good idea!

I would not use x on a raspberry pi. I would run on things you can run on a web browser. If there are things you need to run in a gui then run it on a windows or a Linux desktop.

Great advice and I appreciate you taking the time. I know I’ll have to adapt to the engines I get. I like the idea of having additional digital sensors in locations where sensors aren’t now. Just need the boat!

@@TheFloridaCaptain If you like sensordata I can suggest high and low level sensors for fuel tanks and coolant expansion tank. Both are mandatory in commercial shipping. Low fuel is obvious and high fuel against overfilling. Low coolant can indicate leaks and high coolant can indicate overheating.

I’m probably going to pick your brain soon! I’ll look up sensordata

@@TheFloridaCaptain sure thing

I did not. I’ll check this out.

I have a Nuc for the windows computer and that’s a great idea.

I’m going to look at Home Assistant next so expect a video. But, I do think I need SignalK (though I could be wrong!)

I mean... Home Assistant is great and all... but I feel like something more dedicated to Marine-ish applications would be better fitting (eliminate variables, latency, etc when it comes to processing real-time data)

I’m thinking about HA for non critical systems. House lights etc. future vid!

@@TheFloridaCaptain HA with Zigbee sensors has been great on my boat this season. Agreed- non critical its a great tool. Im using BBN as a secondary system backing up my Furuno system.

I need to do better about links to my build lists. In the meantime, here's the two you requested! SunFounder PiPower Raspberry Pi UPS Power Supply amzn.to/4fTClg2 TICONN Waterproof Electrical Junction Box IP67 ABS Plastic Enclosure with Hinged Cover with Mounting Plate, Wall Brackets, Cable Glands (Clear, 8.7"x6.7"x4.3") amzn.to/4dQcGmi

Thanks for the advice

Ya and a small PC or thin server rather then the PI. Better, cheaper, $40 and customizable. There’s zero need for the IO in this project of done right.

I might do this. Let’s see how it goes with a Pi 5 too.

I’m looking at Home Assistant soon!

Thanks!

I might one day. Part of the experiment was seeing how low I could keep the cost. No doubt I’ll have some failures (on land) and improve some things.

I’m convinced! Pi5 with SSD coming soon to video!

With an analog backup, maybe. I’ll have working analog garages on the engines. I’ll have a compass, etc. The reason this is on a board in my house is for stress testing. Lots of cruisers and sailors are going this path.

@@TheFloridaCaptain Good on you man, its just a scary thing when you think how basic systems on SOC's fail and in non-life/death situations. If you have a backup, awesome!

A huge part of this for me is learning. I WANT to know how something fundamentally works even if I choose a black box system (Simrad etc). Thanks for sharing!

No, the Whaler needs a worthy mothership!

@@TheFloridaCaptain That’s is very true make her proud

It’s fun for sure!

As in testing for police nearby? ;). Tell me more!

Easier yes and there may be times when I’ll go that route but I prefer the reliability of a hard line.

I’m missing the boat for this project! But it’s coming soon I hope!