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RaspberryPi - OpenPlotter


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Yes I've built such a system. It all depends on where you plan on using it.

On an open deck I advise you don't. Under a really good dodger or inside a cabin, OK.

As KIS says, the screen is an issue but solvable. Daylight visible and waterproof a lot harder. OpenCPN really needs a mouse to use it and that's a real PITA because once again finding a weatherproof mouse/trackball isn't simple or cheap.

In the end I bought a Simrad G09 for my deck display and have the Pi belowdecks hooked up to an 18" monitor that I can turn on as & when I need it.

FKT

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I have one, but it is setup as a headless (sans monitor) black box that's velcro'd to the top of the VHF at the nav station . It's main job is to collect all the boats data and throw it out on wifi so it can be read by every tablet, phone and laptop on the boat. VNC or SSH is used to connect directly to it's desktop via the tablet, phone or laptop but I find  in reality it's not something I use regularly other than for maintenance as I just prefer to install OpenCPN directly on those devices and connect it to the NEMA stream from the Pi. It's also a little mini file server that contains the charts and electronic copies of all the equipment manuals for the boat. Occasionally, I dump a movie on it too so we can watch it on the projector via wifi out in the cockpit.

Power wise, I chose to use a Pi3 (later models are the Pi3B+ and Pi4) as my setup doesn't need horsepower and the first iteration of the model 3 uses less power than the later variants and this all helps because it runs 24/7 as it's essentially setup to go on and off with the instruments.

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1 hour ago, Toecutter's Ghost said:

I have one, but it is setup as a headless (sans monitor) black box that's velcro'd to the top of the VHF at the nav station . It's main job is to collect all the boats data and throw it out on wifi so it can be read by every tablet, phone and laptop on the boat. VNC or SSH is used to connect directly to it's desktop via the tablet, phone or laptop but I find  in reality it's not something I use regularly other than for maintenance as I just prefer to install OpenCPN directly on those devices and connect it to the NEMA stream from the Pi. It's also a little mini file server that contains the charts and electronic copies of all the equipment manuals for the boat. Occasionally, I dump a movie on it too so we can watch it on the projector via wifi out in the cockpit.

Power wise, I chose to use a Pi3 (later models are the Pi3B+ and Pi4) as my setup doesn't need horsepower and the first iteration of the model 3 uses less power than the later variants and this all helps because it runs 24/7 as it's essentially setup to go on and off with the instruments.

Yep, really good use-case. I bought a Pi 4 and it runs very hot compared with the earlier models. One advantage is that they changed the BIOS so now it's possible to boot direct from a USB device rather than the somewhat fragile SD card. I haven't updated mine yet but it's on the list of things to do.

My current plan is to install some Arduino's with ethernet shields and use them as monitoring devices etc sending their data via broadcast UDP to a Pi server.

I think there's maybe 4 of the Pi 3B models about the place here including one with a complete OpenCPN setup on it I use as a play-toy and test station.

FKT

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45 minutes ago, Fah Kiew Tu said:

Yep, really good use-case. I bought a Pi 4 and it runs very hot compared with the earlier models. One advantage is that they changed the BIOS so now it's possible to boot direct from a USB device rather than the somewhat fragile SD card. I haven't updated mine yet but it's on the list of things to do.

My current plan is to install some Arduino's with ethernet shields and use them as monitoring devices etc sending their data via broadcast UDP to a Pi server.

I think there's maybe 4 of the Pi 3B models about the place here including one with a complete OpenCPN setup on it I use as a play-toy and test station.

FKT

Cool. I once busted a very expensive SD card trying to insert it into some gadget. That's when I found out that they're as brittle as 78 rpm records from the days of yore! If you're dabbling with Arduino, check out ESP32 based microcontrollers. They have wifi and bluetooth onboard and a low power mode. The raspberry foundation has also just released a new microcontroller ("pico") boasting improved speed and memory etc but I think it lacks onboard wifi/bluetooth.

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3 hours ago, Toecutter's Ghost said:

I have one, but it is setup as a headless (sans monitor) black box that's velcro'd to the top of the VHF at the nav station . It's main job is to collect all the boats data and throw it out on wifi so it can be read by every tablet, phone and laptop on the boat. VNC or SSH is used to connect directly to it's desktop via the tablet, phone or laptop but I find  in reality it's not something I use regularly other than for maintenance as I just prefer to install OpenCPN directly on those devices and connect it to the NEMA stream from the Pi. It's also a little mini file server that contains the charts and electronic copies of all the equipment manuals for the boat. Occasionally, I dump a movie on it too so we can watch it on the projector via wifi out in the cockpit.

Power wise, I chose to use a Pi3 (later models are the Pi3B+ and Pi4) as my setup doesn't need horsepower and the first iteration of the model 3 uses less power than the later variants and this all helps because it runs 24/7 as it's essentially setup to go on and off with the instruments.

That's what I'm thinkin mostly, as a tool to get instrument data and ais over wifi and display on my tablets.  I gotta lot to read up on...

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11 minutes ago, bgytr said:

That's what I'm thinkin mostly, as a tool to get instrument data and ais over wifi and display on my tablets.  I gotta lot to read up on...

Out of curiosity, where are you reading about this?  (It’s something I know nothing about...I know about OpenCPN, but little beyond that.  What are benefits to doing this, etc.  I need to read up ok this stuff too...)

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50 minutes ago, Toecutter's Ghost said:

Cool. I once busted a very expensive SD card trying to insert it into some gadget. That's when I found out that they're as brittle as 78 rpm records from the days of yore! If you're dabbling with Arduino, check out ESP32 based microcontrollers. They have wifi and bluetooth onboard and a low power mode. The raspberry foundation has also just released a new microcontroller ("pico") boasting improved speed and memory etc but I think it lacks onboard wifi/bluetooth.

I'll take a look at them. Really I prefer to avoid too many wifi devices so I ran a cabled ethernet system in the boat.  My Simrad plotter is a wifi/dhcp server and I'd rather not have 2. I'm still waiting on the Arduino nano ethernet shields to show up. First supplier said they shipped, 4 weeks later, nothing had arrived so I registered a goods not received complaint with eBay, refund less than 24 hours later. Makes me think they had no stock and were hoping I'd forget about it.

I saw the pico come out. Not sure if it has any advantage for me over an arduino ATM.

I've got a Digital Yacht IKonvert box which bridges from NMEA2K to ethernet and via SignalK to OpenCPN but it only spits a limited subset of data out as NMEA0183 strings via tcp/ip and that's a bit limiting for what I like doing. And I don't want to go down the rabbit hole of implementing a SignalK parser in Java.

Getting a bit far afield here.

FKT

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7 minutes ago, Fah Kiew Tu said:

I'll take a look at them. Really I prefer to avoid too many wifi devices so I ran a cabled ethernet system in the boat.  My Simrad plotter is a wifi/dhcp server and I'd rather not have 2. I'm still waiting on the Arduino nano ethernet shields to show up. First supplier said they shipped, 4 weeks later, nothing had arrived so I registered a goods not received complaint with eBay, refund less than 24 hours later. Makes me think they had no stock and were hoping I'd forget about it.

I saw the pico come out. Not sure if it has any advantage for me over an arduino ATM.

I've got a Digital Yacht IKonvert box which bridges from NMEA2K to ethernet and via SignalK to OpenCPN but it only spits a limited subset of data out as NMEA0183 strings via tcp/ip and that's a bit limiting for what I like doing. And I don't want to go down the rabbit hole of implementing a SignalK parser in Java.

Getting a bit far afield here.

FKT

There's no recipes yet, you're good. 

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23 minutes ago, Jud - s/v Sputnik said:

Out of curiosity, where are you reading about this?  (It’s something I know nothing about...I know about OpenCPN, but little beyond that.  What are benefits to doing this, etc.  I need to read up ok this stuff too...)

OpenPlotter is basically a canned build for the Pi that includes OpenCPN and some other stuff. What I ended up doing was getting a Dell Chromebook 11 that draws hardly any power and hacking it to take Linux and then installing OpenCPN.

It was kind of a PITA getting Linux on there, but I only paid $40 for it and it draws minimal power.

image.thumb.png.cf4e9a4bb75a64d23ef9fb978acb5659.png

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4 hours ago, Toecutter's Ghost said:

I have one, but it is setup as a headless

I tested a headless version but didn't take it to sea. I ran it 24/7 in harbor for a few weeks and it was okay. My motivation was to have current AIS data immediately available on the chart when I remoted in and an AIS alarm to alert me. My feeling was that it could work in a pinch but it was janky enough that I wouldn't want to count on it. Pi's have gotten better since then and there are other SBCs that might be worth consideration, too. Depends on the exact problem at hand, of course.

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2 hours ago, Fah Kiew Tu said:

I bought a Pi 4 and it runs very hot compared with the earlier models.

The newer firmware and OS versions have fixed this. I have a Pi4 desktop that I’m playing with and it runs nicely with no fan even under high CPU load.  

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1 minute ago, Alex W said:

The newer firmware and OS versions have fixed this. I have a Pi4 desktop that I’m playing with and it runs nicely with no fan even under high CPU load.  

Ah, interesting - must do a full update and see what happens. I wanted to put one of mine in a passively cooled aluminium case but as I added a real-time clock chip to the IO bus, it wouldn't fit. I could mill the case out to make it fit, but the time/project list indicated not. Or at least not yet.

I'm quite a fan of the Pi computers.

FKT

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I ran openplotter on  PI4,  as a trial during last summers vacation.  We didn't run it 7/24 but turned it off at the end of the day with the other instruments.   That did cause a problem as killing by turning off the power will eventually corrupt the SD card. I hot a hat with a battery that shuts it down gracefully when power is lost and all is good so far.  

I did like the convenience of using any phone / tablet and it will be on-board  again after the water gets soft again

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1 hour ago, weightless said:

I tested a headless version but didn't take it to sea. I ran it 24/7 in harbor for a few weeks and it was okay. My motivation was to have current AIS data immediately available on the chart when I remoted in and an AIS alarm to alert me. My feeling was that it could work in a pinch but it was janky enough that I wouldn't want to count on it. Pi's have gotten better since then and there are other SBCs that might be worth consideration, too. Depends on the exact problem at hand, of course.

I've had the Pi on the boat for about 2 years now with no major problems. Due to the small size, I've got a 3B I originally used as an AIS receiver shoved in a drawer as a backup. I've also got a phone app that let's me monitor the Pi's running status and temps and let's me do an orderly shutdown (when I remember). My experience with it is that it has been pretty much bulletproof and and has run for up to a month without a shutdown or restart.

1 hour ago, Fah Kiew Tu said:

I'll take a look at them. Really I prefer to avoid too many wifi devices so I ran a cabled ethernet system in the boat.  My Simrad plotter is a wifi/dhcp server and I'd rather not have 2. I'm still waiting on the Arduino nano ethernet shields to show up. First supplier said they shipped, 4 weeks later, nothing had arrived so I registered a goods not received complaint with eBay, refund less than 24 hours later. Makes me think they had no stock and were hoping I'd forget about it.

I saw the pico come out. Not sure if it has any advantage for me over an arduino ATM.

I've got a Digital Yacht IKonvert box which bridges from NMEA2K to ethernet and via SignalK to OpenCPN but it only spits a limited subset of data out as NMEA0183 strings via tcp/ip and that's a bit limiting for what I like doing. And I don't want to go down the rabbit hole of implementing a SignalK parser in Java.

Getting a bit far afield here.

FKT

Truth be told, I have a wired Ethernet system too and don't use the wifi on the Pi. I use a small 5V wifi router on the wired network instead to get the Pi's data on air. Doing it this way means I can switch the Pi off and still have access to the Internet on everything without having to change SSID.

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16 hours ago, kent_island_sailor said:

I keep almost doing it and then realizing once you get a decent monitor it costs more and draws more power than a laptop.

I kept almost doing it until I bought a B&G Zeus that can repeat itself wirelessly to my tablet. Now I can sit in the cabin and create and plan routes just as I would have done with a laptop or Rasberry Pi.

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1 hour ago, Ajax said:

I kept almost doing it until I bought a B&G Zeus that can repeat itself wirelessly to my tablet. Now I can sit in the cabin and create and plan routes just as I would have done with a laptop or Rasberry Pi.

I have kind of come full circle back around to dedicated marine plotters. I have one at the helm and only use it maybe 5% of the time, usually I am looking at OpenCPN or something on my phone like AquaMap. That 5% though is the critical 5% when I really need it and it needs to work in any weather condition, day or night, not mind being operated by wet hands in pouring rain, and be at the helm.

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I've got both options each with their own pros and cons but if I had to go with just one I'd go the tablet route. The reason being that the tablet is the better device when at anchor or on passage and it's multipurpose, something that is always desirable on a boat.

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6 hours ago, Toecutter's Ghost said:

I've got both options each with their own pros and cons but if I had to go with just one I'd go the tablet route. The reason being that the tablet is the better device when at anchor or on passage and it's multipurpose, something that is always desirable on a boat.

I've both options as well but if I could only have one, it'd be the Simrad plotter. Your points are valid, but I'll take reliability over the flexibility any day.

Fortunately neither of us has to choose or live by the other's value judgements.

FKT

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On 1/29/2021 at 3:02 PM, kent_island_sailor said:

That 5% though is the critical 5% when I really need it and it needs to work in any weather condition, day or night, not mind being operated by wet hands in pouring rain, and be at the helm.

I've never been really good at "Gameboy navigation", and would be scared of doing "navigation on the fly". The tricky condition (for me) is coming in with a sidewise current in poor visibility (can't follow transits) which unfortunately is not completely uncommon here. If I try to do it by looking at an electronic map, I go all over the place (especially when boat speed is low) over or under-compensating  my drift whereas if I draw my current vectors, follow a bearing and adjust by comparing the GPS (waypoint bearing + distance ) to where I should be, I nail it! The latter technique needs more planning (you need a mental image of all the turns + compute a compass heading when current is sidewise + max and min waypoint bearings to clear obstructions) but I find it more reassuring.

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1 hour ago, Panoramix said:

I've never been really good at "Gameboy navigation", and would be scared of doing "navigation on the fly". The tricky condition (for me) is coming in with a sidewise current in poor visibility (can't follow transits) which unfortunately is not completely uncommon here. If I try to do it by looking at an electronic map, I go all over the place (especially when boat speed is low) over or under-compensating  my drift whereas if I draw my current vectors, follow a bearing and adjust by comparing the GPS (waypoint bearing + distance ) to where I should be, I nail it! The latter technique needs more planning (you need a mental image of all the turns + compute a compass heading when current is sidewise + max and min waypoint bearings to clear obstructions) but I find it more reassuring.

Everyone has their own favorite way to do things. For this application I am talking places like a twisty-turny channel maybe 50 or 60 feet wide with a wicked current at times. It is a real bitch to run at night or in poor visibility. The turns come way too quick to be laying out courses for legs that might be 100 feet long.

The other application is say a night transit with everything plotted out below for the big picture, but the helm plotter can stay on say the 1 mile scale to keep the helmsman aware of anything unlit near him or nearby AIS targets.

For a longer transit cross-current, this page makes it pretty obvious if the current is setting you:

image.thumb.png.896bd5aa0d4fb73b6bd45add8a6c9578.png

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This isn't even the worst place, but getting up to the red X is a large PITA on a dark and stormy night with no visibility. Having a cockpit readable plotter makes it WAY easier. This shoreline is mostly pitch black too, it isn't like a suburban river with well lit houses every 200 feet.

image.thumb.png.f6739c0e68616cdbb3cd5671d20c19ec.png

 

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12 minutes ago, kent_island_sailor said:

This isn't even the worst place, but getting up to the red X is a large PITA on a dark and stormy night with no visibility. Having a cockpit readable plotter makes it WAY easier. This shoreline is mostly pitch black too, it isn't like a suburban river with well lit houses every 200 feet.

image.thumb.png.f6739c0e68616cdbb3cd5671d20c19ec.png

 

I would just make a GPS route with all the lights in it and keep notes of max / min bearing on the "R 2SD", "R 4", the last red and an imaginary point where the red cross is. Not sure of the scale of the map but you would need serious visibility problem not to enter here by sight.

Not saying that my method is better, just saying that I love my plotter under deck and that I like to do the on deck bit with just 2 numbers!!!

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9 minutes ago, Panoramix said:

I would just make a GPS route with all the lights in it and keep notes of max / min bearing on the "R 2SD", "R 4", the last red and an imaginary point where the red cross is. Not sure of the scale of the map but you would need serious visibility problem not to enter here by sight.

Not saying that my method is better, just saying that I love my plotter under deck and that I like to do the on deck bit with just 2 numbers!!!

None of those marks are lit, they are all painted red or green plywood on a piling. To give you an idea of scale, this is 0.1 miles here:

image.png.b60f7d8d4947d4cc468ae14dae6f7426.png

Going up there on a clear night is a pain enough, but when some storms move in and vis goes to shit it gets much harder. Back in the pre-GPS days we would sometimes just anchor where we were until the storms passed.

 

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2 minutes ago, kent_island_sailor said:

None of those marks are lit, they are all painted red or green plywood on a piling. To give you an idea of scale, this is 0.1 miles here:

image.png.b60f7d8d4947d4cc468ae14dae6f7426.png

Going up there on a clear night is a pain enough, but when some storms move in and vis goes to shit it gets much harder. Back in the pre-GPS days we would sometimes just anchor where we were until the storms passed.

 

If it is not lit I would go elsewhere as soon as the weather turns to bad and coming in with a flashlight is too dodgy! Not so much that you can't come in by GPS but if it is not lit some (here at least!) assume that there is no traffic at night and you risk to run into somebody anchored in the middle without light! I think that @dylan winter wrote somewhere that he doesn't keep on his anchor light on in such conditions, I am pretty sure that he isn't the only one, TBH I don't up a river.

For my education what does "2SD" stands for ?

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17 minutes ago, Panoramix said:

If it is not lit I would go elsewhere as soon as the weather turns to bad and coming in with a flashlight is too dodgy! Not so much that you can't come in by GPS but if it is not lit some (here at least!) assume that there is no traffic at night and you risk to run into somebody anchored in the middle without light! I think that @dylan winter wrote somewhere that he doesn't keep on his anchor light on in such conditions, I am pretty sure that he isn't the only one, TBH I don't up a river.

For my education what does "2SD" stands for ?

2SD is 2 San Domingo Creek to differentiate from other nearby 2s in other creeks ;)

Dark twisty creeks are the norm here and unlit boats are really taking a risk when the crabbers head out before dawn at full throttle. Dylan would rethink his stealth plan before long after about the 5th crab boat passed him at 15 knots 6 inches off his beam to make him aware of what they think of his anchor light habits. Also you are legally responsible for all damage to anyone that hits you.

Here is another tight one, the channel width is about 50-60 feet for sailboats and the current can run over 2 knots and it isn't always aligned with the channel.

image.thumb.png.f78363e38ba51cb6b3d21693718c9bd0.png

 

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I'll stay out of the same-old-same-old on iPads, etc. - but...

Be very careful with SignalK and the apps leveraging/promoting it. It ain't what it seems to be.

I did a pretty extensive review of the tech. You can just google my username and "indentured cruising" and see for yourself.

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27 minutes ago, smackdaddy said:

I'll stay out of the same-old-same-old on iPads, etc. - but...

Be very careful with SignalK and the apps leveraging/promoting it. It ain't what it seems to be.

I did a pretty extensive review of the tech. You can just google my username and "indentured cruising" and see for yourself.

Hmmm - interesting. Too busy to look ATM so any chance of a short executive summary?

I took a very cursory look at SignalK to see if there was or I could write a Java parser, decided it was too much time/effort for reward.

Thing that biases me is, I was team lead on a software project for a biggish 24/7/365 datalogging system for marine data. We solved all these problems over 20 years ago basically using ethernet, tcp/ip and udp. I'm pissed off about the state of marine electronics every time I have to deal with it. All this proprietary secret squirrel shit.

Currently got most of my rudder angle indicator sorted on the bench using stuff that costs peanuts in comparison to what Raymarine and their ilk want for something. I'm waiting on some ethernet shields for Arduino nano processors ATM.

FKT

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3 hours ago, smackdaddy said:

I'll stay out of the same-old-same-old on iPads, etc. - but...

Be very careful with SignalK and the apps leveraging/promoting it. It ain't what it seems to be.

I did a pretty extensive review of the tech. You can just google my username and "indentured cruising" and see for yourself.

AFAIK SignalK is more of an idea than an actual thing.

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8 hours ago, kent_island_sailor said:

AFAIK SignalK is more of an idea than an actual thing.

It's a bit more than that, and I look at it a bit differently.

Signal-K is not about adding data, it's about making the data that you already have useable. NMEA is a wonderful, compact and efficient, just an arcane mess to most mortals. Making that data a bit more readable/useable opens up some opportunities for using things that aren't 'Marine' and allows a bit of innovation to happen (innovation as in using things for other than their intended use).

What I don't subscribe to is that just because you have data, it ends up in the 'Cloud' being mined for your information and sold to the 'Man'. Storing data locally is nothing new, it's just the tracks that you already save on your plotters, but now you are in control of what you want to save and what you want to do with it. 

On FlameSkimmer (Dragonfly 28) I already have plenty of kit with the PO evidently a regular at the Raymarine dealer. But I like playing with this stuff. Step 1 for me was putting in a Yacht Devices Wifi Gateway. Now I could use SailGrib WR (brilliant piece of software that doesn't get mentioned enough) down below and see everything I needed. Step 2 was putting in the Yacht devices Voyage Recorder so I could keep the data and look back at trips. This is all great but it's still a bit limited with how I can use the data still so now I've got Signal-K on a Pi running alongside it all and I'm starting to enjoy what I can do with it. It's not for all, but it will get easier. 

My current project is creating the data to allow me to have a little light display in the cockpit that can assist with upwind sailing (green at optimal AWA and showing too high/low). As a dinghy sailor, I can sail without the instruments, but it's easy to get hooked on the numbers on the display (the apparent wind changes fast at 16kn) and this seems like a nice thing to try. I'm probably only doing it as I'm locked down away from the boat and I can use the Pi at home and Voyage Recorder logs to simulate sails to test it all. 

I'd encourage anyone to have a try.

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4 hours ago, tigger.mike said:

Signal-K is not about adding data, it's about making the data that you already have useable. NMEA is a wonderful, compact and efficient, just an arcane mess to most mortals. Making that data a bit more readable/useable opens up some opportunities for using things that aren't 'Marine' and allows a bit of innovation to happen (innovation as in using things for other than their intended use).

What I don't subscribe to is that just because you have data, it ends up in the 'Cloud' being mined for your information and sold to the 'Man'. Storing data locally is nothing new, it's just the tracks that you already save on your plotters, but now you are in control of what you want to save and what you want to do with it.

To be clear, I have no problem with SignalK itself as a data protocol. I'm a fan of open source. My point in my review is that you should be very careful with those "innovative" products that leverage it - especially if they pull your data into "the cloud" to provide some "service" to you.

Just keep your data on your Dragonfly. Otherwise, you could very well end up cruising for the 'Man'.

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If I want a voyage data recorder, it is a couple clicks away:

https://www.opencpn.org/OpenCPN/plugins/vdr.html

Be careful what you wish for though, if you manage to run someone over this will preserve the evidence.

BTW - a real commercial version of this records radio and bridge audio too and maybe the radar.

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16 hours ago, Fah Kiew Tu said:

Hmmm - interesting. Too busy to look ATM so any chance of a short executive summary?

I took a very cursory look at SignalK to see if there was or I could write a Java parser, decided it was too much time/effort for reward.

Thing that biases me is, I was team lead on a software project for a biggish 24/7/365 datalogging system for marine data. We solved all these problems over 20 years ago basically using ethernet, tcp/ip and udp. I'm pissed off about the state of marine electronics every time I have to deal with it. All this proprietary secret squirrel shit.

Currently got most of my rudder angle indicator sorted on the bench using stuff that costs peanuts in comparison to what Raymarine and their ilk want for something. I'm waiting on some ethernet shields for Arduino nano processors ATM.

FKT

It is pretty annoying. NMEA 0183 is ancient, but it is pretty easy to DIY and read raw data streams. It ended up sort of a half-ass RS422/RS232 hybrid that can have weird voltage issues between PCs and marine gear. That kept me busy back in the day.

NMEA 2000 seems to be a standard except for all the times brand A and B won't work together :rolleyes:

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5 hours ago, kent_island_sailor said:

It is pretty annoying. NMEA 0183 is ancient, but it is pretty easy to DIY and read raw data streams. It ended up sort of a half-ass RS422/RS232 hybrid that can have weird voltage issues between PCs and marine gear. That kept me busy back in the day.

NMEA 2000 seems to be a standard except for all the times brand A and B won't work together :rolleyes:

We basically implemented NMEA0183 over ethernet which was relatively simple to do. Each new instrument we installed, we'd come up with a pseudo-NMEA string for its data. There was a listener for each sender (instrument) with a parser to check for bad data. The good data was passed to a distributor which sent it out via multicast UDP and also via tcp to devices that needed their own dedicated streams-based feed.

Analog data we did an A to D on upstream then sent the digital data out. Serial devices got plugged into a terminal server so their raw data was on the ethernet cabling from source. No rats nests of RS232-422-485 wires everywhere. POE would have made life even sweeter.

We also had aggregators to combine various instruments' output into a single data stream for (usually) 3rd party equipment that needed the input for their own purpose.

Lot of code but all straightforward and understandable, lots faster then CANBus. And anyone at all could listen on a given port, in any language they liked, to see the data. People used Labview and things like Node Red or whatever.

When I look at the mess that's NMEA2000 I want to tear my hair out.

FKT

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  • 2 weeks later...

I'm late to this thread!

I'm using OpenPlotter on my boat - one of my quarantine tasks was to finally take the plunge and upgrade to v2. I run it on this setup tucked away.

From left to right:

  • Raspberry Pi 3B+
    • With USB SSD (850) - boot and data storage
    • Connected via wired ethernet to the boat network
    • (currently) powered via eBay (C.P.T. brand) cheap 12v to USB adapter. I might change this and power everything from the NMEA2000 network next year.
  • Homemade NMEA 2000 interface
  • BME280 sensor connected to I2C for temperature/humidity

Since I have plenty of storage on the mSATA drive on the pi, I'm thinking about doing continuous recording to InfluxDB using the built-in SignalK recorder - then I can re-live all of my glory at a later time. We'll see whenever we finally get sailing again.

It's (obviously) headless - currently I access it using VNC and a laptop. Or just running OpenCPN on the laptop and accessing the data stream on the Pi using NMEA0183 or SignalK. On the project list is to get a small Intel NUC (or similar) and an LCD monitor for the nav station which I can turn on only when required. Sometimes it's nice to have things that don't move around.

IMG_2842-L.jpg

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I did some experimenting with this a couple of years ago. 

Raspberry Pi 3 for with Open Plotter, I used a laptop replacement screen that I got off eBay quite cheaply, its just a 1080p one as for this size that's adequate, I also bought a HDMI driver for the screen, also from eBay. 
My thinking behind it was that just running a laptop screen & a Raspberry Pi was probably going to use less power than a laptop, but I found OpenPlotter so painfully slow when working with either raster or vector charts that I decided it would be easier to use either a laptop, a NUC or something similar. 

IMG_20190625_152247.jpg.4edb52724133544a9a47b07187839305.jpg

 

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On 2/1/2021 at 1:26 PM, Panoramix said:

I would just make a GPS route with all the lights in it and keep notes of max / min bearing on the "R 2SD", "R 4", the last red and an imaginary point where the red cross is. Not sure of the scale of the map but you would need serious visibility problem not to enter here by sight.

Not saying that my method is better, just saying that I love my plotter under deck and that I like to do the on deck bit with just 2 numbers!!!

Though the channel to my YC isn't especially problematic,  I created a GPS "route home" much as you describe to use in case of dense fog or the like. The GPS now has about 5 years of tracks in and out to follow as well.

Roger Long, an N.A. and single-handed cruiser, wrote up an experience where he was following a similar route when a GPS position showed him off-route in very shallow water. Just on the wrong side of a channel marker, as best I remember. Long chased it down with the people who run the GPS system,  and there was a documented brief error in the system for some obscure reason. GPS is quite reliable, but not 100%.

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our GPS has/had a random deviation that changes over time they can change it depending on what ever current crisis or  not

that was done to prevent exact targeting by hostile forces using our system [our military has better systems]

that is why survey GPS uses RTC [real time corrections] from a known fixed location to correct the random deviations by radio link to a remote user

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