Remote access for OpenPlotter

Tally Ho · Oct 9, 2025

I haven’t found a great way to do this, but a few things I am playing with…

1) Rasperry Connect….this allows me to remote into my Raspberry pi on the boat (provided it is connected to the internet) and can see whatever the Pi can display. I have my Pi connected to my NMEA2K network, so if I left the instruments on, I can see wind speed, depth, boat speed, heading, etc. remotely.

2) I am playing around with Tailscale for a different project (Home automation). This can run on a Pi or something else (virtual machine on a PC). Tailscale is a zero config VPN that allows me to access my home automation server(s) from anywhere. I am impressed with it so far, and it is free for private use, up to 3 users and 100 devices. I am not e a tly how this would integrate on something like OpenCPN. But it runs on a Pi.

My marina wifi is iffy at best, so trying to connect fro home is always a crap shoot. And I didn’t like leaving my chart plotter and other instruments on…but they had to be to see my data. If you have a dedicated gps for OpenCPN you might not to leave all of your instruments on. My gps data comes from the CP.

Greg

High Current · Oct 9, 2025

You could invest in a portable hotspot. Data plans from budget carriers like mint or ting can be fairly inexpensive.

To remote in you can use raspberry connect as greg suggested or some other dynamic DNS.

Additionally, you could push the signal K data to a remote cloud server, though it might take some web programming to make it happen. From there you can display it using grafana or some other dashboard.

For notifications, there are also ways to convert email to SMS (google it!) so you can have the pi or whatever ping your phone.

My biggest obstacle to doing this is power consumption. Even at idle, a pi consumes ~3W (72Wh/day). N2k bus plus sensors will surely add to that. My 30W solar panel could probably keep up, but a week of rain might murder the house battery. Makes me miss the electric drive on my old boat- I had 400W of solar and 7.2kWh of storage.

Davidasailor26 · Oct 9, 2025

I have my pi connect to marina wifi, and I have a hotspot connected to Ting for when marina WiFi goes down or we’re out sailing. The pi connects by WireGuard VPN back to a workstation in my house that shows all the data in a Grafana dashboard and helps with notifications if something goes out of bounds.

ds34mail · Friday at 1:40 PM

I am having remote.it (free) running on my raspberry pi, so services on my home service can use the tunnel to the pi straight.
You can also use dyndns from i.e. no-ip.com (free).
Of course, I have the VNC via RealVNC on the pi as well...

I am using a Spitz hotspot/router (comes also with a cloud connection) and the FREE data plan from helium mobile.

marcham · Friday at 4:16 PM

I started off with an RPI / Open plotter, hooked up to wifi and I could remote in. That was a bit clunky.

I now use a Cerbo GX for "house" stuff (fridge and cabin temps, if the bilge pump cycles, batt voltage, confirm shore power is still hooked up) and just use the RPI for OpenPlotter. My Signal K and NodeRed are currently on the CerboGx, but that will shortly be moved over to the RPI to free up the Cerbo GX cpu.

For example, if any bilge pump activates, a signal is sent to the digital input of the Cerbo GX (through an octocoupler) which then triggers an alarm on the boat or through the app and sends me an email.

Cerbo-GX has different ways of creating dashboards accessible through the Web. VRM Is their default dashboard, Signal K has a few options and so does Node-Red (part of Venus Large builds).

Cerbo GX has it's own GPS with a GeoFence and various alarms setup.

Davidasailor26 · Friday at 5:05 PM

SV Temenos said:
I also have a cerbo gx. I have it controlling relays to turn the fridge / freezer on / off and a bilge pump alert. I had two issues with this. To get to the relays I had to drill down too many menus and the remote console didn't always start. As for the bilge pump alert I also used an optocoupler but I kept getting false triggers. I assume noise on the lines. I shorten the 3.3 side of the wires to as short as I could make them, less than an inch, but didn't seem to help. Those issues had prompted me to try going this way. Also I'm having fun.

I had the same problem with sensing my bilge pump runs. In my case the problem seemed most noticeable when we flushed the head and the electric macerator pump started and stopped. I don’t have a Cerbo and I just use python code on the Pi for all the pump sensing. I updated my python code to wait half a second, check if the pump line is still high, and only alert after that.

marcham · Friday at 5:24 PM

SV Temenos said:
I also have a cerbo gx. I have it controlling relays to turn the fridge / freezer on / off and a bilge pump alert. I had two issues with this. To get to the relays I had to drill down too many menus and the remote console didn't always start. As for the bilge pump alert I also used an optocoupler but I kept getting false triggers. I assume noise on the lines. I shorten the 3.3 side of the wires to as short as I could make them, less than an inch, but didn't seem to help. Those issues had prompted me to try going this way. Also I'm having fun.

Which version of the firmware? The new OS / UI makes them one click away through the top left button..

The optocouplers are normally 100% reliable.... Could you have a floating ground? If the trigger input of the optocoupler is 12V, I don't see how spurious RF could trigger it... maybe try a different octocoupler?

Hooking up water/fuel/waste tank level sensors to the Cerbo is also very easy if you have resistance senders.

The reason I moved away from the RPI to the CerboGX is because it is SO EASY to connect things to it. On the RPI, you'd need daughterboards which can add up pretty quickly $$$. The new Victron IO extender creates a huge range of possibilities...

Sorry, Victron fan boy signing-off!

I think this is what you're looking for if you want to stick with the RPI: Raspberry Pi Boat Monitoring

marcham · Tuesday at 6:08 PM

SV Temenos said:
I'm running version 2.91 of the cerbo. I don't see the screen you have. How do you navigate to it? I also love victron so if I can do what I want to do with it that would be great.

That's a pretty old firmware, the new UI is excellent, well worth the update. The firmware can be updated directly from the Cerbo if connected to the internet. The latest firmware is 3.66 i believe.

So long as the Cerbo is connected to the internet, I have full access to all my devices via Victron Connect app or via VRM where I can program alerts (email / or push notifications). Being able to go through the history of the various sensors makes troubleshooting stuff much easier.

Fridge temp monitoring is via Ruuvi Tag
Propane level monitoring is via a Mopeka sensor.
Bilge pump monitoring is via an octocoupler, wired into one of the digital inputs.
My fuel, holding and water tank level sensors are resistive so they plug directly into the Cerbo GX analogue inputs.
The wired temp sensors that came with the Cerbo and Inverter are used for cabin temp and battery temp sensing.
I bought a cheap USB GPS, so I have a geofence and email/ app notification alerts when the boat leaves the dock (before it gets out of wifi range ! )
Lithium battery BMS is connected directly to the Cerbo for DVCC charge control (voltage/current).

Any other data (such as NMEA) can be displayed on a web page, which is accessible via VRM. This is done by using Venus OS Large, which includes Signal K and Node Red. Signal K takes the N2K data (if the Cerbo GX is connected to the network) you can then build dashboards with the SIgnal K plugins or by installing Node-Red which allows you to control most Victron devices connected to the Cerbo.

For example in Node-Red, you could create a rule that if your battery is < 30% SOC, and you are away from your home location and shore power is disconnected, to disable the inverter. Node-Red is a visual (ie: building block) programming language and easy to learn in about a week.