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Integration with existing system

Posted: Sat Jul 27, 2019 2:50 pm
by SeamanStaines
This has started from wanting to do a very simple thing I thought, detect when shore power is disconected when I am away from the boat. I asked Studer who made the inverter for the boat and they came up with a price of nearly £500 to do it. I had to sit down for a while!

Currently, I have a setup on the boat that gives me a permanant internet connection using either a 4G modem or a wireless internet connection. I then have a fixed IP address through a VPN back to the UK which I NAT through to the boat so I can talk directly to my NMEA server (for anchor alarms) and to a couple of local web servers for the solar power and batteries (I also use it for watching TV when I dont have to worry about bandwidth)

I have a couple of raspberry pi units on board, one running Kodi and the other a stripydog NMEA server that converts the NMEA string to TCP/IP from my AIS/GPS and the wind/depth instruments.

Reading all of the documentation on the skippers mate application I am trying to work out how I integrate it with my setup. I really dont want to create a second system in its entirity

As far as I can see I can install skippersmate on one of the existing raspberry pi units without any of the internet/wireless hot spot integration and set an internal fixed IP address to it, then map NAT to any relevant ports for external access. I am trying to work out the best way to approach this, either take the prebuilt SD image and start removing things, then add the NMEA server or to just install skippersmate (once I have worked out what I need in terms of binaries). Am I correct in saying that I will end up with a local web server that I can then access externally? Also, can skippers mate take the NMEA feed from the local NMEA server rather than having to add yet another GPS unit?

My expereince of linux programming is not much but I have some knowledege, but I got a bit terrified when it started talking about compiling things.

Any thoughts would be much appreciated as I am quite excited about the possibility of sensors and relays.

Many thanks

Re: Integration with existing system

Posted: Sun Jul 28, 2019 9:08 am
by crb
Hi and welcome to the forum. At the boat at the moment but will try to address your querieswhen back in the office tomorrow.


Re: Integration with existing system

Posted: Mon Jul 29, 2019 1:54 pm
by crb
I think that the majority of what ypu require can be accomodated without too much effort. I'm not familiar with the Stripy Dog software but, if it is a reasonably simple installation I would recommend using the SkippersMate iso and install Stripy Dog on top. The other option is to compile SkippersMate from source onto the existong system - that's quite a lot of compiling..........

I'm not too sure what th VPN situation is. I note that you already have a VPN installed. SkippersMate installs a private VPN to enable live access to the system from an external server. I don't think there would be a problem with twin VPNs - ours (OpenVPN) simply opens an extra tunnel on the raspberry enabling access without a fixed IP address.

The answer to the GPS question is - maybe ;) If the Stripy Dog software presents output as a virtual serial port then SkippersMate can be configured to accept input from it. Having had a quick look this would appear to be the case.

Hope this helps. Any further questions don't hesitate to ask.

Re: Integration with existing system

Posted: Tue Jul 30, 2019 8:12 am
by SeamanStaines
Many thanks.

I think I will buy another raspberry pi and set it up from scratch using your SD ISO as it sounds easier and I would rather not break my existing setup. I wont be able to do it till September anyway as we are in Greece and its not the sort of thing you can get :-) Which brings me onto another question, which model raspberry pi? I would normally just buy the latest but I assume you are a long way from the latest raspbian version (Buster) so I guess its a pi3 or wait for Stretch/Buster. I assume you will go straight to Buster. From what I can see providing the skippersmate has an IP address on the LAN and a gateway to the internet its just going to work?

Yes I have run stripydog to a virtual serial IO port so that should work just fine. VPN will work fine. I have a Draytek main router that creates the VPN so any network items plugged in are unaware of it. I also regularly create a second VPN on my laptop (through the main VPN) without issues and I have tested openvpn on that, in any case I can also do policy routing to bypass it if I need to.

Just need to wait for your ISO upgrade

Many thanks

Re: Integration with existing system

Posted: Tue Jul 30, 2019 5:40 pm
by crb
You're right, we've not yet moved on from Raspbian Jessie so a Raspberry 4 won't work. I've read reports of the 4 being more mower hungry and running hot, but have not yet tried one and probably won't until the sailing season is over. We are compiling some of the system libraries for a new product on the zero. This is using Buster and we've found no insuperable problems yet so I don't envisage too many problems moving SkippersMate to Buster (or the Raspberry 4).

The system installs it's own VPN to enable access form the main server to the Boat Control Unit but I don't think this should conflict with your existing VPN and you should also be able to access the Boat Control Unit over your existing VPN. If this works I can see no reason for you to use the main server for access. I could be wrong :D