Using a computer through a tablet

[Billyo]

Ive set up my laptop on the boat to run open CPN and networked it into all the instruments which is great. I know I can set up a router so that I can view open cpn running on the computer, but is there a way for the tablet be used to control the open cpn programme as well?

 

[matthewriches]

If you wished to replicate the screen then you'd do this via a remote desktop application or "VNC" either over the internet for remote control or via your LAN for internal network control, internet connection not required for the latter.

I have a customer viewing his ships PC from a Toughpad via Splashtop which doesn't require internet connection and works with pretty much no latency.

 

[lpdsn]

Alternatively, could you not just feed the same info to OpenCPN on the tablet?

 

[Billyo]

Interesting.

When you say feed the same info into the tablet, I assume you mean routes and waypoints that I set up on the laptop? If so I didnt know this was possible and would make life easier. Assume there a section in the Open Cpn pages on how to do this.

So next step is to get the nav data to the tablet. I have everything running through an Actisense unit to produce nmea0183 for the computer to use. How can i get this transmitted over wifi to the tablet?

Is it as simple as setting up a wifi router on the boat and then just connecting the tablet and computer to it?

 

[matthewriches]

You can set OpenCPN to repeat the NMEA data from your module to your tablet over WiFi if both devices are on the same network and you leave the PC on whilst using the tablet. You can export and import routes, waypoints etc... between the 2 devices. You could store them all in a central network location for ease of use between the 2 devices. Not ideal but it could work.

 

[affinite]

Interesting.

When you say feed the same info into the tablet, I assume you mean routes and waypoints that I set up on the laptop? If so I didnt know this was possible and would make life easier. Assume there a section in the Open Cpn pages on how to do this.

So next step is to get the nav data to the tablet. I have everything running through an Actisense unit to produce nmea0183 for the computer to use. How can i get this transmitted over wifi to the tablet?

Is it as simple as setting up a wifi router on the boat and then just connecting the tablet and computer to it?

I don't believe that (at present) you can share waypoints and routes between devices running OCPN in real-time however I have put in a feature request for this.
To overcome this limitation I run a VNC session on my cockpit repeater (Rugged Tablet) which mimics the chart table navigation computer so I don't have to worry about waypoints and routes being out of sync.
WRT routing NMEA to the tablet there are a number of ways to do it but I use OpenPlotter

OpenPlotter can do all the NMEA multiplexing from multiple devices, over serial, USB, Ethernet or WiFi and has a built-in WiFi Access point to broadcast your NMEA data to multiple wireless client devices.
Best of all it runs on a cheap little Raspberry Pi so I have retired my OCPN laptop which now sits in a cupboard as a backup.
My OpenPlotter connects OpenCPN to data from AIS, GPS, VHF Radio, Autopilot, Seatalk Instruments and wireless instrumentation senders for tank levels and battery measurements etc

http://www.sailoog.com/openplotter
forum http://forum.openmarine.net/

 

[Billyo]

If I run a VNC on the tablet would that give me access to the functionability of the open CPN programme in the laptop? As in, Im going to be in Baja California and have two different charts that I will use for reference as well as Satellite Images, would the VNC allow me to swap between the three in real time or would I have to do it manually at the laptop?

Ive looked at the Raspberry pi and think its probably beyond me!

 

[philld]

You have to run VNC on both machines, the PC would be the server and the tablet the client. The tablet becomes a second display and a second set of inputs for the PC. The VNC application on the tablet displays whatever is shown on the PC, if you can switch the charts at the keyboard on the PC you should be able to do it at the tablet.

 

[GHA]

I don't believe that (at present) you can share waypoints and routes between devices running OCPN in real-time however I have put in a feature request for this.

Not real time but winscp will help to automate syncing from a windows machine & others. Make a batch file to run a script file >

"C:\Program Files (x86)\WinSCP\WinSCP.com" /script=tablet.script



pause

Then the tablet.script file looks like >

open ftp://admin:admin@192.168.43.114:1122/ -rawsettings ProxyPort=0-rawsettings ProxyPort=1 



ls


put "C:\PROGRA~3\opencpn\navobj.xml" /storage/emulated/0/Android/data/org.opencpn.opencpn/files/navobj.xml

That's for an android tablet with "wifi file transfer app' running which gave that IP address, to transfer to Rasp Pi it would be like >

open sftp://USER:PASS@192.168.43.149/ -hostkey="********" -rawsettings ProxyPort=1 ls


put "C:\PROGRA~3\opencpn\navobj.xml" /home/pi/.opencpn/navobj.xml

The "open ......." line can be copied from winscp / site manager / manage / generate session URL which puts in the user/pass & hostkey. .

That's first stab at this, should be easy to backup the navobj file as well, though the other navobj files re backups already.

 

[GHA]

Ive looked at the Raspberry pi and think its probably beyond me!

Really not that hard, copy some downloaded stuff onto an SD card and stick it in the Pi then turn on, though web access would be good first time round to get all the updates.Then it's just another computer