Driving Multiple Kits with Kstars/Ekos?

[kbrown]

Hi,

So far I've only dealt with one remote kit with Kstars/Ekos. It's Raspberry Pi 3 based configured as an WiFi AP running an INDI server + drivers. It has worked fine. But now I've slowly been building another similar setup. This then prompted the question, what if I want to use both of them at the same time? Obviously I can't be connected to two APs at the same time. Not sure if I can even run two sessions of Kstars either? Any ideas?

Cheers,

Kari

Edited February 12, 2021 by kbrown

[JamesF]

Is the desire to be able to manage both these systems from a Windows machine or something else?  I can see how it might be possible on Linux, but I'm mostly ignorant of Windows, and prefer to keep it that way :D

James

[kbrown]

I'm on Linux. My laptop has a built in wifi adapter and i have a wifi dongle too so I guess the easiest would be to have one of them connected to Kit A and the other one to Kit B.

Or maybe Kit B could be connected to Kit A which I connect to from my laptop... Hmm...

EDIT: Btw, I just tried I can run multiple sessions of Kstars so I guess there's no problems there...

Edited February 12, 2021 by kbrown

[JamesF]

1 minute ago, kbrown said:

I'm on Linux. My laptop has a built in wifi adapter and i have a wifi dongle too so I guess the easiest would be to have one of them connected to Kit A and the other one to Kit B.

Or maybe Kit B could be connected to Kit A which I connect to from my laptop... Hmm...

If you have two wifi interfaces then you could probably connect one to each RPi.  I suspect that KStars will only want to run one instance at a time though, so I'd be tempted to look at either running each instance inside a virtual machine and try to map the wifi interfaces to each separately, or to run two desktops on separate virtual consoles using a different login on each and run KStars on both.

I'd guess each RPi will need configuring to have its own network so you don't get a clash there.

Alternatively, could you get each RPi to connect to an external AP and not use the RPi AP at all?  You'd still have to do the messing around to run two instances of KStars, but you'd not need multiple wifi interfaces on your laptop which might make life easier.  It's probably even feasible to set up the laptop to be that external AP, though if your laptop has a wired network interface and you wouldn't otherwise be using it, TP-Link may still sell a small AP that plugs into the wired network port and is powered from a USB port that could do the job for you.

Connecting RPi B to RPi A's AP and routing all traffic through RPi A would probably be quite a faff to set up correctly.  Not impossible though.  However, it would mean that if RPi A failed for any reason, RPi B would be dead in the water as well.

James

[kbrown]

Thanks James. Certainly some food for thought. Think I'll try the two interfaces connected to each RPi first as that's the least amount of faffing about. I did manage to run two Kstars at the same time. Might try doing it for real soon.

 

K

[JamesF]

This is the TP-Link unit I had in mind:

https://www.tp-link.com/uk/home-networking/wifi-router/tl-wr702n/

(I notice they now do a later model which may be faster.)

I have one that I have used when we've been on holiday where there's restricted access to the internet via a local wifi network (eg. they only let you connect a restricted number of devices at a time).  I have a laptop I connect to the public wifi network and then plug in one of these to create a local wifi hotspot to allow all our phones/kindles/tablets/laptops etc. to connect.

James

[JamesF]

2 minutes ago, kbrown said:

Thanks James. Certainly some food for thought. Think I'll try the two interfaces connected to each RPi first as that's the least amount of faffing about. I did manage to run two Kstars at the same time. Might try doing it for real soon.

It's worth a try.  My first concern would be that the two instances could end up fighting over configuration files or external storage of state information.  If the configuration can be the same for both sets of kit that's probably a step forward, but the state data (eg. scheduling information and so on) might be more tricky.

The straightforward way to do things of course is to run KStars on each RPi and connect to them using VNC or something like that, but that may have its own speed and storage compromises to be made, and I'd assume you've already thought of that and discarded the idea.

James

[kbrown]

2 minutes ago, JamesF said:

It's worth a try.  My first concern would be that the two instances could end up fighting over configuration files or external storage of state information.  If the configuration can be the same for both sets of kit that's probably a step forward, but the state data (eg. scheduling information and so on) might be more tricky.

Oh yes. Didn't think of that. Maybe I can run them in a container or something...

3 minutes ago, JamesF said:

The straightforward way to do things of course is to run KStars on each RPi and connect to them using VNC or something like that, but that may have its own speed and storage compromises to be made, and I'd assume you've already thought of that and discarded the idea.

I did this in the beginning and didn't like it. Just painfully slow and unreliable to use.

[kbrown]

Another hacky way to get around the potential config clash problem might be to run the other Kstars session under a different user. That way they would have completely separate configs...

[JamesF]

6 minutes ago, kbrown said:

I did this in the beginning and didn't like it. Just painfully slow and unreliable to use.

I had a feeling that might be the case

James

[JamesF]

Just now, kbrown said:

Another hacky way to get around the potential config clash problem might be to run the other Kstars session under a different user. That way they would have completely separate configs...

I quite like this as a possible method.  More than using two virtual machines, anyhow.  It makes the configuration etc. easier to copy/back up if you want to upgrade or something.

There is also a "virtual X server" application that effectively appears as a display to any applications connected to it.  That might provide a way forward  that doesn't mean switching between virtual consoles.  Possibly it would be easier to get the virtual console method (with two different users) working first however.

James

[kens]

If your RPis are both set up as hotspots you probably want to make sure each one has a different IP address or at least a different Wifi SSID.