Sorry I didn't reply sooner--I don't come to the boards as often as I should. Anyway, about 3 months ago I made a few changes to the PMC8 driver to make it more reliable for TCP connections, and I've been using the EXOS2 PMC8 exclusively over TCP ever since. I have found it very reliable. I'm not sure whether there would be any difference for iEXOS100--I know the firmware is different, but I was under the impression that it's all pretty much the same.

Just to check, you might want to verify that you have the latest version of the driver (0.3). I think it should be in the latest kstars/indi builds.

Perhaps a difference is that I am running in infrastructure mode using my LAN or a hotspot instead of a direct ad-hoc connection to the mount? See espmc-eight.groups.io/g/WikiSubmissions/topic/37662303#8

I used to have lots of problems with the time, but I don't think that had anything to do with the mount, as I don't think recall there being a way for the driver to even tell the mount what time it is. Anyway, I bought a cheap GPS dongle (HiLetgo VK172) and started using the GPSD driver. That seems to have cleared everything up.

Right, I did not find any time setting procedure in the driver source code either. I wonder then why does the mount actually need the GPS coordinates, if it does not care about time and only uses relative coordinates...? I will have another look at the documentation, I am probably missing something.

I only tried TCP connection with the direct association to the mount. More complex connection has no meaning in the middle of the fields (except the Astroberry were used as the AP, of course). Anyway, the only point would be UDP with the possibility to switch between ExploreStars and Astroberry without actually switching the modes, but it would probably not cooperate so well either. So, in the end, wired is probably the best solution anyway.

I have also connected a GPS sensor to the Astroberry, but (obviously) it does not work inside the house when testing the mount. In the field I was quite satisfied with the results of the go-to navigation at first (after I finally managed some decent polar alignment). I was just surprised that it was lost later. But I am not sure that the polar position of the scope was really kept when I parked the scope and disconnected from power. When I got home, I noticed the axes were not exactly in the neutral positions. Maybe the "parked" position wasn't aligned to the NCP anymore - (but why?) - and I probably just did not check when turning the mount on again later...?

The mount/PMC8 controller itself doesn't actually know much beyond its rotation (relative to where it started when you powered up), declination (ditto), and each axis' tracking rate. All of the smarts to translate that into where the mount is actually pointing in the sky are in the client. So the PMC8 itself would never see, for instance, the time or GPS. But the client needs to know this so that it can figure out where to tell the PMC8 to move. As far as polar alignment goes, this means that you'll lose all of the data that the client is using to compensate for polar alignment if you cut the power to the Astroberry. So unless you have a good polar alignment physically to start with (e.g. using the polar scope), then yes you'd have to start over again once you restored power to the Astroberry.

What kind of problems were you experiencing when you were working with the wireless connection? Was the mount just not slewing at all, or was it slewing to wrong places?

For what it's worth, I have actually been quite surprised to find that I can switch between ExploreStars and Indi in the field quite nicely if I have a good physical polar alignment and am sure to disconnect the other client first. This is using my Pi as an AP. I'm not sure there's too many reasons to actually switch in the field, though. Now, if both could be connected simultaneously, that might be more interesting.

I think that EXOS2 can communicate by TCP and UDP simultaneously, while iEXOS-100 cannot. I think I have read it somewhere in the discussions.

The problem was that I wasn't able to establish wireless connection between INDI and the mount and there is no surprise: I tried it manually as well and I never got any response from the mount when using UDP, while I got some response (but with a delay too great) when trying TCP. It seemed to be a problem of the mount, but it might as well be something I forgot or wireless interference... no idea.

What is the easiest way to achieve a better polar alignment beyond the physical one in INDI?

There's a software toggle between TCP and UDP on the EXOS2. I've just been using TCP.

With the EXOS2, the driver would receive an unexpected and nonsensical response every now and then while slewing. That threw the driver off, and the driver would timeout. Packet sniffing seemed to indicate that it was coming from the mount, but it never happened using ExploreStars, so we couldn't figure out what the deal was. Anyway, I modified the code to just discard the response and then it worked fine. I wonder if the iEXOS-100 is doing something similar, but at a different time, such as during the initial handshake.

When I need a good physical polar alignment, the only thing I do is use the polar scope along with the PolarisView app on my phone to figure out the appropriate rotation of the alignment guide in the polar scope. I often end up resyncing after the first slew and every now and then after that, but it at least gets me within a few degrees, so my target is typically at least within the field of view of my low-power lenses. I think part of the problem is just that I'm pushing the weight limit. Most of the time, though, I'm plate solving, so I'm not really needing pinpoint accuracy, and I keep my Pi powered and connected throughout the night anyway.

I was reading your first posts more closely, and slewing to the entirely wrong part of the sky sounds like a problem with the time or location. That could happen for a number of reasons, such as a misconfiguration of the mount driver. I ended up having a lot of sporadic problems with slewing to below the horizon and other very wrong positions with an older GPS dongle (circa 2009). I eventually realized that, depending on when the GPS signal was initially acquired, the GPS daemon was returning the right location but the wrong year (more specifically, the Pi wasn't figuring out what the right epoch was). Even though KStars would eventually show the right time, that initial wrong timestamp from the GPS was taking priority somehow. Those problems went away with the new dongle, so I never did figure the problem out exactly. Of course, your problem was probably something completely different and equally random.

Concerning the physical alignment, I am sure it is much easier using a proper polar scope rather than the poor "polar tunnel" on the iExos-100. However, I wonder whether there is some possibility to achieve a software correction of the alignment in INDI or some of its clients similar to the 2/3-star alignment function in the ES ExploreStars application?

I also tried the joystick control and I am a bit disappointed by the fact the speed of the movement cannot be controlled by the angle of the joystick axis. It is just fixed to a single speed. Is it a limitation of the joystick driver or the PMC8 driver? Can it be improved?

You don't see mapping for "Slew Rate" Up and Down?

Oh, thanks, I found it now! But what should I set there? It seems to be adapted to buttons changing the speed up and down, but how to make the speed dependent on the axis angle/value?

So, it looks like there is a system for SW alignment in INDI (www.indilib.org/api/md_libs_indibase_ali...ent_white_paper.html), but it is probably not implemented into the PMC8 driver, right? It should not be difficult, but I am afraid I am not the right person to try it.

As for the joystick control: if I understand it correctly, it is not possible to change the speed by the joystick angle, is it? Since I am making my own joystick controller, I could implement fake speed_up/slow_down button presses dependent on the angle inside the controller. (However stupid it feels.) But it would have some limitations. The first one is the fact that the speed cannot be changed for the two axes independently - only both together, right? The second is that I am limited to the four speeds currently defined in the PMC8 driver, right? Unfortunately, even the fastest speed (256x) is too slow compared to the maximal slew speed used by the mount. It seems to be easy to add more speeds to the driver so that I could manage it myself; the only question is what is the maximum speed possible/allowed.

As I can see in the code, the current speed of 256x is also set as the maximal speed limit for the driver. Higher speeds are "currently unsupported". I suppose the reason is the need to increase and decrease the speed in gradual steps in order to protect the motors? That is at least something I have seen the documentation from ES.

Another limitation: when using the joystick, I actually cannot move the other axis while one is moving, only one axis movement at a time is possible. Is this a purpose as well?

Also, the joystick gets never connected to the PMC8 driver automatically - I always have to trigger connect manually after start. Saving the settings does not help. The worst thing is reconnecting the joystick, then I have to go to the joystick driver settings (not PMC8) and manually disconnect and connect again. Well, I know, nothing is perfect and I can make some scripts, I am just not sure whether to report such minor issues to someone.

If you have some background, you can always hack the code yourself to fix whatever minor issues you're facing. It's all open source. For the joystick, it appears that USEJOYSTICK is indeed getting saved to config.. so if it not getting saved or is saved properly but not loaded properly, then someone needs to debug the driver and find out why.