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.

Maybe the joystick is not available at the moment the INDI drivers start and turns off again? I noticed that happens with the mount as well. It is not a plug and play system, it only tries once...?

Yes, I would like to contribute, I just do not trust myself. My first experiments ended with a damaged mount and I had to return it. I only tried to telnet and query the firmware version and still the mount stopped working. A discouraging experience. So, when I see something is not implemented by a more competent person, I am afraid there might be some good reason for that. I will try to get deeper into the INDI system, if I can, but I will surely always try to raise questions before trying to actually "fix" something that should not be played with for some good reason.

I really like the whole INDI system architecture, but I still wonder about some details of the implementation, such as the array-like implementation of switches and the reason for such implementation decisions (what happens if I try to switch on more then one option? etc.). I should probably get some time to study the documentation closer before trying to hack something (and break it).

I've tried using the joystick with the PMC8 every now and then. I think my observations were generally the same as yours. It seemed like it was one axis at a time only, and I would sometimes need to go and re-enable the joystick in the PMC8 driver (though oddly enough I don't think it was something I always needed to do). I can't really comment on the speeds. I was using it for minor corrections after a goto, so I didn't want the mount to move quickly anyway.

It bugged me a bit at the time, but I filed it away as something to look at later, as I had other priorities and I'm usually away from the mount when I'm using Indi anyway. But I might be willing to look into it when I get a break from work projects again in a week or so. Or test anything you come up with .

I'm a bit surprised telnetting into the PMC8 and querying it would have bricked the mount. I've done a lot of dumb things with mine and it keeps on ticking. On the other hand, it does take a little while to understand the Indi architecture. If it's any encouragement, I think the real reason why something is not implemented by a more competent person is not that it can't be done, but rather a shortage of competent people who are interested enough in using Indi to control the PMC8. I mean, I'm a lawyer for crying out loud--I shouldn't be allowed to touch the driver .