I am rather new to astronomy. I tried playing around a bit with an ETX90 a few years ago, without much success, as I was mostly focused on visual observation. The emergence of EAA pushed me to give it another try, this time focussing on photography. The reason being that I live in a rather big city (Milan, Italy), and I came to believe that EAA is the pnly possibility to do *some* astronomy where I live.
So I got myself an AZ-GTi (with its own tripod). I already have a Nikon D3300, and I had a Raspberry Pi 3 with 1GB memory lying around. I got myself all the necessary cables and accessories (dovetails, plates etc.) and connected everything. My plan is to add the OTA of the ETX90 to my instrument set once I am up and running with the above stuff. So, currently, I have the az-gti mount on its tripod (in altaz mode, I will consider trying equalorial when I am more experienced), connected via usb cable to the raspberry pi, which is fixed to the mount's top with adhesive velcro. The DSLR is connected via USB to the Pi, and the Lens is a Kit 55-300 zoom by Nikon.
I have Astroberry running on the Pi, connectivity is fine and I am having everything running correctly. I was hoping to place the whole set on the balcony and run Kstars from my study. Unfortunately the Pi's wifi signal is unable to reach it, not sure whether it is the aluminum case I am using for the Pi or maybe the balcony's door glass is somehow shielding wifi signal. So I am currently using a Chiormebook sitting next to the balcony door and connecting via VNC to the Pi.
So my first goal was trying to get the whole setup to know where it is and where it should point. I placed the mount+DSLR level north, turned everything on, and tried platesolving to see what would happen.
The first issue I encountered is that upon launching ekos and starting my profile, KStars shows my rig centered on Polaris. But it is actually in home position (level+north). Browsing the docs I found out about the default parking position, so I set that to the encoder values at which the scope is in altaz 0-0 position. Is this the correct thing to do or is there some other way to get Indi to know that the mount is level-north? Without fixing this, any attempt at platesolving would fail. I guess this is due to the fact that while the scope is level north, with ekos thinking it is aligned to polaris, the platesolver is outside its tolerance. Also, KStars would crash from time to time while platesolving. Maybe due to the fact that my Pi is 1GB only?
Second issue is with focusing, I can take shots from my DSLR only when lens is set to manual focus, otherwise capture fails. If I wish to try Ekos focuser tool, do I need to have lens set to manual?
Third issue is with FOV. I input my rig's parameters, i.e. 300mm focal length, 6000x4000 sensor, 3.9 um pixel size, and the test pictures I took of the sky look very different, in scale, from what I expected looking at simulated FOV in KStars or other online telescope simulators. It looks much wider than I expected. I will have to find out whether there is some other setting which I need to adjust.
So this is where I am currently. I will post updates about my progress, and would appreciate any inputs on what I may be doing wrong.
I can't answer all of your questions. I can only say that a 1 GB Pi is going to struggle, and probably occasionally crash. That's not enough RAM for a full KStars. What you could do, is just run INDI (the hardware drivers) on the Pi, and run KStars on a laptop or desktop inside your house, and KStars talks to the INDi drivers over WiFi.
Which brings me to the WiFI performance of the Pi. The built-in WiFi is already very weak, because there is no antenna. Then adding a metal case doesn't help any. What I do is I use a USB WiFi dongle. I get much better WiFi range and speed using that, and disabling the built-in WiFi.
Thanks, for my current tests Pi3 with 1GB sort-of works, but it is quite clear that I will have to upgrade once I want to become more serious and once Pi availability becomes reasonable.
I will definitely think about adding an external wifi dongle, although once I account for (1) DSLR, (2) az gti mount (3) GPS dongle and (4) wifi dongle, I am already out of USB ports, unless I add an USB hub to the mix, making the whole setup a bit more unwieldy.
I fixed my goto problems after I set the Home position to north level. I wonder why this is not the default for what is mainly an alt-az mount.
I have now tried to play a bit with the focuser module, trying to get it to control the DSLR's lens focus motor, but was not very successful: if I set the lens to manual, indilib appears unable to control the focus motors, while if I set it to automatic, then it tries to adjust the focus whenever I take an exposure. I will play a bit more with this but my feeling is that using the focuser module with my setup is a no-go.