LXD55 and SLT127 - Connecting either/or to Bluetooth/WIFI/RS232 (your advice!)

[doctorbond]

Hi,

My first post. I have been enjoying astronomy for a couple of years, with myself and the kids, and ready to move to remote control of one or both telescopes I currently own. I plan to upgrade them but for the moment this is what I have. 

I realise the advice I am asking for is for two different mounts. I appreciate therefore, that it will be different and also the same, so I thought I would ask for both at the same time. Aplogies!

Celestron SLT127 

• Nexstar controller with serial port in the bottom, i dont know which model controller...
• AUX port on side of the mount
• SLT 127mm Maksutov-Cassegrain 

Meade LXD55

• Autostar controller, with serial port in the bottom  - not sure which one, i think it is 497
• AUX port on side of the mount
• 8" (200mm) Schmidt Newtonian Reflector

Computer

• Ah i need to buy one....so that may be a factor in the answers below (i.e what to buy!)

I would like to connect them (either/or) to a computer just to have some fun with. I would like to control the mounts if I can, and would also like to fit a webcam for viewing, Basically so I have a fully remote scope which I can set up in the garden and then retire inside. I realise that it is only really suitable for the moon and planets, but thats ok for now. This will work well in the colder months (i.e jan/feb) with the kids, who have so far really enjoy it, but not missing the wow factor. I think being able to take some footage and maybe stack/compile some images will bring that (bigger scopes too one day!)

My starting questions are

1. Should I have a crack at getting them operationally remotely, or should I really start with newer mounts?
2. What is better - bluetooth or WIFI? I realise that 232 is still at the heart of it?
3. That said are RS232 cables the way to go and I forget about trying to use bluetooth or WIFI
4. I think I can use the AUX to control the SLT, even with no hand controller, but that this will not work on the LXD55, and that must have a working hand controller
5. In terms of the computer, i guess this will depend on the answers. Do i search out a RS232 computer, or will the USB to RS232 work without too much hassle. 
6. Any particular operating system (i.e Win 10?)
7. Software.....something for the webcam, and of course some astronomy software....!

If it all seems reasonable, then what is the easiest starting point? I am an engineer, and I can do fiddly things, but it is all a little new to me in terms of the technology. So im not sure I want to jump straight into a full blown homebrew build unless that is the only way for reliability.  

Any experience or advice, I am all ears. I am based in Cornwall, UK, so any links to things that are a proven path to work (to buy) then go for it!  

P.S

Long term I would like a 12 - 14" scope for other objects for now, I figure its better to maximise what I have.

P.P.S 

Ideally i would run both mounts, maybe not at the same time, but maybe.....I have two kids and they both want a go plus me, at the same time! 

 

Edited October 3, 2022 by doctorbond

[Cosmic Geoff]

Rather than answer this point by point, I would just say that when I first thought of buying my 127mm Mak SLT, I was thinking that I could fit an astro camera to it and view and control remotely...

All this is more difficult in practice than it may seem to the uninitiated.   The SLT mount is not what I'd choose for a remote-controlled outfit.  I do have a setup that is capable of achieving the degree of GoTo pointing accuracy you would require for finding objects by remote control, but it relies on plate-solving (q.v.)

The interfaces do involve RS-232 ports, but nobody uses computers incorporating these physical ports these days, and the relevant control port on my EQ-5 Synscan mount is physically a USB port, but still requires a special driver for reasons too tedious to describe here.  And it is controlled via Windows 10. Any recent laptop will probably suffice.

The challenge is that Goto Mounts have a limited aiming accuracy, and astro cameras have a practical field of view that is often rather small.  Providing an astro camera that combines a large field of view (for finding things) with high resolution (for viewing fine planetary detail) could prove expensive.

The view of a planet as seen via a live-view setup on a laptop screen will be familiar to planetary imagers - the view is surprisingly bad!  The detailed views produced by planetary imagers involve 'lucky imaging' (q.v.) via processing a video of several thousand images, and substantial post-processing.

If this has not put you off,  I suggest that you acquire a useful laptop, e.g. a used Dell Vostro Windows 10 business laptop a few years old,  and an inexpensive astro camera. and try setting this up with one of your telescopes (without any remote control or remote viewing) .  The difficulties of your project will then become apparent. 🙄

[doctorbond]

Thank you for the advice. Informative! You haven't put my off, but you make some really great points that I need to consider 

May I ask two more things. The specific dell model you mentioned...is it just great value for money based on its age such as performance, or is it that but with other useful features such as serial port etc? I see it has decent spec for the money.

When you say astro camera, can you help me a little more. Maybe a quick link so I get the idea? Do you mean something with a wire or a DSLR. What software would I start with?

Indeed it does sound like a lot of work, but what the heck I might as well try it, then like you say if that has not put me off. I can pursue Bluetooth or wifi or 232 control as well!

 

 

Edited October 4, 2022 by doctorbond

[Paul M]

I had a go at interfacing my SLT mount to my computer via APT (imaging software) and Stellarium. It was a while ago and can't remember the details. I bought this cable :  https://www.firstlightoptics.com/celestron-mounts/lynx-astro-ftdi-usb-to-serial-adapter-for-celestron-handsets-5m.html  for the job and it worked. Also needed to download some drivers which I remember being a pain in the butt as I first needed to download a Celestron software loader if I remember correctly.

Although I did get it to GOTO selected targets it wasn't possible to plate solve due to trailing in the image.

To cut to the chase, here is what I said about the result of my effort at the time:

 

On a brighter not, I have successfully imaged with the 127 Mak scope mounted on my EQ6 Pro mount. That mount is overkill for the scope but it served to demonstrate the imaging potential of the scope!. 

[doctorbond]

Hi Paul, 

Thanks for the post . I have had a good skim of your link, and will have a proper look over the next day or so (im out tomorrow).  Alot of it is currently over my head, but I am an engineer and can figure out, just all quite new to me! I am at the very least encouraged, and excited by what you achieved, even with a different mount!! =)

I note that essentially with the SLT mount 

• "So in conclusion. This will never be an imaging mount. Even if it performed better thsn it does field rotation would severely limit exposure times. But I think it'll adequately track the conjunction if the sky is clear. Maybe well enough to allow me to get some images."

Perhaps my Meade LXD55 will be more useful, or perhaps I just need to trade them for something newer. In any case while I learn all about "cameras",  and "programs" and "stacking" and all those things I don't yet understand. I have decided to just go ahead and purchase the RS232 cables for both scopes, and just have a play. I think that is the "easiest" way to just get "up and running".  

I told a small lie, I actually have 4 computers kicking around, but they are all ancient, mind you so are my mounts, so maybe that will help at least. Or note, those driver issues don't sound like fun!. 

Luke

 

 

[Paul M]

You don't need a fancy computer to control a mount or even do imaging. Any old PC that will run W10 is good to go. The problem with earlier versions of Windows is driver availability and compatibility. There are enough ruts in the road to gathering your first image without falling foul to software compatibility! The computing effort is all in the image processing. That can warm your CPU nicely!!

If I was to give one piece of advice though it would be get a decent mount. The SLT mount is not the tool for imaging with. I actually used mine a couple of nights ago for the first time in a couple of years. I've pimped my Mak with a new diagonal and along with the SLT mount is now based at my get-away dark sky location in Cumbria. It'll be great for fun visual.

I've been shot down previously on here for suggestion an HEQ5 class mount as the minimum for imaging. Well, true it's a bit more than minimal but it will work and will serve you very well whilst retaining a good second hand value. There are the mini tracking/goto mounts but they are designed for DSLR camera/lens combos or very light telescopes. That might be a way to go but the cost still adds up.

I don't know the LDX55, is that just the scope? What mount is it on?

[Cosmic Geoff]

On 04/10/2022 at 20:36, doctorbond said:

May I ask two more things. The specific dell model you mentioned...is it just great value for money based on its age such as performance, or is it that but with other useful features such as serial port etc? I see it has decent spec for the money.

When you say astro camera, can you help me a little more. Maybe a quick link so I get the idea? Do you mean something with a wire or a DSLR. What software would I start with?

I

The Dell Vostro is just an example.  (It happens to be the model I am using for imaging).  It's just a fairly up to date type with SSD instead of HDD, and USB3 ports, and consumes far less power than my older Vostro.  There are lots of laptops on Ebay as dealers buy business clearouts and sell them on. Any computer with serial ports belongs in a science museum. 🙂

Astro camera - look up the details of the ZWO cameras in my signature.

[doctorbond]

Thanks for the replies. Apologies for my simplistic understanding. I have to say it has a been a very steep learning curve, with a bewildering number of new terms and methods, but I'm enjoying it, and I think I am getting there. 

Thank you, I now have my eye on the ZWO cameras, and laptop spec. They are in my budget between now and Christmas. I will research both some more. I also understand for planets and DSO I will need different cameras, and probably better scopes too. 

For this week, I have dusted off an old laptop, bought a suitable Celestron control cable, and I have a HD webcam which I have modified to fit a 1.25 eyepiece. I have downloaded both SharpCap 4.0 and Celestron CWPI. I read abit about "registack", and "stellarium" and loads of other programs, but its a lot to take in, so I am going to try those first two programs, just to see if I can successful move the scope and capture an in image. It sounds like my laptop may not last long!

While I want to be able to image planets and DSO, and all that cool stuff, I will be happy enough just having a live view of the moon to get me over the first hump. 

I think my Meade LXD55 which is a German equatorial mount will be better for imaging, but I'm not going to worry about that for a moment, as the hand controller is fussy. So I am just going to focus on the Celestron SLT to keep things "as simple as possible", while i learn about all the things like cameras, software, and auto gliding and etc, then learn about how to do it all better. 

 

[lvan]

You might find this useful:

You could probably skip the raspberry build and get an asiair plus if you wanted to simplify the process.