×
INDI Library v1.8.1 Released (09 Sep 2019)

Monthly maintenance release INDI v1.8.1

Celestron SLT Mount question

1 month 4 weeks ago
tekkydave
Fresh Boarder
Fresh Boarder
Posts: 4
More
Topic Author
Celestron SLT Mount question #41228
I have a Celestron SLT mount with the 127 Mak scope which I would like to be able to control remotely from inside the house.
I also have a Starsense accessory which performs the initial 3-star alignment automatically via plate solving. This works without issue. The only problem is the align needs to be initiated from the HC.

One problem most Celestron owners will have realised is that the mount control and pointing model is within the HC which therefore must normally remain attached. The only exception in my case is if I bought a Celestron SkyPortal device which allows a tablet or phone to take the place of the HC. The alignment can then be initiated remotely from the app. However, the Skyportal app wont control a focuser or camera :(
Celestron have produced a new Windows application, CPWI which will also allow remote alignment but it also doesn't allow control of a camera. It does allow control of a focuser but only Celestron's (suprise!)

My preferred setup would be:

- A raspberry pi at the mount connected to home wifi and running indi server - controls mount, focuser, camera, dew controller etc etc
- PC inside house running Kstars/Ekos on Ubuntu connected to pi via network

I have tested this setup on the bench and it will happily control the scopes slew and also allow me to have a remote focuser and camera. The problem is I can't initiate the mount's initial alignment this way (unless anyone knows a way). The only workround is to align the scope using the HC and then plug in the Pi and retire inside. Maybe it sounds a bit lazy but I would prefer to be able to do everything remotely.

The question I suppose is this:

If I buy the SkyPortal and run it in AP mode so it is connected to my home wi-fi will I still be able to use Kstars/Ekos (as above) to control it all once the initial alignment has completed?

I don't know if the celestrongps driver can connect to the mount via the SkyPortal. It connects fine via the serial socket in the base of the HC but the Skyportal replaces the HC.

I hope that all makes sense and I'm open to any alternative suggestions (apart from dump the scope and get a better mount - no funds for that I'm afraid).

Please Log in or Create an account to join the conversation.

1 month 4 weeks ago
knro
Administrator
Administrator
Posts: 7157
Karma: 51
Celestron SLT Mount question #41232
This situation is common and unfortunately the "norm" among Celestron users. Perhaps Chris Rowland can share some of his thought on this matter?

How about hibernation? If you hibernate the mount and then woke it up remotely, doesn't it retain the alignment?

Jasem Mutlaq
Support INDI & Ekos; Get StellarMate Astrophotography Gadget.
How to Submit Logs when you have problems?
Add your observatory info

Please Log in or Create an account to join the conversation.

1 month 4 weeks ago
tekkydave
Fresh Boarder
Fresh Boarder
Posts: 4
More
Topic Author
Celestron SLT Mount question #41233
Sadly the scope will be set outside on it's tripod each time so hibernate isn't an option.
Looking again at the celestrongps indi driver there is an option on the Connection tab to change the mount connection to 'Ethernet'. I wonder if this would connect through to the Skyportal device?

Then we would have:

Kstars/Ekos on client PC --> network --> wifi (on router) --> Skyportal --> Mount

Anyone tried this?

Cheers
Dave

Please Log in or Create an account to join the conversation.

1 month 4 weeks ago
wvreeven
Platinum Boarder
Platinum Boarder
Posts: 987
Karma: 6
More
Celestron SLT Mount question #41234
I wonder why you want to perform an initial alignment. Why not simply use the plate solving capabilities of Ekos to slew to the object you want to image? That's what I always do (using a SkyWatcher mount but that's irrelevant for my argument) and it works like a charm. Yes the first slew right after finishing polar alignment (which always involves manual intervention by the way so you'll be outside anyway) typically is off by a few degrees. But usually it only takes three or four iterations to center the object of my choice and to be able to start imaging. What am I missing?


Wouter

ASI1600MM-Pro Cooled and filter wheel with a SkyWatcher Esprit 80 ED on a SkyWatcher HEQ5-Pro

ASI1600MM-Pro Cooled and filter wheel with an 8" TS Ritchey-Chrétien on a SkyWatcher EQ6-R

Please Log in or Create an account to join the conversation.

1 month 4 weeks ago
tekkydave
Fresh Boarder
Fresh Boarder
Posts: 4
More
Topic Author
Celestron SLT Mount question #41235
My mount is Alt-Az. Not sure if that makes any difference.

Dave

Please Log in or Create an account to join the conversation.

1 month 4 weeks ago
ChrisRowland
Gold Boarder
Gold Boarder
Posts: 172
More
Celestron SLT Mount question #41236
I've no idea about SkyPortal, I don't know if any sort of alignment could be done remotely or if it could be connected through Ethernet.

However the control code is only designed to work through the connector on the base of the HC so for SkyPortal to be useful it would have to look like a HC which I doubt that it does.

In the Windows world you could use NexRemote, this emulates a HC, which you could run on a Windows machine indoors connected through a long RS232 cable.

CPWI is a replacement for NexRemote, it is also Windows only.

Wouter's suggestion is a good one but the SLT Alt Az mount doesn't have the Quick Align option that the GEMs have (this is because Meade have a patent on using a terrestial reference for aligning an AltAz scope). The closest is Solar System or one star alignment. I'd probably go for that, or given StarSense use that. I'd get SS going while I was getting everything else sorted and by the time I was ready it would be finished.

It would be nice to initiatate SS alignment remotely through the RS232 port but that's up to Celestron. Joining their TeamCelestron forum and asking will do no harm.

A new mount control driver could theoretically be written that communicated directly with the mount motors, possibly using the HC as a bridge This would be rather like EQMOD but using the Celestron motor control method rather than the SkyWatcher motor control.

Please Log in or Create an account to join the conversation.

1 month 4 weeks ago
tekkydave
Fresh Boarder
Fresh Boarder
Posts: 4
More
Topic Author
Celestron SLT Mount question #41237
Thanks for the suggestions. The StarSense handset I have does have a quick align option but not sure if it's the same thing as the GEMs. You just set the date,time,location then set the scope level & pointing North.

The problem with Nexremote is it doesn't allow alignment via the StarSense whereas CPWI does. CPWI will connect via USB, Serial or via a SkyPortal device. It would be perfect if that's all I wanted to do.

I think you are right about just setting the StarSense auto-align going and switching over to using the RPi once it is aligned - seems like the simplest solution.

I can't see anyone writing a new mount controller as so much of the internal workings are proprietary and obscured by the HC. It would have to bypass the HC and talk directly to the internals via the AUX bus. A lot of work for no real reward considering the mount and ota together are only worth about £300.

Thanks for your ideas though.

Dave

Please Log in or Create an account to join the conversation.

Time to create page: 0.673 seconds