Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

DIY Plate Solve Assist for existing GoTo Mounts?

  • Please log in to reply
9 replies to this topic

#1 hcf

hcf

    Viking 1

  • -----
  • topic starter
  • Posts: 755
  • Joined: 01 Dec 2017

Posted 16 February 2020 - 03:37 PM

I have been working on adding platesolving for manual or DIY motorized mounts. The PSWAI (Plate Solved Where Am I, PushTo like) a year ago. More recently the Plate Solved GoTo (PS-G2) for my DIY motorized EQ mount.

 

I recently added Sky Safari control to the PS-G2 using a subset of the LX200(GPS) command set to do this. The python script to do this runs on a linux machine/mount side raspberry pi, talks to Sky Safari (using WiFi) on one side and to the Arduino controlling the mount on the other side. It also connects to the camera. On a GoTo command from Sky Safari, it iteratively does photo capture and platesolving followed by a slew to get an accurate GoTo.

 

M50 using PS-G2

 

Someone here had asked me about adding PlateSolving to existing GoTo mounts to automatically correct the error in GoTo using platesolving.

Adding the LX200(GPS) interface for SSPro control for the PS-G2 got me thinking about this problem. Low/Mid range GoTo mounts often have inaccurate GoTos either due to bad mechanics/balance/alignments.

 

You would need  a small camera piggybacked (like on the PSWAI) and aligned to the scope, and a linux machine (raspberry pi) to run the platesolver on.

 

Yi with frame,lens,Tadapter,IRfilter
 

You could add a python script "middleware" sitting between SkySafari and the mount, say on a raspberry pi connected to the mount. If the protocol used is well known, like the LX200, it should be possible for this python middleware script to pass all command/response from Sky Safari to/from the mount, except for the GoTo slew command. Upon detecting the GoTo slew command it would do a series of platesolve sync and slew commands to the mount to get a very accurate GoTo. Sky Safari would connect to the Pi, instead of the mount.

 

Another way to do this would be to do  platesolve sync using the piggybacked camera like APers. With something like Indi/Ekos/Stellarmate this would be able to work for a large number of supported cameras and mounts. You would need to find a way to automatically do platesolve sync after every GoTo from Sky Safari. I know at least one person trying to do this.

 

This is just an idea at this point.

 

Any reason why it won't work? Is it worthwhile? Anyone interested in trying?
It is supposed to fix bad alignment, mechanical slips, mount bumping kind of issues for GoTo mounts and make them very accurate.


  • lambermo likes this

#2 bobzeq25

bobzeq25

    ISS

  • *****
  • Posts: 24,240
  • Joined: 27 Oct 2014

Posted 16 February 2020 - 04:02 PM

It could work, but it's not worth the effort.  People have already done exactly that, and the software is available.

 

Examples are Sequence Generator Pro, Voyager, and NINA.  Each of them will tell the mount to GOTO a target, then snap a short picture (since all you need are some stars).  They platesolve it, then send the correction to the mount.  It may take 2 or 3 iterations.  The desired degree of accuracy is adjustable.

 

All automatically.  You tell the program to "go fetch M106", and hit the Go button.  And it does.

 

It uses catalogs of objects, and usually includes at least one.  You can use the internal catalog, or one of your own.  It works on objects, it works on RA and DEC coordinates.

 

Examine the gray menu for Voyager.  Note the many options, telling the mount to GOTO, precisely pointing to a target (with one button press), platesolving an image, syncing the mount to your target or coordinates.  You name it, it does it.  <smile>

 

https://voyager.tour...?title=OnTheFly


Edited by bobzeq25, 16 February 2020 - 04:13 PM.


#3 hcf

hcf

    Viking 1

  • -----
  • topic starter
  • Posts: 755
  • Joined: 01 Dec 2017

Posted 16 February 2020 - 04:14 PM

It could work, but it's not worth the effort.  People have already done exactly that, and the software is available.

 

Examples are Sequence Generator Pro, Voyager, and NINA. 

Yes, but only for AP.
I am thinking more of cheaper/simpler/easier to use solution for visual astronomers.


  • RossW likes this

#4 bobzeq25

bobzeq25

    ISS

  • *****
  • Posts: 24,240
  • Joined: 27 Oct 2014

Posted 16 February 2020 - 04:15 PM

There's no reason it wouldn't work for visual.  You'd simply direct the program to the camera you're using.  You do need a camera, right?  <grin>

 

NINA is free.

 

How much simpler does it get than selecting a target or coordinates, and pressing one button?


Edited by bobzeq25, 16 February 2020 - 04:18 PM.


#5 hcf

hcf

    Viking 1

  • -----
  • topic starter
  • Posts: 755
  • Joined: 01 Dec 2017

Posted 16 February 2020 - 04:45 PM

There's no reason it wouldn't work for visual.  You'd simply direct the program to the camera you're using.  You do need a camera, right?  <grin>

 

NINA is free.

 

How much simpler does it get than selecting a target or coordinates, and pressing one button?

Yes you would still need a camera :) But it does not have to be an expensive astro camera as the requirements are less.

 

Is anyone using NINA for visual? Does it connect to Sky Safari? Does it need a windows laptop?

It looks like the INDI/EKOS/KSTARS solution I mentioned, but for Windows. 



#6 OldManSky

OldManSky

    Skylab

  • *****
  • Posts: 4,418
  • Joined: 03 Jan 2019
  • Loc: Valley Center, CA USA

Posted 17 February 2020 - 12:05 AM

Yes you would still need a camera smile.gif But it does not have to be an expensive astro camera as the requirements are less.

 

Is anyone using NINA for visual? Does it connect to Sky Safari? Does it need a windows laptop?

It looks like the INDI/EKOS/KSTARS solution I mentioned, but for Windows. 

NINA will do the goto/platesolve/sync/adjust cycle with my uncooled, inexpensive guide camera.  It doesn't have to be an expensive astro camera, just any old ASCOM-driven camera.

 

NINA will connect to a number of "planetarium" programs.  I connect it to Cartes du Ciel.  I don't specifically know if it will work with Sky Safari.

And no, it doesn't need a Windows laptop.  I run it on a little windows miniPC, under $200, which sits at my mount and I remote into by either wifi or wired network.  There's currently no Linux version, though.

 

I applaud your effort.  But I'm also kindof with Bob -- this exists in a number of software packages already, several of them free, and not requiring complicated hardware.  But don't let us dissuade you -- if you've got a better idea, run with it!


  • bobzeq25 likes this

#7 aa6ww

aa6ww

    Mercury-Atlas

  • *****
  • Posts: 2,783
  • Joined: 23 Oct 2011
  • Loc: Sacramento, Calif.

Posted 17 February 2020 - 01:13 AM

Keep at it. The visual astronomer would use this if it worked and it was very simple.

 

...Ralph

 

 

Yes, but only for AP.
I am thinking more of cheaper/simpler/easier to use solution for visual astronomers.



#8 hcf

hcf

    Viking 1

  • -----
  • topic starter
  • Posts: 755
  • Joined: 01 Dec 2017

Posted 17 February 2020 - 12:16 PM

Well, inspite of Platesolving being so successfully used in AP/EAA, I don't see anyone using it to direct GoTo for visual astronomy.

 

NINA will do the goto/platesolve/sync/adjust cycle with my uncooled, inexpensive guide camera.  It doesn't have to be an expensive astro camera, just any old ASCOM-driven camera.

Do you mean using the guidecam through the guide scope, or the guide cam connected to the main scope? Is this the ASI290MM in your sig? Low cost for AP is still in a very different ballpark than low cost for visual smile.gif. And not having ASCOM /Indi drivers does get in the way of low cost camera solutions (under $100) for both Nina and Indi.

 

NINA will connect to a number of "planetarium" programs.  I connect it to Cartes du Ciel.  I don't specifically know if it will work with Sky Safari.
And no, it doesn't need a Windows laptop.  I run it on a little windows miniPC, under $200, which sits at my mount and I remote into by either wifi or wired network.  There's currently no Linux version, though.

That is actually good news. It means they have some kind of an API to connect to planetarium programs. I see Stellarium listed on their site. Since it is open source, hopefully someone will add a Sky Safari interface.
 

I applaud your effort.  But I'm also kindof with Bob -- this exists in a number of software packages already, several of them free, and not requiring complicated hardware.  But don't let us dissuade you -- if you've got a better idea, run with it!

I am not questioning that there is free software to do this. The Indi ecosystem can do it too, Maybe that is the solution, and they just need to be packaged and setup as a mountside computer which boots up and connects to a tablet planetarium app to do the platesolved assist to goto, Both NINA and Indi do have a large compatibilty list of mounts and cameras.

But it seems inefficient to have to drag in so much AP stuff in for what may be a simple protocol switcher which could be  100 lines of python code and a open source platesolver.


Edited by hcf, 17 February 2020 - 05:28 PM.


#9 lambermo

lambermo

    Apollo

  • -----
  • Posts: 1,103
  • Joined: 16 Jul 2007
  • Loc: .nl

Posted 17 February 2020 - 12:57 PM

I like the LX200 middleware idea.

I'm worried though about timeouts, I mean the client program does not know your middleware is iterating towards an acceptable solution and that may take time.

-- Hans


  • hcf likes this

#10 hcf

hcf

    Viking 1

  • -----
  • topic starter
  • Posts: 755
  • Joined: 01 Dec 2017

Posted 17 February 2020 - 01:08 PM

I like the LX200 middleware idea.

I'm worried though about timeouts, I mean the client program does not know your middleware is iterating towards an acceptable solution and that may take time.

-- Hans

Yes, timeouts can be a problem. For the PS-G2 on my DIY motorized mount, I had to do the platesolve control iterations on a separate thread to prevent this (otherwise Sky Safari timesout and disconnects).




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics