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LX85 AudioStarII remote control via external tools, ASCOM

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#1 barnold84

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Posted 29 August 2021 - 11:46 AM

Hi,

I‘m currently trying to automate the LX85 mount with its AudioStarII handbox. My control software is NINA and I‘ve installed the generic Meade ASCOM driver. A few specific questions but feel free to chime in with general comments or suggestions:
- How well does the ASCOM platform and drivers cover the functionality from the handbox?
- Do I need to run an alignment when the handbox is started or can I turn the mount on in zero/polar home position and directly send a slew command to a reference star with a sync to update the internal model?
- What’s the guide rate of the scope? Is it 0.5 sidereal? Can it be set in the handbox or somehwere?
- What type of guiding would I select in the ASCOM driver, pulse guiding or guide by slew?

I have plenty more questions but let me stop here in case you have suggestions which would send me in a whole different direction?

Cheers and cs!

Björn

#2 Piet Le Roux

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Posted 30 August 2021 - 03:42 AM

I have heard of a Autostar II handbox, the LX200 use them, But not of a AudioStarII handbox. The LX85 use a Audiostar controller. 



#3 barnold84

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Posted 30 August 2021 - 04:01 AM

You’re right. It’s a mistake from my side. It’s the AudioStar handbox.

#4 michael8554

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Posted 31 August 2021 - 07:50 AM

"- How well does the ASCOM platform and drivers cover the functionality from the handbox?"

 

The Meade ASCOM Generic Driver only talks to the mount motors, for Guiding purposes mostly.

 

It will supply the Guide Rate, and RA and Dec positions.

 

Add a Virtual Handbox on a PC and you get the full Autostar, and maybe Audiostar, functionality.

 

"- Do I need to run an alignment when the handbox is started or can I turn the mount on in zero/polar home position and directly send a slew command to a reference star with a sync to update the internal model?"

 

If you have previously fully aligned the mount and then PARKed and switched off.

 

Then you can switch on, enter time and date, then GoTo a star and SYNCH.

 

"- What’s the guide rate of the scope? Is it 0.5 sidereal? Can it be set in the handbox or somehwere?"

 

If its like a LX200GPS then Guiderate defaults to 0.66, but can be altered in Setup / Telescope / Guiding Rate.

 

"- What type of guiding would I select in the ASCOM driver, pulse guiding or guide by slew?"

 

The Meade ASCOM Generic Driver has no selection, it's pulse guide by design.



#5 barnold84

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Posted 31 August 2021 - 08:17 AM

Thank you for your reply! I still have some more questions:

 

"Add a Virtual Handbox on a PC and you get the full Autostar, and maybe Audiostar, functionality."

Do you have a link for me, where I could download this or where I can find some instructions?

 

"If you have previously fully aligned the mount and then PARKed and switched off.
Then you can switch on, enter time and date, then GoTo a star and SYNCH."

 

That means that if I haven't parked the scope, I'll need to do an alignment procedure for the driver to know the correct position (and possibly side of pier?)

 

"The Meade ASCOM Generic Driver has no selection, it's pulse guide by design."

The version that I downloaded is 1.3.1361, dated Aug/4 2021. I can see a dropdown which gives me more than just pulse guiding.

 

Björn



#6 michael8554

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Posted 31 August 2021 - 08:27 AM

For a Planetarium and Virtual Handbox, download Autostar Suite from the Meade site.

 

Might be on a CD supplied with the mount ?

 

"The Meade ASCOM Generic Driver has no selection, it's pulse guide by design."

The version that I downloaded is 1.3.1361, dated Aug/4 2021. I can see a dropdown which gives me more than just pulse guiding.

 

Then you should select pulse guiding.



#7 atsidor

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Posted 13 September 2021 - 09:45 AM

Björn, have you had any success getting up and running with your LX85 and latest Meade ASCOM generic driver? I am running the same setup. However, I use APT instead of NINA.

 

As alluded to in another of my threads, I am having trouble getting APT to do a small nudge to center an object after a plate solve. Instead, it executes a full go-to and ends up not really making much progress toward centering. Anyway, curious to know your results, if any, so far.



#8 barnold84

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Posted 13 September 2021 - 09:54 AM

Hi,

 

We didn't have time to do further tests. In the meantime, I had been in touch with Andrew (OzAndrewJ) and he confirmed to me that this full-goto is normal behavior. I haven't made any further tests but there is one thing I want to check: according to the official LX200 protocol, there is a precision mode (not to be confused with the precision slew, where the mount approaches a close-by star before making the final move). If one doesn't use precision mode, RA and Dec are only accurate down to minute/arcmin. In precision mode, also seconds/arcseconds should be considered. Hopefully this gives the final accuracy. This setting is done in the ASCOM driver setting before connecting the mount.

 

But besides this our LX85 has a bad Dec backlash which I should try to fix. However, I've a feeling that we'll change the mount for some other brand (Skywatcher or iOptron) in the near future.

 

Björn



#9 atsidor

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Posted 13 September 2021 - 10:40 AM

Thanks Björn. Yes I was curious about this precision setting in the ASCOM driver as well. I thought it was related to the high precision slew you mention. Did not realize there was another "precision" mode. I've always left that setting to be "unchanged" in the driver set up. However, I can do some playing around to see what it does.

 

I also wonder if you pre-select a certain slew rate on the handbox (say, 1 or 2), if it would then affect a resulting move commanded by the ASCOM driver? I am completely ignorant here but just a random idea I will try.



#10 atsidor

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Posted 17 September 2021 - 10:18 AM

A few updates on below. No success. Has anyone been able to get an AudioStar-controlled mount to do "near" go-tos without going through the full go-to slewing? Not sure if there is a driver/control software combo that does this successfully.

 

 

Thanks Björn. Yes I was curious about this precision setting in the ASCOM driver as well. I thought it was related to the high precision slew you mention. Did not realize there was another "precision" mode. I've always left that setting to be "unchanged" in the driver set up. However, I can do some playing around to see what it does.

I tried forcing to "high precision" in the driver setting but did not appear to have any effect on go-tos as far as I could tell. But pretty limited testing so I don't want to say anything definitively.

 

 

I also wonder if you pre-select a certain slew rate on the handbox (say, 1 or 2), if it would then affect a resulting move commanded by the ASCOM driver? I am completely ignorant here but just a random idea I will try.

This also did not have any effect on go-tos. 



#11 OzAndrewJ

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Posted 17 September 2021 - 06:23 PM

Gday atsidor

You are flogging a dead horse.

If the ASCOM driver is asked to "goto", then it sends a goto to the mount

and the mount will re do the full process.

What you need is something in the calling app ( not ASCOM driver ), that knows that when close

it should pulseguide to get there, vs do a short goto.

 

As to precision, the setting only changes how data is interchanged/reported with the real world,

it has no effect on the internal accuracy used for gotos.

Andrew Johansen Melbourne Australia



#12 atsidor

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Posted 18 September 2021 - 06:39 AM

Gday atsidor

You are flogging a dead horse.

If the ASCOM driver is asked to "goto", then it sends a goto to the mount

and the mount will re do the full process.

What you need is something in the calling app ( not ASCOM driver ), that knows that when close

it should pulseguide to get there, vs do a short goto.

Understood and makes sense. I hoped there was maybe a simple setting I was missing :) I reached out to APT developers to see if that is something that could be done there.

 

As to precision, the setting only changes how data is interchanged/reported with the real world,

it has no effect on the internal accuracy used for gotos.

Andrew Johansen Melbourne Australia

Ok good to know - always wondered what that meant. Thanks again Andrew!



#13 atsidor

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Posted 22 September 2021 - 10:28 AM

Another update here for what it's worth. I did some more extensive checking of this slewing behavior in Stellarium with the Telescope Control plugin. I connected to the mount through the ASCOM Meade Generic driver.

 

It seems like the odd slewing behavior is limited to near the meridian. The large slew only occurs if the target is roughly +/- 30 deg in RA from the meridian. If the target is within that "band", the initial slew will take it away from the meridian, first placing the pointing location outside that band and then it will slew back to the object. Thus, in theory, if you are at a target on the meridian, it will first slew away by ~30 deg (2h) in RA and then back to your target. This behavior appeared to be pretty consistent across two separate sessions.

 

I tried a 2nd ASCOM driver for kicks (Meade Universal) and it also exhibited the same behavior. So is this a setting or something internal to the mount? Is there anything to be done?

 

Sorry I've hijacked this thread. Crossing my fingers that the Meade experts here will have some insight laugh.gif

 

Edit: I should add, outside this ~60 deg band, goto slews go more or less directly to the target. And for "near" targets, there are small, low speed pulses as I would kind of expect.


Edited by atsidor, 22 September 2021 - 10:34 AM.


#14 OzAndrewJ

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Posted 22 September 2021 - 03:46 PM

Gday atsidor

No idea why it would happen near the meridien

As i noted, the mount first aims for a target a set time behind the target.

This results in longer distances as at the equator, but shouldnt be affected by the meridien.

 

Andrew Johansen Melbourne Australia



#15 atsidor

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Posted 22 September 2021 - 04:49 PM

I guess the next thing would be to try this test disconnected from a PC using only the handbox to see if it's something with the ASCOM drivers/commands or something within Meade's code. I'm kind of stumped.

 

Is there some logging output that would be helpful for diagnosing?


Edited by atsidor, 22 September 2021 - 04:49 PM.


#16 OzAndrewJ

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Posted 22 September 2021 - 05:34 PM

Gday atsidor

 

re logging, nope, as goto commands are send and forget.

Unless you open the mount and put logic analyser leads onto the internal comms

you wont get anything.

Andrew Johansen Melbourne Australia



#17 atsidor

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Posted 23 September 2021 - 09:31 AM

Gday atsidor

 

re logging, nope, as goto commands are send and forget.

Unless you open the mount and put logic analyser leads onto the internal comms

you wont get anything.

Andrew Johansen Melbourne Australia

I'm beginning to think that this is "normal" behavior for this mount and not some sort of errant issue. The go-tos are fine in all cases (i.e. you get to the target eventually). But within this band near the meridian, it takes a circuitous route to get there. From my observation in those cases, it goes something like this

 

1. Slew away from the meridian in RA (at high speed)

2. Slew most of the DEC to the target (at high speed)

3. Slew back toward the meridian in RA (at high speed)

4. Execute the final go to approach (at lower slew rate) targeting a point slightly ahead of the object, as you mentioned, and then wait for it to "catch up"

 

I tried with the handbox only this morning (no PC connection) and observed exactly the same behavior, so it is something internal to how the mount handles go-tos. Is it some sort of collision avoidance behavior? Safety mechanism? I really don't know at this point. 

 

Another observation: if I'm outside of this meridian band, and I execute a go-to twice on the same object (i.e. select object -> go-to -> wait to arrive at target -> go-to again), it doesn't move the scope. This seems to be different behavior than other Meade mounts based on what I've read elsewhere on the forums.

 

Sorry for the long post. I am very intrigued to figure this out. I'm going to try posting something in the Mounts forum to see if I can solicit feedback from other LX85 users as well.


Edited by atsidor, 23 September 2021 - 09:32 AM.



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