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

Unreliable Starsense

  • Please log in to reply
15 replies to this topic

#1 Gamewarden

Gamewarden

    Mariner 2

  • -----
  • topic starter
  • Posts: 217
  • Joined: 20 May 2019
  • Loc: Centreville, Ontario, Canada

Posted 19 September 2020 - 09:42 AM

Folks

I have a Celestron 6SE and use Starsense for alignment. I also have used CPWI, Skyportal and the HC. I connect my scope to my laptop with a USB 2 cable to HC. Point my scope north, level along with tripod level. I can get Starsense to align no problem most times. Yes date, time and location are correct.

 

My problem is Star sense is very unreliable. 50 percent of the time it works and then suddenly it will slew my scope to zenith and jam my camera. This seems to be completely random. Sometimes it happens about the 3rd slew when aligning, sometimes I have been slewing to different objects for an hour going along nicely and then the next slew it will just travel to zenith . I think it would keep flipping but my camera will jam before it goes straight through.

 

Just asking if others have found this to be true with their Starsenses. Very frustrating when you are operating remotely and cannot see your scope.

 

Its just not trustworthy.

 

Maybe once I get an alignment I should unplug SS to see if this is really the problem or maybe it is my mount????

 

Thanks Mark


Edited by Gamewarden, 19 September 2020 - 09:45 AM.


#2 Maritime

Maritime

    Vostok 1

  • *****
  • Posts: 143
  • Joined: 19 Aug 2020

Posted 19 September 2020 - 09:52 AM

How do you power it?  That sounds like a voltage issue.



#3 terrypaula

terrypaula

    Ranger 4

  • *****
  • Posts: 330
  • Joined: 20 Feb 2018

Posted 19 September 2020 - 09:58 AM

First I'd make a concerted effort to purchase a red flashlight for those dark remote areas.

Are you saying that you can't set the limits on the scopes movements or are you saying it just takes off all by itself to Zenith?  I've been using a StarSense unit for a long time and I don't believe I've seen an se mount do what your saying.  Can you elaborate a little bit more?  Is CPWI and the firmware all up-to-date? This really fixed all the problems I had with mine.recently I've started actually using mine for AP.



#4 Tfer

Tfer

    Vostok 1

  • -----
  • Posts: 191
  • Joined: 05 Sep 2019
  • Loc: Northern Alberta, Canada

Posted 19 September 2020 - 10:22 AM

The movement described only happened to me once, and it was during alignment.  Scope did it’s first positional move, took the pic, and it went straight past the zenith... 

 

it was my fault.
 

I’d forgotten to press the PowerTank button twice.  The first press of the power button just checks power level; the second press causes the lights the activate in sequence, and power flows to the output.  I’d inadvertently powered the scope with the AA batteries that I keep installed as backup, in case the cord comes unplugged.


Edited by Tfer, 19 September 2020 - 10:22 AM.


#5 terrypaula

terrypaula

    Ranger 4

  • *****
  • Posts: 330
  • Joined: 20 Feb 2018

Posted 20 September 2020 - 10:35 AM

I forgot about those little AA batteries myself, did I ever feel stupid for not removing them when I set things up.  I also find that most of my problems are my fault; either by not double-checking the cable connections or not powering something sufficiently. As a general rule I learn something new about astronomy and my equipment every time I am able to get under the stars.  I always, while in my dark area, have a red flashlight glowing just a little 5 watt Red LED Flashlight can save an astronomer a lot of money.  I saved me from a very bad cord wrapping I found happening one night.  I know from using both SE or Evolution mounts you have to keep track of your clearances and cords.

 

I found that by having the wireless dongle and the computer com cable connected to the mount will give some real head scratching issues.  I found out you can't have both connected it at the same time it seems to confuse CPWI as to what to use for the connection and about half way through alignment the system crashes.

It would be nice to align the scope using the handset buttons rather then the computer screen.  It's rather difficult to use CPWI's directional keys Not everyone uses a camera to do their star alignments like me.  For us who don't have a big income buying a camera for alignments aren't going to break the bank anymore. You don't need much of a camera for star alignments and I truly believe it's worth the extra expense.  I decided it would be a good idea for me to purchase an inexpensive hand paddle and run it through the mount's auto guide port.  It's a bunch easier to do the alignments now with my physical limitations.

My StarSense after calibrating to just one star, accurately, is good to go for the whole season using it for almost all visual observing.  (I pick the biggest and brightest star I can for a calibration star that doesn't set in my area.)  For AP purposes you really need to have as accurate NCP alignment the StarSense has that capability using both ASPA and the StarSense User Auto-Align together and I calibrate it to at least 3-stars as far apart as I can.  It's not all that much more time involved, I usually have the whole routine done in about 20mins.  First I perform as accurate of a manual polar alignment as I can with the mount's polar scope.   Then I perform an auto align followed by the ASPA.  On top of that I perform another auto align to check for errors.  But by aligning the mount this way I've never seen long stars or crescent stars in my images.

It would also be nice if we didn't have to use a Celestron focuser, that doesn't fit refractors



#6 robbieg147

robbieg147

    Messenger

  • -----
  • Posts: 424
  • Joined: 23 Mar 2020
  • Loc: Kent, England

Posted 20 September 2020 - 02:41 PM

I always power my mount separately from everything else, I recommend making sure it has plenty of power. I have never seen Starsense do this, sounds like the encoders are resetting due to momentarily loss of power?



#7 Gamewarden

Gamewarden

    Mariner 2

  • -----
  • topic starter
  • Posts: 217
  • Joined: 20 May 2019
  • Loc: Centreville, Ontario, Canada

Posted 20 September 2020 - 06:03 PM

I power my mount with hydro so no problems there. Yes the mount will work for sometime perfectly and start another slew and it will head for zenith. It is very unreliable throughout the night. It has done this while using CPWI to control the scope and with just using the HC. There is no traceable action I can think of that causes this. I guess I will just have to keep eliminating things one at a time to discover the cause, I never use batteries always hydro. It is getting colder and planning to move inside so I would like to get this sorted.

 

I am thinking of putting some kind of low power lights on the mount so I van watch it and try to prevent it from hitting at zenith. I can usually see in CPWI that my reticle just disappears and I will know the mount is going straight up.

 

Iget the mount aligned usually before this happens and get good goto results so I think that eliminates the date time etc wrong entrie.

 

Has this happened regularly to anybody with an SE mount???



#8 Tfer

Tfer

    Vostok 1

  • -----
  • Posts: 191
  • Joined: 05 Sep 2019
  • Loc: Northern Alberta, Canada

Posted 21 September 2020 - 11:26 AM

The only time the StarSense is active is during alignment.  It does no pointing or tracking after that.

If your issues occur after you read "Alignment Successful." it's the mount, not the StarSense.



#9 robbieg147

robbieg147

    Messenger

  • -----
  • Posts: 424
  • Joined: 23 Mar 2020
  • Loc: Kent, England

Posted 21 September 2020 - 03:37 PM

My problem is Star sense is very unreliable. 50 percent of the time it works and then suddenly it will slew my scope to zenith and jam my camera. This seems to be completely random. Sometimes it happens about the 3rd slew when aligning, sometimes I have been slewing to different objects for an hour going along nicely and then the next slew it will just travel to zenith . I think it would keep flipping but my camera will jam before it goes straight through.

 

As said above if you have been slewing successfully to different objects for a hour or so when the problem occurs then this is not being caused by Starsense.

 

I assume you are doing a Starsense auto align? in this case Starsense will goto the same positions each time avoiding zenith while aligning, it can only be the mount sending the scope to zenith?

 

If you have plenty of power to the mount then sounds like it could perhaps be a dodgy cable somewhere?



#10 terrypaula

terrypaula

    Ranger 4

  • *****
  • Posts: 330
  • Joined: 20 Feb 2018

Posted 22 September 2020 - 12:28 PM

I really don't believe it's your StarSense causing your problem.  Last night I did my alignment slewed to the first star to chack the alignment.  It looked just as it should, centered.  I put the lens cap on my StarSense camera and used the unit, without an issue, for the rest of the night.  The only time you should need it to use the StarSense camera after your initial alignment is if you want to add a target to your alignment/calibration.

 

I'd be making sure the power isn't running low or the power cables aren't making contact properly; strange things can happen to an under or intermittently powered system.

 

How are your settings if it has to do a meridian flip?  When I have to cross the meridian my scope takes the LONG way around and avoids Zenith totally.  What are your settings for doing a meridian flip??

 

The StarSense unit should have t the very least 5amps continuous power.


Edited by terrypaula, 22 September 2020 - 12:54 PM.


#11 audioengr

audioengr

    Ranger 4

  • *****
  • Posts: 358
  • Joined: 09 Aug 2020

Posted 22 September 2020 - 12:51 PM

When you start Starsense, have you pointed the Az roughly at polar north, set the Axis to 0,0 using the HC and loosened the Alt clutch and put the OTA at horizontal?  I think it might expect these things, otherwise it does not know how you have the OTA aimed to start with.



#12 Michael_Swanson

Michael_Swanson

    Author of The NexStar Users Guide

  • *****
  • Vendors
  • Posts: 3,256
  • Joined: 23 Apr 2003

Posted 23 September 2020 - 11:49 PM

Hi Mark,

 

It definitely sounds like a power issue.  You say you are using "hydro" - what exactly are you using to power your scope?  Are you sure the power connector is 5.5mm outside diameter and 2.1mm inside diameter?  If it is 2.5mm inside diameter (somewhat common) that loose connection will definitely cause problems.  Even some 5.5/2.1mm connectors are too short (barrel too short) and cause issues.

 

Best regards,
Mike Swanson
https://www.NexStarSite.com



#13 Tfer

Tfer

    Vostok 1

  • -----
  • Posts: 191
  • Joined: 05 Sep 2019
  • Loc: Northern Alberta, Canada

Posted 23 September 2020 - 11:54 PM

Hi Mark,

 

It definitely sounds like a power issue.  You say you are using "hydro" - what exactly are you using to power your scope?  Are you sure the power connector is 5.5mm outside diameter and 2.1mm inside diameter?  If it is 2.5mm inside diameter (somewhat common) that loose connection will definitely cause problems.  Even some 5.5/2.1mm connectors are too short (barrel too short) and cause issues.

 

Best regards,
Mike Swanson
https://www.NexStarSite.com

In Ontario, “hydro” is the term used for simply plugging into the wall.  120hz mains power.



#14 Michael_Swanson

Michael_Swanson

    Author of The NexStar Users Guide

  • *****
  • Vendors
  • Posts: 3,256
  • Joined: 23 Apr 2003

Posted 24 September 2020 - 12:07 AM

Interesting - I presume the local power plant in Ontario is primarily hydroelectric.

 

Mark - AC power adapters are notorious for inspiring confidence while letting you down on the job.  What is the DC power rating of the AC adapter and let us know about the dimensions of the connector (as discussed in my previous message).

 

Best regards,
Mike Swanson
https://www.NexStarSite.com


  • Tfer likes this

#15 rnyboy

rnyboy

    Ranger 4

  • -----
  • Posts: 387
  • Joined: 29 Oct 2019
  • Loc: Rochester, NY (Bortle 7/8)

Posted 27 September 2020 - 09:05 AM

Hi Gamewarden...  So far so good with the StarSense and SE mount.  Lately I'm getting sub-4' rms errors and even high-mag gotos are pretty good with Saturn and Jupiter usually just outside an f/25 fov, and normally a bit high to boot, so some kind of alignment bias it seems.  The last calibration of my StarSense was done on a star at f/20 using SharpCap's virtual reticle for centering, so the StarSense to OTA calibration should be pretty darn good right now. 

 

Like Mike S. said, maybe worry about power.  One time I thought I was running on the AC adapter and had the cigarette DC plugged in instead so I ran down the mount internal batteries when I was first testing out the StarSense inside the house due to all the slewing StarSense does; and once those batteries were low the mount really did crazy things.  I actually called Celestron thinking there was likely something wrong with the then new StarSense and while we were exchanging emails I discovered the plug error and, of course, that solved the problem.

 

It took a fair amount of time to run the batteries down even with StarSense plugged in and trying to do an alignment so I would think if your batteries are good that even if the AC  does have an issue I would think the power to slew the mount and operate StarSense would now be coming from the batteries.  I had pretty much brand new Li-batteries in the mount at the time and although they have a lot of amp-hours I do have some doubts about their voltage compared to alkaline batteries but they seemed to work OK for about an hour or so with that excessive slewing that was going on.

 

Maybe the cheapest test would be to run the scope of an external DC supply or purchase a new AC adapter and see if you still get the problem, if not than just chalk it up to a faulty AC PS.  If I understand your problem description it doesn't sound like a StarSense problem because once the model is established StarSense is doing nothing but sitting on your OTA and the gotos are being done by the mounts internals using the StarSense model generated when you did the initial alignment. 



#16 Noah4x4

Noah4x4

    Soyuz

  • *****
  • Posts: 3,779
  • Joined: 07 Apr 2016
  • Loc: Colchester UK

Posted 27 September 2020 - 01:25 PM

The two primary causes are likely to be power (as identified) or WiFi (or USB) and the OP mentions both. 

 

I have found Celestron WiFi unreliable in the UK. That includes experience of Evolution and first, second and third generation SkyPortal Dongle devices. The problem is that the 2.4Ghz channel is now too cluttered and levels of interference in urban areas can overwhelm Celestron WiFi. I now control my scope using two computers networked over the 802.11ac  5Ghz channel embracing Windows Remote Desktop. Far more reliable than Celestron WiFi.

 

The OP also mentions using USB cable to laptop. USB2 has a maximum length of 14.6 feet (USB3 merely 9 feet) beyond which you need Active/Powered repeaters (which can be hit or miss!). I found control using USB a tad problematic until I reduced the length of my USB cable to laptop. Then eventually switched to having a scope side mini-computer, then wirelessly networked that to a second computer as I have described. 

 

This issue is NOT Starsense since as mentioned before in earlier posts, once it reports 'scope aligned' it has done its job. Wild slews are typically caused by disconnects between scope and control device be these the result of 'lost data packets' when a WiFi stream hiccups or similar loss of connection over (too long) USB. 




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