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LX200 GPS Alignment and Updating Woes

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#1 Sean Norwich

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Posted 10 June 2021 - 05:20 PM

Hi there,

 

Apologies if this is a long post - I have a complex problem which I'd like to explain clearly.

 

I have a couple of issues with my LX200 GPS which may or may not be related to each other, and I'm hoping someone has a clue what is happening - as I don't !

 

I've seached all through various forums and other online sources, but I have no idea what's happening and how simple, complex or expensive the solution might be. I'd be eternally grateful if anybody recognizes what's happening.

 

My scope

 

- 15 year old 10" LX200 GPS, with an Autostar 2, running software version 2.0i.
- Recently pier mounted in a new observatory.
- I moved house and it's been in its box for 3-4 years until now. It hasn't had a lot of use as I was always working away.
- On a wedge and manually aligned North pretty well.

 

The issues:

 

Alignment:

 

- After 2-star aligning to Arcturus then Altair, for example, if I then try to GoTo say M57, the scope points 20-30 degrees away-  ie nowhere near the selected object. If I then try to go back to Altair, again I end up miles away.

- On start-up, GPS position acquision can take 10 mins and then isn't always successful.

 

Settings Loss:

 

- Even after Parking the scope before powering down, Date and Time are not saved upon reboot. Lat / Long / Site / Polar Mount / some other settings ARE saved though - which seems strange.

 

 

What I've Done:

 

As the scope has been out of use for a while, I changed the little CR2023 battery on the motherboard. If it had gone flat, I reasoned this could be why some settings aren't saved, which might then throw the whole alignment out.
- It didn't make any difference

 

I then reasoned that if the firmware / GPS software is out of date, that could be the problem. So I tried to upgrade it.

 

- My Win 10 laptop only has USB ports, so I have to use a USB / serial adapter to connect to the RS232 cable from the scope.
- Tried using both Meade ASU and Starpatch
- Laptop cannot detect the Autostar 2, regardless of what USB serial adapter and RS232 cables I use. I've tried 3 adapters and 2 different RS232 leads, including a Meade AutoSuite lead, which you'd think would work.
- I've downloaded adapter drivers, and connected cables and adapters to the 2 different scope RS232 sockets in every combination. I've also tried selecting different COM ports in the software. Nothing works.

 

So I don't know if out-of-date firmware is affecting positioning, if I have a dead GPS module - or both. Or there could be something else ?

 

I'd be eternally grateful for any help to point me in the right direction (pun intended...) - it's a nice scope and I've built a great little home for it - would be a shame if I can't get it to reliably find the objects I want to see and photograph - but I have no idea where the problem(s) actually lie.

 

Thank you in adavnce for any help offered.
Sean



#2 Bean614

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Posted 10 June 2021 - 05:54 PM

Search this forum for "Week Rollover Issue" from April 2019. It affected ALL older GPS mounts from ALL manufacturers. 



#3 nitegeezer

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Posted 10 June 2021 - 05:57 PM

The LX200 needs to see full RS232 levels on the serial ports, not the lower levels that some adapters provide. I know that the FTDI chipset provides these levels, you USB serial adapters may not.

The LX200 does not have a real time clock, so time is never saved.

Your firmware is definitely out of date and the best way to correct that is StarPatch once you get the serial link working. Until then, go into the Telescope menu and set the GPS to OFF. You will now have to enter time, date, and location manually, but the mount should work correctly.
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#4 michael8554

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Posted 11 June 2021 - 05:36 AM

If it's permanently mounted, do you need GPS ?

 

The mount will work correctly without an Update if you disable GPS in Setup / Telescope / GPS Alignment.

 

Then switch off, switch on, enter time and date manually, no time wasted waiting for the GPS to do that for you.

 

Do you have the Site Lat. and Long. set correctly ?    Setup / Site

 

Are the USB-to-RS232 Adapters showing up in Windows Device Manager, with no errors ?

 

Which COM port number is showing in Device Manager ?  Try setting it to 3 or 4. 

 

Is the plug for the RS232 port on the mount 6-pins wide ? (Meade #507 cable).  The 4-pin wide plug  (Meade #505) will work if inserted centrally.

 

Download OzAndrewJ's  "MyScope"  software, which on startup searches for a working COM port:

 

http://members.optus...om.au/johansea/


Edited by michael8554, 11 June 2021 - 05:49 AM.


#5 Sean Norwich

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Posted 11 June 2021 - 05:57 AM

Hi there,

 

Thank you so much for all your input !

 

I obviously had a few misunderstandings about clocks being saved etc etc so thaks for clearng those up - troubleshooting is easier if you know exactly what's supposed to happen and not happen.

 

I've ordered a new lead to connect with the telescope and handset as the lack of connectivity probably has to be sorted first.  Once I've got the Autostar 2 updated, you guys are probably right - these issues will all go away.

 

Chris Carlson at Pixsoft has been really helpful wrt the connectivity and port issues. My laptop shows connection to COM 3, but I can't get any old or new drivers to work. So I'll get a UGreen lead plus one of Chris' USB-ASTAR leads, so between them one should work.

 

Chris also suggested an application called HyperTerminal to see if the PC and the handset can talk to each other, eliminating cable issues and other COM port bugs.

 

Thanks again guys - and when I've finished painting the new observatory I'll post some pictures in the relevant section on CN.

 

Best regards

Sean



#6 LoveChina61

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Posted 11 June 2021 - 05:49 PM

Concerning the alignment issue, it has long been known that the LX200 GPS scopes will have a malfunction when doing the 2-star alignment. Since your scope is mounted on a pier, just do the 1-star alignment and you are good to go!

Mike


Edited by LoveChina61, 11 June 2021 - 05:50 PM.


#7 Sean Norwich

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Posted 12 June 2021 - 01:59 PM

Hi Guys,

 

I got hold of a UGreen DB9 USB to RS232 serial lead today and it's worked a treat ! Installed the drivers on the Win10 laptop, connected to the telscope and it conected straightaway through COM4 - it was the other serial leads I tried that were obviously the issue.

 

I now have v4.2 on the Autostar 2 and will try out an alignment / guiding test tonight.

 

Many thanks for all your help - not only with the IT bit, but I also understand better now how the scope does what it does, and the information it uses (and doesn't use) to align and guide.

 

The manual only explains so much, but once I have a functioning telescope I can have a play with it and fully see how it works.

 

Thanks again !

Sean



#8 OzAndrewJ

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Posted 12 June 2021 - 05:39 PM

Gday Sean

 

What version of 4.2????

ie did you load 4.2l using Meades ASU

or the patched 4.2g using Starpatch???

Several people have reported odd things happening with aligning in 4.2l

 

Andrew Johansen Melbourne Australia



#9 Sean Norwich

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Posted 13 June 2021 - 06:27 AM

G'Day Andrew,

 

(I was nearly a Ten-Pound-Pom myself as a small kid but the family stayed in the Uk...)

 

Anyway I used Starpatch and Autostar now has 4.2g loaded onto it.

 

I tried the alignment last night without much success:

 

 - I put in my actual local time, the date andput Daylight Saving on, as it's currently British Summer time here.

 - I used Arcturus in 1 star alignment mode, with the GPS turned off.

 - Centered on Arcturus and hit ENTER to center it.

 - Then tried GoTo Altair, but again I was 15-20deg 'behind' Altair (ie where Altair would have been an hour or so earlier...

 

 This got me thinking (always dangerous...) - perhaps I'm getting the time settings wrong, and the scope is slewing to where the GoTo object was an hour earlier ?

 

So I then repeated alignment several more times -  adjusting the time by an hour, Daylight Saving on and off, to see if the scope would slew to Altair correctly, but no joy.

 

With GPS turned off, the scope relies on accurate time and date. The date is impossible to get wrong, but I then wondered if I was inputting the time incorrectly ?

 

So my next question is - do you

 

1 - enter the time in UT, then enable Daylight Saving, or

2 - enter the local time (currently UT+1 hr here) and enable Daylight Saving 

 

My lat and Long are correctly entered and off Google Maps - I don't know what else could be causing the GoTo errors.

 

Thanks

Sean



#10 michael8554

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Posted 13 June 2021 - 10:31 AM

Hi Sean

 

Now that you have updated, have you turned GPS back on ?

 

If you then manually enter time and date i believe you will confuse the mount.

 

If you have GPS turned OFF:

 

The first message on the Autostar is DST ON or OFF

 

During BST select YES, and then enter the time from your wristwatch HH MM, you can choose AM,  PM, or 24Hr format

 

Meade sensibly avoids US and UK date confusions, so next you enter 13 June 2021

 

First time out after an update you might have to GoTo and centre several stars to get a wide Star Alignment, say Deneb, Spica, and Regulus.

 

Andrew could advise on best Star Alignment method.

 

Then PARK.



#11 OzAndrewJ

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Posted 13 June 2021 - 05:47 PM

Gday Sean

As you are polar mounted, and one star aligned, the accuracy of Gotos is totally dependent

on how well the "mechanical" alignment of the RA axle is.

Have you drift aligned to see how accurate the mechanical alignment is???

If so, and the GPS is OFF, you need to manually enter your local date/time

The mount will convert this to UTC internally for its calculations by using the current setting of the sites timezone and DST setting.

The quickest way to confirm the data is correct is to use the secondary menus in the handbox.

Go to the LST screen and read out what it says,then compare this to a web based app for your site.

If the two dont match, then possibly something is wrong.

 

Do you ever connect a PC app after aligning???

There is a known problem if you let an app change the date/time after aligning

so pls confirm thats not happening

 

Andrew Johansen Melbourne Australia



#12 Sean Norwich

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Posted 14 June 2021 - 02:18 PM

Hello Andrew,

 

Thanks for your reply - it's cloudy so I haven't been able to retry aligning over the last couple of nights.

 

 - I do have a PC connected, but I've just been running the camera control software for my Canon 450D, and I'm not aware of anything running on the PC that may be adjusting the Autostar's time setting.

 

 - I haven't got as far as drift aligning the RA drive yet - could RA drive mechanical error cause a 15-20 deg error when slewng about 45 deg from Arcturus to Altair ?

 

 - By the way, what does DST mean and how do I look it up as you suggested ?

 

Many thanks

Sean



#13 MikeBY

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Posted 14 June 2021 - 04:00 PM

15 degrees off is almost certainly a DST (Daylight Savings Time) or Timezone error. Perhaps your Timezone setting has the wrong sense  (+ or -). 
Having the wrong sense when you are at UT -1 (lets say you put in +1) will give you a 30 degree pointing error. Subtract a Daylight Savings Time setting error and

you are at 15 degrees of error. 

 

Check the site Timezone and Daylight Savings time settings and correct as necessary. 
I find that after changing these settings it's best to power off, set the scope at RA 0/0 , DEC 90 and then power up and start the alignment over. 
 



#14 Sean Norwich

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Posted 15 June 2021 - 03:34 AM

Hello Michael,

 

Thanks for your help - I have the GPS turned off now, so the only date and time the scope can use are the ones I manually enter.

 

I've used the local time (ie off my wristwatch) and applied DST as it's British Summer Time here in the UK, so 1 hour ahead of UT.

 

My timezone is 0 as I'm in the UK.

 

I thought too that an approx 15deg error looked suspiciously like being an hour ahead / behind of a star's position, but although I tried to adjust for this on my last attempt, the sky clouded over before I could really rigourously go through the full alignment process. I'll try it over the next couple of nights, weather permitting, and see if it works.

 

Cheers

Sean



#15 michael8554

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Posted 15 June 2021 - 07:23 AM

"- By the way, what does DST mean and how do I look it up as you suggested ?"

 

DST is Daylight Saving Time, what we call BST in the UK

 

Did you mean " what does LST mean ?"  Local Sidereal Time.

 

https://www.iiap.res...ipt/calclst.php

 

Check your Site setting, the handbox settings for Norwich should be in this format  52 06 North, 001 18 East.

 

I assumed that as you are pier mounted, you were Polar Aligned.

 

So PA before any further steps.




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