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INDI Library v1.8.1 Released (09 Sep 2019)

Monthly maintenance release INDI v1.8.1

Celestron AVX - bypass manual interaction on start up

7 months 4 weeks ago 7 months 4 weeks ago by cb245.
cb245
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Celestron AVX - bypass manual interaction on start up #36486
The mount always moved to the indexes without any issues when the command was sent.

The movement to the stop happened during a test slew to a selected object. The mount was pier-west pointing east. The scope was misaligned at this point, but still indicating east. I then selected an object to the west. The mount then slewed westward without performing a meridian flip, this kept the OTA continuing under the counterweight bar until the stop was reached.

During the tests, the HC was not used for any commands to the mount.

The configuration for the time settings was "KStars Updates All Devices". I will need to check the time indicated on the HC in future tests.

Thanks. Hope this helps.


PS - I would be interested in hearing more of you thoughts on how to perform a remote alignment. I may get a chance to field test this weekend. I now have my Raspberry Pi camera driver ported over to Mate, and want to field test it as well.

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7 months 4 weeks ago
ChrisRowland
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Celestron AVX - bypass manual interaction on start up #36498
Thanks for that.

One thing that would help is to report the time when something strange happens. This would help me to find the correct place in the log.

The thing to remember is that this align process does not do an alignment. It recovers the last alignment done assuming that the mount is at the align switch position. This is useful for a permamently mounted mount but less so if you are portable.

I've not thought this through but something that could be worth trying is to do this align then slew to a bright star and use the mount's manual altitude and azimuth controls to centre the star. It may also be worth using the HC to do an undo sync command first. I'm not sure if a sync offset is saved with the alignment.
This process may also work with the Park/unpark process for mounts without switches.
It will be worth levelling the tripod both when doing the real alignment using the HC and when trying to recover this alignment.

I wouldn't expect a precise align, getting within a few tens of arc minutes would be good.

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7 months 3 weeks ago
cb245
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Celestron AVX - bypass manual interaction on start up #36601
I managed to to some more indoor testing tonight. I spent some time trying to reproduce a misalignment situation, but all 'align's were successful, with the exception of one which was not really driver related.

At 21:24, I intentionally launched KStars and aligned before the time updated on the RasPi. This caused KStars to indicate the correct time, but a date of 2/11/16, and the HC retained the pre-updated time and date. At 21:25, I powered down to avoid hitting the limit on the mount. At 21:32, I re-powered the mount from the position near the limit switch, performed the 'align', and the alignment was restored. This time issue was possibly the cause of the issue that I had a couple of days ago. I was testing hibernate and power cycling and not really paying attention to whether the time updated before launching KStars/EKOS.

One thing to note is that it did not matter whether Hibernate was enabled or not when performing the align.

Attached are the logs.

PS - I had the mount cable disconnect at 21:58. At 22:54, connection to the mount was re-established and then a successful align.
Attachments:

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7 months 3 weeks ago
ChrisRowland
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Celestron AVX - bypass manual interaction on start up #36609
Thanks for the feedback, from what I can see this is working. Exactly how good a realignment is will depend on how accurately the index position is reached and the time is set.

The 17-53-02 log shows that the initial time read from the HC was 2016-02-11T11:45:49, offset -5. This could have come from a start up before the Pi time was correct
The time and location are both set from the Pi a little after the initial update is done.

From what I can see the 21:24 log shows the correct times in the log and the time seems to be set correctly but certainly if the Pi has the wrong date or time then these will be sent to the HC.

Changing the time will affect the alignment because for an equatorial mount the mount axis operates in hour angle and it uses the local sidereal time - computed from the longitude and time - to convert from that to right ascension.

The StarSense HC won't accept changes to the time or location after it is aligned because of this, if you force it then it requires a new alignment.

The mount can do an alignment regardless if hibernate is called or not, with hibernate the current position of the mount axes is remembered and restored, with align the mount axes are assumed to be at the index position. What I do is check that the HC version supports the align command and that the mount is a CGX or CGX-L

What I'd like is to have the ability to do an align for mounts without switches by prompting the user to move the mount to the index position. I can do this with the ASCOM driver by showing a message box asking the user to do this but there doesn't seem to be any comparable way to do this in INDI.

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