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INDI Library v1.8.5 Released (19 Apr 2020)

April 2020 release of INDI Library v1.8.5 introduces new drivers while providing fixes and improvements to existing devices and core framework.

Re:Figuring out a meridian flip?

2 months 1 week ago
hy
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Re:Figuring out a meridian flip? #50991
Also, FWIW, here's a screenshot of my Ekos Mount Tab right now: photos.app.goo.gl/ieY2mLgo8j4MZR5q7
You can see that a Meridian Flip is planned in 46 minutes. Really, it should happen when the next image capture completes after 46 minutes.
You can see the hour angle (HA) is -34 minutes, which means, in 34 minutes the telescope will be pointing at the Meridian, but I've told it
to perform the flip 0.2 hours after that, so it won't flip for 46 minutes.
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2 months 1 week ago
TallFurryMan
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Re:Figuring out a meridian flip? #50993
In the Mount tab, you can set at which time offset around the meridian you want the flip to occur, in RA hours.

If you want the mount flip to occur when the object you are tracking crossed the meridian half an hour ago, type 0.5 in.

It is important to remember that there is no "do a flip" procedure. Ekos will simply ask the mount to slew to the target again, and the mount driver will choose the right orientation based on the current object position in the sky.

Because the mount may not be perfectly polar aligned, or the geographical position may not be precise enough, it is important to provide a RA delay that is large enough. If it isn't, in the general case, Ekos would ask a slew but the mount would retain the original orientation per its own sidereal time calculation. Afterwards, no further slew would be requested and there would be a risk that the scope hit the pier.

-Eric

HEQ5-Pro - Atik 314E - Orion ED80T - DMK21 on Orion 50mm
DIY 3D-printed Moonlite and FWheel RGB/LPR
KStars and indiserver on two Atom 1.6GHz 1GB RAM Linux, VPN remote access
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1 month 1 week ago
mpaul73
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Re:Figuring out a meridian flip? #52370
Still having issues with Meridian Flip. Left the scope running to capture 80 subs last night. When I got up this morning it had only captured 56. Looked outside to see the camera smashed into the mount and and a "click" "click" "click" sound coming from the mount. I am hoping it's ok I have not tested it yet.

I was shooting M63. While I was still up the HA reading as something like -00h 50m 10s. I checked the "Flip if HA" if more than 0.20 and selected the hour button. I thought I was all set to get some sleep and get my 80 subs but I guess not! Any ideas ANYONE what went wrong?

Equipment: Skywatcher HEQ5 - Stellarvue 80mm access - Canon 6D (unmodified) - Stellarvue 50mm Guide Scope - ZWO ASI290MM Mini - Rasp Pi4

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1 month 1 week ago
ChrisRowland
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Re:Figuring out a meridian flip? #52372
A log might show but my guess is that the flip failed and the mount kept going until it found a hard stop. As for why the flip failed maybe the flip point is more than 0.2 hours past the meridian. It seems a lot though.

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1 month 1 week ago
wvreeven
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Re:Figuring out a meridian flip? #52373

ASI1600MM-Pro Cooled and filter wheel with a SkyWatcher Esprit 80 ED on a SkyWatcher HEQ5-Pro
ASI1600MM-Pro Cooled and filter wheel with an 8" TS Ritchey-Chrétien on a SkyWatcher EQ6-R

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1 month 1 week ago
mpaul73
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Re:Figuring out a meridian flip? #52376
I'll look for the logs and try and post them.

Equipment: Skywatcher HEQ5 - Stellarvue 80mm access - Canon 6D (unmodified) - Stellarvue 50mm Guide Scope - ZWO ASI290MM Mini - Rasp Pi4

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1 month 1 week ago
mpaul73
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Re:Figuring out a meridian flip? #52380
How do I figure out the flip point?

Equipment: Skywatcher HEQ5 - Stellarvue 80mm access - Canon 6D (unmodified) - Stellarvue 50mm Guide Scope - ZWO ASI290MM Mini - Rasp Pi4

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1 month 1 week ago
hy
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Re:Figuring out a meridian flip? #52382
You can do this manually, standing next to your telescope (that is, looking at it so you can see if it changes sides). Slew to a star that's a little before (east) of the meridian and plate-solve (align) so that you're reasonably confident about your position. One of he tabs in your mount's indi control panel should indicate "West pointing East" and you can look at your hour angle.. Now from there, slew to some position near there further west, just past the meridian. Does the mount stay on the same side? What is the hour angle now? If it didn't change sides, slew further to the west and repeat. Keep doing this until your mount decides to change sides and note the hour angle. This should give you a reasonable idea of how to set that hour-angle parameter on the Ekos "Flip if HA > " input box. Perhaps set it to a little more than that hour angles where your mount decided to flip (of course, make sure the scope wont be hitting your tripod at that hour angle).

You should make sure before you do all this that
- your computer's time is set properly to the local time,
- the entries in the indi control panel mount tab, "site management" sub tab seem right (e.g. for UTC time, UTC offset, latitude and longitude.
- You can park and slew properly -- e.g. when you start from a parked position and slew to some object, it points to within a few degrees of the object you wanted it to point to (e.g. it doesn't need to be exact, but shouldn't be e.g. 30-degrees off), and that it returns to pointing near the north star when you park.

Hy

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2 weeks 5 days ago
edh
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Re:Figuring out a meridian flip? #53715
I have been doing some experimenting with the meridian flip for the past few days. I have found that the meridian line on the Kstars map does not match the HA displayed in the Ekos telescope window. It can be a few minutes off. Also the telescope meridian flip point can be several degrees from the actual telescope meridian point and several degrees from the Kstars/Ekos meridian. To enable an automatic meridian flip, an object must be selected that is East of meridian for both the telescope mount and Ekos. And the flip is executed successfully only if the mount is West of the mount meridian point when the meridian flip goto command is sent to the mount.

Things to do to investigate the issue:
1) In Kstars select an object just East of the meridian line and note the HA time when that object actually crosses the line. HA = 0 is the reference time for the triggering of the goto command that causes the meridian flip. The goto command is sent to the mount when the HA>xx limit is reached.
2) Manually move the telescope with the hand controller or the Kstars telescope movement controls to the point where the counterweight bar is perfectly horizontal. The difference between the telescope location and the meridian line on the Kstars map can be determined by noting the RA position of the cursor on the map in the lower right corner of the map. This may not be the telescope meridian flip point.
3) To determine the telescope mount meridian flip point. select an object sufficiently far to the East that causes the mount to slew to that object with the telescope on the West side of the mount. Periodically press the Kstars goto button until the mount actually does the flip. Watch the HA position in the Ekos telescope window and note the HA position when the flip occurs.

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2 weeks 5 days ago
ChrisRowland
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Re:Figuring out a meridian flip? #53716
What version of KStars are you using? Hy and I have been working on the meridian flip process recently and it will now retry if the flip falis. It also reports the pier side in the mount tab and can implement a HA limit that is intended to stop the mount tracking into the pier if it is in the wrong pointing state. This may all only be in the sources, not a released version at present. It all requires that the mount reports the pier side. If is doesn't none of this will be done.

in your section 2 some mounts report the mount axis positions. It may be worth watching the Ha or Ra axis position as the mount moves through the meridian. I would expect it to move through 180 or 0/360 degrees at that point. I would esxpect that the target pier side would change as the axis direction goes through 180 or 0.

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2 weeks 4 days ago
edh
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Re:Figuring out a meridian flip? #53774
Kstars: 3.4.2

My primary mount is a Celestron AVX. I don't think it reports HA or the pier side.

I have been doing the testing during the daytime without a doing an accurate alignment to real objects. Some of the differences between the mount and Kstars/Ekos should be reduced after doing a real alignment with stars.

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2 weeks 4 days ago
ChrisRowland
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Re:Figuring out a meridian flip? #53787

edh wrote: Kstars: 3.4.2

My primary mount is a Celestron AVX. I don't think it reports HA or the pier side.


The AVX definitely reports pier side. Ha is always derived from the mount Ra, the time and the longitude. I have one and made sure that the driver uses the mount pier side command.

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