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Forum Index : Microcontroller and PC projects : Question about ASTRO

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Frank N. Furter
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Joined: 28/05/2012
Location: Germany
Posts: 1077
Posted: 11:40am 22 Feb 2026
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Hi,
to calculate the hour angle for my telescope, I need the sidereal time in addition to the right ascension of the object.

The sidereal time is calculated in the background for the ASTRO command.
Is there a way to read out the sidereal time (possibly with PEEK)?

Frank
Edited 2026-02-23 17:37 by Frank N. Furter
 
Frank N. Furter
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Joined: 28/05/2012
Location: Germany
Posts: 1077
Posted: 07:09pm 25 Feb 2026
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Is there really no way??? That's a shame! Then I'll have to calculate the sidereal time separately after all... Very annoying...  

Frank
 
PilotPirx

Senior Member

Joined: 03/11/2020
Location: Germany
Posts: 125
Posted: 12:03pm 26 Feb 2026
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Hi Frank,
unfortunately, I can't help you,
but I would like to know which GoTo mount you have for your telescope?
Is it an open interface?

Peter
 
matherp
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Joined: 11/12/2012
Location: United Kingdom
Posts: 11189
Posted: 12:07pm 26 Feb 2026
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The sidereal time is returned by GPS(SIDEREAL) but there isn't currently an option to  get it from a defined location and time without a GPS
 
Frank N. Furter
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Joined: 28/05/2012
Location: Germany
Posts: 1077
Posted: 07:00pm 26 Feb 2026
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@PilotPirx:

The telescope mount is an old Vixen Super Polaris:
https://www.photoinfos.com/astronomie/VixenSuperPolaris.htm

The mount and telescope are mounted on a portable column.
The main tube itself is a Newtonian with a 5 1/4" inch mirror.
My mount is still equipped with two stepper motors, and I have a simple electronic tracking system for it.

Maybe I can upload a picture of it here sometime (if anyone is interested)...

I also have a kadadioptrically shortened 5 1/4" inch Newtonian telescope - it would be interesting to build a tracked, azimuth mount for it. It would be great to control it with the new commands.


@matherp:

Thank you for your reply! Is there no way to trick the system into thinking it has GPS? (e.g., by sending an artificially generated GPS telegram from one hardware pin to another?)

I have already considered using a routine to change the right ascension until the azimuth outputs 180° as the result. Then the entered right ascension should correspond to the sidereal time.


Frank
 
matherp
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Joined: 11/12/2012
Location: United Kingdom
Posts: 11189
Posted: 07:41pm 26 Feb 2026
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In the next beta I'll add a parameter to the location command that returns the sidereal time for the time specified
 
Frank N. Furter
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Joined: 28/05/2012
Location: Germany
Posts: 1077
Posted: 07:50pm 26 Feb 2026
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That's great! Thank you very much!!!      

Frank
 
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