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Author Topic: Green Swamp Software GS Server  (Read 152 times)

PhilCrompton

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Green Swamp Software GS Server
« on: January 01, 2021, 21:47:57 »

Hi Tom,

I am currently investigating and testing moving over to a new ASCOM driver for SkyWatcher mounts from Green Swamp Software called GS Server. This is being actively developed, unlike EQMOD and the code base is readily available on Github and written using .NET.

So far I have only come across one problem. Unlike EQMOD which sends an AxisStop (:K) whenever the slew speed changes GS Server only sends a :K command if the slew direction is changing or if you are going from highspeed to lowspeed.

The upshot of this is that if the mount is already tracking and you attempt a slow slew with the RA axis in it's normal direction the slew does not start. Additionally, once you do manage to get it slewing at low speed in the RA direction and attempt to return to sidereal rate the mount continues at the slow slew speed.

I have spoken to Rob Morgan the author and he would prefer to keep his code matching the Skywatcher rules and apparently Skywatcher mounts do not need the :K command if only the speed and not the direction is being changed. They just require the :I command.

Is there a reason why the Astro EQ firmware requires a :K when only the speed is changing. How difficult would this be to change?

If it is possible to change the firmware I am sure I am not the only person who would like to finally have an alternative to EQMOD.

To illustrate I have attached a log dump for GS Server showing the commands being sent to the mount. I have commented the lines to help understand what is going on.

Kind regards and Happy 2021

Phil

p.s. You can find GS Server here:

https://sites.google.com/view/greenswamp/

and on Facebook.
 
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TCWORLD

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Re: Green Swamp Software GS Server
« Reply #1 on: January 04, 2021, 01:08:59 »

Hi Phil,

The lack of a :K command shouldn't matter - that just instructs the axes to stop.
The AstroEQ is quite happy to receive the :Ixxxxxx command while running, then :J command sequence to initiate the change in speed. IIRC this what Indi does too, for which I'd made adaptions to support.

I presume you are using the latest firmware?
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Tom Carpenter (AstroEQ)

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Re: Green Swamp Software GS Server
« Reply #2 on: January 04, 2021, 01:11:47 »

Ah, wait a moment.

I think I known what's happening.

When requesting a slew in the same direction as it is currently running (if the axis is already moving), the AstroEQ doesn't need the :J command following :I. Indi just issues :I without :J.

The problem with the extra :J command being issued, is that the motor is already running when it's sent, which means it locks up waiting for it to stop running so it can start a new movement (nothing has told it to stop).

I can probably make a simple adaption to the :J parsing such that if the axis is in an updatable state, it ignores :J.
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Tom Carpenter (AstroEQ)

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Re: Green Swamp Software GS Server
« Reply #3 on: January 04, 2021, 01:20:30 »

If you could give the attached firmware a try.

Just update the hex/ folder in the latest config utility version with the attached files
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Tom Carpenter (AstroEQ)

PhilCrompton

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Re: Green Swamp Software GS Server
« Reply #4 on: January 04, 2021, 09:47:56 »

Hi Tom,

Your fix worked. Thank you for the quick response.

Kind regards,

Phil

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TCWORLD

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Re: Green Swamp Software GS Server
« Reply #5 on: January 04, 2021, 10:16:47 »

Great. Will push the new version to github once I've done some checks with EQMOD and indi.
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Tom Carpenter (AstroEQ)