New communication protocol

[Dessislav Gouzgounov]

Hello,

I have built a new Open Source Telescope control system based on Arduino Due. The name of the project is rDUINOScope and more information can be found on the project website: http://rduinoscope.co.nf/

The rDUINOScope is capable of receiving commands via Bluetooth - SlewTo, Status and others.
I'm now looking for a way to connect it to Stellarium and found your Plug-In which can handle Bluetooth communication.

I'd like to know the communication protocol of the Plug-In in order to implement it in rDUINOScope, or it could be that I send you my protocol and you include it in your plugin.

Please let me know :)

Best Regards,
Dessislav Gouzgounov

[gzotti (georg-zotti)]

Thanks for your interest. Actually the best way would be if you download Stellarium sources (http://stellarium.org/wiki/index.php/Bzr_checkout), make necessary changes to the telescope plugin so that it works with your creation while still working with all other devices, and submit a branch/merge proposal. We cannot test anything without the proper hardware. (Also for other requesters: please fix things for your new telescopes, and send patches to help others -- we just don't have your mounts and cannot help!)

I was not even aware that our plugin would directly communicate over Bluetooth, maybe you must use the connecting piece of software called StellariumScope? In this case, make your rDUINOscope work with StellariumScope, this does not involve Stellarium sources, but we cannot give any advice about the protocol. You may have to implement ASCOM for your device. You can write a short subsection for the user guide (section 14.4) if it works.

[Dessislav Gouzgounov (deskog)]

Hello,

Thank you for the prompt reply.

I intend to map BT module to a COM port from the OS and use the RS232 communication protocol over BT communication. I might be wrong but I think this should work..... or is it ?

I prefer not to dig into Stellarium code, but append mine as I know it better. In this case can you provide me with a typical SlweTo command string that you send over RS232 ? ... the ASCII values for any of the implemented mounts. I should be able to mimic it.

[gzotti (georg-zotti)]

Cannot comment on BT, I never used it.

Stellarium sends GOTO commands to devices listed in section 14.2.5 of the user guide. Whatever their protocols require. I have not written this plugin and would have to study the sources myself. I used it with EQ3 and EQ6, but cannot say more.

[Dessislav Gouzgounov (deskog)]

I understand. Is tehre anyone who can provide this information:

".... I prefer not to dig into Stellarium code, but append mine as I know it better. In this case can you (anyone) provide me with a typical SlweTo command string that you send over RS232 ? ... the ASCII values for any of the implemented mounts. I should be able to mimic it. "

[Alexander Wolf (alexwolf)]

I'm sorry, but how exactly you plan "...not to dig into Stellarium code" for adding of the implementation of your own protocol? Of course you can implement standard Meade LX200 or Celestron NexStar protocols, but Stellarium are known those protocols already and current wishlist is not required for it.

[Dessislav Gouzgounov (deskog)]

Well, obvioulsy someone created the plug-in, and owns it. Additionally there is a feature\bug request list which made me to believe that I'm not supposed to dig in the code.... not that I want to either.

But a previous reply stated simply "No we won't implement you because..... I understand those arguments and thus decided to take a different course of action.

Anyhow, thank you for your support.

[Alexander Wolf (alexwolf)]

Perfect! How exactly we can add your protocol without hardware, who support it, and specification of your protocol? And why we should add implementation of LX200 or NexStar protocols into your software?

[Alexander Wolf (alexwolf)]

I'm sorry, but seems I was misunderstand you: are you want add support of your own protocol or you want to know of already supported protocols?

[gzotti (georg-zotti)]

The obviously simplest solution is if rduinoScope implements either LX200 or NexStar protocol. Given that Stellarium implements both in an amount that it works with existing products, it will also work with rduinoScope, and it does not require changes of Stellarium (which will have to be maintained without testing).

I think it does not make much sense to develop a new protocol and change Stellarium to support it as third derivate of the TelescopeClient abstract class. Please simply implement LX200 or NexStar GOTO. You can use whatever docs you find online, or/and take inspiration from Stellarium sources. And you are the only one who can test your development currently.

[gzotti (georg-zotti)]

See http://www.vhersey.com/2015/07/raspberry-pi-telescope-control/ for another example
 using https://svn.code.sf.net/p/stellarium/code/trunk/telescope_server/. There are still a few more projects.

[Dessislav Gouzgounov (deskog)]

Thank you for providing directions guys.

I have really used LX200 protocol and addedd support to the #rDUINOScope Arduino based Open Source GoTo.
The system is now working with Telescope Control plugin via Bluetooth and it works like charm (getCoords and SlewTo).

Something I noticed is that the request from the plugin happens every almost second for each axis. This basically slows down the entire system a bit.

I was wondering is there a way to reduce this "call for coordinates" to let's say once every 5-10 seconds?
Additionally is there a protocol (not LX200 one) that "calls for coordinates" with one request (not 2 separate requests) ?

[gzotti (georg-zotti)]

Although this has nothing to do with Stellarium, a quick Google: "LX200 protocol" brought http://www.meade.com/support/LX200CommandSet.pdf which indicates that no such function exists in the protocol.

A similar search for "NexStar protocol" provided http://www.celestron.com/media/795779/1154108406_nexstarcommprot.pdf

which shows that this other available protocol includes such call.

[Dessislav Gouzgounov (deskog)]

I might have not been clear enought... sorry.

My question was plugin wise... In the implementation of the plugin, is there a protocol where the plugin makes call not every second, but once every 5 - 10 seconds ?

It seems that for LX200 protocol, the plugin call telescope mount every second, but for me it makes much more sense if this call from the plugin happens not so often... like every 5-10 sec.

[gzotti (georg-zotti)]

This is the point where *you* must start studying the code.

[Alexander Wolf (alexwolf)]

The bug report was moved to https://github.com/Stellarium/stellarium/issues/442