Computer control of my CG5 mount

[x6gas]

Ever frustrated by the cloudy skies I thought I'd have a go at computer control of my CG5 mount.

Having read around a little bit, I was prepared for this to be a real pain and was expecting to have to shell out on a few extra bits and bobs to get it to work. However, despite a few false starts, I'm very pleased to say that's proven not to be case. Here's the story in case it is of interest to anyone else.

Firstly, I am rather surprised that the standard communication between computers and mounts is via an RS232 port - why? Technology has come on so much in the past 20 years (while I've been away from the hobby) that I can't quite believe that there isn't USB plug'n'play functionality - maybe someone can explain (there must be a good reason!).

Anyway, I had an old Dell laptop kicking about that actually had an RS232 port so I thought that I'd try to set that up first since it seemed the simplest route. This was a mistake, obviously!

To test the coms between the laptop and the mount, I installed NexStar Obsever List (NSOL) which is a nice bit of free software that was very useful for checking the connection. Connected up, but nothing worked so I ran through the very helpful NSOL help on communication problems trying different start-up orders etc. Turns out that Dell laptops are known to have problems with RS232 coms to 'scopes and, apparently, some work and some don't. Mine, it seems, doesn't!

So I thought I'd try to run the 'scope from my Netbook. This was actually my prefered option since the Netbook (Samsung NB30) is light, portable and packs 7 hours battery life.

I had an old RS232 -> USB cable kicking around - it was a very cheap e-bay purchase a few years ago and frankly I was 90% sure it wouldn't work - but I thought I'd give it a go. After installing the drivers for the cable, I connected everything up, fired up NSOL clicked the 'Get Scope Position' button to test the connection, but no joy. I was pretty much ready to give up at this point, but the help file for the cable mentioned that Windows XP (which I run on the Netbook) sometimes overrides the driver and uses it's own. So I found the driver in Device Manager, clicked update driver and manually installed the driver that came with the cable (SemiTech USB-HID -> COM device). Tried the connection using NSOL and voila! The scope reported it's position and I was able to slew the 'scope around using NSOL to my heart's content.

Next I thought I'd see how hard it would be to use Stellarium to control the mount. (I think Stellarium is fantastic by the way.) The answer is, it's dead simple. Go to the configuration window, select Plug-ins and then Telescope Control select a few simple and obvious configuration options and it worked straightaway.

So I'm dead chuffed that I can control the 'scope from my Netbook and it really wasn't too hard to set up.

I haven't tried this route with the Dell laptop but I see no reason why it won't work and then I'll still have an RS232 port for use with a modified webcam if I ever go down that route (unless Dell ports don't work with them too!).

Just need some clear skies now!

[RascalUK]

My cheap eBay Serial > USB didn't work and has caused me a week of annoyance. Just replaced it, on advice, with the one from Astronomiser and it worked first time.

Stellarium is cool as a control though isn't it?

[x6gas]

Stellarium is cool as a control though isn't it?

I just read your thread after posting this one. Stellarium has certainly given me something to do inspite of all this cloud.

As I say above, my problem was XP selecting the wrong driver, but I know these USB -> RS232 converters can be a pain.

[Bizibilder]

Interesting idea - will it work on other mounts?

[Zakalwe]

Interesting idea - will it work on other mounts?

I have heard that el-cheapo USB-RS232 converters can cause a lot of problems. ones using the Prolific chipset seem to work well.

Stellarium can control other mounts.....I can use it to control my nexstar and (if you use StellariumScope) it can talk to the ASCOM platform, and then onto loads of others (for instance, it can talk to my EQ6). CdC cas also drive the scopes, using the ASCOM platform (although CdC isn't as pretty or as user-friendly as Stellarium)

You can also use the EQMOD software to control ASCOM capable 'scopes. There is a lot to learn with this software (tell me about it) but it does become a little intuitive once you play with it. it is an incredibly useful platform, allowing you to polar Align, GOTO, align the mount, as well as doing things like automating mosaic imaging.

Finally, I lost a potentially good Lunar imaging session on Thursday, trying to get a new Windows 7 laptop to communicate (via a USB-RS232 converter) to my Nexstar. Windows was using it's own driver and was causing a resource conflict in Device manager (I was back to the bad old days of jugging IO and IRQ addresses-anyone remember the fun installing soundcards and the like under DOS, Win 3.1 and Win 95?).

[Glider]

Stellarium works OK with my CG5-GT Goto. I use the latest Stellariumscope rather than the built in mount support. This allows slew, sync and stop control.

[leenewtoastro]

just need webcam comms now

[Zakalwe]

just need webcam cooms now

Sharpcap is pretty sweet.

[leenewtoastro]

but your still sitting outside at the scope?

i don't understand why using the pc at the scope has any benefit over the h/ctrl . totally understand for observing as it saves back aches etc

but then i guess if your doing that may as well use pc to slew save picking the h/ctrl up?

[x6gas]

i don't understand why using the pc at the scope has any benefit over the h/ctrl .

Well for me, returning to astronomy after years away, I have Stellarium next to me anyway to help me re-learn the sky and what everything is called so being able to click on something in Stellarium and have the scope slew straight to it will be much easier and quicker than finding it on the hand controller. Personal preference I guess and I'll have to see how I get on in a proper observing session...

[leenewtoastro]

yeah i get that x6 happy gazing