Monday, February 01, 2021

connected to the mount!

Another breakthrough today.

With the Vixen Super Polaris mount back inside—and defrosted—I was curious to test some things. I'm really keen to have remote control of the IDEA GoToStar motor driver system and hand controller. Handy when the temperature goes below -17°C.

motorised remote focusing

Kicked around, briefly, the idea of building my own focuser to turn the knobs of the Williams Optics external focuser. I'll do more research later.

Oh. There's an opportunity to borrow a focuser... Would it fit on the C8? I'll have to do a little experiment there.


First up was to see if there was a virtual hand controller that might work with my weird setup. 

I've used the Celestron NexRemote with the N11GPS at the CAO. I recall playing with a virtual HC when writing about EQMOD. Saw a video where someone used CPWI. Learned about the clever SynScan app for slates recently while researching Stellarium hookups. For the first time, I used the old StellariumScope, a week or so ago.

Google directed me to a Cloudy Nights post (from Apr-May 2020) where someone was writing their own VHC. Cool. It looked good. But then one of the commenters said, essentially, why bother, and suggested ASCOMPad. Huh. Downloaded version 2.09 from the EQMOD site.

Tried it. It did not respond when I tried to select the mount. Then, after jumping around and trying different things, I saw it connect to the Vixen SkySensor driver. Once. Then nothing happened. It was after successfully connecting with and using the simulator. Tried a few more times. Then I stumbled across multiple instances of the app! Sheesh. Cleaned up and tried again. Connected! But then the slew direction buttons did nothing. Hit STOP. It worked! Oh oh. It didn't release. It was like it was jammed on. Had to kill app to regain control of the HC. Tried again. Definitely an issue: N, E, W, S, Park not working... When I tried the Sidereal Rate button, it issued a stop to the mount! And locked it up again.

Does ASCOMPad need EQMOD around? It did not seem like it but I downloaded it anyway. No improvement.

Had a look at EQMOD (been a while) but it is specific to SynScan. Synta EQ mounts.

Learned of the AstroEQ project by Tom Carpenter. Sounded promising at first. But didn't get anywhere there. I think it is specifically for building your own motors and motor controller circuit boards! Hard core. Confusing documentation. I bailed.

I'm still not convinced it is a closed matter... Maybe I can try iOptron drivers or other Vixen drivers.

long connection

OK. I had been thinking about this since the Sirius imaging run

I had successfully connected to the camera some 15 metres away and enjoyed working inside while the mount whirred away. 

All the slewing and focusing had to be done outside, by hand.

I "burned up" one solution in the distal control of the DSLR. I used the USB-ethernet IOGEAR adapters. But on Saturday night I couldn't figure out the cabling solution for mount control. Brain freeze?

Rest of the weekend I noodled long cable methods. Now it was a good time to try things. Dug through my old computer cable boxes. Found a bunch of dusty 25-pin serial cables. Found my box of adapters, gender changers, jumper boxes, null modems. Fished through my "travel kit" with backup power cords, old tiny modem, still more adapters, and old console server cables. Piled everything on the desk.

Did the known-good connection between the Windows 10 laptop, Stellarium, Vixen SkySensor 2000 PC ASCOM driver, USB-serial adapter, data cable to the IDEA GoToStar hand controller. That all worked fine.

Test 1: Getting some distance between the mount and hand controller. 

Installed my 6-wire custom extension cable and junction between the IDEA GoToStar hand controller and RA motor driver input. Didn't work at first but it turned out the USB-Serial device had glitched. Out. In. Boop beep. Tried again. Sweet Universe! Stellarium worked. That gave me almost 4.5 meters.

Test 2: Getting some distance between the hand controller and the computer.

Grabbed an unopened bag for a "full loaded" 25-pin serial straight-thru cable. Hooked up all the needed 25-to-9 adapters and a gender bender and inserted this frankencable between the IDEA data control cable and the USB-adapter. Holy Universe, it worked. The old 10-foot serial cable and crazy jumble of adapters worked. So now I had another 3 metres. 

Jumpered in another long serial cable. Nothing. No joy. Tried every cable. Nope.

I had tried it before on a whim and there was no response but I thought I'd give it another go. Some Google searches strongly suggested that you could send serial signalling down ethernet cables... 

Spotted the part number 74-0495-01 on the old TANDBERG console cable adapters. Google sent me to a site where you could buy them. DB9 female to RJ45 female serial console terminal adapters. Serial! It's gotta work. I hooked everything up again, making sure the connectors were secure. Disconnected and reconnected the USB-serial adapter. Green LED power standby good. Issued the Connect command in Stellarium. Double flashing red LED activity working! And the reticule moved to the current star. Yes! Wow. Wow. I have a passive solution with a short ethernet cable.

Spotted in my blog an entry from 2015 where Dan had lent me one of his RJ45-DB9s to get the CAO GBO Optec focuser to work.

With high hopes, I inserted my 50-foot yellow ethernet. Woo hoo! The mount moved and reported its position. 

There it was. Another frankencable but now, suddenly, I had the working path. A 20 metre or so hard line connection. Now, in theory, I could control the mount.

functional diagram for camera and mount connections

That's mad. It's not pretty but this should work.

It's not ideal without slew buttons but it will work if I can decipher alignment issues and perform small slew commands from Stellarium.

Maybe I can try plate-solving too. But that's a whole other rabbit hole.


I've thought about it before; starting thinkin' about it again: writing my own driver.

Last week I watched a brief video on controlling a piece of astro gear (a focuser) with ASCOM. Good demo, highlighting the key steps. With the warning that mount control was the most complex programming.

So I thought about it some more tonight. Revisited the ASCOM site. When I reviewed the 20 supported languages, I saw some familiar names. On spotting Python, I thought, "Well, I was thinking about learning it anyway." Downloaded 3.9 and tried a few things in the CLI interpreter. Gah. Brute force method. Downloaded the Thonny IDE. Syntax issues ahead... as usual, when learning a new environment. Then I wondered what it would be like to connect to the ASCOM environment, system calls, etc. from within Python. Kind of a double whammy.

In the list, of course, there wwere a lot of MS languages. Plus JavaScript. I wouldn't have to relearn or readapt as much, presumably. Geez, it sounded like it could be done inside VBA too! That's what I've worked in most, lately. Anyhoo, I downloaded Visual Studio Community 2019. And then I initiated the .NET download. Big.

What am I getting myself into...

Noted another option: "... modifying the EQASCOM source to interface with your mounts' goto controller." Hmmm. Is this the way to go? A framework will be established. Maybe it'd be as simple as loading in the IDEA instruction set... But what's the code base for EQASCOM?

remote computer control

A completely different approach is to not bother with the long cables per se. Put the controlling computers beside the mount. But then operate the computers by remote control. Load TightVNC on John Gomez. It's already on John Repeat Dance. Then I'm off and running, right?


Wait a second! Is StellariumScope the solution, right in front of my face?

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