To answer this myself. I tested it and it does work. I can slew the mount with no HC attached; only a direct usb connection from an Ubuntu machine running kstars to the usb port of the Celestron focuser attached to my C8/AVX.
This is potentially a very simple and relatively cheap way of getting both automated startup and focuser capability to a Celestron mount.
Note: I observed some timeout issues, but I think that was the driver.
Has anyone tried this? I believe it works under ASCOM. The USB port on the focuser acts as a serial bridge to the AUX ports. If it works using an AVX (for example), we won't need a hand controller or need to build a HBG3.
I would try this myself but I am in the middle of a rebuild.
You will need to recompile it after having modified any appropriate paths in the cpp file. I have been using this for 6 months now, it works well as a fully integrated ekos solution for DSLRs without USB remote support (Like my Sony A57). It is a pain to get everything setup though - You need to recompile if you update stellarmate. You'll need a wifi router as the the FlashAir card has a weak signal.
It's still in early development, and very specific to my setup (I have hardcover folder names); I have yet to test it under fire. I can see it is useful to many people so I will keep working on it over the next few weeks. I recommend you wait a week or two. If you really want to crash EKOS, try this:
indiserver -v -p 8000 indi_sony_a57
Then in EKOS set it to remote: localhost port: 8000
I will put specific instructions in GutHub soon.
I have developed a custom driver that works fine when running with
Indiserver -v driver name
But when I install it (confirmed to be in /usr/bin/ and /use/share/indi) EKOS won't start it. I can select it in the list (as long as it is name indi_drivername).
Am I missing something simple?
I have built a driver that enables me to use my Sony A57 (no remote/usb) in combination with a FTDI bulb cable and a FlashAir WiFi card. This driver is very easily modified for your camera. Actually, since the D5100 and A57 have the same sensor, I think you just need to delete the FlashAir components.
This driver lets me auto focus and frame on a DSLR with no usb tether capabilities. It is still a work in progress, but you are welcome to try it
If you wait a week, I will make it more generic, with FlashAir being optional.