I have an SBIG DSS-7 spectrometer that I am interested in using on something other than a windows machine (which the software runs naively on). The attached camera (ST-402) seems to work very well with Ekos, but it appears there are no options for something like the DSS-7. There is open source software available (for instance, see the bottom of diffractionlimited.com/support/sbig-archives/ and sbig-util on github). There is also the SBIG Linux Devleopment kit (which I assume is what Ekos uses, although I don't know).

So I want some advice about how to go about creating a very simple device to control my spectrometer. The functions I need could not be simpler - I need to be able to flip the slit into and out of view, and also rotate the diffraction grating.

I have some software development experience, but mostly scientific computing / C / IRAF / etc. But I am good at googling!

We're using the SBIG Universal Driver which AFAIK hasn't been updated for years. It also probably doesn't cover spectrometers, but I'm not entirely sure. The most important thing here is the communication protocol. How can we communicate with the spectrometer? Once that figured out, creating a spectrometer INDI driver is quite straight forward.

So get the protocol and we can create the INDI driver soon for it!

Thanks for the response - I'll investigate a bit more but here is what I know.

MaximDL uses "SBIG Universal" 6.12.0 to operate legacy SBIG cameras (see here: diffractionlimited.com/help/maximdl/HIDD_SETUPST7.htm), and they offer DSS support. So if you are using SBIG Universal Drivers already, it's likely the driver is in there.

As far as the protocol, I'll look around the existing Linux solutions for SBIG cameras. I haven't been able to make any of them run, but perhaps they will give clues as to how to talk to the DSS.

Thanks!

Here is the SBIG driver header we use: github.com/indilib/indi/blob/master/3rdparty/libsbig/sbigudrv.h
Again, once you know how to talk to it, either via the SBIG driver or by other means (maybe you can sniff USB traffic?), then we can work on the INDI driver.

Ok well here is the "Control Port Connections and Conventions" appendix from the manual (in it's entirety!)


The SBIG relay port (AO/CFW/Scope Port) controls the motors in the DSS-7. The “X”
relays control the grating and the “Y” relays the slit. Commanding a relay for 0.2
seconds is sufficient to change the slit or grating position. The controls are as follows:
+X relay: rotates grating to clockwise limit
-X relay: rotates grating to counterclockwise limit
+Y relay: rotates slit in (visible through entrance port)
-Y relay: rotates slit out of way
Almost 0.5 ampere is drawn from the battery during actuation, so if you write your own
control software keep the relay times short to avoid exhaustng the battery.

So, since the SBIG driver header includes several AOs and CFWs, which presumably use the same relay port, so it should be pretty easy to modify those controls for the DSS-7?

If this is enough (like, I guess if you know what the "X relay control" and the "Y relay control" are on the AO/SFW relay port), I can open up my device and tell you exactly what the configuration should be. There are basically a set of three configurations of those (X,Y) positions we need, I just don't know exactly what they are without looking inside the box.

Yeah, looks like you have to use trial and error until you figure out exactly what corresponds to what. Once that determined, the rest is straight forward.

Ok so the three modes we want to have access to are

Position Mode: YMINUS, XMINUS (no slit, no grating)
View Slit Mode: YPLUS, XMINUS (slit, no grating)
Take Spectrum Mode: YPLUS, XPLUS (slit, grating)

In principle, "Position Mode" should include some kind of repeated image-taking, like a "focus" mode, but I think that's easy to have enabled anyway.

So is this something you could easily add, or something I should try to develop myself?

I very much appreciate your attention to this, by the way.

Given you have access to the equipment, why don't you try to customize the driver to support this? If you have any issues with any development details, let me know!