What Guide cam for Linux

[SteveBz]

Hi Guys,

My configuration comprises a whole load of cheap optics off ebay, an Arduino driven mount and electronics and a laptop running Linux with a mass of home-brewed Python.  And I only have Linux computers.  My issue is that the guidecam (not shown here) was £22 off eBay and really is not sensitive enough.  I spend a lot of time with my guiderings trying to guide a guide star in view and often failing.  I've come to the conclusion that I need a more specialised guidecam for the job, so that I can avoid using the guide-rings: but it needs to be Linux compatible, and I'm not sure I can find one.  And really I want them to pay me to take it.  I was thinking of a asi 120mc, but the Linux compatibilty seems a bit light weight.  Any thoughts?

Here's the rig it needs to go with:

Focuser

OTA Fans

OTA hub (exposure, autofocus, dewbuster, fan controller...)

Arduino brain (mount control, focus, exposure, temperature, humidity ...)

Here's the python control panel:

I look forward to hearing your ideas.

Regards

Steve

 

[furrysocks2]

The Datyson T7 appears to be something of an ASI120 clone, perhaps appealing to you in improved sensitivity and relative cost. I recently bought a mono T7M, have briefly taken some exposures in oacapture but have never used it as a guide cam. So, two out of three.

[Gina]

The SX Lodestar works with Linux - there's an INDI driver for it.  OTOH the ZWO cameras are cheaper and probably just as good.

[SteveBz]

8 minutes ago, Gina said:

The SX Lodestar works with Linux - there's an INDI driver for it.  OTOH the ZWO cameras are cheaper and probably just as good.

ZWO talks the talk with Linux, but I'm not sure they walk the walk, eg v4l2 drivers.  If they had that I'd snap 'em up.  Am I wrong?

Steve.

[SteveBz]

1 hour ago, furrysocks2 said:

The Datyson T7 appears to be something of an ASI120 clone, perhaps appealing to you in improved sensitivity and relative cost. I recently bought a mono T7M, have briefly taken some exposures in oacapture but have never used it as a guide cam. So, two out of three.

People seem to have got ASI120 etc working with Linux.  I just need to know that I can handle the complexities without too many headaches.

I read your write-up on the T7MM, together with scarily graphic photos of your carpet.  It looks great.

What operating system do you use?

Regards

Steve

[furrysocks2]

9 minutes ago, SteveBz said:

What operating system do you use?

Mint/Ubuntu but probably straight Debian soon.

 

8 minutes ago, SteveBz said:

scarily graphic photos of your carpet.

We have a dog. 

[SteveBz]

2 minutes ago, furrysocks2 said:

Mint/Ubuntu but probably straight Debian soon.

 

We have a dog. 

Fantastic. And does this cam work with v4l2?  What software do you use?

[furrysocks2]

Just now, SteveBz said:

And does this cam work with v4l2?  What software do you use?

It didn't work in guvcview. I then started using oacapture which for which there's a non-v4l2 driver. But I have Windows on my laptop which is what I take to my scope. I've not actually used the T7M in a scope yet at all yet, though.

I know v4l2's been looked into in the past, don't know the current state.

[SteveBz]

1 minute ago, furrysocks2 said:

It didn't work in guvcview. I then started using oacapture which for which there's a non-v4l2 driver. But I have Windows on my laptop which is what I take to my scope. I've not actually used the T7M in a scope yet at all yet, though.

Yes, I saw that James had written an interface for the ASI120.  I believe there is an SDK on github for it.  I don't know how hard it would be to wrap it for v4l2.

I might have a look.  I think I'd need to be sure of this before cracking open the piggy bank.

Steve.

[furrysocks2]

What package(s) are you needing it to play nicely with?

[SteveBz]

opencv2 is the library I use to grab frames and process them for guiding.

[pete_l]

Two possibilities: can you not stack guider subframes within opencv2 to improve the sensitivity of the guider cam?

Alternatively, how about using a larger guide 'scope?

[SteveBz]

1 hour ago, pete_l said:

Alternatively, how about using a larger guide 'scope?

I could do, but I'm not ready for this yet, it's a 50 mm Celestron, so I could ramp it up a notch.

1 hour ago, pete_l said:

can you not stack guider subframes within opencv2 to improve the sensitivity of the guider cam?

I'm playing with this route, actually by using taking a dark frame, subtracting it and then doing opencv2.multiply on the result.  I think I can also fiddle with the gain setting.

Regards

Steve

[GuLinux]

Hi,

Your setup reminds a bit of mine: I have the shooting software implemented as a python module + script on a raspberry pi piggy backing on a headless INDI server.

Main difference is, I don't use any autoguider (yet).

Here's the code: https://github.com/GuLinux/indi-lite-tools/tree/master/pyindi_sequence

The main repo also includes a raspberry pi setup script, a webserver with some logging info, and various API/addons (for instance, I also print status on an OLED display).

 

Strictly answering your topic: ASI cameras work pretty well on Linux - among the best I've tried, I'd say. The ASI120 in itself is a bit of an exception: for many users it just works, but apparently some models do need a firmware update before, and some other models seem to refuse to work at all. I might have incomplete/outdated info though, just go to the ZWO forum and do a quick search.

It would be pretty difficult to get image directly in python though, as they don't support the V4L2 interface. You could however use indi (+ my module if you like).

I might be interested if you can get an autoguider algorithm with python and opencv, the autoguiding feature is the main thing missing in my scripts, if you'd like to contribute it would be cool.

 

Cheers,

Marco

 

 

[pete_l]

2 hours ago, SteveBz said:

I'm playing with this route [ stacking ], actually by using taking a dark frame, subtracting it and then doing opencv2.multiply on the result.  I think I can also fiddle with the gain setting.

Regards

Steve

I'm using opencv2 on a quad-core Orange Pi and that manages to grab 6 frames a second from a webcam. It would be feasible to stack a few and also to use one of the denoise routines to drag a bit more signal out of the data

[SteveBz]

9 hours ago, GuLinux said:

Hi,

Your setup reminds a bit of mine: I have the shooting software implemented as a python module + script on a raspberry pi piggy backing on a headless INDI server.

Main difference is, I don't use any autoguider (yet).

Here's the code: https://github.com/GuLinux/indi-lite-tools/tree/master/pyindi_sequence

The main repo also includes a raspberry pi setup script, a webserver with some logging info, and various API/addons (for instance, I also print status on an OLED display).

 

Strictly answering your topic: ASI cameras work pretty well on Linux - among the best I've tried, I'd say. The ASI120 in itself is a bit of an exception: for many users it just works, but apparently some models do need a firmware update before, and some other models seem to refuse to work at all. I might have incomplete/outdated info though, just go to the ZWO forum and do a quick search.

It would be pretty difficult to get image directly in python though, as they don't support the V4L2 interface. You could however use indi (+ my module if you like).

I might be interested if you can get an autoguider algorithm with python and opencv, the autoguiding feature is the main thing missing in my scripts, if you'd like to contribute it would be cool.

 

Cheers,

Marco

 

 

Hi Marco,

I use this guy's code, which I've embedded in my own gui, for the auto-guiding. You'll see my comments and his replies underneath.  Unless he handled else-where, the main issue his code doesn't work "out-of-the-box" was that the dec calculation doesn't take into account the meridian flip.  I have augmented my own Arduino code to take this account and avoid reversing the dec axes.

https://sy2000.blogspot.co.uk/2014/05/star-autoguide-with-rpi-5-python-code.html?showComment=1508071001050#c561538101832271227

The other night, I was guiding for about an hour or more on Vega.

Good luck.  Anything I can do to help, please just shout.

Steve.

[SteveBz]

17 hours ago, furrysocks2 said:

It didn't work in guvcview. I then started using oacapture which for which there's a non-v4l2 driver. But I have Windows on my laptop which is what I take to my scope. I've not actually used the T7M in a scope yet at all yet, though.

I know v4l2's been looked into in the past, don't know the current state.

Ok, I've done some research and there are some python wrappers for the ASI SDK and as you say, the T7 is detected as an ASI120m*.

It might work.  Maybe I'll borrow a 120 from someone to test and then if it works buy the T7.

The nice thing about the 120s is that the holes in the back are configured for thermo electric cooling pads?

Regards

Steve.

[furrysocks2]

4 minutes ago, SteveBz said:

Ok, I've done some research and there are some python wrappers for the ASI SDK and as you say, the T7 is detected as an ASI120m*.

It might work.  Maybe I'll borrow a 120 from someone to test and then if it works buy the T7.

The nice thing about the 120s is that the holes in the back are configured for thermo electric cooling pads?

Regards

Steve.

The T7 is a different body shape to the ASI120 - I saw a comment somewhere along the lines of "body of a QHY, brains of an ASI".

[SteveBz]

1 hour ago, furrysocks2 said:

The T7 is a different body shape to the ASI120 - I saw a comment somewhere along the lines of "body of a QHY, brains of an ASI".

I saw that too.

It's hard to know which to choose.