5 minutes ago, JamesF said:

Perhaps an ultrasonic wind speed/direction detector might be useful in that instance.  I imagine a rotating cup design might induce a fair bit of vibration.

James

That's a thought - I guess it could do.  But an ultrasonic wind detector is beyond me.  Maybe I'll go back to having the weather station wind instruments somewhere else entirely.

Just now, Gina said:

But an ultrasonic wind detector is beyond me.

I refuse to believe it, Gina :D

I've seen some based around an Arduino that looked quite achievable, even for me.

James

Really???  Where? What I've read so far would indicate considerable complication and difficulty.

Been looking at pipes.  70mm rainwater down pipe seems more rigid than I thought and might work.  No problem making brackets for it to mount onto the dividing framework of the observatory (separates scope room from warm room and really solid). 

6 minutes ago, Gina said:

Really???  Where? What I've read so far would indicate considerable complication and difficulty.

I *think* this is the one I was originally looking at.  It looks kind of familiar, but I'm not at all certain at the moment.  Really annoyingly it appears that I neglected to take a copy of the URL when I added it to my list of possible future projects

https://hackaday.com/2013/08/21/ultrasonic-anemometer-for-an-absurdly-accurate-weather-station/

James

I'd rather use an aluminium pipe than a plastic one.  I wonder how long a standard fan would last in a damp atmosphere.  A stepper motor would be alright electrically.  Maybe the rotor might rust.  When a small water pump I was using died, I took it apart and found the rotor was isolated from the drive coils with plastic, the rotor was the impeller.  Anyway, all this depends on whether the ASI 120MC needs cooling and by how much and I can't really find out until dark.

1 hour ago, JamesF said:

I *think* this is the one I was originally looking at.  It looks kind of familiar, but I'm not at all certain at the moment.  Really annoyingly it appears that I neglected to take a copy of the URL when I added it to my list of possible future projects

https://hackaday.com/2013/08/21/ultrasonic-anemometer-for-an-absurdly-accurate-weather-station/

James

I saw that but couldn't see how it was done - missing something here!

Been trying to get the ASI 120MC-S working ready for trying it at night but no joy!!.  Been trying SharpCap on my W7 laptop which is usually a good standby and never had a problem before.  Didn't recognise the camera.  Read the leaflet that came with the camera and it said it wouldn't work in Wondoze without installing a new driver - which I did.  Still no joy.  Then I noticed on the website that it said it wanted SharpCap 3 or later and I had 2.9 so I tried downloading and installing SC 3.2 - wouldn't install.  Tried Artemis Capture and EZ Planetary software but neither found the camera.  SharpCap showed the camera in the list but gave an error on selecting it.  Looks like it's time to go back into hibernation.  Looks like I can't handle computers any more!  I think it extremely unlikely that the camera is at fault - FLO don't supply faulty goods!

So much for that bout of high self-confidence and raring to go attitude - now thoroughly deflated.

Tried the ASI 178MM camera and SharpCap had no problem with it.  Swapped back to the 120MC which on re-scanning for cameras, showed in the list but selecting it gave error "Camera could not be started" and Error 'ErrorCameraRemoved' from call to ASIOpenCamera(cameraID=0).

Give Firecapture a  try, just to make sure the camera is functioning ok Gina.  <whisper>Or even oacapture, on a Linux box</whisper>

James

Camera is alright.  Downloaded ZWO's "ASICAP" and it works with that.  Just won't work with SharpCap, EZ Planetary or Artemis Capture but that doesn't matter as long as it works with INDI which I shall try later.

Doesn't look like I'm going to be imaging any stars tonight but I guess it's too early to tell.

Try oacapture on Linux. Also make sure you are using a USB3 socket & cable.

Probably will do but ASICAP is working fine.  Just about to connect the camera to the RPi and run KStars/Ekos/INDI and see if it works.

Still on ASICAP with W7 laptop and running 60s exposures.  The image isn't bad.  Camera temperature says 5C - it's outside the window on the window sill.  There is thin high cloud but a number of stars are showing including Orion's belt and sword etc.  There is a small amount of noise which I think would be cured with quite a small amount of cooling.  Of course it's winter and cold outside - it will be a different matter in the summer.

Just finished eating so INDI will have to wait a little longer.

Yippee - working with the RPi and INDI.

30s exposure and gain of just 50.

Solid cloud now.  This is 60s exposure and gain at 100 (seems maximum for this camera), temperature of 2.7°C.  Showing noise now.

At least it's only solid cloud.  We have rain here

James

It's here now too!  Outdoor experiments now curtailed by rain!

Tried to get the Peltier TEC off the large passive cooler but it's stuck firm.  If I try to use more force I'm afraid I'll break it and it wasn't cheap so it seems I'm stuck with that large passive cooler.  Oh well...

Here's a photo of the camera and lens sitting on top of the Peltier TEC on top of the passive cooler,  I'm now thinking about the design of the camera housing (with thermal insulation) and the outer casing together with how to seal everything against moisture ingress.  I'm wondering if I can seal the inner, camera housing as well as the outer casing.  I would feel happier with two layers of wet protection for the camera, in view of the previous catastrophe.  Also, I'm wondering if I can arrange that warmth from the cooler can be arranged to rise into the dome to help with keeping dew off the outside.  Both inner and outer voids will have silica gel packs.

Thinking I might use the DHT22 temperature and humidity sensor to monitor temperature and humidity in the ASC I did a search to see if there was an INDI driver.  Couldn't find one as such but did find a complete weather station in INDI called MeteoStation which I might take a good look at when I get back to my weather station project.

Also, Indiduino ;  An automation solution for astronomical observatories

I was thinking that if I fill the space between camera and it's casing with plastic foam there will be no room for extra air and no need for silica gel pack to dry it but then thought of the air in the camera, so silica gel is a good idea after all...  Of course, the 3D printed camera casing provides thermal insulation as it's filled with lots of mini air pockets.  Maybe a fairly close fitting casing with some space for a silica gel pack.  I've closely examined the camera and there's definitely gaps round the connectors and I can see the PCB inside so the casing is not sealed in any way and there will be air inside the camera with a moisture content.  This will probably condense onto the inside of the casing when it's cooled and heat given off by components may keep the electronics dry but I don't think I'll depend on it.  The place where the USB plugs in seems a good place for the silica gel pack.