Category: Hobbies

Things I do for fun

Posted on

Another Nest bites the dust

While I was playing in the South Carolina QSO party yesterday, I discovered my Nest thermostat decided to flake out and turn the AC on, even though it was saying the AC was off.

It’s not the first time I’ve had a Nest fail on me  before (technically, just the base of the Nest).

No idea if it just happened to be a coincidence, or if it got zapped by some RF while I was playing on the radio. Also a little puzzled as to why the Nest base failed this time and not the other times I’ve been on the radio.

A search of the internet brings up a few forum and email threads that suggest the Nest thermostat base might be susceptible to RFI, probably via RF coupling through the control cable between the thermostat and the HVAC unit.

At the old house, I think the antenna was far enough away that it was never a problem. Here, with the antenna pretty much on top of the roof, RFI into the thermostat via the wiring is a definite possibility.

 

Guess now I need to see if I can add a bunch of ferrites to the wiring.

Posted on

Hard drive motor as a rotary encoder

This is a pretty neat application. I guess I should have saved those motors from the hard drives I’ve dissected.

Found via Hackaday.

Posted on

Phantom volume

The TV started doing this strange thing where the volume would turn down all by itself. Even after turning the volume back up, it would go back down again all by itself. TV works fine after several hours of watching, but then the volume on-screen display (OSD) will pop up randomly and sometimes the volume will change. After a while, the volume OSD pops up with increasing frequency, and the volume drops more and more until eventually it’s doing it all the time.

Ruled out the remote sending out random signals to the TV. Even took the batteries out to guarantee the remote wasn’t doing anything.

The control buttons on the side of the TV are capacitive touch buttons, so I thought maybe those had gone screwy. Opened up  the TV and disconnected the control buttons, but it ended up having no effect. Still ended up with the same behaviour after a few hours of the TV being on.

TV innards
TV innards
TV power supply board
TV power supply board
TV control board
TV control board

At this point, I figure the problem is probably something heat related since the phantom volume changes don’t start happening until the TV’s been on a while. I’m not sure where else to go digging for the problem.

Looks like replacement control boards can be obtained from various sources for not a whole lot of money (definitely less than replacing the TV). Swapping out the control board would probably take care of the problem, unless of course the problem lies elsewhere.

Posted on

Little black spots

On the sun today

Sun 20170329
Sunspots on the Sun 20170329

Still working on getting the hang of getting pictures of the sun with my little solar telescope. A little blurry, but a couple of sunspot groups can be seen pretty easily. At first I thought they were specks of dirt or dust on the telescope optics, but a check of spaceweather.com showed there were indeed two groups of sunspots (2644 and 2645) on the surface of the sun.

Used the little Barlow lens with the camera adapter for this shot. Gives a larger image of the sun but not quite as bright, and the smaller FOV means spending more time hunting for the sun.

Posted on

Celestron EclipSmart photos

It took a little bit of finagling, but I managed to get some photos of the sun with the Celestron EclipSmart telescope and my DSLR (Canon Digital Rebel XT).

Attaching a heavy DSLR (568 grams) to the back of a light weight telescope (456 grams) mounted on a light weight tripod definitely caused some stability issues. Aiming and getting the telescope/camera to stay in position was a challenge. If you’re going to use a DSLR with this telescope, you’ll want a solid tripod with some good locks.

They’re not the greatest photos, and pretty boring because it looks like there’s not much in the way of anything happening on the sun. Can’t see a whole lot of detail in them, but they’re good enough. These images are cropped (1k x 1k) from the original 3456×2304 pixel image.

ISO 400, 1/20 s
ISO 400, 1/30 s
ISO 200, 1/15 s

This is my first time with telescopes and DSLRs, so I still have a fair bit to learn about the process. Astrophotography is something I’ve wanted to get into for a long time. I suspect there will be some new telescopes and camera upgrades in my future.