Ad Astra Observatory

i got the DC power working a little better today. The 12v (battery) and 24v (power supply) are now under the NE corner eave, and they are supplying power to the dome control box and the pier via wires that are attached to the walls, and they even run through an outlet box, in case I ever need to add breakers or switches or whatever expansion is required. 

I also hooked up the dome control switches at the desk, so I can rotate the dome from the warm room! Woot. 

I just summed up several hours’ work in a couple of sentences, but again, running the power cables in a “permanent” way means that I can start to move devices to their final locations. So the battery bank is all set up, and I have all the access I need to low voltage power. I still need to bring 12v and 5v to the pier, but that feels a lot more doable now. I can see where the wires will go, it’s just a matter of running them. 

I admit that was a pretty good stopping point, but I started thinking about next steps, and really all that’s left is dome automation. At this point, I could give the place a good scrubbing, to get out all the sawdust, hook up the computer and the camera, and start rolling. I would have to rotate the dome by hand, but the rest of the facility is already head and shoulders above where the Newark observatory was, as far as ease of use. 

Anyway, dome automation is a big step. To get it working fully, I need several sensors (home and limit switches, and the rotation encoder), and some more circuits built, including the shutter limit switch relay.

I decided that getting the sensors working was the next thing to do. First up, the encoder. I bought some very cool encoders early on in the project; they are designed to be mounted to the face of a motor, and clamp onto the motor shaft to measure it’s rotation. It turns out that the dome motors don’t have an exposed shaft , bummer. So I contrived a plan to attach an encoder wheel to one of the dome wheels, and hopefully when the dome turns, the dome wheel will turn, and voilà. I spent another couple of hours getting the bracket built, and the setup works fine, except that apparently some of the wheels in the dome don’t turn the whole time the dome is turning. 😳 the encoder wheel turned just like I planned whenever the dome wheel turned, but that was about 40% of the time when the dome was turning.  I will find a different dome wheel to attach to. I still think this plan has legs. 

I am also running into a color coding problem. My original plan was to make inputs one color, outputs another, and data cables, a third. I bought a lot of the “output” color of wire, thinking that I would be using a lot of that, and much less of the “input” color.  Well, strictly speaking, the only “outputs” in the system are the motors, which have their own cables, and some planned LEDs, of which there are quite a few, but …

So, as I am running low on “input” color wire, I have decided that I am going to use that only for “human” inputs, and have the “sensor” inputs (home switches and encoder and stuff) be “output” color. I should have plenty of “human input” wire left to do 12v light switches. I am looking forward to tearing into that big spool of “output” wire. Tomorrow. 

Goodnight, Hilltop O.