This project is yet another node in my home’s sensor network. It needed two main functional parts: (1) a motion sensor across the entryway to my bedroom, and (2) a switch to control the lights on my bed (my canopy bed has lots of little LEDs hanging on it). It would communicate wirelessly with the rest of my sensor network and also allow my computer to control the bed lights. Since it would be fairly visible, I wanted it to look pretty. My bedroom kind of has a fairy-tale theme to it. With a starry fairy-tale princess bed, a mushroom table, a hat vine, and dragonflies on the wall behind my bed, I decided that this sensor node should evoke the feel of a forest pond or stream. A while ago, one of my art teachers gave me a bunch of slate because she was curious what I would do with it (thanks Dr. Ushenko!), and I decided it would be perfect for this piece.
I started with the insides. The electronics are a lot like my other sensor nodes, plus a couple darlington transistors to control the power to my bed lights. I designed the circuit boards and then had them made through BatchPCB, like usual. If anyone is curious, I can go into more detail about the circuit design.
I didn’t want a plain old boring switch for my bed lights, so I disguised the switch as a cat-tail reed. The stem is copper rod. In the guts of the piece, this rod is used to actuate a momentary-contact switch, shown to the left of the circuit board in the following picture:
Then it was time to tackle the slate pieces. I love working with new materials, but I was still scared that I would screw things up. I let the project sit for over a month and finally forced myself back to it. It turned out to be fairly easy to cut with a hacksaw. Cutting through all that grit totally destroyed the hacksaw blade, but whatevs, hacksaw blades are cheap. By the way, always wear a mask while cutting this stuff — silicosis is nasty, you don’t want to do that to your lungs. I decided to carve the slate and paint it, using watercolors where I wanted washes of colors that didn’t hide the slate’s beautiful texture and ink where I wanted dark black silhouettes. I carved it with some gouges from my set of x-acto knives. Again, the slate dulled the blades, but those blades are easy to replace. Actually, I found I could use the slate to sharpen them again, if I dragged them backwards through the grooves I had made; I’ll have to see if they dull quickly in the future, though. The next pictures show a couple in-progress shots as I worked with the slate.
The top of the box containing the electronics forms the surface of the pond or stream. It’s painted with blue and green washes and then coated with varnish. I added a couple more cat-tail reeds, but these are just static; they don’t act as switches or anything. I also broke up some of the slate, filed the edges smooth, and glued them to the top as rocks in the water.
Once it was all assembled, it looked like the pictures below!