Background
Before I finished off my final version of the Countdown to Christmas back in the Summer of 2006, I was already looking forward to my next microcontroller (uC) project. This time I wanted to get into some welding and make a wireframe; I settled on a snowman snowfight and whipped up an animated gif (the one above). Being a little burned out from the countdown clock, I decided I wanted to make this one simple and see if I could accomplish it a little more expediently.
The Gist
I decided on the Microchip PIC16F688 for this project because I wanted to use a uC that had an internal oscillator since timing wouldn’t be as critical as with the countdown project. From there it was a matter of sketching out a rough animation and then seeing how I could implement this using the PIC and some muxes.
The Code
The code for this is extremely simple and short. Essentially a pre-programmed animation routine was hardcoded onto the PIC and I slowly step from one light setup to the next in sequence and repeat in the end. The only complexity was adding in a potentiometer to allow the user to speed up/slow down the animation on the fly for a more fluid view. The code can be found here (the .bas file can be opened in notepad). Some of it is commented well, some of it not at all, but it is there as a reference for you. Because of some of the limitations with the compiler I was using, the code ends up being uglier than it should be (the way nested ifs work, etc.).
The Lights
To make things simple this go round, I decided to run everything at 120VAC. This required a mod to the custom SSRs I built for the Christmas Countdown, but it was simply the change of a few resistors. Since I wanted to keep everything at 120VAC, I used strings of 100 count lights and either left them whole (and in cases of the body strung multiple sections together), or cut them in 1/2 (which still runs on 120VAC). Going this path meant I didn’t have to deal with costly transformers! I use colored C7 bulbs for the faces.
The Wireframes
The wireframes were my first attempt at welding (which I got a lot of help on from a friend). I used 1/4″ cold rolled steel which I picked up from a metal supplier (can also be bought from Lowes and Home Depot). We bent the metal rods and joined them together on cut sections of 3″ flat stock. I then drilled holes in the flat stock to put bolts/nuts through to join everything. Doing this, I am able to break everything down at the end of the year (though I never do).
The Outdoor Enclosure
For this outdoor enclosure i used a watertight fishing tackle box. I have holes on the two sides, one for the power cord to come through, and one for all the wires to the different sections to run through. I mounted the circuit board on wood so it wouldn’t be sitting on the bottom if any water got it. I also mounted an outlet in the box an plug my 5V wallwart into it as well as any lights that stay on all the time (like the bodies of the snowmen).