My most glorious summer yet is reaching its end. With about a month and a half before I begin dental school, I pause to reflect on what I’ve done, and what I still plan to do. Unlike previous summers where my time was devoted to academic/thesis requirements, this summer hosted a 9am-5pm job with time to do whatever I want to after. I’ve made great progress in the realm of microcontroller programming, and am nearing the completion of my prime number calculator. I’m very happy with its progress. I think it’s time for some photos.

Here I can be seen working on my prime number calculator. The primary display is nearing completion, and now it’s time to start wiring the buttons, switches, speaker, etc. Note the vintage scope in the background. In the photo it’s showing 60Hz (I couldn’t think of anything more profound to display?) which I’ll say is a representation of the fact that your body is continuously bombarded by electromagnetic radiation whenever you set foot in a house.

This is the current state of the back panel of the prime number calculator. It’s becoming quite complicated.

As you can see, most of the LEDs are working but I’m still missing a few 74hc595 shift registers. It’s not that they’re missing, so much as I broke them. (D’oh!) I have to wait for a dozen more to come in the mail so I can continue this project. Shift registers are also responsible for powering the binary-to-7-segment chips on the upper left, whose sockets are currently empty. Since this project is on pause, I began work hacking a VFD I heard about at Skycraft. It’s a 20×2 character display (forgot to photograph the front) and if I can make it light up, it will be gorgeous.

Here’s a high resolution photo of the back panel of the VFD. I believe it used to belong to an old cash register, and it has some digital interfacing circuitry between the driver chips (the big OKI ones) and the 9-pin input connector. I think my best bet for being able to control this guy as much as I want is to attack those driver chips, with help from the Oki C1162A datasheet. It looks fairly straightforward. As long as I don’t screw up my surface-mount soldering, and assuming that I come up with 65 volts to power the thing (!) I think it’s a doable project.

Update: I found a funny photo from field day. After the tents, antennas, and radios were mostly set up, everyone was exhausted. I was ready to make some contacts! I fired-up my ‘ol netbook and tried communicating over 40m using psk (a digital mode), a mode I’ve never used, with software I’ve never used, on a band I’ve never used. It wasn’t working either. I spent the first several hours in frustration because what I was trying to do wasn’t working, and I couldn’t figure out why. This photo was taken at the height of my frustration =o)