Month: May 2007

Since everyone else is doing it, I decided to hack together my own persistence of vision thing this evening. This is a circuit where you have a single vertical line of LEDs, but if you turn the LEDs on and off fast enough and wave them around, your eyes are fooled into seeing complete letters. It only took about 20 minutes to write the C code to load up onto my trusty ATmega8, then I used a camera with a long shutter period to take the picture to the right.

I realize my blog has devolved into Bob’s Dumb Project Of The Week lately. I’ll have to work on that. Lots of travel is coming my way soon: Toronto this next weekend, Atlanta in three weeks, and Warrenton, VA somewhere in between. I shall report on them soon enough.

I spent part of yesterday and today assembling this monster of a digital clock. The brains behind it, like my previous project, is a Dallas RTC chip; the rest is just microcontroller glue to read the time over the bus and write the hours and minutes to a quartet of seven segment decoders. The arduino microcontroller board can run off of a 9V battery so this assembly is portable, like the, er, $0.50 worth of electronics that are in your wristwatch.

Angeline had a good question for which I didn’t have an entirely satisfactory answer: “Why?”