Category Archives: Programming

Cool bicycle Persistance of Vision project

As an introduction to computers, the kids and I have been building the SpokePOV. The kids have been into bicycle projects this summer, so this is a great crossover project.

The Spoke POV is a project I first saw on There is a kit available from

Photo of completed project from

We are using green LEDs and hope ours will be this cool!

We ordered the kit with the extra ROM so we animate the images. We picked up some 96/4 tin/silver solder from Radio Shack. It is lead free, so I don’t mind the kids using it.

The SpokePOV uses an ATMEL ATtiny2313 microcontroller and and has two rows of 30 LEDs. The LEDs blink out a pattern as the wheel spins that the eye perceives as a complete picture (follow the above links for action photos). There is a hall-effect sensor, so the processor can sense the wheel rotation and calculate how fast it is spinning, to create the proper pattern.

So far, we have a completed circuit board. There is a Windows program to create the images and download to the Spoke POV. We’re having a bit of trouble with that.

PERL Programming

I’ve been working with the PERL on a few projects. The power of PERL comes from two things. The First and most important is it’s Regular Expressions, which are very powerful pattern matching.

This is very useful for processing a long log file, looking for oddities, or when converting data from one file format to another.

PERL is also Interperted, so you can make changes to your program and test them immediately.

I downloaded a copy of PERL from

Try searching for PERL, REGULAR, EXPRESSIONS in your fav. search engine to learn more.