David writes in:

I am interested in fooling around with LEDs. Nothing fancy I just want to learn some basic stuff, and build some easy circuits. I am 65 years old and have some time on my hands so I want to explore these devices. Could you send me a list of some elementary school level books? I have a couple of grand children that I want to play with; and, I think we could have fun and learn some interesting things together. I don’t know what aspect of this technology will interest them, but maybe we will build something that we can attach to an old cd player that will change colors in conjunction with the music.

Well, David, I don’t know about elementary school level books, but I can certainly suggest some kits to start you and your grandkids off. LEDs are a great place to start. They don’t take a lot of background knowledge or equipment to get started. A good first project is to make some LED throwies. All you need are LEDs, coincell batteries, magnets, and tape. You can get LEDs and batteries online, or from RadioShack or Fry’s Electronics if there’s one nearby. From there move on to blinkybugs and vibrobots, and then maybe the Sparkle Labs kit for learning electronics, which comes with an excellent booklet full of illustrations and easy-to-follow instructions for popular and simple circuits. As for making an LED blink in time with music, you could follow this Instructable. You might also like playing around with 555 tmers, as they’re pretty easy to get going, too. There’s a great article on them with sample diagrams in MAKE, Vol. 10. I’m so glad you’re excited about building things with your grandkids!