A while back I wrote about the new Arduino Inventor's Kit from SparkFun. It's quite the package, including an Arduino, a bunch of sensors and output devices, and a dozen or so projects that are easy to build. The kit even includes paper overlays that you place over the solder-less breadboard. The locations of components and wires are printed on the overlay, and you just push them right through the paper into the breadboard to build the circuit.
I wrote previously that my 14-year-old was having a blast with it. He started with the music program, which defines an octave worth of notes and has "Twinkle Twinkle Little Star" programmed into it. After a little discussion of frequency and period he pretty quickly figured out how to add two more octaves to the program, and how to map the notes to additional keyboard characters. He then transcribed some of his violin music and had it play that. I've got him thinking about how he could make it play chords; we'll see if he's able to pull that off.
My youngest son, who in reality is nine, but who in his mind knows that he can do everything and more than his three older brothers can do, demanded the next turn. I had him try out the blinking LED program. He built the circuit himself and downloaded the program and was thrilled to see the yellow and red LEDs blinking. I showed him what numbers to change to make them blink faster or slower, and he had a ball changing them, especially when they blinked so fast that you couldn't see them blinking anymore.
My daughter just wanted to know why the lights were yellow and red, but not pink. At four, her turn with the inventor's kit is still a little ways off.
The kit has been packed away since I last wrote about it due to moving houses, but that is winding down and I hope to get it out soon.
There were some comments on the previous column asking about age appropriateness of the kit for younger kids. My oldest son, who has nearly zero experience with computers or electronics, was able to figure out generally how the program worked in an evening, although the C syntax is still a little beyond him, and I generally have to fix any typos he makes. My youngest doesn't have any idea how the LED program works, but he does understand that it takes longer to count to 100 than it does to 10, and that since the computer is busy counting, the larger numbers make the LEDs blink more slowly. He enjoyed building the circuit and was completely thrilled when he saw it light up for the first time.
I would recommend it for at least age nine and up, as long has you have reasonable expectations about how much your kids will understand about the programming.
For further reading: Arduino Open-Source Controller Platform Gains Ground