Today I built my new prototype on the breadboard and tested it. I had a few problems along the way but was able to debug them fairly easily. I would sometimes put the wrong leg of an LED in or have a resistor touch a leg of an LED and I missed a bit of the code expanding it to 10 pins.

The sequence is for the first LED to light up, a delay of 1/4 second (250), then the next until all ten are lit, and then the first goes off with the rest following. Changing the various delays is easy of course, but I haven’t experimented with that yet.

The prototype is up at the 123D site. There you can see a simulation and the code. One thing about the site that is difficult is the gestured zoom feature – it’s finicky, so if you find yourself stuck with no where to go press refresh on your browser. Using 123D is easy and intuitive. I could easily see using it to curate students’ circuits without the fuss and expense of the Arduino. Without empirical evidence, my guess is that you could function nicely in a class with 4-5 actual Arduinos in a class of 16-20 students using 123D.