A few more LEDs

I found 3 more LEDs. 2 were white and the other blue. Like the original, these were destined to be replacement bulbs for a Christmas light set. I don't know their power requirements, etc. which make for a brave assembly on my new Arduino board. At minimum, I believe, from what I've read, that I should have current limiting resisters in my circuit. But, the risk, I hope, is to the LEDs and not my board. So I wired up my tiny breadboard with these 4 LEDs. First, I should point out, there is no flat side on these LEDs, but they do have one longer wire (anode). But, to be sure that it wasn't an anomaly from the assembly process, I read about a third method of determining the positive and negative leads.

Excuse my crude drawing. If you look inside the LED, the wires meet up to little plates inside. The larger side, on the right in this drawing, is the negative.




With that information in mind I wired up my circuit. I used a program from Fritzing to draw out my wiring diagram. Besides providing this tool, which is designed to work with Arduino, they can even custom build a circuit board to your specifications. So, if you ever design something great and even have ideas to sell it, this program will allow you to prototype the wiring diagram, automatically create a schematic, and design the etchings for a PCB that you can then send off to Fritzing Fab to have it made into reality. I can imagine, someday, when the kids and I have fabricated our robot using a breadboard or two to hold all of our wires, we just might want to have boards made, since they'll be smaller and more durable than components stuck in a breadboard.

So here is my drawing (click for larger version.) You'll even be able to see inside the LEDs, when you enlarge, to see what I was talking about above. Now, we get to play a little. My son came up with some scenarios, and we wrote a sketch to accomplish it.I'll go through that code next time.

BTW, I forgot to mention, there is a fourth way to tell the positive and negative side of an LED. Plug it in, power it up, if it doesn't light, turn it around.