A complete noob question (please don't laugh)

I’m just starting out - I have the Arduino Diecimila, a breadboard, some LEDs, and some wires.
I’m trying to replicate the circuit pictured here: http://www.arduino.cc/en/Tutorial/Loop

My question: all of my LEDs have 2 pins. However, the picture at the above URL appears to show LEDs with only one pin.

Am I wrong? Do I have to order 1-pin LEDs? Break off one of the pins?

Any help would be greatly appreciated.

Thanks.

All LEDs have two pins (the positive and negative supply). there are LEDs with3 pins but not with 1. The longer pin is the positive supply and the shorter is the negative.

In the picture (and in all cases) the ground is connected staright to the Arduino’s ground, while the positive is connected to the Arduino’s +5v but with a resistor in-between. That’s why there is a resistor on each LED in the picture. The value of the reristor varies but a very common value is around 220 Ohms.

Thanks so much for your swift response. I’m still a bit confused though.

In the pic, I only see one pin coming out of each of the LEDs (http://www.arduino.cc/en/Tutorial/Loop ). Are we talking about the same pic? I see that pin connected to the ground of the breadboard. But I don’t see the other pin at all.

Thanks.

Trust us ! There is no such thing as a one pin LED, actually i can’t think of any electronic componet having less than two (or more) pins

The other pin is hidden under the LED, it’s the angle the picture is taken at that hides it.

Thr other pin from each LED is connected to the same row of holes in the breadboard as the resistors.

I don’t think you understand the wiring/internals of a breadboard. See the below pic. The wire at the bottom row you see going to the LEDs is to ground, which would be connected to the shorter pin/cathode. The longer pin/anode goes to the resistors witch in turn go to the arduino.

Additionally I highly recommend you check out the tutorial at this link. I am quite the noobie too and this helped me get my feet wet.

http://www.ladyada.net/learn/arduino/

Trust us ! There is no such thing as a one pin LED, actually i can’t think of any electronic componet having less than two (or more) pins

The other pin is hidden under the LED, it’s the angle the picture is taken at that hides it.

Thr other pin from each LED is connected to the same row of holes in the breadboard as the resistors.

Which is why circuit diagrams are better than photos when building your own circuits! :slight_smile: I appreciate they do make it harder for beginners, but perhaps it would help avoid such errors.

You guys are awesome!
Thanks so much for the help.