String of LEDs experiment

Next I wanted to try out the pins rather than just a constant voltage source (partly to start using it for simple things and secondly to check if my soldering was okay). There are four ports made up of 8 pins each, so I decided to write a program that would light up a string of 8 LEDs  in a row one by one.

There are two ways we could set this up:

Explain the difference between series and parallel resistors here. Mention about drawing too much total current in the parallel case.

So I built it using the single resistor schematic and it worked perfectly first time, except for one issue.. the long leads on the breadboard seem to have a lot of resistance because those LEDs were very dim in comparison.

I tested it on all four ports and amazingly (given my terrible soldering) they all worked!

• Link the arduino page
• Link the teensy page 
• http://www.pjrc.com/teensy/pins.html