As part of the yet to be announced Flow Analytics startup, I have to learn quite a bit more about building hardware. All of my learnings will be blogged for anyone who wants to follow along.

Tonight's learning is simple:

  1. LEDs have a plus and a minus side.
  2. The plus side is denoted by a LONGER lead.


  • Resistors are non-polar (it doesn't matter what side you connect them on); I knew this already but it felt wise to write it down since you always use a resister with an LED
  • A resistor used with an LED is called a ballast resistor and "The ballast resistor is used to limit the current through the LED and to prevent excess current that can burn out the LED. If the voltage source is equal to the voltage drop of the LED, no resistor is required." See Also - LED math is on this link!