Nearly every consumer device makes use of the Light Emitting Diode (LED). This highly versatile device offers an easy way to add an indicator to any project while drawing a relatively small amount of current. Once their operation is understood, adding them to any project is a simple task. This tutorial is a simplified explanation of how a LED works and how to select a current limiting resistor. The LED tutorial here is enough to use LEDs in a project but is not intended to be a thorough explanation.

LED Anode and Cathode

Rob ‘linear’ Arnold has put together a fantastic LED Series/Parallel Wizard.  Not only will it calculate the current limiting resistor you need, it will draw a circuit diagram, and give you full statistics on power usage.  If you are just getting started with Electronics, this is a great resource for learning about LEDs.  Experienced users will enjoy a quick check of their math. The array above is designed for some Blue LEDs I have laying…

The PCB for my very first Arduino shield arrived today from BatchPCB. At first glance everything looks good. The silkscreen with my name and web address didn’t come out so well but that was probably my fault on trying to fit in too much. Looking forward to assembling then with some Blue LEDs!

This pattern is called Row Your Boat. As one of the strips starts to get brighter, a nearby strip will join in the fading.  After completing a fade cycle, they start switching colors. There is a random strobe thrown in there as well.  The first 10 seconds are with a diffuser (piece of paper), the last 10 seconds are without.  The final panel will use a diffuser.

Arduino LED Strips

Initially I tried to get a LCD screen working with my Illuminato based Arduino. After a couple of attempts I realized two things: 1. The Iluminato is not ready for prime time. and 2. I burned out the LCD.  So I decided to move on to the LCD strips I have from Sparkfun.