TinyShield 16 Edge LEDs - AMBER

The TinyShield 16 Edge LEDs allows some cool and easy LED indications using only five I/O signals. The 16 LEDs are mounted around the outside of the board, and can easily be seen even when the LED board is in the middle of a TinyShield stackup. The LEDs are arranged using Charlieplexing, which is a technique to allow for control of multiple LEDs using fewer I/O signals. Available with Red, Green and Amber LED color options.

The TinyShield 16 Edge LED board has 16 LEDs mounted around the edge of the board. These LEDs only use five signals from the TinyDuino using a technique called Charlieplexing, which saves the other I/O for other functions for your project.

A basic example Arduino sketch that works with the TinyDuino and TinyShield 16 Edge LED boards can be downloaded here.

A library for Charlieplexing can be found on the Arduino Playground: http://playground.arduino.cc/Code/Charlieplex

Circuit Details

The TinyShield 16 Edge LED boards use pin numbers IO5, IO6, IO7, IO8 and IO9. Fo example, to turn-on the LED D1 (and D1 only), IO5 should be high, IO6 should be low, and all other pins should be set to an input (this prevents other LEDs from turning-on when they aren’t supposed to).

Note: A problem with Charlieplexing is that you obviously can’t turn-on all the LED’s at the same time. To account for this, you can “flash” them (turn them on and off really quick) at a frequency of at least 50Hz (assuming you don’t want to be able to see them flicker on and off).