ArduIcingaAlert is a perl script that controls leds on an Arduino running firmata or a spark core with a custom firmware. The script reads the json output from a user specified url and uses it to determine the current status of your Icinga instance and notify you visually of problems. It has several options to allow you to select what types of alerts to get.
Code: https://github.com/jjfalling/ArduIcingaAlert