If you are running website on a server you know that many things can happen. It can go down due several reasons and you may notice this only when try to connect or load webpage. In order to avoid long downtimes you need to set up alarm which would ring bells and whistles once it goes down. Kelsey shared a website down alarm project based on Tessel board.
Tessel board simply pings website every second and once trouble is detected it starts alarm which is a large red alarm light. Lamp was modified to be controlled from relay module which plugs directly to Tessel board. Speaking of Tessel boar it is an ARM processor based development board which runs entirely on Node.js. It already has built in WiFi module what makes it great tool for Internet of Things (IoT).