How to shutdown your interactive Art

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If you build a piece of interactive Art with an Arduino, there is not much harm you can cause it by
just powering it down anytime. But when you use a computer, either a PC or a Raspberry Pi, bad things may happen if you just switch off the mains power unannounced.

A common occurrence is that you are asked by the museum or exhibit managers for instructions on how to properly switch off your interactive Art installation. Experience shows us that the more difficult it is, the more likely one day will be done improperly. And I really hate when a piece that took a lot of effort to create goes to waste because of a problem triggered by a "rough" shutdown. 

So one idea that has worked for us is to set up our system as a wireless access point. The person in charge of shutting the system down will use her phone to connect to our wireless network using a password we provided. Once connected just visiting a specific address and port number will cause the shutdown (first time they will write the URL, but other days they can just reload it). 

Acting as an access point means the network will appear on the list of networks available on the cellphones and works regardless the museum has an existing Wifi network (which we do not use) or not. Besides, people are usually happy getting this bit technical with their own smartphone. To keep things simple we do not have any additional security layer and shutdown is performed as soon as the user access the special location. 

The beauty of it is that it can be extremely efficient and simple to implement (no need to install a web server or fancy tools). We just use a simple script as below.



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