The raspberry pi does not actually need to be housed in a case as there are no moving parts or areas of the board that would be damaged by touching. The case does provide an aesthetic appeal but its not essential. There are many variants of case for the pi 2 model b and the price variance is quite wide. There is no right or wrong choice should you decide to use a case.

It is also possible to mount the pi on the back of the TV you use to display the signage which is ideal if you are also powering the pi from the TV USB port. Make sure you are buying the TV mount for the pi 2 model b when you order

 

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