Well perhaps a dial more than a twist, a telephone dial that is. Arduino forum member Msquare has created a fascinating and somewhat portable guessing game that uses an old telephone dial for a form of input. The game is to guess the number displayed with the LEDs in binary, and the user dials in their answer.
It's an original design and also offers a method to learn how dials can be used in general and perhaps applied to other forms of project. For example with a GSM shield you could work on a mobile device with a rotary dial.
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