I am building a circuit with the Raspberry Pi that requires a button about fifty feet away from the central circuit. I am planning on using speaker wire for the connection from the Pi to the button. Is this an OK solution? If so, what gauge of wire should I use, or does it matter? If it isn't an OK solution, what should I use instead?
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2Not really a Pi question. More suited to an electrical site I would have thought. Who can say? If it works it works, it depends on the environment through which the wires are running. Twisted pair as is found in cat 5 cable may be a better choice as it has better immunity to interference. – joan Nov 21 '16 at 17:21
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For right now, I'm going to use a 16 gauge speaker wire, and if it doesn't work, I'll try a cat 5 cable like @joan suggested. – Sub 6 Resources Nov 21 '16 at 22:02
In fact, while this question if not specifically Pi oriented, it is (marginally) relevant to using the GPIO on a long cable.
The wire gauge is irrelevant.
You are in fact connecting an antenna to the GPIO, so you should minimise interference.
Twisted pair is a good idea, but a pair like speaker wire is acceptable.
You should avoid running the wire parallel to any other circuitry.
The most important is to use a low impedance circuit - i.e. a low value Pull up (say 470Ω) near the Pi itself.
answered Nov 21 '16 at 22:49
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Do you think that an RC low pass would additionally help EMI issues besides low impedance of the setup? – Ghanima♦ Nov 21 '16 at 22:54
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@Ghanima It wouldn't hurt, but unless the environment is next to a transmitter the signal level you can get on 15m cable would be low enough to cause no problem, provided it is terminated. – Milliways Nov 21 '16 at 22:58
