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Basic Electronics » Powering I2C remote device?
June 27, 2011 by Ralphxyz |
Can one power a I2C slave with a separate power supply from the mcu power supply? I know one can have multiple masters do they all need to use the same power supply? I tried using a battery for the slave but it didn't work so I thought I'd better ask. In trying to think through the logic I can see where separate power supplies might not work but it does seem practical if you are using remote slaves. If you have to use a common power supply that makes I2C a four wire not a two wire system. I suppose you would call the "bus" two wire. Thanks for the clarification, Ralph |
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June 27, 2011 by Noter |
You will have to have a common ground between the them. So, 3 wires, 2 for I2C and 1 for GND. |
June 27, 2011 by Ralphxyz |
Oh, so the wired common ground (3 wires) would work. That makes sense. Now I wonder if "Earth Ground" would work? Years and years ago I used to setup field telephones while in the Army using "phantom" wiring. We could get a extra circuit using earth ground. I do not see earth ground mentioned in modern day electronics. I know I could run three wires or two pair wiring as easy as two wires but it's so interesting, and I am so cheap. Thanks Paul, Ralph |
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