so that there a 2 wires rather than 3 to connect between the two for purposes of serial communication. And the same question for 3 arduino megas on a common rail and using serial connections?
Gerben
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1 Answer 1
All voltages are ground referenced, hence the ground is the only (supply) connection required. Remote modules can be self-powered and signals will still be discriminated as long as ground is connected.
answered Mar 24, 2015 at 15:24
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thank you for your prompt reply , the 9v and negative rail are connected for purposes of powering the arduino boards anyway. I should have asked Do I need an additional connection between the grounds to that provided by the power connection.wobbler– wobbler2015年03月24日 15:35:21 +00:00Commented Mar 24, 2015 at 15:35
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If they're using a common ground then their grounds should be already connected.Ignacio Vazquez-Abrams– Ignacio Vazquez-Abrams2015年03月24日 15:36:39 +00:00Commented Mar 24, 2015 at 15:36