I want to communicate between two arduino's using one wire (sending and receiving signals - if matched, blink LED by receiver to indicate it), which are separately powered by 9v batteries.

I want to send only just a signal (as a CLK).

  • 2
    Are you talking a one-wire technology or you mean just one wire connecting two arduinos? – user31481 Nov 24 '17 at 12:26
  • Unless you want to work at RF frequencies and use modulation in your communication then you will need at least 2 wires. – Majenko Nov 24 '17 at 13:10
  • @LookAlterno yes, you are correct. Both are separately powered but only single wire used to connecting them (no GND). I want to send only just a signal (as a CLK), if matches receiving arduino blink a LED to indicate it. – Devon Ravihansa Nov 24 '17 at 13:42
  • @DevonRavihansa Edit that info into your question. – gre_gor Nov 24 '17 at 13:51
  • Read and comprehend: hackingmajenkoblog.wordpress.com/2016/12/06/… – Majenko Nov 24 '17 at 18:10

One wire does nothing.

For transmitting power or signal you need a voltage differential, and that means two wires minimum. One wire is for ground, a common base level for the two Arduinos. The other is for the signal itself.

In some cases (cars) you only see one wire connecting things, but the car frame itself is uses as ground.

Edit: This blog The Importance of Sharing Grounds explain the matter in great detail.

| improve this answer | |
  • I want to make a single wire continuity tester using two arduinos, any suggestions?? Thank you. – Devon Ravihansa Nov 24 '17 at 13:53
  • @DevonRavihansa. That's another question. – user31481 Nov 24 '17 at 13:57
  • Two ends are in far distance, so connecting another wire is useless. – Devon Ravihansa Nov 24 '17 at 14:01
  • @DevonRavihansa. The laws of physics are not optional. – user31481 Nov 24 '17 at 14:03
  • Can't we make as AC Tester works? – Devon Ravihansa Nov 24 '17 at 14:11

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