Two voltage measurements using Arduino (need two different grounds)

Discussion in 'Embedded Systems and Microcontrollers' started by akazemian, Feb 25, 2016.

  1. akazemian

    Thread Starter New Member

    Feb 12, 2016
    4
    0
    Hi There,
    I need to measure two voltage readings using Arduino... I use analog pins A0 and A1 to do that.... when I only do one measurement (a wire from pin A0 -or A1- and a wire from Ground) everything is fine and voltage reading is correct (I check that with multimeter), but when I do them both (four wires-two from ground pins) then the numbers are inaccurate. It makes sense since the ground potential level for two readings is not the same but I connect them both to ground of Arduino. I will be grateful if someone can tell me how to fix this problem. For some reason I must use only one Arduino to do this task.
     
  2. shteii01

    AAC Fanatic!

    Feb 19, 2010
    3,392
    497
    Use the same ground pin for the two ground wires.
     
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