Arduino interfaced with labview, analogue read problem

[akash24]

Hi, im having an issue that i need to solve as fast as possible. I was using the setup as shown the picture, it was fine, then all of a sudden the analogue read stoped to work effectively.when no wire is connected it showing 2.5V with a lot of noise.. Any help would be greatly apreciated, thanks

[Nathan_B.]

If no wire (voltage reference) is connected then the pin is floating and you will get random results.  This is normal behavior.

[akash24]

But before i was using it normaly, not connected it was showing 0V, now its fluctuating around 2V, i tried to install news windows, changed cables, try another arduino even install labview on another pc, same problem, do you think its a setting?

[Nathan_B.]

If the pin is not connected to anything, the readings will not be predictable.  Why are you reading a pin that isn't connected?

[akash24]

Actually im doing my final year project, its a stair energy harvester, when no one press the stair, the is no voltage induced, so it was fluctuating, even the reference voltage was not zero. i dont know why before it was good... I found a way to make it 0 with no noise at all, i used a small ceramic capacitor 1000micro farad in parallel. that solved the problem. Thanks anyway

[Nathan_B.]

Ok, so the pin is not unconnected as you previously stated.  That makes much more sense.