I am getting this problem on an Arduino MEGA 2560 and 2 Arduino UNOs (One fresh from box)
When I use the following line of code I am getting a voltage reading with nothing connected to the Arduino.. I should be reding nothing correct?
analogRead(A0);
As of right now I am receiving fluctuating readings which throws any sensor I try to hook up off....
Any ideas
I should be reding nothing correct?
Incorrect .
You have a floating input, there is non reason it should read zero (nothing)
You are picking up noise. Hook up something and try again.
You will only read "nothing" (zero) if you connect A0 pin to Gnd.
Is there a way to filter this noise so that my sensor will not be affected by it or should I take multiple readings and average them....
What sensor would this be? Link to it?
Moving this thread, this is project guidance or general electronics, I think.
shutterflypro:
Is there a way to filter this noise so that my sensor will not be affected by it or should I take multiple readings and average them....
A pull up/down resistor is usually the simplest, yet effective solution.
There's another similar thread, strangely enough.
http://arduino.cc/forum/index.php/topic,151084
A circuit like this (the bottom half) would remove any noise, because it isn't "floating":
In this case the sensor is an LDR.
Reading one of the analog inputs is a standard way to get a random number.
Mark
shutterflypro:
Is there a way to filter this noise so that my sensor will not be affected by it
No, you are misunderstanding; the problem occurs because the input is not connected to anything. Connect it to a sensor that applies a voltage to that input, and the input is no longer floating and you no longer get the problem.
