Arduino Labview Voltmeter

Using Arduino Interfacing w/ Software on the Computer
1

Hi all!
I am using Arduino UNO board to measure a voltage and I`ve made a interface in LabView for that.
The problem that I face is the unstable measurement of current, I cant even read the value because of the "fluctuation". In this case i need to use the first decimal of the measurement but I cant understand where is the problem.

2

In this case i need to use the first decimal of the measurement but I cant understand where is the problem.

You have some code on the Arduino that you didn't show. The code is measuring a voltage, using analogRead() which returns an integer value between 0 and 1023. There ARE NO DECIMAL POINTS or digits after the decimal in integer values.

So, you have unnecessarily created yourself a problem.

3

//

void setup() {
Serial.begin(9600);

}

void loop() {
int sensorValue=analogRead(A5);
float voltage= sensorValue * (5.0 / 1023.0);
Serial.println(voltage);
delay(1000);

}
///

This is my code, but when I try to read the values, they are varying too much. I ve made an printscreen to see these values.
https://i.imgsafe.org/cb705e0bec.png

4

What is supplying the voltage that you are measuring? Print the raw value, NOT the value that you have diddled with.

5

What do you mean by raw value ? Like "Serial.println(sensorValue)" ?
Now i uploaded again the same code and only 0 value is displayed...

6

What do you mean by raw value ? Like "Serial.println(sensorValue)" ?

Yes.

Now i uploaded again the same code and only 0 value is displayed...

You have a hardware problem, then.

7

Now, with the same code and nothing connected to analog pins,the raw value displayed is 420 and so on. Is it normal ?

8

Is it normal ?

It is perfectly normal to get garbage from the analogRead() function when there is nothing connect to the pin you are trying to read.