arduino serial monitor shows number without sensor hooked up to Arduino

[mahmoud-Adel]

I have arduino MEGA, and had try different codes to with serial print
but serial monitor shows numbers without sensor hooked up to Arduino
or any connection?!

code like that to measure force..

int fsr=A8;
int force;

void setup()
{

Serial.begin(9600);
pinMode(fsr,INPUT);

}

void loop()
{

force= analogRead(fsr);

force= map(force,0,1023,0,255);

Serial.println(force);

delay(200);

}

and shows that...

[Robin2]

You are just getting noise from the analog pin - quite normal.

...R

[mahmoud-Adel]

and how can i canceled it?!

[mahmoud-Adel]

I have that cable

if I buy that new one,it will change any thing..!

[Robin2]

I did not get the impression that the sensor is connected to the Arduino using a USB cable - are we misunderstanding each other?

Why not just connect the sensor to get the noise to go away?

...R