Arduino "wave" of input noise

Hey gang!

I'm an EE and am currently using Arduino's to finish my senior design project (a wireless fencing strip/piste). I'm using the arduino to simply read the three lines of the weapon ( Called a, b , c). When the button is depressed, the lines a and b should connect.

Since I originally had the code such that the code wrote high to A and read from B, digitally. However, I was having trouble. To fix that, I tried to just read the analog input to see what the differences were.

When the button is pressed, the serial output will say 1023, at a slower rate (yes, I have changed the delay on the code to see if that was the issue). However, I kept getting noise, and the code just wasn't showing a big difference between button depressed (a and b line together) and button not depressed as much as a difference as I'd like.

Just to see, I connected the analog input pin to a resistor and a capacitor to ground in series. I still got the results below:
0
1
2
2
0
3
31
60
63
69
74
74
74
74
54
12
15
8
3
0
0
0
0
7
6
6
8
37
67
68
76
79
87
83
85
58
22
19
9
4
1
3
1
1
7
5
9
1
35
63
68
76
74
75
69
74
63
14
15

You can see the "up and down" of the wave of voltage read. Is there a way to reduce this, and allow for my code to work? Here it is below:

const int epeeAlinePin=2;

const int epeeBlinePin=A3;
const int epeeClinePin=4;



const int LEDpin=12; 




void setup(){
 Serial.begin(9600);
 pinMode(LEDpin, OUTPUT);    
 pinMode(epeeAlinePin, OUTPUT);     
 pinMode(epeeBlinePin, INPUT); 
 pinMode(epeeClinePin, INPUT);     //grounded for the bell guard 

 
  
}


void loop () {
  

digitalWrite(epeeAlinePin,HIGH); 

int Bvalue=analogRead(epeeBlinePin); 




Serial.println(Bvalue,DEC); 

delay(100); 
}

Thanks for the help!

-Kat

Really not clear what you are trying to do or how, nor what you expect to happen.

Circuit diagram is first useful piece of information, as is your description of what you expect v. what you see... It seems to be basically a push-button circuit (but larger ?).

At a guess I would say you had a floating analogue input pin. That is not one that is actually connected to anything. Post your schematic please.