int readVal;
float V2;
int time=400;
int readPin=A3;
void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);


}

void loop() {
  // put your main code here, to run repeatedly
readVal=analogRead(readPin);
V2=(5./1023.)*readVal;
Serial.println(V2);
delay(time);


}