// constants (or #define with no ; at end of line) won't change. They're used here to set pin numbers:
int readPin = A3;
float v2;
int wait = 500;
// Variables will change:
void setup() {
pinMode (readPin, INPUT);
Serial.begin(115200);
}
void loop() {
v2 = (5./1023.)*(analogRead (readPin));
//Serial.print(" = ");
Serial.print(v2);
Serial.println(" volts");
delay(wait);
}