Battery Monitor

Forum 2005-2010 (read only) General Frequently-Asked Questions
6

can anyone help me with displaying the voltage to the hundredths place in the serial monitor?
so far i have this but it outputs 12.60 volts when the true voltage is 12.85

827-829 on the analogRead = 12.85v

int vPin = 5;
int val = 0;

void setup(){
  Serial.begin(9600);
  pinMode(vPin, INPUT);
}

void loop(){
  val = analogRead(vPin);
  Serial.print(val / (645/10), DEC);
  Serial.print(".");               
  Serial.println(val % (645/10) ,DEC); 
  delay(1000);
}

any help?