BatteryStatus.ino

//
// BatteryStatus
//
// A simple script that displays green when the battery
// voltage is ok and red when it is getting low.
//
//  NOTES: 
//    1 - this is the table of actual battery pack
//        voltages and analog sensor readings
//
//  Battery Voltage | sensorValue
//        4.7       |      773
//        3.2       |      578
//        1.6       |      320
//        0         |      0

#define GREEN_LED  1
#define RED_LED    0

// run once, when the sketch starts
void setup()            
{
  // setup the RED and GREEN LED's
  pinMode(BILED, OUTPUT);
}

// run over and over again
void loop() {
  // read battery sensor value and map it to 0-5 volts
  int sensorValue = analogRead(BATTERY);  
  int mappedSensorValue = map(sensorValue, 0, 800, 0, 5);

  if (mappedSensorValue < 3)
  {
    // battery is low ... show red
    digitalWrite(BILED, RED_LED);
  } else {
    // battery is ok ... show green
    digitalWrite(BILED, GREEN_LED);
  }
  
  // pause for 1 sec
  delay(1000);                           
}