/* Arduino Battery Tester Created: 20/01/2016 By Gus Modified N/A By Gus http://arduinomylifeup.com/arduino-battery-tester */ int greenLed = 2; int yellowLed = 3; int redLed = 4; int analogValue = 0; float voltage = 0; int ledDelay = 1000; void setup() { pinMode(greenLed, OUTPUT); pinMode(yellowLed,OUTPUT); pinMode(redLed,OUTPUT); } void loop() { analogValue = analogRead(A0); voltage = 0.0048*analogValue; if( voltage >= 1.6 ) digitalWrite(greenLed, HIGH); else if (voltage > 1.2 && voltage < 1.6) digitalWrite(yellowLed, HIGH); else if( voltage <= 1.2) digitalWrite(redLed, HIGH); delay(ledDelay); digitalWrite(redLed, LOW); digitalWrite(yellowLed, LOW); digitalWrite(greenLed, LOW); }