#define Green_LED D0 // green LED 'Charged' #define Yellow_LED D4 // yellow LED 'Medium' #define Red_LED D5 // red LED 'Dead' int analogValue = 0; float voltage = 0; int ledDelay = 2000; void setup() { pinMode(Green_LED, OUTPUT); pinMode(Yellow_LED, OUTPUT); pinMode(Red_LED, OUTPUT); Serial.begin(9600); } void loop() { analogValue = analogRead(0); voltage = 0.0048*analogValue; Serial.print("Analog: "); Serial.println(analogValue); Serial.print("Voltage = "); Serial.println(voltage); delay(1000); if ( voltage >= 1.6 ) { digitalWrite(Green_LED, HIGH); delay(ledDelay); digitalWrite(Green_LED, LOW); } else if ( voltage < 1.6 && voltage > 1.4 ) { digitalWrite(Yellow_LED, HIGH); delay(ledDelay); digitalWrite(Yellow_LED, LOW); } else if ( voltage <= 1.4 ) { digitalWrite(Red_LED, HIGH); delay(ledDelay); digitalWrite(Red_LED, LOW); } }