#define LED 13

void setup() 
{
  Serial.begin(115200);
  pinMode(LED, OUTPUT);
}

void loop() 
{
  digitalWrite(LED, LOW);
  Serial.println("Adapter");
  Serial.println();
  delay(1000);

  digitalWrite(LED, HIGH);
  Serial.println("Battery");
  Serial.println();
  delay(1000);
}