//Define an external pin for a 2nd LED
#define LED2_PIN 12

////////////////////////////////////////////////////////////////////////////////
//FUNCTIONS
////////////////////////////////////////////////////////////////////////////////
void setup() 
{
// the setup function runs once when you press reset or power the board
// initialize digital pin LED_BUILTIN as an output.
pinMode(LED2_PIN, OUTPUT);
pinMode(LED_BUILTIN, OUTPUT);
  
} //end setup

//////////////////////////////////////////////////////////////////////////////////
void loop() 
{
// the loop function runs over and over again forever

digitalWrite(LED2_PIN, HIGH);   // turn the LED on (HIGH is the voltage level)
digitalWrite(LED_BUILTIN, LOW);
delay(1000);                       // wait for a second

digitalWrite(LED2_PIN, LOW);    // turn the LED off by making the voltage LOW
digitalWrite(LED_BUILTIN, HIGH);
  delay(1000);                       // wait for a second

} //end loop
////////////////////////////////////////////////////////////////////////////////