#include <Ticker.h>

void changeState();

Ticker Blinker(changeState, 500);

//#define LED 51  // PB.2
#define LED 12

//=======================================================================
void changeState()
{
  digitalWrite(LED, !(digitalRead(LED)));  //Invert Current State of LED 
}

void setup() {
  // put your setup code here, to run once:
  pinMode(LED,OUTPUT);
  delay(2000);

  Blinker.start();
}

void loop() {
  Blinker.update();
}