// This example code flashes the Arduino debugging led // in a heartbeat pattern. You do not need to connect a // led, it is already on the board, and is called LED_BUILTIN. void setup() { pinMode(LED_BUILTIN, OUTPUT); } void loop() { digitalWrite(LED_BUILTIN, HIGH); delay(100); digitalWrite(LED_BUILTIN, LOW); delay(100); digitalWrite(LED_BUILTIN, HIGH); delay(100); digitalWrite(LED_BUILTIN, LOW); delay(900); }