uint8_t LED_Pin = 2; // declare LED pin on NodeMCU Dev Kit
void setup()
{
pinMode(LED_Pin, OUTPUT); // Initialize the LED pin as an output
}
void loop()
{
digitalWrite(LED_Pin, LOW); // Turn the LED on
delay(1000); // Wait for a second
digitalWrite(LED_Pin, HIGH); // Turn the LED off
delay(1000); // Wait for a second
}