  Blink the blue LED on the ESP-01 module
  Based on the Arduino Blink without Delay example
  This example code is in the public domain
+ 
+ The blue LED on the ESP-01 module is connected to GPIO1 
+ (which is also the TXD pin; so we cannot use Serial.print() at the same time)
+ 
+ Note that this sketch uses BUILTIN_LED to find the pin with the internal LED
 */
-
-const int ledPin =  1;  // The blue LED on the ESP-01 module is connected to GPIO1 
-                        // (which is also the TXD pin; so we cannot use 
-                        // Serial.print() at the same time
 
 int ledState = LOW;     
 

const long interval = 1000;

void setup() {
  pinMode(ledPin, OUTPUT);
}

void loop()

      ledState = HIGH;  // Note that this switches the LED *off*
    else
      ledState = LOW;   // Note that this switches the LED *on*
    digitalWrite(BUILTIN_LED, ledState);
  }
}
