Closed fareign closed 3 years ago
The internal LED is on D4 Pin.
If the output of D4 is high, the onboard LED is lighting.
Yes, as @goudi76 says, the built-in led is connected to D4. However, it will light when D4 is low, which is why it's off when led 2 is red, and on when it's not. You can see that
Serial.println(LED_BUILTIN);
Serial.println(D4);
both will print 2
in the console, referencing the same pin.
LED2 define D4, will light up the board blue led.