when connecting NodeMcu to usb power, BLUE LED flashes.
I put code to D1 and D4 pins to switch simple LED with resistor.
Why and when BLUE (I suppose this is for wifi or power LED) LED flashes? I have MQTT and when put gpio.HIGH for D4 pin, my RED LED start to flash but BLUE LED on NodeMcu stops. When gpio.LOW then BLUE starts. When gpio.HIGH for D1, BLUE light is present and also RED lLED from D1. I dont get it, when this BLUE LED starts and why it stops only if gpio.HIGH is present on D4 not D1?
Maybe question is pretty stupid but it is irritating to dont know how this BLUE LED works.