ESP8266 Community Forum

- Thu Feb 13, 2020 4:54 am #85641 Hi that does not tie in with the behaviour i see. Its been reverse engineered by someone (not official)
What is strange is that the official documents schematic from AI thinker for the esp12e and esp12f do not show an led at all!
My feeling is that the blue led shows wifi transmits amongst other things and i dont see why it should be connected to GPIO2. Some folks say it shows the TX1 debug log outputs . ive done a system_set_os_print(off) and the onboard blue led still flashes.

- Thu Feb 13, 2020 8:43 am #85648 All the ESP-12 based boards that I have used have had the blue led connected as the above schematic.

Since I don't know what your board is programmed to do I can only assume that what you see is not what you think is happening. If you want to check the connection for the led then use an Ohm meter. Maybe you have a defective board.

- Fri Feb 14, 2020 3:59 am #85669 Many thanks for your reply. Yes one of my esp12 s seems to be wired differently so that is confusing things,
I will do some more work on this as i reckon the onboard led shows wifi transmissions but i cannot find anything that says that as yet. It seems the most logical use for the LED.