Wrong #define LED_BUILTIN for NodeMCU board

[TridentTD]

Basic Infos

ESP8266 Arduino Core 2.4.1 has a mistake (?) #define LED_BUILTIN
for NodeMCU board to pin gpio16 , then when using BLINK example ,
it can't blink the LED_BUILTIN

https://github.com/esp8266/Arduino/blob/master/variants/nodemcu/pins_arduino.h#L35

It should be defined to pin gpio 2 ?

Platform

• NodeMCU 1.0 (ESP12F)
• Core version 2.4.1
• ArduinoIDE
• Windows10

Settings in IDE

• NodeMCU
• 4MB
• lwip V2 & V1.4

[NobleAscent]

This issue is previously covered but I guess they haven't decided to do anything about it. 😢

[lrmoreno007]

The official Nodemcu has the integrated led connected to the GPIO16 pin (with inverse logic by the way).

The led in GPIO2 to which you refer, is integrated into the ESP12e and this is integrated into Nodemcu. But be careful because not all ESP12e cards have this led.

Therefore, LED_BUITIN in GPIO16 is correct.

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQMdY72MOGomZsb1h_nGYNivWbEVOq_hBC34VSR3-S0n3MWpIws

[tablatronix]

@lrmoreno007 is correct, the led on an esp12e is tied to io2/txd1 and is used for com ind, meaning it will blink if you use serial2. io16 is the correct definition for nodemcu.

[5chufti]

@devyte since defines seem to be correct, shouldn't this be closed?

[devyte]

I'm confused. My understanding is that for all boards based on the esp12 reference hw the builtin led is gpio2. Yes, it blinks when using serial2, but it also blinks e.g. with a dht22 shield on a wemos d1 r2.
I also understand that some nodemcu devices have an extra led, which is NOT called builtin, and in the case.of noddemcu it's on gpio16.
Then, the builtin define was changed from gpio2 to gpio16, which is the current state. And now there is a request to change it back, because the blink example doesn't work on that board.
So which is it? Please don't make me dig out my old nodemcu boards to answer this myself, they're somewhere behind 15 months worth of storage.

[tablatronix]

Hmm it was changed at some point?

[tablatronix]

blink works fine on nodemcu (amica), and a wemos v3 pro
maybe they are using some lolin nodemcu without a second led and using the wrong board definition.

Either way it looks fine to me ( unless we add LED_BUILTIN_2 at some point )

IMHO boards with an aux led should be mapped to LED_BUILTIN and ones without should be mapped to esp led. Sounds reasonable to me

[d-a-v]

@TridentTD @NobleAscent Could you elaborate ?
Does your nodemcu board have a led on pin 16 ?

[tablatronix]

Fyi same goes for adafruit huzzah it has 2 leds builtin defined for aux led io 0

[5chufti]

I have only cheap "replicas" of nodemcu boards but even the cheapest without ESP-12 module (esp directly on pcb w/o metal can) has both leds...