ESP8266 Community Forum

- Sat Sep 19, 2015 12:44 pm #29453 Is GPIO2 different from other GPIO pins? I have been using GPIO12-14 for driving Onewire and leds without problems.
Now I needed one more pin and chose GPIO2 to drive a resistor + led. Strange results. When I changed pin 2 to 16 it's OK again. I'm using HW type 03.

- Sat Sep 19, 2015 1:01 pm #29455 I am just getting started with nodemcu, and fairly new to the whole 8266 community. That being said, I can share this. ...After loading nodemcu, I uploaded a simple sketch copied from another source, to simply blink an LED at a 2 sec. rate. The code was using GPIO4. When I loaded it, the led didn't blink. I chased my tail a while, until I checked the condition of other GPIO pins, and found that GPIO 2 had the blink pattern. I've posted the question as to why, so far without response (that I've seen), but GPIO2 will definitely drive an LED.

- Sat Sep 19, 2015 1:26 pm #29458 I agree, GPIO2 did drive a led, no problem there. What puzzles me is that the unit did reset itself randomly.
Having tried all kinds of SW variations and even changing the PCB in vain, I simply changed to GPIO16 and voila.

- Sat Sep 19, 2015 3:31 pm #29470 Odd for sure. Just for the record, I'm playing with an ESP-7, but from what I've gathered the 8266 chip itself should be the same, the configuration of how the pins (and which ones) are brought out to the user seems to be the difference. I have seen variations from ESP-1 to ESP-13 available and even an ESP-14 with variations of some variations