ESP8266 Community Forum

Hello,

I'm asking about these 3 GPIO's because they are used in bootstrapping.

Is there any limitations in using these pins for general input/output after startup condition has been passed?

For example: If I want to drive buzzer, drive LED or read button with these GPIO's.

Thanks,
Tipo

With the information found in our Wiki, you should be able to find any limitations with the GPIO-pins of the ESP8266.

In short: don't assume that GPIO0, GPIO2 and GPIO15 are just like the other GPIO's.
As input, make sure they're properly pulled up or down and as output make sure anything connected (like a buzzer) influences the port at boot (at which time they act as input).