ESP8266 Community Forum

Does anyone know what holding the flash button during reset does? I know that the flash button is tied to D3 or gpio0 and that I can use it as button input in loop. I would like to hold it during reset and do something else but does not appear to work or maybe I am not using it correctly.

can the state of the flash button be used during setup?

thanks

GPIO0 can't be held LOW during setup, otherwise the ESP will go in "upload" mode.
But you can add a delay loop in setup(), let say 5 seconds, and check if button is been pressed AFTER power-up/reset, if it is, then act accordingly.

There is no need for a delay in setup(). GPIO0 can go low immediately in setup(). But not before.

If the GPIO0 is read right at the beginning of setup(), there not much chance that a human can press the button that fast, so it is easier to add a delay, if 5 seconds is too much for you, at least make it 1 seconds.