ESP8266 Community Forum

If I boot the ESP-1 I have with GPIO2 held at 0V I seem to have a blue light on permanently..if I wait a bit and then set to Ov or +3.3V it doesn't happen. seems to be something to do with the booting of the module. I wanted to use this pin as an input but its a bit difficult if the pin cannot be tied low at boot...it works OK if I leave it floating for 0 and set to +v for a 1 but apparently this is not reliable.

If you look at https://github.com/esp8266/esp8266-wiki ... ot-Process, it is normal that pulling down the GPIO2 at boot time won't enter in EXEC mode. Both GPIO2 and GPIO0 needs to PullUp to boot normally. You can use this GPIO as Input, but only after powerup.