ESP8266 Community Forum

TRIROG wrote:Yeah ... Thought of that... The problem is that there could be an unfortunate ocrurence where the module will reboot but the switch would be closed/open which is unacceptable... Do you happen to know if GPIO 0 and 2 are only such GPIOS that cause such results i.e. module not booting to normal mode if connected to GND.?

I think it's only GPIO0 and GPIO2 that have to be HIGH for a normal reboot. I have not seen any reports on other GPIO's that influence the boot.

TRIROG wrote:What happens if GPIO2 is conncted to GND during boot i guess it's not a firmware upload mode .

I guess your guess is correct, but I'm not sure in what mode the ESP is in this situation. It certainly is a mode where a proper reset is required for a normal boot.

In your example of the switch on the garage door you will never know if the level is HIGH or LOW, so you will have to use another GPIO as GPIO0 and GPIO2.

Same problem, do you solved it?

The "Garbage" on on boot (when connecting GPIO_2 to Gnd)is bootloader mode 74400baud look at the wiki......
Modify your circuit to use momentery push buttons, or transistors with delay.....

https://raw.githubusercontent.com/gengu ... BUFFER.jpg

I'm having the same problem...

I have an LED connected to between GPIO2 and GND. When my ESP01 is restarted, it will not boot normally, which is a bummer. If I temporarily disconnect the LED circuit, the board will boot normally, and after reconnecting, my program works as desired (able to toggle the LED over wifi).

Is there anything I can do to get this unit booting normally without having to leave GPIO2 floating?