ESP8266 Community Forum

Posted: **Mon May 21, 2018 2:37 pm**

Hello

I'm programming an ESP-12E module using the Arduino support package. My setup requires a logic level inverter on the Tx pin (only). I built the following which is working OK :

However the ESP8266 will not boot with that attached to it, I need to unplug it at boot time and plug it back in after. Then everything works fine.

Why is this causing the ESP to not boot ? And how can I make it boot anyway?

Thanks !

Posted: **Wed May 23, 2018 7:37 am**

uiguig wrote:My setup requires a logic level inverter on the Tx pin (only)

Why your setup requires such inversion ?

A normal TTL level serial doesn't need that ...

Posted: **Wed May 23, 2018 7:50 am**

Put a pullup on the pin.
Probably you are using the GPIO00 or the GPIO02 that are special pins.

look here :
https://github.com/espressif/esptool/wiki/ESP8266-Boot-Mode-Selection

ESP8266 Community Forum

ESP12E + Logic inverter on Tx = failure to boot ?

ESP12E + Logic inverter on Tx = failure to boot ?

Re: ESP12E + Logic inverter on Tx = failure to boot ?

Re: ESP12E + Logic inverter on Tx = failure to boot ?