ESP8266 Community Forum

- Tue Feb 23, 2016 8:15 am #41714 Hi,
I would like to know if it is possible to use GPIO0 and GPIO15 for input or/and Output ?
Also twice is possible ?

Is there a drawing example with resistor value ?

Thanks for help

Use: ESP8266 ESP-07 ESP-12F ESP-14
Windows 10
Arduino IDE 1.6.13
ESP8266 2.3-RC-2 + git ESP8266 core

- Tue Feb 23, 2016 9:54 am #41723 As long as GPIO0 is HIGH and GPIO15 is LOW during power-up and/or reset, you can use those pins for either input or output after boot sequence.
So, for exemple, you can attach a LED anode on GPIO15, cathode to GND thru resistor.
But doing the same on GPIO0 won't work because it is acting as a pull down to GND, in such case the LED cathode can be attached to GPIO0 and the anode to VCC thru resistor, it will then work, but states will be inverted, meaning that LOW will turn on the LED while HIGH will make it turn off.

- Tue Feb 23, 2016 1:20 pm #41744

..., but states will be inverted, meaning that LOW will turn on the LED while HIGH will make it turn off.

Thanks Martin.
I will try as soon as possible and post what i get.
Best regards

Use: ESP8266 ESP-07 ESP-12F ESP-14
Windows 10
Arduino IDE 1.6.13
ESP8266 2.3-RC-2 + git ESP8266 core