ESP8266 Community Forum

Does anyone know how to use GPIO6, GPIO7, GPIO8, GPIO11 on ESP-12E ?

These 4 pins are SPI pins, SCLK, MOSI, MISO, CS0, however, it should be able to use as GPIOs as well.

The SPI flash chip that holds all your program code is connected on those SPI pins...

That's the reason why so many modules don't break them out. They aren't very useful except if you want to mux the HSPI controller onto the same pins (example is on the Espressif BBS).