boards/esp8266-esp-12x/include/periph_conf.h

Board specific configuration of MCU periphery for ESP-12x based boards.

I2C0_SPEED

I2C bus speed of i2c.h::I2C_DEV 

1
I2C_SPEED_FAST
I2C0_SDA

SDA signal of i2c.h::I2C_DEV 

1
GPIO4
I2C0_SCL

SCL signal of i2c.h::I2C_DEV 

1
GPIO5