Programming Guide for BME280 calls using an ESP8266 module

Does anyone know where I get a programing guide for making calls to a BME280 sensor using an ESP8266. I have the source code and libraries from GitHub. I would like to better understand what the program is doing.

Cheers

I have the source code and libraries from GitHub.

For what? Which specific libraries?

I would like to better understand what the program is doing.

What program?

Please read the "how to use the forum-please read" stickies.

Start with the data sheet of the sensor.

I have used a BME280 with ESP8266. Have a look at my project & code here.