I think it is easier to use nodemcu lua
there is a file system and a LUA 5.1 interpreter
code run from files and knowing the logic you use to describe language programming.
Entry threshold(minimum amount of knowledge) at the below LUA than C++
collected here https://nodemcu-build.com/
selecting only the modules you need are there and the documentation on them. For all the DS18B20 have a ready-made library like LUA and embedded firmware written in C++.
The firmware is better to use a Float(from website usually comes 2 version in the mail).