“There’s nothing more simple than the concept of a wireless mesh network… but there’s nothing more complex than building such a mesh. A steep learning curve is involved ( and, worst af all, the examples you may find never cover the whole story ) !
Here the steps to build your mesh ( we will cover each separately ):
1) build the mesh between nodes - easy
2) add ota ( wireless ) update of the nodes - intermediate
3) add a bridge ( to the internet ) - intermediate
4) an app ( to access the mesh from anywhere ) - intermediate
Let’s start from the first step.
ESP32 development boards ( two or more ), I used a ttgo t-display
PlatformIO development software ( install from here)