I need to connect to a Raspberry-pi from an Android, over a long distance (so via the internet).
My aim is to switch a controller circuit from a remote location, by using internet and android app.
In this case, there are N number of circuit and N number of user mobile. Every circuit will have their dedicated Android mobile app.
I need a protocol that will pass the command from android app to Controller circuit, then the circuit feed back to Android app. I use Python for the server scripting.
The android app and RPI are not in same network, therefore I can not make direct communication between them. For example, Consider, Subhankar has a home automation system in Delhi, and right now He went to London, but he has to start and stop his "water pump" daily, by remote control. This case Subhankar has the "android app" and his home automation system has "Raspberry pi".
Which communication protocol will be best to achieve this?