i want to create a wireless sensor network.
I'm using nodeMCU+ PIR MOTION like nodes and i want to use arduino mega+(ethernet shield & wifi shield or wifi modele) for the sink.
what should i use ???
thank you 
Why not another nodeMCU?
Why not use a Raspberry PI and configure it as a MQTT server with sub/pub type of platform?
(you can even install W/LAMP on it.. so you can have Apache, PHP and a MySQL database for logging sensor values..etc)
i'm a beginner .
i need the sink to have a big memory to impliment something on it and i never worked with Raspberry PI.
so what should i do???