I am in the process of creating a simple and cheap Wi-Fi PCB design that can send and receive messages to an app (through a cloud of course). I intend to attach this PCB to a fish tank temperature gauge and a fish tank heating tube.
Basically here are the only forms of communication between the PCB and my app:
Send temperature readings when requested by app user
Receives requests to change temperature high or lower
Turn heating device on/off
I need to configure the PCB so that it can communicate with a cloud service (installing SDKs, frameworks, and program logic to handle sending/received messages through cloud)
What components do I need in my PCB that allows me to achieve these tasks? And what is the bare minimum flash and processing that can handle those tasks, or do I not even need processor chip or flash memory? I'm a beginner with PCBs.