I am looking to buy some Raspberry Pi computers to do various tasks. For example, maybe one could water a plant when requested. The part I am struggling to find help with is creating a server where a Raspberry Pi can send and receive information from the other Raspberry Pi. For example, it may send a request to a Raspberry Pi to complete a certain task and another Raspberry Pi may send data back from a sensor. I haven't bought any of the products I will need yet but have a budget of around £150 (about 190 dollars) and was thinking of using Raspberry Pi Pico mini computers to control sensors, motors and servos etc whilst using a Raspberry Pi 4 as the hub where all the data goes to. Please can you show me a good way of doing this and also advise me on whether my budget is unrealistic or of any products I may need that I haven't considered. Below are the products I assume I will need:
1 Raspberry Pi 4 (not sure on what model)
1 Raspberry Pi Pico (just to get started I will buy more) - could an Arduino work better for this use case?
A transceiver of some kind but I'm not sure
Male/Female wire connectors
GPIO hat for the Raspberry Pi Pico
motor controller Raspberry Pi add-on boards
Servos, motors, sensors etc
Raspberry Pi Pico wifi adapter HAT
I'm not sure how well I explained that but I appreciate any help/advice that you can give. One of the tags I gave my post was "sockets" as I know this may be a potential solution. I am probably going to use sockets but would just appreciate an experts opinion before I invest.