I need to connect 2 RPi's to a test network and make them linked to a smart contract. In my eyes, I would deploy the smart contract off my computer to the Ropsten test network, make the RaspberryPi's nodes in the network and sync them to the smart contract deployed. Is this correct?
Can you please suggest any tutorials/ reference?
Thank you.
Your approach looks fine. If you want to build this project on ethereum, here is a brief tutorial on how to build a private chain on ethereum and deploy a smart contract on it.
Hope it helps!