The coffee machine in our office is controlled by blockchain NFTs and a Raspberry Pi:
Once authenticated, an owner of the NFT can select their coffee type on their phone which then signals the Raspberry Pi to make whatever coffee type was selected by jumping the contacts that used to be pressed by the machine's buttons (which have been removed).
It's a cool gimmick, fun to show off to visitors, gives us a nice record of who is making coffee (since each NFT's owner is unique and trackable), limits users to those with the NFT without us having to build usernames/passwords, and is also how I make my coffee each afternoon.
It doesn't write individual orders to the chain. It could if we funded a wallet to pay the gas to write those records but right now it just does authentication of NFT ownership to grant access, which is conveniently free. The history logs are stored locally.
If an EU user tries to make coffee we redirect them to a "this content is unavailable in your region" page so I think we're 100% good to go with GDPR compliance.
It's a Nespresso Lattissima-- the old version where the buttons were physical push-to-press. We pulled the buttons off and soldered wires to the board inside via a 4-channel relay.
Once authenticated, an owner of the NFT can select their coffee type on their phone which then signals the Raspberry Pi to make whatever coffee type was selected by jumping the contacts that used to be pressed by the machine's buttons (which have been removed).
It's a cool gimmick, fun to show off to visitors, gives us a nice record of who is making coffee (since each NFT's owner is unique and trackable), limits users to those with the NFT without us having to build usernames/passwords, and is also how I make my coffee each afternoon.