Michael Portera has a large collection of Magic: The Gathering (MTG) cards and he wondered how much they were worth. For those not in-the-know, MTG is a “customisable card game” launched in the 1990s in which you put together a deck of cards from your collection and seek to win games in which you are pitted against other players’ decks. There are around 20,000 official cards (as well as countless unofficial ones!) and some of them are quite rare and, therefore, quite valuable.
Michael has constructed a card-feeding mechanism out of LEGO and then written scripts on his Raspberry Pi to scan them with a camera module, recognise them (courtesy of AWS Rekognition) and then call an API to get the expected value of the cards. A full write-up of the project, including the code, is available here. You can see the mechanism in action below: