I mentioned elsewhere in the thread about my nostalgia for the Vic-20 and friends. Here's a book I remember taking out of the library when I was a kid: https://drive.google.com/file/d/0Bxv0SsvibDMTZ2tQMmpyOWtsRFk... I didn't ever build any of the robots from the book (there weren't really any useful electronics suppliers in town, and I hadn't yet discovered the magic of Digikey...), but I still feel like I learned a lot thinking about how it would work.

I just flipped through it again, and I'm 99% sure that the circuits in that book would work just fine with a Raspberry Pi. Obviously you wouldn't use PEEK and POKE in BASIC to program it, but if the programming environment that Kano is providing gives you any kind of GPIO access, this could be an awesome platform to introduce basic hardware hacking.