[jerome-jh]

Going on with my Arduino idea: when they have enough of C you can do some assembly. You can teach interrupt handling, the source of all concurrency on a single core, in C or asm. You can do communication on an unreliable link (2 boards & LEDs), sensor conditioning. A wheeled robot may help some students "seeing the world from the computer eyes", although they may be a bit too old for that.

Of course data structures are best taught in C on a desktop. Functional programming is certainly interesting but further apart from how a modern computer works.

During my studies I even did opcode programming on antic 8085 dev boards, with a 20 keys keyboard (hex digits, reset, run, memory up/down). You can't imagine how much fun that was, akin to woodworking or pottery. That certainly grounded a number of ideas on programming, that may look otherwise mystic to students.