I suggest an Arduino kit, with some servos, photocells, LEDs, switches etc. There's no screen on it, so they have to get used to the idea of dealing with inputs and outputs. This forces you to think deeply about what's going on.
Later, they could hook up an LCD screen and keypad to do things, if they want.
Later they could move away from the world of 5 volt I/O and into the world of 3.3 volt and less Raspberry Pi, etc, where things get trickier in terms of noise, etc.
Later, they could hook up an LCD screen and keypad to do things, if they want.
Later they could move away from the world of 5 volt I/O and into the world of 3.3 volt and less Raspberry Pi, etc, where things get trickier in terms of noise, etc.