I used Arduino sets to teach kids electronics and minimal programming. We created various simple devices with sensors and motors using resistors, capacitors and

I used Arduino sets to teach kids electronics and minimal programming. We created various simple devices with sensors and motors using resistors, capacitors and transistors to construct interfaces between digital inputs/outputs and analog devices. This way kids understand why we need analog components in digital circuits. The simplest possible example is R + LED to limit the current. You can explain that R is a thin tube which limits amount of electrons flowing to the LED. Then you can demo the R-divider to cut the voltage on the digital input. Then add a capacitor and demo kids the slowly flashing LED driven by digital output. Use oscilloscope to visualize the signal - it's hard to understand how capacitor works. Then use transistors and MOSFETs to drive motors. I also created a 3D printed parts to assemble working models like the radar, barrier and real clock driven by the stepper motor.