The moment a child sees an LED light up because they wrote the line is worth every minute of setup.
A two-hour shape to try
- Play the finished thing first (5 min)
- Break it — change one number, watch what breaks (15 min)
- Build the smallest possible loop together (25 min)
- Add the sensor or button they actually care about (30 min)
- Put it in a 3D printed box they designed (20 min)
- Take it home working
A Pico or Uno can be a forgiving first board: both support small experiments, quick restarts, and a path back when beginner code does not behave. They are not impossible to misconfigure, so the adult still keeps a known-good example and recovery steps nearby.
The kid leaves with something that moves or lights or beeps when they want it to. That is the whole curriculum for session one.