Today: pick what you are building and get it on paper. Nothing gets wired today.

The ten

All of them use only what you learned in Unit C. All of them can be finished in two build sessions.

• Night light — comes on by itself when the room gets dark.
• Door alarm — something comes close, the buzzer sounds.
• Reaction game — an LED lights at a random moment, first to press the button wins.
• Parking sensor — beeps faster the closer something gets.
• Traffic light — three LEDs in the right order, with a button for the crossing.
• Plant minder — tells you when its corner is too dark for a plant.
• Gate — the servo opens a barrier when something is near, and closes after.
• Sound machine — buttons play different notes on the buzzer.
• Bin that thanks you — the servo opens the lid when you come close.
• Your own — if you can draw it and say what it senses, take it to your teacher.

The plan — four boxes on one page

Do this on paper. All four, before you touch a single wire.

1. The sentence. It senses ____ and then it ____. Write it at the top.
2. The drawing. What it looks like when it is finished. Label the parts.
3. The parts list. Numbered. Then go to the bin and physically hold every single one.
4. The order. What you will wire first, second, third. Hardest thing first.

How you will know it works

One more line, and the teams that write it always do better.

• What should happen: when I ____, it should ____ within ____ seconds.
• That sentence is what you will test in Session 24, and what visitors will try in Session 25.

Teacher check

Before you leave, walk your teacher through all four boxes. They are checking one thing: can this be built in two sessions with what is in your bin?

Before you pack away

• The plan is finished, on one page, in your notebook.
• Every part on your list has been held in your hand today.
• Your teacher has seen it.
• The first job for next session is written down.