The semaphore signaller
Inventors (Intermediate), mission I9 Signals & Remote Control, lesson 2 of 6.
Hook
Before phones, sailors sent messages with flags. Can a machine do it?
Fair test
Make a code table: which crank positions mean A, B, C? Send a 3-letter word.
Bonus challenge
Send a secret word to another team across the room. Did they get it right?
The build
Semaphore Signaller: Two flag arms driven by two cranks through gears, so each arm can point to 8 positions: a letter code you can read across a room.