The Parts Bench
Robotics runs on a small shelf of recurring parts: things that sense, things that move, the electronics that feed them, the brains that close the loop and the mechanics holding it together. Each entry carries a memory hook — because knowing instantly why a stepper skips silently is exactly the kind of fact that fades.
sensors
actuators
drive & power
brains & wiring
mechanisms
♃
H-bridge
drive & powerlets one motor run both ways through four switches
🔩 Memory hook
Draw four switches around a motor and the circuit spells a letter H. Close one diagonal: forward. The other: reverse. Both on one side: smoke — which is why driver chips exist.