Arduino — who decides?
Arduino vs. computer?
STUPID — Follows only the code lines we give it.
Arduino pins?
DECIDE — We need to SET each I/O pin to input or output.
* What does INPUT do? What does OUTPUT do?
What are the three pin groups?
DIGITAL — 1 / HIGH or 0 / LOW — recall the water-glass thresholds.
ANALOG — Like a voltmeter — returns 0–1023 on our Uno.
POWER — Voltage supply and GND.
What is the DIGITAL sub-group?
PWM — 0–255 controls the percentage of each cycle spent ON.