4 · Input → process → output

Remember "sense → think → act"? Computer scientists describe the same idea with three words you'll hear a lot: input → process → output. It's the heartbeat of every computer and every robot.

• Input is information coming in — from a sensor, a button, a microphone, a keyboard.
• Process is the thinking in the middle — the program decides what the input means and what to do about it.
• Output is the result going out — a light turns on, a motor spins, a sound plays, words appear on a screen.

It maps cleanly onto what you already know:

The micro:bit is a perfect example because you can see all three on one tiny board. Its inputs include two buttons, an accelerometer (it feels motion and tilt), a compass, a temperature sensor, and a light sensor. Its outputs include a 5×5 grid of 25 red LEDs and, on newer versions, a speaker (Micro:bit Educational Foundation, n.d.). In between sits the process: the program you write that says, for example, "if the board is shaken (input), show a smiley face on the LEDs (output)."

Once you have this frame, programming a robot stops feeling mysterious. You're always answering three questions: What's my input? How should I process it? What output do I want?

Check yourself. A motion-sensing porch light turns on when someone walks up at night. Name its input, its process, and its output.

Sources

Micro:bit Educational Foundation. (n.d.). micro:bit features overview. https://microbit.org/get-started/features/overview/