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Part 1 · Welcome to the semiconductor world
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Every smart thing stands on the same four floors.

Smart doorbell, smart factory, smart city, self-driving car — the marketing changes, the building does not. Something has to sense the world and turn it into numbers. Something has to carry those numbers somewhere. Something has to decide what they mean. And something has to push the answer back out as motion, light or heat. Four floors, and all four are made of semiconductors. Once you can see the floors, “smart” stops being a slogan and becomes a checklist.

  1. Sense

    An image sensor is millions of light-sensitive junctions, each counting photons for a fraction of a second.

  2. Think

    This floor gets the headlines, but it is useless alone. A model with no sensors has nothing to be right about.

  3. The loop

    Acting changes the world that sensing measures. That is what makes it a system rather than a gadget.

Sense, move, think, act — then round again.
  1. 1SenseAn image sensor is millions of light-sensitive junctions, each counting photons for a fraction of a second.
  2. 2ThinkThis floor gets the headlines, but it is useless alone. A model with no sensors has nothing to be right about.
  3. 3The loopActing changes the world that sensing measures. That is what makes it a system rather than a gadget.
A thermostat, 1960

A bending metal strip senses, and the same strip closes the switch. Two floors, no numbers.

A thermostat, today

A sensor chip, a radio, a processor and a driver. Four floors — and far more interesting ways to be wrong.

“Smart” only means all four floors got built. Ask which floor someone is actually selling you.