Sensors & Robots (Intro)

A robot is a machine that senses the world, decides what to do, and then acts. It does this with three working parts: a sensor that takes in information, a controller (the brain) that decides, and an actuator that moves or signals back to the world. Once you spot those three parts, every robot starts to look the same — even a self-driving toy car or a vacuum that bumps your couch.

Sensor, Controller, Actuator

1. Sensor — measures something in the world (light, sound, distance, touch, heat).
2. Controller — the small computer that reads the sensor and decides what to do.
3. Actuator — does the action: spins a motor, lights an LED, beeps a speaker.

Common Sensors and What They Detect

• Camera — light and images. Used to recognize faces or read a sign.
• Microphone — sound. Used by voice assistants and clap-to-clap toys.
• Touch sensor — contact and pressure. Triggers when something presses it.
• Distance sensor — how far away an object is. Helps a robot avoid walls.
• Temperature sensor — heat. Switches a fan on when the room is too warm.
• Light sensor — brightness. Turns a lamp on when the room gets dark.

Inputs vs Outputs

An input is information coming INTO the robot — a sensor reading or a button press. An output is the robot acting OUTWARDS — a motor spinning, an LED lighting up, a sound playing. The controller in the middle is what links them together with simple rules: "if input X, then output Y".