A standard momentary push button. It reports pressed only while a finger is holding it down, then goes right back to unpressed. This is the first input most students wire, and it is the one that teaches the difference between a program that waits and a program that checks.

Locks into place when flipped, so it holds its state after the student lets go. That makes it the right choice for anything that should stay on or stay off, like a power control or a setting the program reads once at startup.

A knob students physically turn. Instead of on or off it gives a whole range of values, which makes it the friendliest possible introduction to analog input. Students can see their number change in real time as they turn it. Both curricula use it, so it is in the Brain DeCoded kit and the Lift-Off kit.

Detects a warm body moving nearby, the same way a motion-activated porch light or a store alarm does. Students immediately recognize the behavior, which makes it a strong hook for conditionals and for talking about energy conservation.

A small lever switch used as a touch or crash detector. When something bumps the lever, the program knows. In the missions it becomes the sensor that tells a hatch it is fully closed and a lander that it has touched down.

Reports a raw value that changes with temperature. Because the reading is raw rather than degrees, students have to map it to something meaningful, which is a genuinely useful lesson in how sensor data becomes information.

Sensitive to sound intensity, so it detects a clap or a shout rather than recognizing words. Students use it to trigger an alert, and it is a reliable crowd pleaser in a room full of people willing to make noise.

Measures how much light is falling on it. Real systems use this for solar panel monitoring and automatic dimming, and that is exactly what students build with it: a panel that finds the brightest direction and follows it.

Pairs an LED that emits infrared light with a phototransistor that detects it. When an object is close enough to bounce that light back, the sensor notices. Students use it to detect an obstacle without touching it.

Reads how much moisture is in the soil around it. This is the sensor that closes the loop in the automatic garden mission: the program decides when the plant is dry and then does something about it.

Measures distance with sonar. It sends out a pulse of sound and times the echo, which means students are working with the same principle a bat or a submarine uses. It gives a real distance rather than a raw value, so the number means something right away.

Light emitting diodes, the very first thing students control. A single LED turning on because of a line of Python is the moment physical computing clicks. They come back again and again as status lights, countdown indicators, and warning lamps. The kit includes red and white LEDs on plug-in boards, plus loose red and amber LEDs in the Mission 10 breadboard set.

Eight pixels in a circle, each one individually addressable in any color. Because students control the pixels by index, it is a natural way into loops and lists: one ring makes a status display, a progress meter, or an alert animation.

Spins continuously in either direction rather than moving to a specific angle. Students control speed and direction, which makes it the right motor for anything that needs to keep turning, like a fan or a conveyor.

Moves to a specific angle within a 180 degree range and holds it. Students give it a number and it goes there. It is in both curriculum kits: a Brain DeCoded model that moves with the data, a Lift-Off solar panel that tracks a light source, and a lander leg that deploys on command.

An electrically controlled switch. CodeX cannot drive a water pump directly, so the relay stands in between: a tiny signal from the program flips a much larger circuit on and off. This is the component that teaches students how a small controller runs big equipment.

A small submersible pump, and the payoff of the automatic garden mission. The soil sensor reads dry, the relay closes, the pump runs, and the plant gets watered. Students build a complete sense-decide-act loop they can watch work.

The small board that gives each peripheral a labeled place to plug in. It comes with both curriculum kits and it is the piece everything else depends on, so it is worth naming out loud on day one rather than treating it as packaging.

A small voltage divider that halves the voltage coming from an analog sensor so CodeX can read the sensor's full range instead of clipping at the top. Any mission with an analog sensor uses it.

A grid of connected holes that lets students build and test a circuit without soldering. It is where the course graduates from plugging in finished modules to wiring a component pin by pin.

The bundle of colored wires that connects peripherals to the connector board, and the breadboard to CodeX. They come with both curriculum kits, and students use them to make every connection in Lift-Off Mission 10 by hand.

Limits the current flowing through part of the circuit so everything runs smoothly and nothing gets more current than it should. Small, easy to lose, and a good first look at why resistance matters.