Crack the Code Components Kit Only

Jargon buster

Plain-language definitions for the technical terms used above.

LDR

A light-dependent resistor is a component whose resistance changes with light level. It is useful for simple brightness sensing, and an ADC board is needed to turn its changing analogue voltage into numbers a microcontroller or computer can read.

LED

A light-emitting diode (LED) is a small electronic component that emits light when current flows through it in the correct direction. Because it only conducts one way, its polarity matters, and a through-hole LED must be soldered the correct way around to light up.

photocell

A light-sensitive component whose electrical resistance changes with the amount of light falling on it. It matters when choosing or using light sensors, automatic lights, or brightness-detecting circuits because its response speed, resistance range, and sensitivity affect how reliably it detects light levels.

potentiometer

A variable resistor usually turned with a knob or shaft to create an adjustable electrical signal. It is often used for inputs such as volume, brightness or position, so it helps beginners learn how a microcontroller reads changing values.