Uno R3 Learning kit

Jargon buster

Plain-language definitions for the technical terms used above.

DC

DC means direct current, where electricity flows in one constant direction, as supplied by batteries, USB ports and many plug-pack power supplies. When a product specifies DC, it runs from a DC supply rather than mains AC, so you need to provide the correct voltage and polarity.

Gyroscope

A gyroscope measures rotation, such as how fast a board is turning around its X, Y, and Z axes. This matters for projects like gesture controls, balancing robots, and motion tracking where tilt or rotation changes need to be detected.

LCD

LCD stands for liquid crystal display, a screen technology that uses a backlight and liquid crystals to show images or text. It matters because LCD modules usually need a display driver and enough controller pins or a bus interface to send image data.

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.

RGB

Short for red, green and blue, the three primary colours of light that are mixed in varying amounts to make a wide range of colours. In electronics RGB can refer to an LED or pixel that blends these three colours, or to a colour signal or interface that carries separate red, green and blue channels.

servo

A servo is a motor with built-in position control, usually told to move to a specific angle by a control signal. It matters when you need repeatable movement, such as steering, arms, flaps, or linkages, rather than continuous spinning.

SMD

SMD means surface-mount device, a component style designed to be soldered directly onto the surface of a circuit board rather than through holes. SMD parts are compact and mounted flat on the board, which suits smaller and mass-produced designs.