Arduino Uno DIP Edition

Jargon buster

Plain-language definitions for the technical terms used above.

AVR

AVR is a family of 8-bit microcontrollers (made by Microchip, formerly Atmel) used in many classic Arduino-style boards such as the Uno and Nano. They are widely supported but older, which can be a limit for memory- or speed-intensive tasks.

Bootloader

Small starter software on a microcontroller that lets new code be uploaded before the main program runs. Knowing how to enter bootloader mode matters when you need to program the board or recover it after a faulty sketch.

COM port

A COM port is how a computer (chiefly under Windows) presents a serial port to software, whether a physical RS-232 port or a virtual port created when a USB-to-serial device is plugged in. Software can then communicate with the connected device over serial using a terminal or configuration program.

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.

DFU

Device Firmware Update is a mode that lets you load new firmware onto a board over USB. It matters when recovering a board or installing firmware without using a separate programmer.

EEPROM

A type of non-volatile memory that keeps stored data even when power is turned off. In a sensor module, it can be used to store settings or calibration data so they do not need to be re-entered every time.

Flash memory

Flash memory is non-volatile memory that retains stored data even when power is removed, and can be erased and rewritten in blocks. It lets data such as firmware, settings or saved records persist across power cycles.

GND

GND is the ground or reference connection (0 V) for a circuit. When connecting two devices together, their grounds must be joined so both agree on what counts as a low or high signal.

I2C

I2C is a two-wire communication bus used by many sensors and small modules. It matters because several I2C devices can share the same two wires, but each device needs a compatible address and your controller must support I2C.

IDE

Short for Integrated Development Environment, a program used to write, run and manage code. It matters because some learners prefer a traditional coding workspace instead of a guided notebook-style lesson.

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.

microcontroller

A microcontroller is a small computer on a single chip that runs a stored program and controls connected inputs and outputs such as buttons, sensors, displays and communication interfaces. In a device built around one, it is the part that executes the code and coordinates the device's behaviour.

PCB

A printed circuit board (PCB) is a board, usually rigid, with etched copper tracks that connect electronic components together without loose wiring. Components are mounted on the board and signals route between them through the copper layout.

PWM

Pulse Width Modulation is a way for a digital pin to simulate variable output power by switching on and off very quickly. It matters for controlling things like LED brightness, motor speed, or servo-style signals from a microcontroller pin.

RX

RX means receive, usually showing data being received by the board. An RX indicator LED can help with troubleshooting USB or serial communication.

SCL

The clock line used by the I2C bus to keep data transfers timed between a controller and connected devices. When wiring I2C, SCL must be connected to the SCL pin on every device sharing the bus.

SDA

The data line used by the I2C bus to carry information between a controller and connected devices. When wiring I2C, SDA must be connected to the SDA pin on every device sharing the bus.

Shield

An add-on board that plugs into a main controller board to give it extra features such as sensing, motor control or communication. Knowing a product supports shields helps you judge whether it can connect neatly into an existing maker-board setup.

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.

SPI

A fast serial communication bus often used for displays, memory cards, and sensors. It matters because SPI devices need specific pins for clock and data, plus a separate chip-select line for each device.

SRAM

Fast temporary memory used by a processor while a program is running. More SRAM helps with projects that handle larger data buffers, networking, displays, or more complex code.

TTL serial

A simple serial data connection that uses microcontroller logic-level voltages (typically 3.3 V or 5 V) rather than the higher, inverted voltages of computer RS-232. When a device lists TTL serial, it can usually wire straight to a microcontroller's UART pins or to a USB-to-TTL serial adapter, but it needs a level converter before connecting to a true RS-232 port.

TX

TX means transmit, usually showing data being sent from the board. A TX indicator LED can help you see when the board is communicating or uploading code.

UART

UART is a simple asynchronous serial interface that sends data over separate transmit and receive wires, usually labelled TX and RX, with both ends set to the same baud rate. It is a common way for microcontrollers and other serial devices to exchange data.