Industrial 8-Channel ESP32-S3 WiFi Relay Module (With POE)

Jargon buster

Plain-language definitions for the technical terms used above.

BLE

BLE stands for Bluetooth Low Energy, a Bluetooth mode designed for low power use and broad compatibility with modern phones and computers. It connects well to battery-powered and mobile devices, including Apple hardware, though it behaves differently from Bluetooth Classic and its serial-style profiles.

CAN bus

CAN bus is a reliable two-wire communication network originally designed for vehicles and now common in machinery and robotics. It matters when you need multiple controllers or devices to share status and control messages in a noisy electrical environment.

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.

DIN

As a pin label, DIN stands for 'data in', the input through which a device receives serial data from a controller, as found on SPI displays, LED drivers and other serial modules. DIN can also refer to the German standards body of that name, as in a round multi-pin DIN connector or DIN-rail mounting.

ESP32

ESP32 is a family of low-cost microcontroller chips and modules from Espressif with built-in WiFi and Bluetooth. They support programmable firmware and over-the-air updates, and are commonly programmed with toolchains such as the Arduino core and ESP-IDF.

IoT

Short for Internet of Things, meaning physical devices that connect to networks or the internet to send data or be controlled remotely. It matters if you want projects such as connected sensors, remote controls or classroom data-logging activities.

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.

MicroPython

A version of the Python programming language made to run on microcontrollers. It matters because it lets beginners write readable code to control LEDs, sensors, motors and displays without needing to start with lower-level languages.

microSD card

A microSD card is a small removable flash memory card used to store data such as audio, images, logs or program files. Its capacity and formatting (often FAT32 or exFAT) affect how much can be stored and whether the card needs preparing before use.

Relay module

A relay module uses an electrically controlled switch to let a low-power microcontroller control a separate circuit. It matters when switching devices that need different voltages or more current than a microcontroller pin can safely handle.

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.

RTC

A Real-Time Clock keeps track of time even when the main processor is asleep or powered down, usually with a small backup battery. It matters for data logging and tracking projects that need accurate timestamps.

Tolerance

Tolerance tells you how far the real resistance value may be from the printed value. A 1% resistor is useful when a circuit needs more predictable behaviour than a looser 5% or 10% part.

USB Type-C

USB Type-C is a small, reversible USB connector used for power, data and sometimes video on many modern devices. The connector itself does not guarantee a particular speed or voltage, so check the supported USB version, data rate and whether it carries more than 5V via USB Power Delivery.

USB-C

USB-C is a small, reversible USB connector that can carry power, data and, on some devices, video over a single cable. The same connector can range from charging only to high-speed data, so the functions a given port actually supports vary.