---
title: "Ethernet3 Library for WIZnet W5500"
url: "https://maker.wiznet.io/sophia/projects/ethernet3-library-for-wiznet-w5500/"
markdown_url: "https://maker.wiznet.io/sophia/projects/ethernet3-library-for-wiznet-w5500/md"
type: "UCC: User Created Content"
author: "stefan staub"
author_url: "https://registry.platformio.org/libraries/sstaub/Ethernet3"
editor: "WIZnet"
editor_url: "https://maker.wiznet.io/"
original_author: "stefan staub"
original_url: "https://registry.platformio.org/libraries/sstaub/Ethernet3"
published: "2025-11-12"
language: "en"
hardware: ["WIZnet W5500"]
likes: 0
views: 363
comments: 0
source: "WIZnet Makers (https://maker.wiznet.io/)"
---

# Ethernet3 Library for WIZnet W5500

> An advanced Ethernet library for Arduino that supports WIZnet W5500-based modules such as WIZ850io and WIZ550io.

Original author: stefan staub (source: https://registry.platformio.org/libraries/sstaub/Ethernet3)

## Components

- **WIZnet W5500** x 1 ([docs](https://docs.wiznet.io/Product/Chip/Ethernet/W5500))

WIZnet parts: W5500 ([Datasheet](https://docs.wiznet.io/Product/Chip/Ethernet/W5500/datasheet?utm_source=maker&utm_medium=project&utm_campaign=w5500), [product hub](https://maker.wiznet.io/products/w5500/))

## Article

**Ethernet3** is an enhanced Ethernet library designed for developers working with WIZnet’s **W5500** Ethernet controller.
Built upon the standard Arduino Ethernet library, it adds powerful configuration and diagnostic capabilities to help you manage hardware behavior and network parameters more precisely.

### 🚀 Key Features

**Custom DHCP Hostname**
Set a recognizable device hostname using `Ethernet.setHostname("MyDevice")`.

**Advanced PHY Control**
Adjust speed (10/100 Mbps), duplex mode, and power-saving options with `Ethernet.phyMode()`.

**Wake-on-LAN Support**
Enable remote wake-up capability via `Ethernet.WoL(true)`.

**Link & MAC Status Reading**
Retrieve link status, speed, duplex mode, and MAC address information directly.

**Customizable Hardware Pins**
Define your own chip-select (CS) and reset (RST) pins using `Ethernet.setCsPin()` and `Ethernet.setRstPin()`.

**Adjustable Socket & Buffer Size**
Tune maximum socket numbers and buffer sizes to fit your application’s requirements.

### 💡 Supported Hardware

WIZnet W5500-based modules (e.g., **WIZ850io**, **WIZ550io**, **USR-ES1**)

Arduino Ethernet Shield 2 and compatible boards

### ⚙️ Typical Applications

IoT devices requiring stable wired connectivity

Industrial control systems

Remote monitoring & data logging solutions

---

Source: https://maker.wiznet.io/sophia/projects/ethernet3-library-for-wiznet-w5500/