---
title: "PoE FeatherWing: Add WIZnet W5500 Ethernet + 4W PoE Power to Any Feather (Drop-In Compatible)"
url: "https://maker.wiznet.io/junlee0615/projects/poe-featherwing-add-wiznet-w5500-ethernet-4w-poe-power-to-any-feather-drop-in-compatible/"
markdown_url: "https://maker.wiznet.io/junlee0615/projects/poe-featherwing-add-wiznet-w5500-ethernet-4w-poe-power-to-any-feather-drop-in-compatible/md"
type: "UCC: User Created Content"
author: "Electronics-Lab"
author_url: "https://www.electronics-lab.com/poe-featherwing-ethernet-featherwing-4w-poe-power/"
editor: "WIZnet"
editor_url: "https://maker.wiznet.io/"
original_author: "Electronics-Lab"
original_url: "https://www.electronics-lab.com/poe-featherwing-ethernet-featherwing-4w-poe-power/"
published: "2026-01-15"
language: "en"
tags: ["W5500", "PoE", "Ethernet", "Feather", "IoT"]
hardware: ["Patrick Van Oosterwijck PoE FeatherWing (Silicognition)", "WIZnet W5500"]
likes: 0
views: 732
comments: 0
source: "WIZnet Makers (https://maker.wiznet.io/)"
---

# PoE FeatherWing: Add WIZnet W5500 Ethernet + 4W PoE Power to Any Feather (Drop-In Compatible)

> A FeatherWing that delivers WIZnet W5500 Ethernet plus up to 4W isolated IEEE 802.3at PoE—so one Ethernet cable can power and network your Feather.

Original author: Electronics-Lab (source: https://www.electronics-lab.com/poe-featherwing-ethernet-featherwing-4w-poe-power/)

## Components

- **Patrick Van Oosterwijck PoE FeatherWing (Silicognition)** x 1
- **WIZnet W5500** x 1 ([docs](https://docs.wiznet.io/Product/Chip/Ethernet/W5500))
- Software: **Arduino IDE** ([docs](https://www.arduino.cc/en/software))
- Software: **WIZnet io Library** ([docs](https://github.com/Wiznet/ioLibrary_Driver))

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

## Introduction

Let’s start with the problem.

Feather boards are great for fast prototyping, but real deployments often need two things: **stable wired Ethernet** and **simple power wiring**.

This project solves both in one move. The **PoE FeatherWing** gives your Feather a real Ethernet port and lets it run from **Power over Ethernet**, so one cable can handle networking and power.

## WIZnet Product Integration

Here’s the key integration point: the board uses **WIZnet W5500** as its Ethernet controller.

That choice matters because it keeps things familiar.

If you’ve used the Adafruit Ethernet FeatherWing, you already know the software model—SPI-based networking with a W5x00-style stack.

In short: **Feather ↔ SPI ↔ W5500 ↔ Ethernet**.

## Technical Implementation

Now let’s break down what’s on the board.

**PoE section**: isolated **IEEE 802.3at Class 1** PoE, supporting **Mode A and Mode B**, with up to **4W output**.

**Ethernet section**: **WIZnet W5500** handles the network interface.

**Identity section**: a **24AA02E48** chip provides a **globally unique MAC**, which is a big deal for field deployment.

There’s also a small but useful detail: a **solder jumper** to route the W5500 IRQ to a Feather pin for boards that need it (like certain Feather-form-factor Linux SBC setups).

## Reproduction Guide

Let’s reproduce the setup in a simple, practical way.

**Stack the PoE FeatherWing** onto your Feather (headers installed).

Plug an **Ethernet cable** into the RJ45 and connect it to a **PoE switch or injector**.

In firmware, use the **same W5500-compatible libraries** you’d use for an Ethernet FeatherWing.

Bring up networking with **DHCP first**, then switch to a static IP if your deployment requires it.

If your Feather platform expects an interrupt line, bridge the **IRQ solder jumper** so the W5500 IRQ is connected.

## Core Features and Performance

Here’s what this board enables.

**One-cable deployment**: Ethernet + power in a single RJ45 run.

**Real globally unique MAC**: no per-device MAC editing during manufacturing.

**Drop-in compatibility**: same size and connections as the common Ethernet FeatherWing.

**PoE budget**: up to **4W**, great for low-power sensors, controllers, and small gateways.

## Code Snippet

Here’s the core logic pattern you’ll use—initialize the W5500, then start DHCP.

#include <SPI.h>

#include <Ethernet.h>

// Typical FeatherWing default CS is often IO10, but confirm for your Feather

static const int W5500_CS = 10;

byte mac[6];

void setup() {

Serial.begin(115200);

while (!Serial) {}

Ethernet.init(W5500_CS);

// If you have a unique MAC source (like 24AA02E48), load it here.

// Otherwise, use a placeholder for quick tests.

if (Ethernet.begin(mac) == 0) {

Serial.println("DHCP failed. Check link / PoE / switch settings.");

for (;;) {}

}

Serial.print("IP: ");

Serial.println(Ethernet.localIP());

}

void loop() {

// Your application code here

}

That’s it—the rest is your application layer.

## Applications and Extensions

Let’s talk about where this really shines.

**Building automation nodes**: wall/ceiling devices powered from the network closet.

**Industrial monitoring**: stable wired comms where Wi‑Fi is unreliable.

**Remote sensor clusters**: easy deployment with centralized power.

**Tiny gateways**: Feather + PoE + Ethernet as a small edge endpoint.

Extensions you might add:

*(planned)* power budgeting notes per sensor load

*(planned)* MAC auto-read helper so firmware is 100% per-unit automatic

## Conclusion

To wrap up, the PoE FeatherWing is a clean deployment-focused design.

By combining **WIZnet W5500 Ethernet** with **isolated 802.3at PoE (4W)** and a **globally unique MAC**, it turns the Feather ecosystem into something you can actually install at scale.

If you’re building Feather-based devices for real-world installs, try this architecture—and consider W5500 as the compatibility anchor for your Ethernet stack.

---

Source: https://maker.wiznet.io/junlee0615/projects/poe-featherwing-add-wiznet-w5500-ethernet-4w-poe-power-to-any-feather-drop-in-compatible/