---
title: "How to Connect STM32 and W5500 to OneNET Cloud Using MQTT over Ethernet?"
url: "https://maker.wiznet.io/ronpang/projects/how-to-connect-stm32-and-w5500-to-onenet-cloud-using-mqtt-over-ethernet/"
markdown_url: "https://maker.wiznet.io/ronpang/projects/how-to-connect-stm32-and-w5500-to-onenet-cloud-using-mqtt-over-ethernet/md"
type: "UCC: User Created Content"
author: "小蚂蚁2020"
author_url: "https://www.bilibili.com/video/BV13e411v7hB?spm_id_from=333.788.videopod.sections&vd_source=ab013cc5ffdecedae5ee47ae256d7306"
editor: "WIZnet"
editor_url: "https://maker.wiznet.io/"
original_author: "小蚂蚁2020"
original_url: "https://www.bilibili.com/video/BV13e411v7hB?spm_id_from=333.788.videopod.sections&vd_source=ab013cc5ffdecedae5ee47ae256d7306"
published: "2026-02-27"
language: "en"
likes: 0
views: 299
comments: 0
source: "WIZnet Makers (https://maker.wiznet.io/)"
---

# How to Connect STM32 and W5500 to OneNET Cloud Using MQTT over Ethernet?

> This project demonstrates how to connect STM32 and the WIZnet W5500 Ethernet controller to the OneNET cloud platform using MQTT.

Original author: 小蚂蚁2020 (source: https://www.bilibili.com/video/BV13e411v7hB?spm_id_from=333.788.videopod.sections&vd_source=ab013cc5ffdecedae5ee47ae256d7306)

## Article

## How to Connect STM32 and W5500 to OneNET Cloud Using MQTT over Ethernet?

## (STM32와 W5500으로 OneNET 클라우드에 MQTT 이더넷 연결하는 방법)

---

### Project Summary (57 words)

This project demonstrates how to connect STM32 and the WIZnet W5500 Ethernet controller to the OneNET cloud platform using MQTT. By leveraging hardware TCP/IP offloading over wired Ethernet, the system achieves reliable Industrial IoT communication and scalable cloud integration suitable for education and production environments.

---

### System Architecture Overview

#### Hardware Components

**STM32**

Sensor sampling

MQTT client implementation

Command parsing

**W5500**

Hardwired TCP/IP stack

8 hardware sockets

SPI communication interface

Ethernet PHY

**OneNET Cloud**

MQTT broker

Web dashboard

Device management

---

### Network Architecture & Protocol Flow

#### Communication Flow

Sensors → STM32 → SPI → W5500 → Ethernet → Internet → OneNET MQTT Broker

#### Protocol Stack

| Layer | Responsible Component |
| --- | --- |
| Application | STM32 |
| MQTT | STM32 |
| TCP/IP | W5500 |
| Physical | Ethernet |

---

### MQTT Operation Sequence

TCP connection via W5500

MQTT CONNECT

Authentication with OneNET

Topic subscription

Telemetry publish

Remote command reception

---

### Why Use W5500 for MQTT Cloud Systems?

Hardware TCP/IP offloading reduces MCU workload

Stable wired Ethernet connectivity

Simplified firmware complexity

Deterministic communication timing

Industrial-ready reliability

---

### Ethernet vs Wi-Fi for MQTT

| Aspect | Ethernet (W5500) | Wi-Fi |
| --- | --- | --- |
| Stability | High | Variable |
| RF Interference | None | Possible |
| Firmware Complexity | Lower | Higher |
| Long-Term Deployment | Strong | Moderate |

---

### Industrial IoT Perspective

This design reflects industrial gateway architecture:

Edge data processing on STM32

Hardware-isolated network layer

Secure cloud integration

Scalable multi-node deployment

---

### FAQ (WIZnet-Focused)

**Q1: Why use W5500 instead of Wi-Fi for OneNET MQTT?**
A: W5500 provides hardware TCP/IP offloading and stable wired communication, improving reliability.

**Q2: Does W5500 support MQTT directly?**
A: No. MQTT runs at the application layer over TCP managed by W5500.

**Q3: Is this suitable for Industrial IoT?**
A: Yes. Ethernet-based MQTT communication is common in industrial deployments.

**Q4: How many simultaneous connections are supported?**
A: W5500 supports up to 8 hardware sockets.

**Q5: Is this good for learning IoT cloud integration?**
A: Yes. It demonstrates complete embedded-to-cloud workflow.

---

### Tags

#W5500 #STM32 #OneNET #MQTT #IndustrialIoT #Ethernet #CloudIntegration

---

---

## 🇰🇷 KOREAN VERSION

## STM32와 W5500으로 OneNET 클라우드에 MQTT 이더넷 연결을 구현하는 방법은?

## (How to Connect STM32 and W5500 to OneNET Cloud Using MQTT over Ethernet?)

---

### 프로젝트 개요 (57단어)

이 프로젝트는 STM32와 WIZnet W5500 이더넷 컨트롤러를 사용하여 MQTT 프로토콜을 통해 OneNET 클라우드에 연결하는 방법을 설명합니다. 하드웨어 TCP/IP 오프로딩과 유선 이더넷을 활용하여 교육 및 산업용 IoT 환경에 적합한 안정적인 클라우드 통신을 구현합니다.

---

### 시스템 구성

STM32: 센서 수집 및 MQTT 처리

W5500: 하드웨어 TCP/IP 이더넷 통신

OneNET: MQTT 브로커 및 대시보드

---

### 네트워크 아키텍처

Sensors → STM32 → SPI → W5500 → Ethernet → Internet → OneNET

TCP/IP는 W5500이 처리하고 MQTT는 STM32에서 구현합니다.

---

### 산업용 관점

유선 기반 안정성

낮은 MCU 부하

24/7 운용 가능

확장성 높은 구조

---

### FAQ

**Q1: 왜 W5500을 사용하나요?**
A: 안정적인 하드웨어 TCP/IP 통신을 제공하기 때문입니다.

**Q2: MQTT는 어디에서 처리되나요?**
A: STM32 애플리케이션 레벨에서 처리됩니다.

**Q3: 산업용에 적합합니까?**
A: 네, 산업용 IoT 환경에 적합합니다.

**Q4: 동시에 몇 개의 연결을 지원합니까?**
A: 최대 8개의 하드웨어 소켓을 지원합니다.

**Q5: 교육용으로 적합합니까?**
A: 네, 전체 IoT 워크플로우를 학습하기 좋습니다.

---

Source: https://maker.wiznet.io/ronpang/projects/how-to-connect-stm32-and-w5500-to-onenet-cloud-using-mqtt-over-ethernet/