---
title: "STM32F401RE_MQTT with W5100 ethernet shield"
url: "https://maker.wiznet.io/Hannah/projects/stm32f401re-mqtt-with-w5100-ethernet-shield/"
markdown_url: "https://maker.wiznet.io/Hannah/projects/stm32f401re-mqtt-with-w5100-ethernet-shield/md"
type: "UCC: User Created Content"
author: "kallmanjaa"
author_url: "https://github.com/kallmanjaa/STM32F401RE_MQTT"
editor: "WIZnet"
editor_url: "https://maker.wiznet.io/"
original_author: "kallmanjaa"
original_url: "https://github.com/kallmanjaa/STM32F401RE_MQTT"
published: "2023-12-01"
language: "en"
hardware: ["WIZnet W5100 ethernet shield"]
likes: 0
views: 473
comments: 0
source: "WIZnet Makers (https://maker.wiznet.io/)"
---

# STM32F401RE_MQTT with W5100 ethernet shield

> This project involves implementing MQTT communication using an STM32F4 microcontroller and the Wiznet W5500 Ethernet module.

Original author: kallmanjaa (source: https://github.com/kallmanjaa/STM32F401RE_MQTT)

## Components

- **WIZnet W5100 ethernet shield** x 1 ([docs](https://www.wiznet.hk/en/open-source-hardware/102-w5100s-ethernetshield.html?search_query=W5100+ethernet+shield&results=84))

## Article

This project showcases the implementation of an MQTT communication system using the STM32F4 microcontroller and the Wiznet W5500 Ethernet module. Key features of the project include:

**MQTT Communication:**

- The STM32F4 microcontroller is configured to communicate over MQTT, enabling seamless messaging with an MQTT broker.

**Wiznet W5500 Integration:**

- The Wiznet W5500 Ethernet module is employed to facilitate network connectivity for the STM32F4 microcontroller.

- SPI (Serial Peripheral Interface) is utilized to interface with the W5500 module, enabling reliable and efficient communication.

**Network Initialization:**

- The project initializes the W5500 module and establishes network connectivity, providing a foundation for MQTT communication.

**MQTT Client Configuration:**

- The MQTT client is configured with essential parameters, including client ID, QoS (Quality of Service), username, password, and server IP/port.

**Publish-Subscribe Mechanism:**

- The code enables the STM32F4 microcontroller to both publish and subscribe to MQTT topics, allowing bidirectional communication.

**Periodic Message Publication:**

- A routine for periodic publication of MQTT messages is implemented, demonstrating a continuous and automated messaging process.

**Error Handling and Debugging:**

- The project incorporates error handling mechanisms and utilizes the USART2 UART interface for debugging output, ensuring robust and reliable operation.

**SPI Communication:**

- The SPI interface is employed for communication between the STM32 microcontroller and the W5500 Ethernet module, optimizing data transfer efficiency.

This project serves as a comprehensive example of integrating the Wiznet W5500 Ethernet module with an STM32F4 microcontroller to enable MQTT communication over a network. The utilization of SPI ensures efficient data exchange, making it a robust solution for IoT (Internet of Things) and networked applications.

---

Source: https://maker.wiznet.io/Hannah/projects/stm32f401re-mqtt-with-w5100-ethernet-shield/