Wiznet makers

Welcome to WIZnet Maker

or

Don't have an account yet?

Welcome to WIZnet Maker

or

Already have account?

Reset Password

Know your password?

Need an account?

gavinchang

Published July 12, 2026 ©

105 UCC

25 WCC

68 VAR

0 Contests

4 Followers

0 Following

Original Link

How to Build FreeRTOS MQTT Networking with WIZnet W5500 on STM32F103?

This education and maker-oriented project uses WIZnet W5500 with STM32F103RET6 and FreeRTOS to build a wired Ethernet MQTT node.

COMPONENTS
PROJECT DESCRIPTION

How to Build FreeRTOS MQTT Networking with WIZnet W5500 on STM32F103?

Summary

This education and maker-oriented project uses WIZnet W5500 with STM32F103RET6 and FreeRTOS to build a wired Ethernet MQTT node. The STM32 firmware manages FreeRTOS tasks, MQTT configuration, topic subscription, data reception, diagnostics, and application behavior, while W5500 provides the Ethernet MAC/PHY, hardwired TCP/IP stack, socket engine, and internal Tx/Rx buffering. The GitCode project identifies the platform as STM32F103RET6, FreeRTOS V10.0.1, STM32 firmware library V3.5, W5500 Ethernet module, and MQTT, but the visible repository page exposes README-level information rather than inspectable source files.

What the Project Does

The project is a complete STM32 + FreeRTOS + W5500 + MQTT example resource for learning and prototyping wired IoT communication. A related CSDN mirror states that the example connects STM32 to an MQTT server, performs topic subscription, and receives data; it also describes the main configuration point as user_mqtt.h, where the MQTT server IP address, port, username, and password can be modified.

The practical data flow is:

STM32F103RET6 application → FreeRTOS task layer → MQTT client logic → W5500 socket layer → SPI → W5500 → RJ45 Ethernet → router, local broker, cloud broker, PC test tool, or gateway.

For education, this project is useful because it separates the embedded network stack into visible layers: RTOS task scheduling, MQTT application protocol, W5500 socket behavior, SPI transactions, and Ethernet PHY/link state. For maker use, it gives a practical starting point for local telemetry, small automation nodes, sensor gateways, relay controllers, MQTT dashboards, and bench-tested wired network devices.

Where WIZnet Fits

The exact WIZnet product is W5500. It sits between the STM32F103RET6 and the Ethernet connector. STM32 communicates with W5500 through SPI, chip select, reset, and optionally interrupt. W5500 handles Ethernet MAC/PHY operation, hardwired TCP/IP processing, socket state transitions, and packet buffering.

WIZnet documents W5500 as a hardwired TCP/IP Internet controller with SPI access up to 80 MHz, an embedded 10/100 Ethernet MAC and PHY, support for TCP, UDP, ICMP, IPv4, ARP, IGMP, and PPPoE, 8 independent sockets, and 32 KB internal memory for Tx/Rx buffers.

This split is important in a FreeRTOS MQTT design. FreeRTOS should schedule the network task, MQTT task, sensor task, command task, and diagnostic task. MQTT should handle topic-level behavior. W5500 should handle the bounded Ethernet transport path: socket state, link status, Tx free space, Rx received size, TCP connection state, and buffer movement. That keeps the STM32 firmware focused on application timing and MQTT logic instead of implementing a full software TCP/IP stack.

Implementation Notes

The GitCode repository confirms the project target and license link, but the visible page did not expose inspectable source files. Therefore, the snippets below are not claimed to come from the GitCode archive. They are verified reference snippets from WIZnet’s official ioLibrary_Driver, which WIZnet lists as its official W5500 driver resource and which includes Ethernet drivers plus Internet services such as DHCP, DNS, HTTP server, and MQTT client.

File: Ethernet/wizchip_conf.h
What it configures: WIZnet chip selection and W5500 SPI interface mode.
Why it matters: this is the firmware boundary where an STM32 + FreeRTOS project selects W5500 and confirms that the host interface is SPI.

 
#define W5100 5100 #define W5100S 5100+5 #define W5200 5200 #define W5300 5300 #define W5500 5500 #define W6100 6100

#elif (_WIZCHIP_ == W5500) #define _WIZCHIP_ID_ "W5500\0"

#ifndef _WIZCHIP_IO_MODE_ #define _WIZCHIP_IO_MODE_ _WIZCHIP_IO_MODE_SPI_ #endif
 

This matters because MQTT over W5500 depends on a working lower layer first: chip selection, SPI access, socket initialization, and network configuration. WIZnet’s official driver repository describes ioLibrary as an Internet Offload Library for WIZnet chips and states that the driver provides Berkeley Socket type APIs.

File: Ethernet/W5500/w5500.h
What it configures: W5500 register access for local IP, socket mode, socket status, and socket buffer state.
Why it matters: education labs and maker projects need register-level visibility to distinguish wiring faults, SPI faults, IP configuration errors, MQTT broker errors, and socket-state problems.

 
#define setSIPR(sipr) \
    WIZCHIP_WRITE_BUF(SIPR, sipr, 4)

#define getSIPR(sipr) \
    WIZCHIP_READ_BUF(SIPR, sipr, 4)

#define setSn_MR(sn, mr) \
    WIZCHIP_WRITE(Sn_MR(sn),mr)

#define getSn_SR(sn) \
    WIZCHIP_READ(Sn_SR(sn))
 

A practical FreeRTOS architecture should map W5500 work into a bounded network task. That task should initialize W5500, configure IP settings, connect the MQTT socket, service keepalive timing, process received MQTT data, and report errors to a diagnostic queue. The CSDN mirror states that the project uses FreeRTOS task management, W5500 Ethernet connectivity, and MQTT subscription/data reception on STM32F103RET6.

Practical Tips / Pitfalls

  • Validate SPI and W5500 chip identity before starting FreeRTOS MQTT debugging.
  • Route W5500 reset to an STM32 GPIO so firmware can recover Ethernet without rebooting the whole board.
  • Keep SCLK, MOSI, MISO, and chip-select traces short on maker prototypes.
  • Put MQTT broker parameters in a dedicated configuration header, but avoid hard-coding production credentials into public examples.
  • Treat W5500’s 8 sockets as limited resources; reserve sockets for MQTT, diagnostics, local service, discovery, and future tests.
  • Log PHY link state, IP address, socket status, MQTT connection state, reconnect count, and last broker error.
  • Test broker downtime, cable removal, DHCP failure, duplicate IP, long idle keepalive, and task starvation.

FAQ

Q: Why use WIZnet W5500 for an STM32 FreeRTOS MQTT project?
A: W5500 gives STM32 wired Ethernet with hardwired TCP/IP, 8 sockets, and 32 KB internal Tx/Rx buffering. That lets the STM32 firmware focus on FreeRTOS task design, MQTT topics, payload handling, and diagnostics while W5500 handles the lower Ethernet and TCP/UDP transport.

Q: How does W5500 connect to the STM32F103 platform?
A: W5500 connects through SPI using SCLK, MOSI, MISO, chip select, reset, 3.3 V, and ground. Interrupt is optional for a simple polling example, but useful when receive, disconnect, timeout, or send-complete events should wake a FreeRTOS network task.

Q: What role does W5500 play in this project?
A: W5500 is the wired Ethernet transport engine for MQTT. STM32F103RET6 runs FreeRTOS, configures MQTT parameters, subscribes to topics, receives data, and handles application behavior; W5500 manages Ethernet MAC/PHY operation, hardwired TCP/IP processing, socket state, and packet buffers.

Q: Can beginners follow this project?
A: Yes, if the lesson is staged. The recommended order is STM32 project setup, SPI wiring check, W5500 reset check, IP configuration, socket test, MQTT broker configuration in user_mqtt.h, topic subscription, data reception, then FreeRTOS task-priority tuning. The related CSDN mirror specifically identifies user_mqtt.h as the place to adjust MQTT server IP, port, username, and password.

Q: How does W5500 compare with Wi-Fi for maker MQTT nodes?
A: Wi-Fi is better when the device must be cable-free. W5500 is better when the project needs repeatable wired behavior, visible PHY link state, explicit reset control, fixed socket resources, and simpler bench diagnostics. For education and maker MQTT experiments, W5500 makes the network boundary easier to inspect than a wireless module hidden behind a higher-level driver.

Source

Original source: GitCode repository “STM32FreeRTOSW5500MQTT资源文件介绍: STM32基于FreeRTOS与W5500实现MQTT通信的完整项目示例.” The visible page identifies STM32F103RET6, FreeRTOS V10.0.1, STM32 firmware library V3.5, W5500 Ethernet module, MQTT, and an MIT license link, but it did not expose inspectable source files during verification.

Related CSDN mirror: “STM32+FreeRTOS+W5500+MQTT 资源文件介绍.” The article states CC 4.0 BY-SA licensing and describes STM32F103RET6, FreeRTOS task management, W5500 Ethernet connection, MQTT subscription/data reception, user_mqtt.h configuration, Keil build/download, and test flow.

Related technical overview: “探索物联网的无限可能：STM32+FreeRTOS+W5500+MQTT 项目推荐.” The article describes the same platform and frames the project for IoT data exchange, industrial automation, smart home, and agricultural monitoring examples.

WIZnet product reference: W5500 documentation and feature list, including hardwired TCP/IP, SPI up to 80 MHz, embedded 10/100 Ethernet MAC/PHY, 8 sockets, 32 KB internal buffer memory, and supported services including MQTT through WIZnet software resources.

WIZnet driver reference: official ioLibrary_Driver, including W5500 support, Berkeley-style socket APIs, DHCP, DNS, HTTP server, and MQTT client components.

Tags

#W5500 #WIZnet #STM32F103 #FreeRTOS #MQTT #Education #Maker #Ethernet #SPI #Registers #Firmware #NetworkStack

 

STM32F103에서 WIZnet W5500으로 FreeRTOS MQTT 네트워킹을 구축하는 방법은?

요약

이 교육 및 maker 중심 프로젝트는 STM32F103RET6과 FreeRTOS에서 WIZnet W5500을 사용해 유선 Ethernet MQTT 노드를 구축합니다. STM32 firmware는 FreeRTOS task, MQTT configuration, topic subscription, data reception, diagnostics, application behavior를 관리하고, W5500은 Ethernet MAC/PHY, hardwired TCP/IP stack, socket engine, internal Tx/Rx buffering을 제공합니다. GitCode 프로젝트는 플랫폼을 STM32F103RET6, FreeRTOS V10.0.1, STM32 firmware library V3.5, W5500 Ethernet module, MQTT로 식별하지만, visible repository page는 inspect 가능한 source file이 아니라 README 수준의 정보만 노출합니다.

프로젝트가 하는 일

이 프로젝트는 유선 IoT 통신을 학습하고 prototype을 만들기 위한 STM32 + FreeRTOS + W5500 + MQTT complete example resource입니다. 관련 CSDN mirror는 이 예제가 STM32를 MQTT server에 연결하고, topic subscription을 수행하며, data를 수신한다고 설명합니다. 또한 주요 configuration point는 user_mqtt.h이며, 여기에서 MQTT server IP address, port, username, password를 수정할 수 있다고 설명합니다.

실제 데이터 흐름은 다음과 같습니다.

STM32F103RET6 application → FreeRTOS task layer → MQTT client logic → W5500 socket layer → SPI → W5500 → RJ45 Ethernet → router, local broker, cloud broker, PC test tool 또는 gateway

교육용으로는 RTOS task scheduling, MQTT application protocol, W5500 socket behavior, SPI transaction, Ethernet PHY/link state를 계층별로 볼 수 있다는 점이 유용합니다. Maker 용도로는 local telemetry, small automation node, sensor gateway, relay controller, MQTT dashboard, bench-tested wired network device의 실용적인 시작점이 됩니다.

WIZnet이 들어가는 위치

이 프로젝트에서 사용되는 정확한 WIZnet 제품은 W5500입니다. W5500은 STM32F103RET6과 Ethernet connector 사이에 위치합니다. STM32는 SPI, chip select, reset, 선택적으로 interrupt를 통해 W5500과 통신합니다. W5500은 Ethernet MAC/PHY operation, hardwired TCP/IP processing, socket state transition, packet buffering을 처리합니다.

WIZnet 문서 기준으로 W5500은 최대 80 MHz SPI access, embedded 10/100 Ethernet MAC and PHY, TCP, UDP, ICMP, IPv4, ARP, IGMP, PPPoE 지원, 8개 independent socket, Tx/Rx buffer용 32 KB internal memory를 제공하는 hardwired TCP/IP Internet controller입니다.

이 분업은 FreeRTOS MQTT 설계에서 중요합니다. FreeRTOS는 network task, MQTT task, sensor task, command task, diagnostic task를 scheduling해야 합니다. MQTT는 topic-level behavior를 처리해야 합니다. W5500은 socket state, link status, Tx free space, Rx received size, TCP connection state, buffer movement 같은 제한된 Ethernet transport path를 담당해야 합니다. 이렇게 하면 STM32 firmware는 full software TCP/IP stack 구현 대신 application timing과 MQTT logic에 집중할 수 있습니다.

구현 참고 사항

GitCode repository는 project target과 license link를 확인할 수 있게 하지만, visible page는 inspect 가능한 source file을 노출하지 않았습니다. 따라서 아래 snippet은 GitCode archive에서 나온 코드라고 주장하지 않습니다. 아래 코드는 WIZnet이 공식 W5500 driver resource로 제공하는 ioLibrary_Driver에서 가져온 검증된 reference snippet입니다. ioLibrary_Driver는 Ethernet driver와 DHCP, DNS, HTTP server, MQTT client 같은 Internet service를 포함합니다.

파일: Ethernet/wizchip_conf.h
설정 내용: WIZnet chip selection 및 W5500 SPI interface mode
중요한 이유: STM32 + FreeRTOS project가 W5500을 선택하고 host interface가 SPI임을 확인하는 firmware boundary입니다.

 
#define W5100 5100 #define W5100S 5100+5 #define W5200 5200 #define W5300 5300 #define W5500 5500 #define W6100 6100

#elif (_WIZCHIP_ == W5500) #define _WIZCHIP_ID_ "W5500\0"

#ifndef _WIZCHIP_IO_MODE_ #define _WIZCHIP_IO_MODE_ _WIZCHIP_IO_MODE_SPI_ #endif
 

MQTT over W5500은 lower layer가 먼저 안정적으로 동작해야 합니다. 여기에는 chip selection, SPI access, socket initialization, network configuration이 포함됩니다. WIZnet 공식 driver repository는 ioLibrary를 WIZnet chip용 Internet Offload Library로 설명하며, Berkeley Socket type API를 제공한다고 설명합니다.

파일: Ethernet/W5500/w5500.h
설정 내용: local IP, socket mode, socket status, socket buffer state를 위한 W5500 register access
중요한 이유: Education lab과 maker project는 wiring fault, SPI fault, IP configuration error, MQTT broker error, socket-state problem을 구분하기 위한 register-level visibility가 필요합니다.

 
#define setSIPR(sipr) \
    WIZCHIP_WRITE_BUF(SIPR, sipr, 4)

#define getSIPR(sipr) \
    WIZCHIP_READ_BUF(SIPR, sipr, 4)

#define setSn_MR(sn, mr) \
    WIZCHIP_WRITE(Sn_MR(sn),mr)

#define getSn_SR(sn) \
    WIZCHIP_READ(Sn_SR(sn))
 

실용적인 FreeRTOS architecture에서는 W5500 작업을 bounded network task로 매핑하는 것이 좋습니다. 이 task는 W5500 초기화, IP setting 구성, MQTT socket 연결, keepalive timing 처리, received MQTT data 처리, diagnostic queue로 error 보고를 담당해야 합니다. 관련 CSDN mirror도 이 프로젝트가 STM32F103RET6에서 FreeRTOS task management, W5500 Ethernet connectivity, MQTT subscription/data reception을 사용한다고 설명합니다.

실무 팁 / 주의점

  • FreeRTOS MQTT debugging을 시작하기 전에 SPI와 W5500 chip identity를 먼저 검증해야 합니다.
  • W5500 reset은 STM32 GPIO에 연결해 전체 board를 reboot하지 않고 Ethernet을 복구할 수 있게 해야 합니다.
  • Maker prototype에서는 SCLK, MOSI, MISO, chip-select trace를 짧게 유지해야 합니다.
  • MQTT broker parameter는 전용 configuration header에 넣되, production credential을 public example에 hard-code하지 않아야 합니다.
  • W5500의 8개 socket은 제한된 자원으로 다뤄야 합니다. MQTT, diagnostics, local service, discovery, future test용 socket을 예약해야 합니다.
  • PHY link state, IP address, socket status, MQTT connection state, reconnect count, last broker error를 기록해야 합니다.
  • Broker downtime, cable removal, DHCP failure, duplicate IP, long idle keepalive, task starvation을 테스트해야 합니다.

FAQ

Q: STM32 FreeRTOS MQTT 프로젝트에 왜 WIZnet W5500을 사용하나요?
A: W5500은 STM32에 hardwired TCP/IP, 8개 socket, 32 KB internal Tx/Rx buffering을 갖춘 유선 Ethernet을 제공합니다. 따라서 STM32 firmware는 FreeRTOS task design, MQTT topic, payload handling, diagnostics에 집중하고, W5500은 하위 Ethernet 및 TCP/UDP transport를 처리합니다.

Q: W5500은 STM32F103 platform에 어떻게 연결되나요?
A: W5500은 SCLK, MOSI, MISO, chip select, reset, 3.3 V, ground를 사용하는 SPI로 연결됩니다. Interrupt는 단순 polling example에서는 선택 사항일 수 있지만, receive, disconnect, timeout, send-complete event가 FreeRTOS network task를 깨워야 하는 구조에서는 유용합니다.

Q: 이 프로젝트에서 W5500은 어떤 역할을 하나요?
A: W5500은 MQTT를 위한 유선 Ethernet transport engine입니다. STM32F103RET6은 FreeRTOS를 실행하고, MQTT parameter를 설정하며, topic을 subscribe하고, data를 수신하며, application behavior를 처리합니다. W5500은 Ethernet MAC/PHY operation, hardwired TCP/IP processing, socket state, packet buffer를 관리합니다.

Q: 초보자도 이 프로젝트를 따라갈 수 있나요?
A: 가능합니다. 다만 수업을 단계적으로 구성해야 합니다. 권장 순서는 STM32 project setup, SPI wiring check, W5500 reset check, IP configuration, socket test, user_mqtt.h에서 MQTT broker configuration, topic subscription, data reception, 그다음 FreeRTOS task-priority tuning입니다. 관련 CSDN mirror는 user_mqtt.h가 MQTT server IP, port, username, password를 조정하는 위치라고 설명합니다.

Q: Maker MQTT node에서 W5500은 Wi-Fi와 비교하면 어떤 차이가 있나요?
A: Wi-Fi는 device가 cable-free여야 할 때 더 적합합니다. W5500은 repeatable wired behavior, visible PHY link state, explicit reset control, fixed socket resource, 더 단순한 bench diagnostics가 필요할 때 더 적합합니다. Education 및 maker MQTT experiment에서는 W5500이 higher-level driver 뒤에 숨겨진 wireless module보다 network boundary를 관찰하기 쉽습니다.

출처

Original source: GitCode repository “STM32FreeRTOSW5500MQTT资源文件介绍: STM32基于FreeRTOS与W5500实现MQTT通信的完整项目示例.” Visible page는 STM32F103RET6, FreeRTOS V10.0.1, STM32 firmware library V3.5, W5500 Ethernet module, MQTT, MIT license link를 식별하지만, 검증 중 inspect 가능한 source file은 노출하지 않았습니다.
https://gitcode.com/open-source-toolkit/f30ad

Related CSDN mirror: “STM32+FreeRTOS+W5500+MQTT 资源文件介绍.” 해당 article은 CC 4.0 BY-SA licensing을 명시하며, STM32F103RET6, FreeRTOS task management, W5500 Ethernet connection, MQTT subscription/data reception, user_mqtt.h configuration, Keil build/download, test flow를 설명합니다.
https://blog.csdn.net/gitblog_09814/article/details/143002751

Related technical overview: “探索物联网的无限可能：STM32+FreeRTOS+W5500+MQTT 项目推荐.” 해당 article은 같은 platform을 설명하고, IoT data exchange, industrial automation, smart home, agricultural monitoring example로 project를 소개합니다.
https://blog.csdn.net/gitblog_09763/article/details/143145106

WIZnet product reference: W5500 documentation and feature list, including hardwired TCP/IP, SPI up to 80 MHz, embedded 10/100 Ethernet MAC/PHY, 8 sockets, 32 KB internal buffer memory, and supported services including MQTT through WIZnet software resources.
https://docs.wiznet.io/Product/Chip/Ethernet/W5500

WIZnet driver reference: official ioLibrary_Driver, including W5500 support, Berkeley-style socket APIs, DHCP, DNS, HTTP server, and MQTT client components.
https://github.com/Wiznet/ioLibrary_Driver

태그

#W5500 #WIZnet #STM32F103 #FreeRTOS #MQTT #Education #Maker #Ethernet #SPI #NetworkStack #Firmware #Socket #EmbeddedNetworking

Documents
Comments Write