STM32-Serial-to-Ethernet-Converter

👤AUTHOR

vorun
An embedded systems developer focused on STM32, low-level peripheral programming, bare-metal drivers, and lightweight network stacks.
He builds educational microcontroller projects, custom bootloaders, and minimal network gateways using pure C and open hardware tools.

🔗 GitHub: https://github.com/vorun/STM32-Serial-to-Ethernet-Converter

🎯PROJECT DESCRIPTION

This project implements a Serial-to-Ethernet Converter that bridges RS232, RS485, and CAN communication to Ethernet TCP using:

• STM32F103C8T6 (Blue Pill)
• WIZnet W5500 (Hardware TCP/IP Ethernet Controller)

The device works as a transparent Serial ⇄ TCP gateway—similar to industrial devices like USR-TCP232—allowing legacy serial devices to be accessed remotely over a network.

Compared to software-based ENC28J60 designs, the W5500 drastically improves performance, reliability, and reduces MCU load by handling TCP/IP in hardware.

🧩COMPONENTS

🧠 Hardware

• STM32F103C8T6 development board
• RS232 (5V level, USART1)
• RS485 (3.3V, USART2)
• CAN (5V, CAN peripheral)
• WIZnet W5500 Ethernet Controller (SPI1)

🧰 SYSTEM OVERVIEW

    [TCP Client: PC / Server / Application]
            ↑       ↓
      Ethernet (TCP/IP)
            ↑
    WIZnet W5500 Ethernet
            ↑  SPI
     STM32F103 MCU
            ↑  UART
      Serial Device (Sensor/MCU)

The STM32 simply reads/writes socket buffers via SPI,
while the W5500 handles TCP/IP packetization and link management.

This ensures:

• deterministic latency
• low CPU overhead
• stable operation under heavy traffic

✔ KEY FEATURES

🔹  Multi-Protocol Serial Support

• RS232 (DB-9)
• RS485 (3.3V differential)
• CAN (5V transceiver)
  All mapped to Ethernet TCP.

🔹  Transparent Serial Bridge

Data passes between TCP client and serial port without modification:

• TCP → UART
• UART → TCP

This makes it compatible with:

• PLCs
• sensors
• CNC controllers
• industrial monitors
• legacy devices

🧪USE CASES

• Industrial PLC Ethernet integration
• Remote serial port server
• SCADA / HMI communication
• CNC machine networking
• CAN-bus monitoring over LAN
• Legacy equipment modernization

📌  This UCC focuses on the hardware capabilities of the design. The original project provides hardware resources only—no official firmware or ready-to-use software stack is included. Users are expected to build their own S2E firmware or integrate custom communication protocols using STM32 and the W5500.