--- title: "W5500-Ethernet-Controller-for-Raspberry-Pi-Pico-W" url: "https://maker.wiznet.io/sophia/projects/w5500-ethernet-controller-for-raspberry-pi-pico-w/" markdown_url: "https://maker.wiznet.io/sophia/projects/w5500-ethernet-controller-for-raspberry-pi-pico-w/md" type: "UCC: User Created Content" author: "Wimdeschoen" author_url: "https://teams.microsoft.com/l/message/19:2f7ec233-62c4-4310-ae79-4c9fde21ab9c_da54b902-6998-4454-a8bd-9682b5ccd7bf@unq.gbl.spaces/1757643294304?context=%7B%22contextType%22%3A%22chat%22%7D" editor: "WIZnet" editor_url: "https://maker.wiznet.io/" original_author: "Wimdeschoen" original_url: "https://teams.microsoft.com/l/message/19:2f7ec233-62c4-4310-ae79-4c9fde21ab9c_da54b902-6998-4454-a8bd-9682b5ccd7bf@unq.gbl.spaces/1757643294304?context=%7B%22contextType%22%3A%22chat%22%7D" published: "2025-09-12" language: "en" likes: 0 views: 2312 comments: 0 source: "WIZnet Makers (https://maker.wiznet.io/)" --- # W5500-Ethernet-Controller-for-Raspberry-Pi-Pico-W > A comprehensive MicroPython driver and Modbus TCP client for the WIZnet W5500 Ethernet controller, specifically designed for industrial automation and PLC commu Original author: Wimdeschoen (source: https://teams.microsoft.com/l/message/19:2f7ec233-62c4-4310-ae79-4c9fde21ab9c_da54b902-6998-4454-a8bd-9682b5ccd7bf@unq.gbl.spaces/1757643294304?context=%7B%22contextType%22%3A%22chat%22%7D) ## Article ## W5500-Ethernet-Controller for Raspberry Pi Pico W ### Project Overview This project delivers a **comprehensive MicroPython driver** and **Modbus TCP client** for the **WIZnet W5500 Ethernet Controller**, enabling reliable communication between the **Raspberry Pi Pico W** and **industrial PLCs (Programmable Logic Controllers)** such as the **Siemens S7-1500**. It is specifically designed for **industrial automation environments**, providing features like **automatic recovery after cable disconnects, ARP table management, and detailed diagnostic tools**. From an R&D perspective, this project can serve as a valuable reference for: **Future Single Pair Ethernet (SPE) implementationsWIZnet driver improvement and optimization efforts** --- ### Key Features **Complete W5500 Driver**: Full SPI register control and Ethernet stack integration **Robust Connection Handling**: Automatic recovery from cable or network interruptions **Modbus TCP Client**: Reliable industrial-grade communication with Siemens PLCs **Connection Diagnostics**: Socket debugging, ARP resolution scripts, and improved diagnostic suite **Multi-Socket Management**: Up to 8 simultaneous hardware sockets **MicroPython Optimized**: Non-blocking operations, memory-efficient register access --- ### Hardware Requirements Raspberry Pi Pico W WIZnet W5500 Ethernet Module SPI Pin Wiring | W5500 Pin | Pico Pin | Function | | --- | --- | --- | | SCK | GP10 | SPI Clock | | MOSI | GP11 | Master Out | | MISO | GP12 | Master In | | CS | GP13 | Chip Select | | RST | GP15 | Reset | | VCC | 3V3 | Power Supply | | GND | GND | Ground | --- ### Quick Start **Basic W5500 Setup** `from w5500_driver import W5500 # Initialize hardware w5500 = W5500(sck_pin=10, mosi_pin=11, miso_pin=12, cs_pin=13, rst_pin=15) # Configure network w5500.set_mac_address("02:08:DC:15:00:28") w5500.set_ip_address("192.168.1.100") w5500.set_subnet_mask("255.255.255.0") w5500.set_gateway("192.168.1.1") # Check PHY status phy = w5500.get_phy_status() print(f"Link: {'UP' if phy['link'] else 'DOWN'}")` --- **Siemens PLC Communication** `from w5500_driver import W5500 from siemens_modbus_client import SiemensModbusTCP # Initialize hardware w5500 = W5500(sck_pin=10, mosi_pin=11, miso_pin=12, cs_pin=13, rst_pin=15) # Create Modbus TCP client plc = SiemensModbusTCP(w5500, local_ip="192.168.123.29", plc_ip="192.168.123.10") if plc.connect(): # Read holding registers data = plc.read_holding_registers(0, 10) print(f"PLC Data: {data}") # Write to PLC plc.write_single_register(100, 1234) plc.disconnect()` --- ### File Structure `├── w5500_driver.py # Core W5500 driver ├── siemens_modbus_client.py # Modbus TCP client for Siemens PLCs ├── detailed_socket_debug.py # Socket debugging tools ├── arp_debug_script.py # ARP resolution diagnostics ├── improved_diagnostics.py # Enhanced diagnostic suite └── simple_reset_test.py # Basic connectivity tests ` --- ### Core Components **W5500 Driver (**`**w5500_driver.py**`**)** Full SPI register access (VDM mode) TCP/UDP socket management Network configuration utilities PHY status monitoring Hardware/software reset **Siemens Modbus Client (**`**siemens_modbus_client.py**`**)** Supported Modbus Functions: `read_holding_registers(start, count)` – FC3 `write_single_register(address, value)` – FC6 `write_multiple_registers(start, values)` – FC16 `read_input_registers(start, count)` – FC4 Built-in features: ARP management, auto-reconnect, industrial timeouts --- ### Diagnostic Tools `**improved_diagnostics.py**` → Run complete hardware tests `**arp_debug_script.py**` → Clear ARP tables and fix link issues `**simple_reset_test.py**` → Quick connectivity test `**detailed_socket_debug.py**` → Monitor socket states `# Run diagnostics exec(open('improved_diagnostics.py').read()) # Clear ARP and reset from arp_debug_script import clear_arp_and_reset clear_arp_and_reset(w5500)` --- ### Advanced Usage **Custom Retry Settings** `w5500._write_reg(0x0019, 0x00, [0x13, 0x88]) # 500ms w5500._write_reg(0x001B, 0x00, 0x0F) # 15 retries ` **Force ARP Mode** `mr = w5500._read_reg(0x0000, 0x00, 1)[0] w5500._write_reg(0x0000, 0x00, mr | 0x02)` **Multiple Socket Management** `status0 = w5500.socket_open(0, 0x01, 8000) # TCP status1 = w5500.socket_open(1, 0x02, 8001) # UDP for sock in range(8): w5500.socket_close(sock)` --- ### Technical Specifications **SPI Modes**: 0 & 3 **SPI Frequency**: Up to 80 MHz (tested at 10 MHz) **Socket Count**: 8 independent hardware sockets **Buffer Size**: 32KB (16KB TX + 16KB RX) **Protocols**: TCP, UDP, IPv4, ICMP, ARP, IGMP, PPPoE **PHY**: 10/100 Ethernet with auto-negotiation --- ### Industrial Relevance & Future Outlook Validates **WIZnet W5500** as a robust solution for **industrial automation and PLC communication** Provides **open-source reference code** for **system integrators and engineers** Offers **R&D teams valuable insights** for: Enhancing WIZnet’s driver ecosystem Exploring **Single Pair Ethernet (SPE)** adoption Building more resilient industrial networking stacks --- ### Contributing Test with real hardware Ensure MicroPython compatibility Include diagnostics for debugging Document new features Validate cable disconnect/reconnect scenarios --- ### References WIZnet W5500 Datasheet Modbus TCP Specification Siemens S7-1500 Modbus Documentation --- **Author:** Wim Deschoenmaeker **Hardware:** Raspberry Pi Pico W + WIZnet W5500 **Application:** Industrial automation & PLC communication --- Source: https://maker.wiznet.io/sophia/projects/w5500-ethernet-controller-for-raspberry-pi-pico-w/