Wiznet makers

📌 Key Features

W5500 SPI Ethernet — ENABLE_ETHERNET flag Introduces EthernetConfig.cpp and EthernetConfig.h — new files not present in the original FluidNC. Integration into WifiConfig.cpp is done via #ifdef ENABLE_ETHERNET conditional compilation. When this flag is enabled at build time, W5500 Ethernet initializes.

Shared SPI bus with SD card — SPI2_HOST W5500 shares the SPI2_HOST already owned by FluidNC's SD card driver. Rather than calling spi_bus_initialize() again, W5500 is added as a second device on the existing bus. CS is GPIO 14, INT is GPIO 9, SPI speed is 20 MHz.

Native ESP-IDF Ethernet stack Follows the standard ESP-IDF W5500 driver initialization sequence: esp_eth_mac_new_w5500(), esp_eth_phy_new_w5500(), esp_netif_new(), esp_eth_start(). Automatically attaches to the lwIP TCP/IP stack with DHCP client.

Full GRBL compatibility preserved Retains the original FluidNC's complete GRBL compatibility. No changes to G-code send/response protocol. Supports all GRBL G-code commands. Works with existing G-code senders (UGS, CNCjs, Candle, etc.).

WebUI preserved FluidNC's built-in browser-based WebUI (Esp32_WebUI) works normally over an Ethernet network. Control the CNC machine from a PC, smartphone, or tablet.

YAML-based machine configuration Uses the same YAML configuration file system as the original FluidNC. Machine configuration can be changed by editing config.yaml alone — no firmware recompilation needed.

📌 System Architecture

📌 Core Code — EthernetConfig.cpp

Key structure of the newly added EthernetConfig.cpp:

// GPIO pin definitions (dpCREATOR R2 board)
#define W5500_CS_GPIO   14
#define W5500_INT_GPIO   9
#define W5500_SPI_HOST  SPI2_HOST  // Shared with SD card
#define W5500_SPI_HZ    20000000   // 20 MHz

void ethernet_init() {
    // 1. spi_bus_initialize() NOT called — SD card driver already owns the bus
    // 2. Add W5500 as second device on existing SPI2_HOST
    spi_device_interface_config_t spi_devcfg = {};
    spi_devcfg.clock_speed_hz = W5500_SPI_HZ;
    spi_devcfg.spics_io_num   = W5500_CS_GPIO;

    // 3. Create ESP-IDF W5500 MAC/PHY
    eth_w5500_config_t w5500_config =
        ETH_W5500_DEFAULT_CONFIG(W5500_SPI_HOST, &spi_devcfg);
    w5500_config.int_gpio_num = W5500_INT_GPIO;

    esp_eth_mac_t* mac = esp_eth_mac_new_w5500(&w5500_config, &mac_config);
    esp_eth_phy_t* phy = esp_eth_phy_new_w5500(&phy_config);

    // 4. Install driver + attach lwIP netif + event handlers
    esp_eth_driver_install(&eth_config, &s_eth_handle);
    esp_netif_attach(eth_netif, esp_eth_new_netif_glue(s_eth_handle));
    esp_eth_start(s_eth_handle);
}

📌 Build & Flash

Requirements: PlatformIO, ESP-IDF v5.x (ESP_IDF_VERSION_MAJOR >= 5)

# 1. Clone the repository
git clone https://github.com/val218/fluidNC-with-w5500-support

# 2. Enable ENABLE_ETHERNET flag (platformio.ini or build_flags)
# build_flags = -DENABLE_ETHERNET

# 3. Build and upload
pio run -t upload

# 4. Serial monitor
pio device monitor --baud 115200

Machine configuration:

1. Upload config.yaml via USB/serial or WiFi
2. WebUI: navigate to http://<ethernet IP>/

Release tag: v4.0.3_r2_w5500 (based on upstream FluidNC v4.0.3)

📌 Role and Application of the WIZnet's Chip

Chip model: W5500

In this fork, the W5500 adds a wired Ethernet path to FluidNC's networking layer. Specifically:

• G-code streaming stability: Delivers G-code from sender to CNC machine reliably without WiFi EMI interference
• WebUI serving: Serves the browser-based FluidNC WebUI over an Ethernet network
• DHCP client: Automatically connected to the ESP-IDF lwIP stack
• Shared SPI with SD card: Added as a second device on the existing SPI2_HOST bus without calling spi_bus_initialize() again — no resource conflict

Why W5500: CNC environments are electrically noisy. Switching noise from stepper drivers and VFDs interferes with 2.4 GHz WiFi. If the WiFi connection drops mid-job, G-code streaming stops and the workpiece is ruined. W5500 wired Ethernet is immune to this interference.

📌 Supported Hardware

W5500 pin assignments in this fork are confirmed for the dpCREATOR R2 board:

Other ESP32-based CNC boards can be supported by modifying the GPIO pin definitions in EthernetConfig.cpp.

📌 G-code Flow Diagram

📌 Market & Application Value

DIY CNC makers, home machining shops, small manufacturers, and laser cutter users are the core market. Particularly valuable for CNC machine operators in industrial environments where EMI makes WiFi unstable. Leverages the full existing FluidNC ecosystem (G-code senders, WebUI, YAML configuration) while upgrading network reliability to W5500.

📌 WIZnet Strategic Value

This fork demonstrates W5500 entering the CNC firmware ecosystem as a practical solution to WiFi instability. The design pattern of reusing an existing SPI bus (SD card + W5500 shared on SPI2_HOST) is a clean, reusable reference implementation for adding W5500 to resource-constrained ESP32 systems with minimal code changes.

📌 Summary

This FluidNC fork integrates W5500 wired Ethernet support into FluidNC CNC firmware via EthernetConfig.cpp and the ENABLE_ETHERNET compile flag. W5500 shares the SD card's SPI2_HOST bus, uses the standard ESP-IDF W5500 driver, and preserves full FluidNC GRBL compatibility and WebUI. In EMI-heavy CNC environments, W5500 delivers stable G-code streaming and WebUI access that WiFi cannot guarantee. GPLv3 licensed.

📌 FAQ

Q1. What is the difference between this fork and the original FluidNC? The core difference is the addition of EthernetConfig.cpp and EthernetConfig.h, plus ENABLE_ETHERNET conditional integration code in WifiConfig.cpp. This enables W5500 SPI Ethernet for wired network operation.

Q2. Is there a conflict between W5500 and the SD card on the same SPI bus? No. W5500 is added as a second device on the SPI2_HOST already owned by the FluidNC SD card driver, without calling spi_bus_initialize() again. The CS pin (GPIO 14) separates the two devices — no conflict.

Q3. How do I enable the ENABLE_ETHERNET flag? Add -DENABLE_ETHERNET to build_flags in platformio.ini. Building without this flag retains the original FluidNC WiFi behavior.

Q4. Is it compatible with existing FluidNC G-code senders? Yes. Full GRBL compatibility is preserved. Connect existing G-code senders (UGS, CNCjs, Candle, etc.) to the Ethernet IP address and they work as-is.

Q5. Can I use it on boards other than dpCREATOR R2? Modify the GPIO definitions in EthernetConfig.cpp (W5500_CS_GPIO=14, W5500_INT_GPIO=9, SPI pins) to match the actual wiring on your target ESP32-based CNC board.

Q6. Can WiFi and Ethernet be used simultaneously? This fork focuses on adding W5500 Ethernet. Simultaneous WiFi + Ethernet operation is not explicitly implemented. The ENABLE_ETHERNET flag activates Ethernet initialization at build time.

Q7. Does the WebUI work over Ethernet? Yes. FluidNC's built-in browser-based WebUI (Esp32_WebUI) works normally when accessed via the Ethernet IP address.

Q8. What is the release version? Tag v4.0.3_r2_w5500 — based on upstream FluidNC v4.0.3 with W5500 support added.

Q9. Is DHCP automatic? Yes. Automatically connected to ESP-IDF's esp_netif and lwIP stack. The assigned IP address appears in the serial monitor as IP: xxx.xxx.xxx.xxx.

Q10. What is the license? GPLv3 — same as the original FluidNC.

📌 Reference Links

• GitHub: https://github.com/val218/fluidNC-with-w5500-support
• Original FluidNC: https://github.com/bdring/FluidNC
• FluidNC Wiki: https://github.com/bdring/FluidNC/wiki