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FluidNC Setup

FluidNC is an ESP32-based CNC controller firmware with WiFi. ncSender can connect to it and run jobs, but some ncSender features only work with grblHAL (see Not Available on FluidNC).

Connection

Set up the connection in Settings → General → CNC Connection Setup.

  • USB: pick the serial port and 115200 baud.
  • WiFi: pick Ethernet as the connection type and enter the board's IP address. Then pick a Protocol: Telnet (port 23) or WebSocket (port 81).

ncSender uses the one connection you save. If the controller reboots, ncSender reconnects by itself.

Configuration

FluidNC stores its settings in a YAML config file instead of numbered $ settings. Edit it in Settings → Config:

  1. Open Settings → Config. Controller Config loads from the board. Click Refresh to load it again.
  2. Change the values you need. Unsaved changes shows until you save.
  3. Click Save to Controller.
  4. Restart the controller to apply the changes.

Status Reporting

FluidNC uses the same GRBL-style status format. ncSender handles a few FluidNC differences:

  • Homing: ncSender never shows Homing Required for FluidNC. Homing is up to you.
  • Work position: FluidNC status reports leave out the work offset, so ncSender works it out itself. The DRO still shows the right work position.
  • Spindle speed: the RPM shown is the measured speed, and it winds down smoothly after M5.
  • Pins: probe and tool setter pins are read from FluidNC's own format.

Alarms

FluidNC alarm codes use the format N: Description (for example 1: Hard Limit). ncSender fetches alarm descriptions with the $A command.

Firmware Information

Send $I to get FluidNC build information, including:

  • Firmware version
  • Board configuration
  • WiFi status
  • Axis count and configuration

Not Available on FluidNC

  • Firmware settings table. Use the Config tab instead.
  • Machine Setup Wizard. It sets grblHAL settings only.
  • Calibration guides. FluidNC keeps steps/mm in its config file, which the guides can't edit yet.

Tips

ESP32 Reset

Some USB connections can reset the ESP32 when ncSender connects. ncSender handles DTR/RTS carefully to avoid this. If the board still reboots on connect, use the USB cable and port recommended for your board.