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FluidNC Setup

FluidNC is a WiFi-enabled CNC controller firmware based on ESP32 that ncSender fully supports.

Connection

  • USB — Serial connection at 115200 baud
  • WiFi — Connect via the FluidNC WiFi interface

Boot Sequence

FluidNC sends boot messages ([MSG:INFO:...]) during startup. ncSender suppresses these from the terminal to keep the display clean.

Configuration

FluidNC uses YAML-based configuration files instead of numbered $ settings. Configuration is managed through FluidNC's web interface or config file.

Common Settings

ncSender reads FluidNC settings for:

  • Axis configuration (travel limits, homing direction)
  • Spindle configuration
  • Probe and tool setter pin assignments
  • Kinematics type

Status Reporting

FluidNC uses the same GRBL-compatible status format. ncSender handles FluidNC-specific behaviors:

  • Homing detection — FluidNC detects homing via Home→Idle state transition (different from grblHAL's cycle counter)
  • Pin normalization — FluidNC uses native Pn:P/Pn:T format for probe/TLS pins

Alarms

FluidNC alarm codes use the format N: Description (e.g., 1: Hard Limit). ncSender fetches alarm descriptions via the $A command.

Firmware Information

Use $I to get FluidNC build information, including:

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

Tips

WiFi vs USB

When both WiFi and USB are available, ncSender prefers WiFi (WebSocket) for communication. USB is used as a fallback.

ESP32 Reset

Some USB interfaces can trigger an ESP32 reset when connecting. ncSender handles DTR/RTS carefully to avoid this, but if you experience unexpected reboots on connect, check your USB cable and port.