Mac Drivers and USB Communication

Smoothieware works well on macOS without additional drivers. Both V1 and V2 use standard USB CDC/ACM (virtual serial port) and work out of the box.

Smoothieware V1 (Smoothieboard) appears as both a USB Mass Storage device and a virtual serial port on macOS. While no drivers are required, there are some common SD card issues that Mac users should be aware of.

Smoothieware V2 provides improved USB handling with better SD card access control via MSD mode (controlled by pushbutton or command). No additional drivers are required.

SD Card Issues on macOS

V1: Slow to Unmount Due to Spotlight Indexing

Smoothieware V1 (Smoothieboard) appears as a USB Mass Storage device on macOS, and Spotlight indexing can cause the SD card to take a very long time to unmount or eject. This is especially noticeable when large STL files are on the card.

Solutions

Solution 1: Disable Spotlight Indexing

Type this Terminal command when the SD card is mounted:

mdutil -i off /Volumes/Smoothie/

This disables Spotlight indexing for the Smoothie SD card volume.

Solution 2: Prevent Indexing with a Marker File (Recommended)

Place an empty file named .metadata_never_index at the volume root:

cd /Volumes/Smoothie/
touch .metadata_never_index

This creates a marker file that tells macOS not to index this volume.

Recommended: Solution 2 (marker file) is preferred as it is persistent and will continue to work even if you reformat the SD card and restore the marker file.

Note: Solution 1 needs to be re-run each time the SD card is mounted on a new Mac.

V2: Improved SD Card Handling

Smoothieware V2 provides better SD card access control. The MSD (Mass Storage Device) mode is controlled via a pushbutton or command, preventing accidental USB mounting and Spotlight indexing issues. This design is much more reliable on macOS.

Serial Communication

Both V1 and V2 use standard USB CDC/ACM (virtual serial port) for communication. No additional drivers are required on macOS.

The board will appear as a serial device at /dev/tty.usbmodem* (the exact name may vary).

You can connect using any serial terminal program such as:

  • Screen (built-in): screen /dev/tty.usbmodem* 115200
  • CoolTerm
  • Serial (Mac App Store)
  • Pronterface (for 3D printing)
  • USB - General USB communication documentation
  • SD Card - SD card setup and usage
  • Pronterface - Recommended host software for 3D printing
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