Connecting to Smoothie

Smoothieboard supports multiple connection methods to communicate with your machine. Choose the method that best fits your use case and environment.

Available connection methods

Smoothie supports several ways to connect and communicate:

USB - Virtual serial port and mass storage device via single USB cable (easiest for beginners)
Ethernet - Remote connectivity via RJ45 Ethernet cable; requires network infrastructure
UART - Hardware serial port via USB-to-UART adapter (good for debugging boot messages)
Telnet - Access over Ethernet network (via network module)

USB - Virtual serial port and mass storage via single USB cable; supports dual USB with host expansion
Ethernet - Network connectivity for remote control and OTA firmware updates
UART - Hardware serial port via USB-to-UART adapter (improved debug output)
Telnet - Network-based terminal access (similar to v1)

Connect the cable - Plug a USB cable into the Smoothieboard and your computer
Install drivers (Windows only) - See Windows drivers for older Windows versions
Open host software - Launch Pronterface, bCNC, or LaserWeb
Select serial port - Choose your Smoothieboard’s COM/serial port from the software
Connect and send commands - See Console Commands for available commands

Configure network - Set to true in your config
Set IP address - Use network.ip_address auto for DHCP or specify a static IP
Connect cable - Plug Ethernet cable into Smoothieboard and your router
Access via Telnet - Connect using Pronterface with IP:23 or terminal client
Find IP address - Check your router’s admin interface or use a network scanner

Get adapter - Purchase a USB-to-UART adapter (FTDI TTL cable, 3.3V)
Connect to board - TX/RX/GND to UART pins on Smoothieboard header
Install drivers - Follow adapter manufacturer’s instructions
Open terminal - Use Putty, Picocom, or Cutecom at 115200 baud (boot) or 9600 baud (configured)
Monitor boot messages - See debug output during startup and communicate with board

Connect the cable - Plug a USB cable into the Smoothieboard’s USB2 Device port and your computer
No drivers needed - V2 uses standard USB CDC/ACM and MSC classes (all platforms supported)
Open host software - Launch Pronterface, bCNC, or other compatible software
Select serial port - Choose your Smoothieboard’s COM/serial port from the software
For SD card access - Press the MSD button on the board to toggle mass storage mode, or use a command

V2 USB Advantages:

Enable network - Set to true in your config
Configure IP - Use network.ip_address = auto for DHCP or specify static IP
Connect cable - Plug Ethernet cable into Smoothieboard and your router
Access board - Use web interface (port 80), Telnet (port 23), or SFTP (port 115)
Find IP address - Check router’s interface, use network scanner, or enable serial console

V2 Network Advantages:

Get adapter - USB-to-UART adapter rated for 3.3V logic (FTDI TTL, CH340, etc.)
Connect - TX/RX/GND to UART pins on Smoothieboard header
Install drivers - Follow adapter manufacturer’s instructions
Open terminal - Use Putty, Picocom, or Cutecom at 9600 baud initially
Monitor startup - View detailed boot messages and debug information

Important: Set in your config (default 115200 after boot)

Method	Best For	Advantages	Considerations
USB	Beginners, single-machine operation	Simple setup, no network needed, portable	Cable length limits, potential EMI issues
Ethernet	Production, remote access, noisy environments	Long distances, reliable, network features	Requires network infrastructure, static IP recommended
UART	Troubleshooting, debugging boot issues	Direct hardware access, boot messages	Slower, requires USB adapter, not for production

Use a short, high-quality, shielded USB cable (under 2 meters / 6 feet)
Ferrite beads on the cable help reduce EMI
Keep the cable away from large motors, welders, and electrical noise sources
Connect both machine and computer to the same power strip
If experiencing disconnects, switch to Ethernet for a more stable connection

Use a standard Ethernet cable (CAT5e or better)
Connect to a proper Ethernet router (not directly to computer without crossover configuration)
Set a static IP address to avoid DHCP timeouts
The network stack has buffer limitations with some DHCP servers

Use a short, high-quality USB cable (under 2 meters / 6 feet)
V2’s improved power delivery makes it more tolerant of longer/cheaper cables than v1
Avoid EMI interference from large motors and electrical noise
Provide external 5V power via the 5vin header if experiencing power-related issues
Allow momentary stabilization when entering MSD (mass storage) mode

Use a standard Ethernet cable (CAT5e or better)
Connect via a proper Ethernet router for best reliability
Set a static IP address for predictable access
Check the Ethernet link LED on the RJ45 connector to verify connection
V2’s FreeRTOS+TCP stack is more robust than v1’s uIP and handles DHCP better

For in-depth information on each connection method, see:

USB Documentation - Serial communication, mass storage, drivers, and best practices
Network (Ethernet) Documentation - IP configuration, DHCP, static IP, web server, telnet access
UART Documentation - Hardware serial port, baud rate configuration, troubleshooting
Bluetooth Serial Documentation - Wireless serial connectivity (if available)
WiFi Documentation - Wireless network connectivity (module-dependent)

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