There are 3 different ways to connect Octoprint to Smoothie:

• Ethernet
• USB
• UART pins

Octoprint can't connect via network natively, so we'll use socat (a fork of famous netcat) to create a local pipe to route traffic to Smoothie

First install it (all the following examples are for OctoPi):

sudo apt-get install socat

Now try this command (replace SMOOTHIE_IP with your Smoothieboard address, like 192.168.0.10)

sudo socat pty,wait-slave,link=/dev/ttySmoothie,perm=0660,group=tty tcp:SMOOTHIE_IP:23

You'll see no output (that's ok). Leave the command running. We'll finalize that later.

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Proceed to Octoprint Web UI

Go to OctoPrint Settings → Serial Connection:

Set Additional serial ports to /dev/ttySmoothie

Save, then reopen the same settings page.

Set Serial Port to /dev/ttySmoothie

Set Baudrate to maximum: 250000

Save and close

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Now try to connect to the printer. If it connects, we should finalize the configuration and add socat to system startup

Open /etc/rc.local

sudo nano /etc/rc.local

Go down with ↓ key until you reach the end of the file. The last line is usually exit 0. Before this line add the following (replace SMOOTHIE_IP with Smoothie IP address):

socat pty,wait-slave,link=/dev/ttySmoothie,perm=0660,group=tty tcp:SMOOTHIE_IP:23 &

Save & exit: Ctrl+O, ⏎, Ctrl+X

Reboot and check if it works.

Try to print (stream) some file from Octoprint (not from Smoothie's SD card). You may notice that it streams gcode awkwardly slow even on a fast network connection. That's how it happens for some of the users. That means you should prefer USB to Ethernet connection.

It might be woking for you. Please leave a note somewhere if the speed is fine via socat.

Still you can upload to SD (slow too: 1 MB/min for some users) and use Octoprint to start / stop jobs and control printer status

Described on Octoprint wiki at https://github.com/foosel/OctoPrint/wiki/Setup-OctoPrint-with-Smoothie .

Set the “Ignore any unhandled errors from the firmware” setting in Octoprint.

TODO add some more documentation here