README-Octoprint.md
I use OctoPrint to deal with my 3D printers, an Ender 3 S1 and an Ender 3 V2. Each one has a separate Raspberry Pi running Octoprint.
I use Cura to cura to 'slice' the .stl files into gcode. And then I tell Cura to send the gcode file to OctoPrint to print. I believe Prusa Slicer has octoprint capabilies as well as Cura. You need a Cura plugin ( Marketplace -> Plugins -> OctoPrint Connection). You have to do the API key dance. Then test and use it enough to decide what you like to don't like.
Cura doesn't really make it easy to swith between two OctoPrints. Oh, it can be done but it's not easy and sometimes I think I should restart Cura. Never a good sign when that is a troubleshooting method. Still, I don't control Cura or the plugins so ignore that first world problem.
I don't like fan noise. Anywhere. That not a positive thing with 3D printers. So, my Printers are a (audible) distance away from normal activities. Even so I want to turn them off when not needed. But not too soon, 3D printers need to cool down somewhat before turning off the power.
I don't like to walk to the printer to turn things on and then walk to the computer to slice and print. I also don't like having the print finish and I don't know about it because I'm busy with something else.
I'm going to integrate those things into my Hubitat Home automation system using MQTT. Why MQTT ? - because it (en)forces operations I believe are good: It doesn't tie me to Hubitat. They will work whether or not Hubitat is up and running. The printers will work if MQTT is down but that's not fun to deal with. Not a problem I worry about. By tieing into the Home Automation system I can turn the room lights on or off. Or change the color of bulb based on printer status - like the light outside of a darkroom?
If you spent some time looking at Octoprint plugins you've found some that claim to do some of these things. You may have found them wanting.
Basically, there is a lot of little fiddly things to do and missing a step can prevent things from working. Oh, you have to google all the instructions because it is way too much to put any details here.
Obviously you need Octoprint, most likely on a Raspberry Pi (I use a couple of old 3b's) If you want to see pictures in real time (you do), then you need a compatible camera and camera mount. And lighting. And Light switches and ...
You'll spend quite a lot more than that $35 computer board. Maybe more than a free puppy.
You want a static IP for your Octoprint puppy. Go fool with your router.
If you like Dashboards you can put image captures on your Hubitat dashboard. It is not something I promote because I never use it nor remember what the url is. It's not hard to find the Octoprint descriptions.
MQTT uses a publish/subscribe paradigm. Muliple things can pubish to a topic and multiple things can be notified if something is published on the topics they subscribe to. A Broker sits in the middle to notify the 'some things' when the other things publish.
I use 'Mosquitto', there are other brokers. I run it on Linux (Raspberry OS is Linux). I have run Mosquitto on a Pi4 along with some other thigs. It's a very light load. You could run it on the some machine you have octoprint on - you just need to get command line access to your octoprint (google it) - not hard to do.
Then sudo apt install mosquitto-clients
I do not use login names and passwords with my broker. Too much typing for
false security, IMO. Hint: you don't have to configure MQTT but you do it your
way.
You want a static IP for your MQTT Broker machine. Really. go do it. Mine is 192.168.1.3 (aka 'stoic.local' in my mdns) Hubitat doesn't like dns names in MQTT.
Rumor is Mosquitto can be installed on Windows. I'd bet homebrew would do it on OSX. Don't care. Octoprint needs to run 24x7, a small Pi running a linux is already in your network. There is no maintenance - I've never had to look at the logs - really! OK, maybe once when there was a login problem.
Since I want to control the power to the printer from Hubitat need an outlet. There are hundreds of choices. You want a zigbee or zwave. NOT WIFI. I use a cheap Sonoff S31 Lite.
Aside from the static IP's, There is one other must do to explain. You need a short name for your Printer. How short? 7 characters. My Ender 3 V2 is 'E3V2' and my Ender 3 S1 is 'E3S1' - see the pattern?
This name is the first word in the notification message that Hubitat flings around. I have very small 1" display screens and 7.5 characters at the largest font is all they can handle on one line. I like to use a large font so I can read it from a few feet away. You can use longer names and regret the time to it takes to redo it my way.
You could modify the code in the driver and any plugin configurations that need it. It's a pretty simple fix, but things would break for me so I'm not going to do it.
This will be easy to configure. Right? We just need the ip address of the MQTT broker and the special topic name.
The Octoprint driver sends Hubitat notifications. It defaults to sending over 100 per print job. There a driver preferences you can set. Minimal - is just start and finish events. Or you can get progress reports every 5% or 10%. You would not want send a lot events to your Cell phone. See Octoprint Monitor/Notifications App
This is a parent app. It will create the children instance but you have to install the driver for both the parent and child. Copy the OctoPrint Monitors App and paste it in Copy the OctoPrint Notifications and paste it in Install the two apps from the Apps -> Add User App
From the Apps you select OctoPrint Monitors App. From there, name and create a child app. When the child App opens - select the Mqtt Octoprint Driver and then pick the additional notification devices. DO NOT use the Mqtt-octoprint driver in the second set- that would create an Endless loop and become very annoying. Bonus points if you know how will you stop it. Better not to try.