Newbie advice, please

I have just got a Creality Ender 3 Pro. I have done a few prints from a microSD card, but I realise I will want OctoPrint!

I have been using various Raspberry Pis for a few years so fairly OK on getting them going.

So I am looking for some recomendations .....

  1. I want to be able to use the RPi to detect a temperature from an 18B20 temperature sensor and switch on a relay. So I need to be able to access the GPIO pins and I would like to programme in Python.
    Can I do this if I use OctoPi?

  2. Is there a 5V DC power supply that I can use on the Ender 3 Pro?
    If not I will just use a power buck and a "wall wart" power supply.

  3. I will want to add a web cam. I will probably use a Logitech C270, but is there a "better" one?

  4. I see that Octoprint has a web interface, but can I still use SSH and SFTP?

  5. Which RPi should I use? My current guess is that a RPi 3B+ is probably best as it runs cooler, although I also have a RPi 4 that I could use. Which is "best"?

Any constuctive advice would be greatly appreciated

Hi there,

  1. Certainly, Octopi will work for that. There is a great plugin, Enclosure Plugin (4.13.1), that will allow you to configure sensor inputs and gipo without having to write any code.

  2. I cant answer for wether your ender can supply power but I would recomend an independant power source. I wouldn't want to overtax the printer power supply. You may also find that once you start adding additional controls you may need more than 5v.

  3. I find the c270 to be sufficient. you may want to print a new front plate with focus control (thingverse). anything else is overkill as it (octopi) doesnt stream mp4 it sends jpg images.

  4. ssh works out of the box to connect to the OctoPI build. note however that the OctoPI build doesn't have a desktop installed on the PI to save resources. I find that the access thru the web interface is robust and sufficient for printing needs but there are no real limits put on the RPI by octoprint.

  5. as I understand it, octopi is not fully supported on RPi4 yet. the 3b+ provides sufficient processing power and built in wireless so it runs nicely. While you can run on older models and the PI w, they may lag with video streaming. If you are familiar with setting up your RPi4, you might try the full install and post your results. After reading thru the instructions, I opted for the OctoPI build image for my RPi3B+

Good luck, and Happy printing.

Brilliant reply - Thanks!!

  1. I had a quick look at the Enclosure plugin and it looks as if it will do most of the work for me! I normally use 18B20 sensors, but it doesn't seem to be listed in the plug in documentation so I will just use one of the supported sensors
  2. I thought that may be the case. I haven't checked the PSU output on my Ender 3 Pro, but I suspect that the output voltage will vary quite a bit when doing a print.
  3. OK I will order one up
  4. Great, I usually run my RPis (I have several!) headless anyway.
    Do you think I could just upload a Python programme and run it alongside OctoPi?
    I wonder if OctoPi just uses a version of "Raspian Lite", if so that would make life very easy!
  5. OK, I will plan on running a RPi3B+ with my "real" version. But as you suggest I will try running the image on my RPi4 just to see what happens and put a commnet on here.

Thanks and regards

Oops! Looked at the Git Hub documentation and the 18B20 IS supported.
Only downside I found is that it is written in Python 2.7 (that's getting old and will be deprecated sometime in the future ....) and I always use Python3 - it really doesn't matter as they can both co-exist on the same RPi.


4,5: If you havent read it already, Foosel wrote this post to cover how to manualy install on a RPi:

She goes in depth on the steps required to install and what the pitfalls are.