OctoPrint is designed to on many platforms, but the Raspberry Pi is the most popular host, probably because it has a large user base and is remarkably cheap (under $40). Here's what you need- both basics and extras.
You need:
a Raspberry Pi (not Pi Zero). These are $35-40, get whatever the current model is since they are the same price and represent the most powerful board.
a microSD card. Get one with decent performance and is at least 8gb large; a 32gb Sandisk U1 is less than $10 at Amazon (make sure to buy it from Amazon, not an unknown third party to reduce the chance of getting a knockoff).
If you want, you can buy a case, but it's even better to browse Thingiverse and find one that mounts to your printer in a nice place.
If you want a webcam (to watch the printer and to make a build timelapse), get one of these:
Camera Module V2 No IR, $25 (infrared filter removed; perhaps handy if you need to take timelapses in low-light and also don't care about the color looking different)
You will need access to the following to access the Pi's interface while setting it up; you might be able to do it using the "boot config" files, but you should have these in case something goes wrong (or if you don't feel like enough of an expert to get the blind config correct)
computer monitor (or TV) with HDMI cable
keyboard with USB connector
mouse with USB connector
SD card writer for your computer
Most of us have these handy for various reasons; if not (for instance, if you only have a wireless keyboard), a basic "slim keyboard" is $13 and a 'travel mouse' is $7. If you truly don't have a TV or computer monitor, you can find one for under $70. I'd suggest getting a smaller screen (16" vs the more-common 21-24" range); they are the same price but for occasional use something that is more compact is helpful for storage and moving.
This is written with USA in mind; I want to expand it, so reply with your country-specific tips. I've included links to Amazon, as generally they are going to be the easiest to buy from. If you have a reason to think element14 or adafruit should be given in links, explain why below. If you think I should use affiliate codes on the links, say so too.
The Raspberry Pi camera also requires a ribbon cable (which are sold in different lengths).
You've provided two great products for the serial cable but I think I'd mention the internal-shielding-or-ferrite-cores minimum requirement.
I think I'd state that the Raspberry Pi's power requirements are 5V @ 2.5A.
As suggestions go, plugging your printer and Raspberry Pi into a UPS will eventually save a long-running print job due to brown-outs.
As an additional suggestion, I think I'd recommend purchasing a second microSD card of the same size. This makes upgrades easier since you then clone before upgrading, swapping the cards each time. It's great for keeping your printer always production-ready.
Of course shopping around is recommended, but for someone looking for a one stop shop for everything Canakit is pretty awesome. I have bought this kit a few times for a few different projects. As far as Octo is concerned the only thing missing would be the camera.
A ASRock BEEBOX J3160/B/BB is also a good hw for octoprint.
(price in germany around 130β¬)
A raspberry costs all together around 60β¬ with supply, case, heatsink, maybe a fan
then you don't need a crapy raspberry and have at the nearly same energy consumption a good hw on which you can run also a desktop enviroment with cura/slic3r/s3d.
When you have more than 1 printer it is a good solution.
At 3+ printers it is a no-brainer
I've came across this guide to find a list of tested webcames working with Octoprint. Since the Gitub was moved here, the link at "see other tested webcams" is not working.
Additionally to it being overkill, I'm quite sure the current version of OctoPi also won't work with the Pi 5 (still haven't had a chance to try it) and neither I nor OctoPi's maintainer can currently give a timeframe when that might change.
So if you do go for a Pi 5 you'll have to install things yourself.
Has anyone tried a Raspberry 3A+? It seems the lack of memory on this is a far bigger issue than I had anticipated. To the point I am trying to find projects that are suitable for the 2 I bought. Certainly not worth the $10 each I saved on them over 3B+
The 3A+ has the same processor as the 3B+ and the same memory (512MB) as the RPi Zero 2 W. Both the 3B+ and the Zero 2 W are supported so the 3A+ should work as well.