Raspberry Pi Zero W

My RPi 2 with the 3D printer has been operating with no problem since 2017 or something like that. The RPi Zero W with the HP LaserJet since around 2019. Fingers crossed, it's been fantastic reliability.

Before we had the ESP32 type products that are now popular, using a Pi was often one of the only easy ways to make simple internet connected devices at home. I remember making smart lights and home sensors, speakers, clocks and all sorts of things using the Pi Zero W. It was cheap, small and easy to get up and running. I and many other people very much used it like a microcontroller.

I have a Pi Zero W that is a spooky-good GPS-backed NTP server. It relies on GPIO for getting tightly-accurate PPS pulses from the GPS module (which a USB-connected Arduino won't help me with -- the timing would be much sloppier). I have also used a different Pi Zero W with an SDR dingle to decode APRS weather data, while also using GPIO to read a local DS18B20 temperature sensor and to switch a solid-state relay. I could have done this last thing with any random Linux-ey PC plus an Arduino, but then I'd have two problems. (It would have also cost me rather substantially more money: I bought these Zero Ws very, very cheaply from Microcenter.)

"How thick does my rope need to be?" I serve a website for my 3D printers from a Raspberry Pi (some are 3B+, some are Zero-W). It's just for "the set of people in the house who use the 3D printers", so the Pi is fine and obviously a viable candidate. I have an ESP32 (or it might be an ESP8266 even; I'd have to look) that serves a status page for the boiler and near-boiler temps. That's also in-house only, but even that's on the slow side. https://imgur.com/a/JmeXYnj What is the load this site is expected to serve? To what visitors? How static/cacheable is it? For me, an RPi goes a long way for anything in-house. Out of the house traffic, I'd look at a cheap VPS pretty early in the journey.

I have a raspberry pi Zero W as my garage door opener[1]. Wired into the interior buttons and send relevant signals to an open or close the door. I got tired of replacing batteries in the remotes due to heat/freezing cycles. Hooked up a SignalWire SMS number to a webhook that the PI is listening on. Now I can send an SMS text to the garage door to get it to open. Have other pi's doing many things, but that's the most creative so far. [1] https://blog.penguincoder.com/garage-opener-1/

I have run a Raspberry Pi Zero W with 5mp camera and MotionEye software outside for 3 Christmas seasons to control an animated display. I trigger on movement and capture still and video images to the SD card and automatically upload them over WiFi to my ftp server. I can monitor a live stream anytime too. MotionEye does everything. This setup runs in a small waterproof enclosure and runs a bit warm (35-45C) that dissipates any condensation or rain on the fisheye lens. This might help you with snow accumulation.

RPi Zero W, set up as an stand-alone wifi access point, running off a usb battery pack. I used it with an ssh client on my phone for Python code and writing while traveling. Old Thinkpad with no battery just after ext3 with journaling came out. I would yank the cord without shutting it down. Never lost data ;-)

For a hobbyist, they're quite nice for "I want to SSH into a thing, write my tools on Linux, and still have access to SPI / I2C / GPIO, USB, and whatever hats can plug into that." The Hat form factor, while not technically great and frequently overpriced, is also nice for distribution; both inside a team commercially and on the web as a hobbyist, it's a lot easier to share software and say "hey, buy this pi, this hat, and run this" than "fab this PCB / solder this bundle of nonsense to an ESP." For a company, they're also nice for "I want to make an IoT device that's heavier weight than an ESP32 and/or I only want to hire Linux Application People and not Firmware People; what's the cheapest Linux module I can get that's widely supported, backed by a real company, and has regulatory approvals" - Pi Zero W. My understanding is this exact pattern is why it's harder to get them as a hobbyist. I use them widely in automotive reverse engineering; ESP32 can and does work just as well or better for an end product, but for experiments it's really nice to have a self-contained appliance to SSH into and use SocketCAN on rather than some bespoke firmware project to manage and iterate on. Given the price and availability issues I suspect the market is "correcting" a bit and companies are hiring Firmware People and switching to true MCUs in places they'd previously have avoided doing so, but it was definitely a thing for a long time.

As a nerd of a certain age I’ve been deeply attracted to retro computing. Even going so far as to place bids on 30 year old Atari STs on eBay since that was a computer I had in the late ‘80s/early ‘90s. But in recent days, through the use of modern emulators I’ve dabbled in these retro systems and I’ve come to the conclusion that they’re just bad. They are fine for the enjoyment of certain games and reliving or just getting a reminder of my younger years. Yet these home computers of that era lack so much. No MMU, no FPU, no IP networking. Very limited CPU cycles and memory. Even switching from home computers of the era to workstation class system, it’s pure frustration at the limits on what can be done. Don’t get me wrong, for a lot of my computing needs I could probably get along just fine with a next cube or a late model Mac II. But on the other hand you’ll pay hundreds or thousands of dollars for these systems, while I can go on Amazon and spend ~$200 for a mouse, keyboard, cheap monitor, and a raspberry pi zero w and I’ll have a more capable system in every way. For just a little more money I can buy a tiny PC that is able to emulate near perfectly all the computers of my youth. Thank you for attending my Ted talk.

I don't know about "all the knowledge ever", but to give you a baseline, the entire Wikipedia with images but without editing history, as last archived by Kiwix in May, 2022, is 90 Gb. A web server can run just fine on e.g. Raspberry Pi Zero W ($10), exposing any such content to any smartphone etc able to connect to it via WiFi (Kiwix sells preconfigured SD cards for their content, even). So, assuming that most people already have a phone or a laptop or even something like a Kindle, the only non-negligible cost here is storage. And a 1 Tb SD card can be had for under $150 right now. So if anything, I think OP is overly conservative, given that their estimate was "$200 per person ". Unless that counts the devices used to consume the content, and not just storage and the server.