Pi in the sky: Seven tips for finding the single board computer of your dreams

2022-07-03: Updated for AtomicPi

Raspberry Pi boards have been intermittently available this year. They’re still very useful, but your odds of going into a retailer and picking up a few at list price are about as good as Ethereum hitting $5k this month. In other words, don’t hold your breath.

That being said, this type of single board computer is not completely unobtainable, even in today’s supply-chain-constrained market. Here are seven tips for finding the SBC of your dreams. 

1. Check local retailers

This is a long shot, but for some people in some regions, it may still work. My local shop, Central Computers in Silicon Valley, has had them intermittently for a couple of months at reasonable prices. 

2. Check official distributors 

You can find sellers of the Pi boards on the official Raspberry Pi website. Stock may vary from day to day, and preorders may be possible, so check early and often if you’re pursuing this option. 

3. Check Amazon

Right now, I see a number of shippable Pi 4 boards in 4GB and 8Gb on Amazon. They’re pricey, with the 4GB board around $144 and the 8GB board around $195. But if you have to have it for work, or if you’ve found a way to profit majorly from using one of these boards, it may be the way to go. 

4. Consider kits

You may be thinking “I don’t need a power supply, a microSD card, a case, and all the other stuff,” but even when backorders weren’t considered, I saw starter kits with the Pi 4 board available in quantity at the above options. Right now, my local shop has the Okdo starter kit with the 8GB board for $160, limit one per customer. The bare board is $90 but out of stock, as are all of the standalone boards. So if you need access to a board soon (hopefully with someone else footing the bill), this is a very viable option. 

5. Can I interest you in a Pi400?

The Raspberry Pi 400 computer is a Pi 4b equivalent in a different form factor. The board should have the same performance as a 4GB Pi4b, and even when boards and kits were unavailable, the Pi 400 was readily available in a standalone unit at about $80 or a kit with power adapter for $110. Prices on Amazon are a bit higher (like $120 for the standalone or $180 for the kit), but still lower than the 4GB standalone board mentioned at Amazon above.  

You won’t be able to use your Pi cases or enclosures with the Pi 400, since it’s wider, but you can consider building your own stand or looking on Thingiverse and the like for 3d-printable enclosures for these boards. 

See Jeff Geerling’s “Raspberry Pi 400 Teardown” blog post and video to see what’s inside and how you might be able to repurpose the board for your needs. 

6. Check your local marketplaces for new or used boards

You may find some boards locally on Craigslist, Facebook Marketplace, Nextdoor, or the like. eBay is also an option, but it may or may not be local. As I write this post, I see boards in my extended area from $200-325 on Craigslist, and surprisingly $120 and up on Facebook. Someone is selling a complete 8-node cluster, including 6 8GB and 2 2GB boards (and power supply, network switch, tower case, etc) for $1000, which is pretty reasonable for the current market.

With these local marketplace options, be sure to buy locally, and if possible, try the board out before paying (if it’s not sealed). With eBay, read the ad carefully and be aware of buyer protections available to you.

7. Look into other small computer options

Raspberry Pi is the most famous card-sized board, probably with the longest run and best name recognition, But you can also look at things from the RockPi boards to ODROID, to LattePanda x86.

Intel NUC (NUC5PPYB/NUC5PPYH) on a 3d-printed stand with memory and HDMI dummy plug.

You may also be able to find bare board Intel NUC systems (like the remnants of the legendary Rabbit doors from a few years ago) that, while not exactly as tiny and requiring a bit more than 3-5 watts, may well do what you need. 

See the Rabbit Overview (October 2020)
and the Rabbit Launch system build (December 2021)

For example, there are some i3 and even i7 boards here on eBay for as low as $95 shipped (searching under the “motherboard” category). When I searched under “Desktops & All-in-Ones” I found some of the old Rabbit boards (quad core Pentium with Gigabit Ethernet) for around $50 each. You’ll have to add a DDR3 SODIMM, a power supply, and probably storage of some sort, but even then you can get a 4GB system for around $100 or so. 

NVI

If you don’t need an ultra-modern OS, you can also look into systems like the Jetson Nano (which I believe easily runs Ubuntu 18), or even Jetson TK1 (Ubuntu 14/16) from NVIDIA. These outdated boards are still quite interesting, and have many uses if you can “outsource” the security to a system with a newer platform.

And yet another option I found after posting this – Digital Loggers, a Silicon Valley company better known for their Ethernet-connected power controllers (mentioned in a previous post and used in my shop) are apparently the folks behind the AtomicPi Intel Atom-based single board computer. It takes a little bit more work to power, but for $50 you get a board based on the Atom x5-Z8350 1.44GHz CPU with 2GB RAM and 16GB EMMC on board, a breakout board, and an AI camera module. 

Unlike the other boards mentioned, I have not tried this one, but it’s worth a look if you can handle the limitations and get your 5V 3A power into it yourself. 

Where do we go from here?

I’m realizing I have a few boards that may be worth dusting off and using, or even selling. There’s a Pi 3b+ cluster in need of an expansion, and some other projects in the works for the upcoming holiday weekend. 

What are you doing with single board computers, and have you found any tips and tricks I missed? Share in the comments!

Rabbit Launch: Loading up the NUC cluster with a usable operating system

As you saw in my 3D Printing series, after years of pondering a 3D printer, I was finally inspired to buy one when a pile of clusters came up on eBay from the defunct rabb.it video streaming service. In this series, I’ll take you through turning a rabbit door into some useful computing resources.

You can do something similar even after the clusters are sold out; a lot of people have probably bought the clusters and ended up not using them, so you’ll see boards on eBay or local marketplaces… or you can adjust the plans here to other models.

The previous installment, Rabbit Reorganization, can be found here. Stay tuned for more coverage.

Update December 2021: This post languished in the drafts folder for about a year. I’ve updated links, and I’ll be reporting on some changes since the October 2020 launch of this cluster soon.

Let’s NUC this cluster out

  1. Install memory, SATA cable, and SSD
  2. Upgrade BIOS and set some annoying settings
  3. Install your operating system
  4. Set up central control

Install memory, SATA cable, and SSD

This is the least interesting part of the process, but you’ll need to do it before you can install an OS.

Start by loading the SODIMM of your choice onto the board. If you’re using an SSD like I am, you’ll connect the SATA cable to the black SATA connector next to the front USB stack, and the power cable to the beige connector perpendicular to the SATA connector. If you’re using a standard SD card, plug it into the SD slot to the right (as shown with the MAC address label). If you’re going with netboot (local storage? where we’re going we don’t need local storage!), just connect your network cable.

Upgrade BIOS and set some annoying settings

I created a bootable FreeDOS USB drive with Rufus, a common free software product used to create bootable USB media from ISOs (think Linux, Windows, etc). From there, we get the latest BIOS from Intel’s Download Center and place the file on the bootable drive. (Further BIOS instructions available on Intel Support.)

As of December 2021, 0079 is the latest BIOS, released April 20, 2020. You’ll need to search for NUC5PPYH even though the board’s model is PPYB.

Connect a monitor and keyboard, plug in the bootable drive, and apply power (or just reset the board). Use the F7 key to go into onboard flash update and load the BIOS file from the flash drive, or choose to boot from the flash drive and use the DOS-style flasher from there.

When you’ve done the upgrade and the system has rebooted, go into the BIOS with the F2 key and choose BIOS default values. Then go into the menus to enable all the USB ports (for some reason the default is to enable ports 1-3, leaving physical port 4 and header ports 5-6 disabled) as well as the SATA port if you are using that for storage. I’d also check the boot order (move net boot down in preference or disable outright if you don’t plan to use it). You can choose other settings as desired, and then press F10 to save and reboot.

Install your operating system

The easiest way to roll out the NUC side of the door would be to netboot an installation infrastructure like Cobbler. One of the first things I did when I went to work for the Mouse 10 years ago was setting up Cobbler for a deployment of RHEL 5.5.

Sure enough, Cobbler is still a thing, with very recent updates. I was able to get partway there this time and then, after several dozen runs to the garage and back to power cycle nodes, I gave up and installed from local media.

For CentOS 8, I did a manual install booting from a Rufus-created USB drive, with the SSD installed. I configured my storage and network options by hand, as well as user and root credentials. This left an “anaconda.ks” kickstart file on the installed system, which I copied to a second flash drive.

For the additional systems, I plugged both the CentOS 8 installer and the drive with the kickstart file into the NUCs and booted from USB. I ran into some strange storage issues with the drive not being blank, despite having chosen the kickstart option. Ideally, you would boot from the USB installer, it would find your kickstart config, and just roll out the software without intervention from there.

After that, if your DHCP server doesn’t assign hostnames you like, you can go in and set hostnames with hostnamectl or the like.

Set up central control

If you use a configuration management platform like Ansible, Puppet, Chef, cfengine, or the like, you’ll want to set those up at this point.

I’ve gone with the lightweight method so far, with shared SSH keys from a management host (an Intel NUC with CentOS on it, originally intended to be the cobbler server).

Use ssh-keygen to create your key files, and then ssh-copy-id can be used to push out the keys to your hosts. Then look into a more manageable option.

Where do we go from here?

As I finish this post in December 2021, a year after the original build, I’m looking at going back and making a few changes to the cluster to bring it up as a Kubernetes platform.

With the demise of CentOS as many of us know it, I’m planning to replace the installed OSes with Ubuntu LTS. I’m planning to test out some cryptocurrency cpu-based mining, and run Kubernetes platform(s) on it as well, and bring my second door up to speed (the RAM has been sitting in a box in the living room for a year now).

There’s a chance I’ll even do some lightweight Chia farming, using either bus-powered USB hard drives or some of the extra power connectors from the fused expanders for standard Seagate externals.

For those of you who have bought and built up these doors, what did you do with them? Feel free to share details and blog post links in the comments. I’ll put interesting ones into the body of this post as I see them.

Money Pit: 3D Printing Part 3 – OctoPrint and OctoPi

This is one topic in a series of what I’m calling “money pit” projects. To be fair, it’ll be money and time pit topics, and nothing that you’d really have to get a second mortgage on your house to do… but things always get a bit out of hand.

This project is the 3D Printing project. Expect it to be an ongoing series, and I’m hoping to have some friends join the effort and offer their feedback as well. Links and prices are accurate as of November 2020, and may get updated in the future… but don’t count on it.

See the previous parts for the lead-in to this project. From here we’ll get into the enhancements and early printing.

Octopi / OctoPrint

The first day or two, I was running out to the garage to check on prints, and shuttling the included 8GB MicroSD card back and forth to load print files onto it. Since the only storage the printer has is this MicroSD card, I couldn’t add files during a print run, and it got somewhat tiring.

Enter OctoPrint and OctoPi.

OctoPrint is an open-source management program and web front-end for many/most 3D printers. It communicates with the printer over a USB cable. It can be installed on a Linux, Windows, or MacOS computer. However, you might not want to dedicate a full-sized computer to this task.

OctoPi is a Raspbian (Raspberry Pi Debian image) based distribution with Octoprint and the video streamer software included. you just need a Pi 3B or later board (and case and power supply) and an SD card with OctoPi installed. Older boards will work, but with the camera option or other intense plugins (like gcode viewers) you won’t like it according to the folks behind OctoPrint and OctoPi. Continue reading

Money Pit: A quick sidebar on my 3D printing (mis-)adventure

You’ve seen the first two parts of my 3D printing series, and I promised part three in the near future.

I decided to postpone the third part a little bit, in order to share a cautionary tale and some printer gore with you. I’m hoping this will be a one-time error, but if you’re like me, you might not think it’s so bad until it shuts down your printing operation for a week or two and potentially costs you $30+ in replacement parts.

First, the gore

Second, the TLDR

(tl;dr means too long;didn’t read. However, I hope you’ll read on.)

Continue reading

Money Pit: 3D Printing Part 2 – First Round of Enhancements

This is one topic in a series of what I’m calling “money pit” projects. To be fair, it’ll be money and time pit topics, and nothing that you’d really have to get a second mortgage on your house to do… but things always get a bit out of hand.

This project is the 3D Printing project. Expect it to be an ongoing series, and I’m hoping to have some friends join the effort and offer their feedback as well.

See the previous part (The Back Story, The Rationale, and The Assembly) for the lead-in to this project. From here we’ll get into the enhancements and early printing.

Our first round of enhancements include:

  • Power protection
  • Metal extruder and printed filament guide
  • PEI print bed
  • Upgraded Bowden tubing

I mentioned OctoPi / OctoPrint in the first installment, so I’ll leave the details out this time other than to say you really should set one of these up. Let me know in the comments if you’d like more details in a future post. 

Continue reading