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!

Three ways to build low profile Chia (and forks) nodes

This is another piece on a part of the Chia and cryptocurrency landscapes. See previous posts at https://rsts11.com/crypto

Need to set up a lightweight VPN to get into your low profile node remotely? Check out Stephen Foskett’s writeup on Zerotier. I’m using it on my Pi nodes to reduce NAT layers.

Many if not most Chia farmers run a full node on their farming / plotting machine. Some larger farms will use the remote harvester model, with a single full node and several machines farming plots on local storage. 

If you’re using Flexfarmer from Flexpool, or just want a supplemental node (maybe to speed up your own resyncing, or to supplement decentralization on the Chia network), you might want a dedicated node that doesn’t farm or plot. And for that use case, you don’t really need dual EPYC or AMD Threadripper machines. 

In fact, a well-planned Raspberry Pi 4B 4GB or 8GB system, with an external USB drive, will do quite well for this use. If you want to do a few forks as well, or another blockchain full node, a moderately-recent Intel NUC would do quite well for not much more. 

So here we’ll look at three builds to get you going. Note that any of these can run a full node plus Flexfarmer if you want, or just a full node. 

If you don’t already have Chia software and a full node installed, go ahead and install and sync the node on a full scale PC. it may save you five days of waiting. My original build for this use case was to test the blockchain syncing time from scratch.

Syncing from a semi-optimal Pi 4B from scratch took about 8 days, for what it’s worth. One member of the Chia public Keybase forum reported about 28 hours to sync on an Intel Core i5 12600k. 

Caveat: Raspberry Pi boards are a bit more challenging to find and even harder to find anywhere near the frequently-touted $35 price point, or even under $150. And for Chia nodes, you want a minimum of the 4GB Pi 4B (8GB wouldn’t hurt). So while it’s possible to run on older hardware, it’s not recommended.

 

You might also be able to run on a Pi400 (the Raspberry Pi 4B in a keyboard case, which is much easier to find for $100 or so, complete). I plan to test this soon.

 

Raspberry Pi with external USB SSD. 

This was my initial build, and today it’s running at the Andromedary Instinct providing an accessible full node for about 10-15 watts maximum. 

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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.

Building the Intel NUC Chia Plotter

In an earlier post, I shared a design for a Chia plotter/farmer based around the Intel NUC NUC10i7FNH tiny computer.

Today I built that machine, and it’s running its first plot as I type this.

If you landed here, you might be interested in my other recent Chia posts:

Pricing disclaimer: All prices, availability info, and links are accurate as of the writing of this article (May 3, 2021) unless otherwise noted. Prices vary from day to day and availability does too. Use this info with a grain of salt especially if you are reading this in 2022 or beyond.

Here’s a quick rundown of what was involved in the process.

Shopping List

Feel free to shop in your preferred venues online or locally, or if you already have components, use them. These links are Amazon affiliate links, and if you use them, I get a few bucks to go toward my next hardware adventure. (I bought my NUC and RAM from Central Computer, a local computer store in Silicon Valley, and the NVMe drive came from Amazon.)

Base computer – NUC10i7FNH1 currently $570 at Amazon. You want the i7, and you want the FNH which is the “high” case that holds a 2.5″ drive as well as the m.2.

RAM – 32GB (2x16GB) DDR4 2666 or better SODIMM. Crucial 16GBx2 kit around $182 at Amazon. You can install 64GB, but you probably don’t need it with this processor.

Boot drive – I used a Samsung PM851 that’s not available on Amazon at the moment. Any 2.5″ SATA drive will do, even a HDD. Amazon has the WD Blue SSD 250GB for $45 or 500GB for $60. If you have something else on hand that’s at least 120GB, go ahead and use it, or if you want some internal plot storage, get something bigger. 

Plotting drive – 2TB Inland Premium NVMe is popular with its 3200TBW rating, about $240 on Amazon but out of stock for the next week. If you watch your drive life, you can use cheaper NVMe or even SATA m.2 storage. But check the TBW (Total Bytes Written, or Terabytes Written) and warranty for your drive and take that into account. 

OS install drive – Get a USB 3.0 drive with 16GB or more space, and use Balena Etcher or Rufus to burn Ubuntu 20.04 LTS to it.I like the Sandisk Ultra 32GB for price point and quality, about $10 at Amazon

External long-term plot/farm storage – I’ll be using an 8TB external drive in the near term, but you can use whatever you have, even NAS storage. 

Bonus: Staging disk. A user on r/chia suggested using a staging drive to copy your final plot file to, so that your plot process ends faster than if it has to be copied to slow disk. You can then automate moving the plot files to your external HDD at your leisure, and get back to plotting again up to an hour faster. For this, you can use an external USB 3.0 or better SSD like the WD My Passport SSD ($150 for 1TB), Crucial X8 ($148 for 1TB), or pretty much any SSD that will hold a batch of your plots (1TB will hold 9 plot files). You can also use a directory on your NVMe drive for this, but make sure you don’t let it fill up.

Continue reading

Rabbit Reorganization: Building low power clusters from a rabb.it door

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, or you can adjust the plans here to other models.

Part 2 is out: Rabbit Launch: Loading up the NUC cluster with a usable operating system (but read this one first).

The first thing I will put out there is that these are not latest-and-greatest state-of-the-art computers. If you’re looking for a production environment or DDR4 high density memory, keep looking. But if you want an inexpensive modular cluster that’s only about 5 years out of date, there’s hope for you in here.

Update – As of December 2021, I’ve updated some of the links and prices, and updated the description to show that the door clusters have been sold out for some time.

The original cluster

eBay seller “tryc2” has several hundred of these “door clusters” from rabb.it, a now-defunct video streaming service that closed up shop in mid-2019. I call it a “door cluster” as the 42 inch by 17 inch metal plate resembles a door, and gives you an idea of the ease of manipulating and fitting the environment into your home/homelab as it is delivered.

The cluster bundle would have set you back US$300, plus tax where applicable. The seller seems to have had a thousand or so and they were sold out by late 2020. [Updated 2021]

The cluster includes 10 Intel NUC quad-core boards (mine were NUC5PPYB quad-core Pentium; my friend Stephen Foskett got some that were newer NUC6CAYB Celeron boards which took more RAM). These boards feature one DDR3L SODIMM slot (max of 8GB), one SATA port with a non-standard power connector (more on this later), Gigabit Ethernet, HDMI out with a headless adapter (to fool the computer into activating the GPU despite no monitor being connected), four USB ports, and a tiny m.2 slot originally intended for wireless adapters.

In the center of the “door” are five NVIDIA Jetson TK1 boards. These were NVIDIA’s first low-end foray into GPU development, sold to let individuals try out machine learning and GPU computing. There are much newer units, including the Jetson Nano (whose 2GB version is coming this month), if you really want modern AI and GPU testing gear, but these are reasonably capable machines that will run Ubuntu 14 or 16 quite readily. You get 2GB of RAM and a 32GB onboard eMMC module, plus a SATA port and an SD slot as well as gigabit Ethernet.

The infrastructure for each cluster includes a quality Meanwell power supply, a distribution board assembly I haven’t unpacked yet, two automotive-style fuse blocks with power cords going to the 15 computers, and a 16 port Netgear unmanaged Gigabit Ethernet switch. With some modifications, you can run this entire cluster off one power cord and one network cord.

What’s missing?

So there is a catch to a $300 15-node cluster. The Jetson nodes are component complete, meaning they have RAM and storage. However, the NUCs are barebones, and you’ll need some form of storage and some RAM.

For the Jetson nodes, you’ll need an older Ubuntu machine and the NVIDIA Jetpack software loader. For the installation host, Ubuntu 14.04 is supported, 16.x should work, and later versions are at your own risk. You’ll also need an Ethernet connection to a network shared with your Ubuntu machine, as well as a MicroUSB connection between your Ubuntu host and the Jetson, to load the official software bundle.

For the NUCs, you’re looking at needing to add a SODIMM and some form of storage to each. I bought a bunch of 8GB SODIMMs on eBay ($28.50 each) to max out the boards. For storage, I tried USB flash drives and 16GB SD cards and had OS issues with both, so I bought the MicroSATACables NUC internal harness for each board, along with Toshiba Q Pro 128GB SATA III SSDs (these are sold out, but there’s a Samsung SM841N currently available in bulk for the same price, about $25 each).

If you do get a cluster bundle with the two-memory-slot NUC boards, you have two options beyond the above. The easy and documented option is to look for 4GB SODIMMs instead of 8GB; you may save a buck or two, or if you’re like me, you may have a box of 4GB SODIMMs from various upgrades and not have to buy anything. The other option is to update your BIOS on the NUC and try out 2x 8GB. For some uses, 16GB will be worth the cost (vSphere or other virtualization clusters). I’d suggest going with a known quantity to update the BIOS to the latest version, and then trying 2x 8GB.

One other thing you may need is a pack of spare fuses. I know they do their job, as I blew a few of them while plugging and unplugging the boards. But you may wish to have a few extras around. They’re the standard 3 amp “mini blade” fuse that can be found at auto parts stores (although my local shops tended to have one card of them, if that, on the shelf). You can also buy a 10 pack for $6.25 (Bussmann brand) , a 25 pack for about the same price (Baomain brand) or a 100 pack (Kodobo brand) for about $9.

Choose your own adventure

There are two paths to take once you have your gear collected and connected.

  1. How do we lay out the gear?
  2. What do we do with it?

I’ll look at my journey on both paths in upcoming episodes of this series. Spoiler: I’ve 3d-printed stacking plates for both the NUCs and the Jetsons, and am still working on how to mount the remaining pieces so I can e-waste the door piece. And as I write part 1, I still haven’t figured out what to do with the clusters.

Where do we go from here?

If you’ve bought one of these clusters (or more than one), feel free to chime in on the comment section and let me know what you’ve done with it. And stay tuned to this post (or @rsts11 on Twitter or Facebook) for updates on the next installments.