Another Homebrew Linux Board Success Story

It’s truly incredible what the hobbyist is now capable of. While it would have seemed all but impossible a few years ago, we’re happy to report that yet another dedicated hardware hacker has managed to spin up their own custom Linux single-board computer. Creator [Ian Kilgore] tells us the only goal when developing CATFOOD (yes, that’s the name) was to gain confidence with at-home board production, so it looks like a success to us.

To those who’ve been keeping an eye on this sort of thing, it will probably come as no surprise to hear [Ian] was inspired by the work of [Jay Carlson], who arguably kicked off this whole trend when he put together a bevy of homebrew Linux boards in an effort to compare different System-in-Package ICs. His incredibly detailed write-up of the experience and lessons learned along the way has emboldened other brave souls to take up the challenge.

The USB-C powered board uses an ARM i.MX 6ULL processor and features DDR3, NAND flash, and an Ethernet interface. That last one was the biggest deviation from the reference design, which meant it took a little fiddling to get right. For anyone playing along at home, [Ian] collected up the lessons learned while developing CATFOOD, bringing the whole learning experience full circle.

If you’re interested in more homebrew Linux SBCs, we’d highly recommend reading up on the WiFiWart developed by [Walker]. Over the course of about six months, we got to watch the open hardware board go from concept to a diminutive first prototype.

New Raspberry Pi Zero 2 Upgrades To Quad-Core Processor

Over the years, we’ve seen a steady stream of updates for the Raspberry Pi Foundation’s flagship single-board computer (SBC), with each new release representing a significant boost in processing power and capability. But the slim Raspberry Pi Zero, released all the way back in 2015, hasn’t been quite so fortunate. Beyond the “W” revision that added WiFi and Bluetooth in 2017, the specs of the diminutive board have remained unchanged since its release.

That is, until now. With the introduction of the $15 USD Raspberry Pi Zero 2 W, the ultra-compact Linux board gets a much-needed performance bump thanks to the new RP3A0 system-in-package, which combines a Broadcom BCM2710A1 die with 512 MB of LPDDR2 SDRAM and a quad-core 64-bit ARM Cortex-A53 CPU clocked at 1 GHz. In practical terms, the Raspberry Pi Foundation says the new Zero 2 is five times as fast as its predecessor with multi-threaded workloads, and offers a healthy 40% improvement in single-threaded performance. That puts it about on par with the Raspberry Pi 3, though with only half the RAM.

Otherwise, the new Zero 2 isn’t much different from the original. It’s the same size and shape, meaning existing cases or mounts should work fine. You’ll also find the micro SD slot, CSI camera connector, dual micro USB ports, and mini HDMI port in the same places they were in 2015.

Frankly we’re a little surprised they didn’t switch over to USB-C (at least for the power port) and micro HDMI to bring it in line with the Pi 4, but of course, they presumably didn’t want to break compatibility with existing Zero projects. At least we won’t have to wait for a second edition to add wireless, as the Zero 2 W offers 2.4 GHz 802.11 b/g/n WiFi and Bluetooth 4.2 out of the box.

We’ll have samples of the new Zero 2 W in hand shortly, so keep an eye out for a detailed overview of this highly anticipated new member of the Pi family. In the meantime, let us know what you think about the new hardware in the comments. Is it a worthy successor to the original $5 Pi Zero?

MC68k SBC with a monitor, keyboard and mouse

Motorola 68000 SBC Runs Again With A Raspberry Pi On Top

Single-board computers have been around a long time: today you might be using a Raspberry Pi, an Arduino, or an ESP32, but three decades ago you might find yourself programming a KIM-1, an Intel SDK-85, or a Motorola 68000 Educational Computer Board. These kind of boards were usually made by processor manufacturers to show off their latest chips and to train engineers who might use these chips in their designs.

[Adam PodstawczyƄski] found himself trying to operate one of these Motorola ECBs from 1981. This board contains a 68000 CPU (as used in several Macintoshes and Amigas), 32 kB of RAM, and a ROM program called TUTOR. Lacking any keyboard or monitor connections, the only way to communicate with this system is a pair of serial ports. [Adam] decided to make the board more accessible by adding a Raspberry Pi extended with an RS232 Hat. This add-on board comes with two serial ports supporting the +/- 12 V signal levels used in older equipment.

It took several hours of experimenting, debugging, and reading the extensive ECB documentation to set up a reliable connection; as it turns out, the serial ports can operate in different modes depending on the state of the handshake lines. When the Pi’s serial ports were finally set up in the right mode, the old computer started to respond to commands entered in the terminal window. The audio interface, meant for recording programs on tape, proved more difficult to operate reliably, possibly due to deteriorating capacitors. This was not a great issue, because the ECB’s second serial port could also be used to save and load programs directly into its memory.

With the serial connections working, [Adam] then turned to the aesthetics of his setup and decided to make a simple case out of laser-cut acrylic and metal spacers. Custom ribbon cables for the serial ports and an ATX break-out board for power connections completed the project, and the 40-year-old educational computer is now ready to educate its new owner on all the finer points of 68000 programming. In the video (embedded after the break) he shows the whole process of getting the ECB up and running.

[Adam] made a similarly clever setup with a Commodore 64 and an Arduino earlier. [Jeff Tranter] recreated a similar 68000 development board from scratch. And a few years ago we even featured our own custom-built 68k computer.

Continue reading “Motorola 68000 SBC Runs Again With A Raspberry Pi On Top”

WiFiWart Boots Linux, Moves To Next Design Phase

Over the last few months we’ve been keeping an eye on WiFiWart, an ambitious project to develop a Linux single-board computer (SBC) small enough to fit inside a USB wall charger. Developer [Walker] says the goal is to create an easily concealable “drop box” for penetration testing, giving security researchers a valuable foothold inside a target network from which to preform reconnaissance or launch attacks. Of course, we don’t need to tell Hackaday readers that there’s plenty of other things you can do with such a tiny open hardware Linux SBC.

Today we’re happy to report that [Walker] has gotten the first version of the board booted into Linux, though as you might expect given a project of this complexity, there were a few bumps along the way. From the single missing resistor that caused U-Boot to throw up an error to the finer points of compiling the kernel for an embedded board, the latest blog post he’s written up about his progress provides fascinating insight into the little gotchas of bringing up a SBC from scratch.

Once the board was booted into Linux, [Walker] started testing out different aspects of the system. A memory benchmark confirmed the finicky DDR3 RAM was working as expected, and he was able to load the kernel modules for the dual RTL8188 interfaces and connect to a network. While the two WiFi modules are currently hanging off the board’s full-sized USB ports, they will eventually be integrated into the PCB.

Critically, this prototype board is also allowing [Walker] to get an idea of what the energy consumption of the final hardware might be. Even at full tilt, this larger board doesn’t go over 500 mA at 5 VDC; so if he designs the power supply with a maximum output of 1 A, he should have a nice safety margin. As mentioned in the previous post, the plan is currently to put the PSU on its own board, which will allow more effective use of the charger’s internal volume.

With the software and hardware now largely locked in, [Walker] says his attention will be turned towards getting everything small enough to fit into the final form factor. This will certainly be the most challenging aspect of the project, but with a growing community of hackers and engineers lending their expertise to the cause, we’re confident the WiFiWart will soon be a reality.

Putting An Ultra-Tiny Linux Board In A Phone Charger…Eventually

Among security professionals, a “drop box” is a device that can be covertly installed at a target location and phone home over the Internet, providing a back door into what might be an otherwise secure network. We’ve seen both commercial and DIY versions of this concept, and as you might expect, one of the main goals is to make the device look as inconspicuous as possible. Which is why [Walker] is hoping to build one into a standard USB wall charger.

This project is still in the early stages, but we like what we see so far. [Walker] aims to make this a 100% free and open source device, starting from the tools he’s using to produce the CAD files all the way up to the firmware the final hardware will run. With none of the currently available single-board computers (SBCs) meeting his list of requirements, the first step is to build a miniature Linux machine that’s got enough processing power to run useful security tools locally. Obviously such a board would be of great interest to the larger hacker and maker community.

The RTL8188CUS is likely to get integrated later on.

So far, [Walker] has decided on his primary components and is working on a larger development board before really going all-in on the miniaturization process. As of right now he’s planning on using the Allwinner A33 to power the board, a sub-$10 USD chipset most commonly seen in low-cost Android tablets.

The A33 boasts a quad-core Cortex-A7 clocked at 1.2 GHz, and offers USB, I2C, and SPI interfaces for expansion. It will be paired with 1 GB of DDR3 RAM, and an SD card to hold the operating system. Naturally a device like this will need WiFi, but until [Walker] can decide on which chip to use, the plan is to just use a USB wireless adapter. The Realtek RTL8188CUS is a strong contender, as the fact that it comes in both USB and module versions should make its eventual integration seamless.

Even if you’re not interested in the idea of hiding security appliances inside of everyday objects, this project is a fascinating glimpse into the process of creating your own custom Linux board. Whether you’re looking to put into a wall wart or a drone, it’s pretty incredible to think we’ve reached the point where an individual can spin up their own miniature SBC.

New Part Day: Hackboard 2, An X86 Single-Board Computer

From the old Gumstix boards to everyone’s favorite Raspberry Pi, common single-board computers (SBCs) have traditionally had at least one thing in common: an ARM processor. But that’s not to say hackers and makers haven’t been interested in an SBC with a proper x86 processor. Which is why the $99 Hackboard 2 is so exciting. With a modern x86 chip at the core it’s akin to a small footprint desktop motherboard, but with all the extra features that we’ve come to expect in a hacker-friendly SBC.

So what’s the big deal? In a word, compatibility. The fact that these diminutive computing devices shied away from the x86 architecture that most of us have been using on our desktops and laptops since the 1980s originally introduced software compatibility issues, but this was largely outweighed by the advantages of ARM. The latest NVIDIA Jetson is running on an ARM chip for the same reason the smartphone in your pocket is: they’re smaller, cheaper, and more energy efficient than x86.

However they’re rarely more powerful. Even the latest and greatest Raspberry Pi 4, often touted as a viable desktop replacement thanks to its quad core Cortex-A72, will get absolutely trounced by the pokiest of Intel’s Celeron CPUs. The performance gap is just too great. While the Pi can admirably handle most of the tasks the hacker community asks of it, there will always be a call for a board that puts raw processing power before anything else.

Sucking down nearly 40 watts at full tilt, the Hackboard 2 isn’t the SBC you’d want to use for a solar powered weather station. But if you’re putting together a set top box to play back video and run the occasional emulator, its Celeron N4020 processor and Intel UHD 600 GPU represent the most powerful combination available for a device of this size.

Continue reading “New Part Day: Hackboard 2, An X86 Single-Board Computer”

Help, I’m Buried Alive By Tablets!

It’s fair to say that many Hackaday readers will have a propensity for hoarding electronic or tech junk. Who hasn’t hung on to something because “It might be useful someday”? Spare a thought for [Mike Drew], who in his own words is “buried alive by tablets”. In this case the tablets are Intel-based ones that look as though they ran one of those cut-down Windows versions, and they appear to be rejects from a repair shop processing customer returns that he saved from the dumpster. They are missing their backs, and not all of their screens work, but they amount to a tidy pile of Stuff That’s Too Good To Throw Away.

The exact spec is a 1.4 GHz quad-core Atom with 4 GB of RAM and 32 GB of Flash, and appear from the photos to have HDMI and USB 3 interfaces. Happily they run Linux Mint 20 so they have plenty of potential, but there is only so much that one person can do with them before running out of ideas. He tells us he’s made a Folding@Home cluster, but beyond that he’s open to suggestions. Depending on the age of the commenter no doubt he’ll be exhorted to run Beowulf or mine Bitcoin, but we’d suggest more sensible ideas.

So, what would you do with them? They lack the handy GPIO port of a Raspberry Pi, but with suitable USB peripherals could you use them in any lowish-power distributed node project where the popular SBC would be the usual choice? Perhaps something like WeeWX, or OpenEnergyMonitor. Or how about distributed mesh network nodes, after all there’s an x86 port of LibreMesh. It’s obvious that there’s plenty of potential to be found, so help [Mike] with his problematic bounty in the comments.