New Part Day: An Open Source Ethernet Switch In The Palm Of Your Hand

April 21, 2020 by Tom Nardi 91 Comments

When you can get a WiFi-enabled microcontroller for $3, it’s little surprise that many of the projects we see these days have ditched Ethernet. But the days of wired networking are far from over, and there’s still plenty of hardware out there that can benefit from being plugged in. But putting an Ethernet network into your project requires a switch, and that means yet another piece of hardware that needs to get crammed into the build.

Seeing the need for a small and lightweight Ethernet switch, BotBlox has developed the SwitchBlox. This 45 mm square board has everything you need to build a five device wired network, and nothing you don’t. Gone are the bulky RJ45 jacks and rows of blinkenlights, they won’t do you any good on the inside of a robot’s chassis. But that’s not to say it’s a bare bones experience, either. The diminutive switch features automatic crossover, support for input voltages from 7 V all the way up to 40 V, and management functions accessible over SPI.

If you want to get up and running as quickly as possible, a fully assembled SwitchBlox is available to purchase directly from BotBlox for £149.00. But if you’re not in any particular rush and interested in saving on cost, you can spin up your own version of the Creative Commons licensed board. The C++ management firmware and Python management GUI isn’t ready for prime time just yet, but you’ll be able to build a “dumb” version of the switch with the provided KiCad design files.

The published schematic in their repo uses a Microchip KSZ8895MQXCA as the Ethernet controller, with a Pulse HX1344NL supplying the magnetics for all the ports in a single surface mount package. Interestingly, the two images that BotBlox shows on their product page include different part numbers like H1102FNL and PT61017PEL for the magnetics, and the Pulse H1164NL for the Ethernet controller.

Make Networks Wired Again

There’s no question that WiFi has dramatically changed the way we connect devices. In fact, there’s an excellent chance you’re currently reading these words from a device that doesn’t even have the capability to connect to a wired network. If you’re looking to connect a device to the Internet quickly, it’s tough to beat.

But WiFi certainly isn’t perfect. For one, you have to contend with issues that are inherent to wireless communications such as high latency and susceptibility to interference. There’s also the logistical issues involved in making that initial connection since you need to specify an Access Point and (hopefully) an encryption key. In comparison, Ethernet will give you consistent performance in more or less any environment, and configuration is usually as simple as plugging in the cable and letting DHCP sort the rest out.

Unfortunately, that whole “plugging in” part can get tricky. Given their size, putting an Ethernet switch into your project to act as an internal bus only works if you’ve got space to burn and weight is of little concern. So as appealing as it might be to build a network into your robot to connect the Raspberry Pi, motor controllers, cameras, etc, it’s rarely been practical.

This little switch could change that, and the fact it’s released under an open source license means hackers and makers will be free to integrate it into their designs. With the addition of an open source management firmware, this device has some truly fascinating potential. When combined with a single board computer or suitably powerful microcontroller, you have the makings of a fully open source home router; something that the privacy and security minded among us have been dreaming of for years.

The Options For Low Cost ROV Tethers

January 27, 2020 by Richard Baguley 22 Comments

Wireless connections are cool and all, but sometimes you just need a bit of copper. This interesting article on SV Seeker discusses the various ways of making a tether for a remotely operated vehicle (ROV). They experimented with a number of different cables, including gel-filled Cat 5 designed for burial and wrapping the cable in polypropylene rope to keep it protected and buoyant. They also looked at using a single core solid coax cable with an Ethernet to coax converter on either end wrapped in stretch webbing. The upside of using coax would be the length: it can handle over a mile of cable, which should be more than enough for this project. The downside is that they found that the coax stretches under strain, messing with the signal.

Continue reading “The Options For Low Cost ROV Tethers” →

Nintendo Switch Doubles As Network Switch

December 16, 2019 by Tom Nardi 12 Comments

Coming straight to you from the “Department of Redundant Redundancies” comes this clever hack that turns a Switch into a switch. More specifically, a network switch. Not even a half bad one either, judging by the speed tests [Cynthia Revström] performed after setting it all up. We wouldn’t advise you dump your existing network gear in favor of a repurposed game system, but perhaps in a pinch…

Despite what you might be thinking, there’s no hardware modifications at work here. This is a fully functional Nintendo Switch that’s just had two USB to Ethernet adapters plugged into it. The secret ingredient is the addition of some Penguin Power, up and running on Nintendo’s latest and greatest thanks to a project called switchroot.

With Linux running on the system, all [Cynthia] had to do was make sure that the USB to Ethernet adapters were supported, and fiddle around with the brctl and ip commands to configure a bridge between the interfaces to get the packets moving. Putting the Switch between the main network and a test computer showed it had a throughput of just over 90 Mbps, which is about all that could be expected from the USB-connected network interfaces.

From here it wouldn’t have taken much more effort to get the system working as a wireless router and providing services like DHCP and NAT to clients. But since Nintendo didn’t see fit to call it the Router, that would’ve offered minimal meme value. There’s always next generation.

Seeing the Nintendo Switch do a surprisingly good job running as an Ethernet switch is even more surprising given the fact that it struggles to function with accessories that are actually intended for it. Though to be fair, the migration to USB-C has been a little rockier than most of us would have hoped.

Doing 10 Gigabit Networking At Home, The Cheap Way

July 24, 2019 by Lewin Day 55 Comments

For the vast majority of us, Gigabit Ethernet is more than enough for daily tasks. The occasional big network file transfer might drag a little, but it’s rare to fall short of bandwidth when you’re hooked up over Cat 6. [Brian] has a thirst for saturating network links, however, and decided only 10 Gigabit Ethernet would do.

Already being the owner of a Gigabit Ethernet network at home, [Brian] found that he was now regularly able to saturate the links with his existing hardware. With a desire to run intensive virtual machines on his existing NAS without causing bandwidth issues, it was time for an upgrade. Unfortunately, the cost of rewiring the existing home network to Cat 6 and procuring hardware that could run 10 Gigabit Ethernet over copper twisted pair was prohibitively expensive.

Instead, [Brian] decided to reduce the scope to connecting just 3 machines. Switches were prohibitively expensive, so each computer was fitted with twin 10 Gigabit interfaces, such that it could talk to the two other computers. Rather than rely on twisted pair, the interfaces chosen use the SFP+ standard, in which the network cable accepts electrical signals from the interface, and contains a fiber optic transciever.

[Brian] was able to get the 3 computers networked for just $120, with parts sourced from eBay. It’s an approach that doesn’t scale well; larger setups would be much better served by using a switch and a less zany network topology. But for [Brian], it works just fine, and allows his NAS to outperform a 15,000 RPM server hard disk as far as read rates go.

If you’re curious about improving your own network performance, it might pay to look at your cables first – things are not always as they seem.

How Do You Get PCI-E On The Atomic Pi? Very Carefully.

June 26, 2019 by Tom Nardi 18 Comments

At this point, you’ve almost certainly heard about the Atomic Pi. The diminutive board that once served as the guts of a failed robot now lives on as a powerful x86 SBC available at a fire sale price. How long you’ll be able to buy them and what happens when the initial stock runs out is another story entirely, but there’s no denying that folks are already out there doing interesting things with them.

One of them is [Jason Gin], who recently completed an epic quest to add a PCI Express (PCI-E) slot to his Atomic Pi. Things didn’t exactly go according to plan and the story arguably has more lows than highs, but in the end he emerged victorious. He doesn’t necessarily recommend you try the same modification on your own Atomic Pi, but he does think this sets the stage for the development of a more refined upgrade down the line.

[Jason] explains that the board’s Ethernet controller was already communicating with the Intel Atom x5-Z8350 SoC over PCI-E, so there was never a question about whether or not the modification was possible. In theory, all you needed to do was disable the Ethernet controller and tack on an external PCI-E socket so you could plug in whatever you want. The trick is pulling off the extremely fine-pitch soldering such a modification required, especially considering how picky the PCI Express standard is.

In practice, it took several attempts with different types of wire before [Jason] was able to get the Atomic Pi to actually recognize something plugged into it. Along the way, he managed to destroy the Ethernet controller somehow, but that wasn’t such a great loss as he planned on disabling it anyway. The final winning combination was 40 gauge magnet wire going between the PCB and a thin SATA cable that is mechanically secured to the board with a piece of metal to keep anything from flexing.

At this point, [Jason] has tested enough external devices connected to his hacked-on port to know the modification has promise. But the way he’s gone about it is obviously a bit temperamental, and far too difficult for most people to accomplish on their own anyway. He’s thinking the way forward might be with a custom PCB that could be aligned over the Ethernet controller and soldered into place, though admits such a project is currently above his comfort level. Any readers interested in a collaboration?

Like most of you, we had high hopes for the Atomic Pi when we first heard about it. But since it became clear the board is the product of another company’s liquidation, there’s been some understandable trepidation in the community. Nobody knows for sure what the future looks like for the Atomic Pi, but that’s clearly not stopping hackers from diving in.

Giving An Old Mac Spotify

December 21, 2018 by Brian Benchoff 15 Comments

The Macintosh SE/30 is the greatest computer ever made, and I’m not saying that just because I’m sitting on a cache of them, slowly selling them to computer collectors around the world. No, the SE/30 is so great because of how powerful it is, and how much it can be expanded. A case in point: here’s an SE/30 that’s a Spotify player. Oh, it does it over WiFi, too.

You might be asking yourself how a computer from 1989 (it’s late enough in the year that we can safely say this computer is thirty years old) can possibly play music over the Internet. While the SE/30 supported an astonishing 128 Megabytes of RAM, it’s still just a bit too slow to play MP3s or any modern audio codec. The 68030 CPU just wasn’t fast enough to play audio, to say nothing of streaming it over a network connection. The trick is that this SE/30 is simply a remote for Spotify Connect. You could theoretically get the Mac to speak, “Alexa, play Despacito” and get the same functionality, but that’s not fun, is it? You need to do it wirelessly.

This is a continuation of one of [ants] earlier hacks that basically put a WiFi to Ethernet bridge inside an SE/30. Tie that together with a Finder extension and you have System 7, with WiFi. That’s a connection to the Internet, but [ants] actual wrote an app to connect to a Spotify playlist, browse tracks, and display album art in beautiful 1-bit color. Writing the app involved dealing with OAuth, which means the MacPlayer isn’t entirely standalone; some of it must be done on a ‘modern’ device. This, along with porting a conversion utility that translates UTF-8 text encoding into something the Mac can understand ties everything together.

With all those pieces, the SE/30 becomes a handsome, functional piece of art. Apple is never going to release a computer like this again, and you’re not going to find a touchbar MacBook being used like this in thirty years time.

Want To Learn Ethernet? Write Your Own Darn AVR Bootloader!

October 30, 2018 by Elliot Williams 25 Comments

There’s a school of thought that says that to fully understand something, you need to build it yourself. OK, we’re not sure it’s really a school of thought, but that describes a heck of a lot of projects around these parts.

[Tim] aka [mitxela] wrote kiloboot partly because he wanted an Ethernet-capable Trivial File Transfer Protocol (TFTP) bootloader for an ATMega-powered project, and partly because he wanted to understand the Internet. See, if you’re writing a bootloader, you’ve got a limited amount of space and no device drivers or libraries of any kind to fall back on, so you’re going to learn your topic of choice the hard way.

[Tim]’s writeup of the odyssey of cramming so much into 1,000 bytes of code is fantastic. While explaining the Internet takes significantly more space than the Ethernet-capable bootloader itself, we’d wager that you’ll enjoy the compressed overview of UDP, IP, TFTP, and AVR bootloader wizardry as much as we did. And yes, at the end of the day, you’ve also got an Internet-flashable Arduino, which is just what the doctor ordered if you’re building a simple wired IoT device and you get tired of running down to the basement to upload new firmware.

Oh, and in case you hadn’t noticed, cramming an Ethernet bootloader into 1 kB is amazing.

Speaking of bootloaders, if you’re building an I2C slave device out of an ATtiny85¸ you’ll want to check out this bootloader that runs on the tiny chip.