Wired Wireless Over Coax

If it’s stupid and it works, then it’s not stupid. There’s no better evidence of that than [Manawyrm]’s networking setup.

She recently had to distribute Ethernet through a building, and there are a few ways to do that. You can use regular old twisted pair, or fiber, but in this case running new cables wasn’t possible. WiFi would be the next obvious choice, but the distance was just a bit too far for ‘regular’ WiFi links. Ethernet over power lines was an option, but there are amateur radio operators in the house, and power lines put out a bunch of interference and noise. The solution was to mis-use existing 75 Ohm satellite TV coax that was just sitting around.

The correct way to do this would be to use a standard DOCSIS modem and become your own cable Internet provider. The equipment to do this is expensive, and if you’re already considering running WiFI over coax, you’re too deep down the rabbit hole to spend real money. Instead, [Manawyrm] simply made a few u.FL to F-connector adapters from u.FL to SMA, then SMA to F-connector adapters.

There are some problems with this plan. WiFi is 50 Ohms, TV coax cable is 75 Ohms. Only one MIMO channel will be available meaning the maximum theoretical bandwidth will be 433 Mbps. WiFi is also at much higher frequencies than what coax is designed for.

With two WiFi antenna to coax adapters, [Manawyrm] simply connected the coax directly to a router set up to bridge Ethernet over WiFi. The entire thing worked, although testing showed it was only getting about 60 Mbps of throughput. That’s not bad for something that was cobbled together out of old parts and unused wiring. Is it surprising that this worked? No, not really, but you’ve probably never seen anyone actually do it. Here’s the proof it does work, and if you’re ever in a bind, this is how you make WiFi wired.

Cool Tools: The Pantorouter Turns Tracing On Its Side

Not too long ago we wrote about a small CNC tool for automating certain parts of the woodworking process. At the time it seemed unusual in its intentionally limited scope but a few commenters mentioned it reminded them of another device, [Matthias]’s Pantorouter. It didn’t take much investigation to see that the commenters were right! The MatchSticks device does feel a bit like a CNC version of the Pantorouter, and it seemed like it was more than worth of a post by itself. The Pantorouter is a fascinating example of another small manual-but-automated tool for optimized for accelerating and improving certain woodworking operations.

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ARM-Based NAS Is A Low Cost, Low Power Beauty

A NAS is always a handy addition to a home network, but they can be a little pricey. [Blake Burkhart] decided to create his own, prioritising budget and low power considerations, with a secondary objective to produce some router and IoT functionality on the side.

A Banana Pi R2 was a good choice to meet these requirements, being a router-based development board that also sports dual SATA connectors and gigabit Ethernet. [Blake] had some retrospective regrets about the performance of this particular SBC, but it does just fine when functioning purely as a NAS.

The enclosure for the device is a three bay hot-swap HDD module, with one of the bays gutted and used for the Banana Pi. It’s a simple idea, elegantly executed, which looks great. To access the ports of the Banana Pi, a custom acrylic side panel was laser cut, which also allowed LEDs to shine through – obligatory for any DIY server/computer build. When mounting this panel to the existing enclosure, [Blake] was reluctant to take his chances tapping the brittle acrylic, instead opting to melt the threads into the plastic with a pre-torched screw. We find that tapping acrylic is usually okay if you take it slow, but heat-tapping does sound fun.

The 12 V fan that came built into the hot-swap enclosure was too loud and awkwardly came in a non-standard size with a non-standard connector. What’s more, a buzzer alarm was triggered any time the fan was disconnected and 0 RPM was detected. [Blake]’s solution was to rewire the power pin of the connector to a 5 V rail; he found that running the fan at 5 V led to much quieter performance whilst keeping the HDDs sufficiently cool.

We find that when it comes to DIY network gear and routers, there are two approaches. Either create your own bespoke solution that perfectly fits your needs, like this perfect home router, or work around your current gear and build some tech to automatically reboot it for you.

 

A CNC Woodworking Tool That Does The Hard Parts

Drawn along in the wake of the 3d printing/home shop revolution has been the accessibility of traditional subtractive CNC equipment, especially routers and mills. Speaking of, want a desktop mill? Try a Bantam Tools (née Othermachine) Desktop Milling Machine or a Carvey or a Carbide 3D Nomad. Tiny but many-axis general purpose mill? Maybe a Pocket NC. Router for the shop? Perhaps a Shapeoko, or an X-Carve, or a ShopBot, or a… you get the picture. [Rundong]’s MatchSticks device is a CNC tool for the shop and it might be classified as a milling machine, but it doesn’t quite work the way a more traditional machine tool does. It computer controls the woodworker too.

Sample joints the MatchSticks can cut

At a glance MatchSticks probably looks most similar to a Pocket NC with a big Makita router sticking out the side. There’s an obvious X-axis spoilboard with holes for fixturing material, mounted to a gantry for Z-axis travel. Below the big friendly handle on top is the router attached to its own Y-axis carriage. The only oddity might be the tablet bolted to the other side. And come to think of it the surprisingly small size for such an overbuilt machine. What would it be useful for? MatchSticks doesn’t work by processing an entire piece of stock at once (that what you’re for, adaptable human woodworker) it’s really a tool for doing the complex part of the job – joinery – and explaining to the human how to do the rest.

The full MatchSticks creation flow goes like this:

  1. Choose a design to make on the included interface and specify the parameters you want (size, etc).
  2. The MatchSticks tool will suggest what material stocks you need, and then ask you to cut them to size and prepare them using other tools.
  3. For any parts which require CNC work the tool will help guide the user to fixture the stock to its bed, then do the cutting itself.
  4. Once everything is ready for final assembly the MatchSticks will once again provide friendly instructions for where to pound the mallet.

In this way [rundong], [sarah], [jeremy], [ethan], and [eric] were able to build a much smaller machine tool without sacrificing much practical functionality. It’s almost software-like in it’s focus on a singular purpose. Why reinvent what the table saw can do when the user probably already has access to a table saw that will cut stock better? MatchSticks is an entire machine bent around one goal, making the hard stuff easier.

It’s worth noting that MatchSticks was designed as an exploration into computer/human interaction for the ACM Conference on Human Factors in Computing Systems so it’s not a commercial product quite yet (we’re eagerly waiting!). For a much more in depth look at the project and its goals and learnings the full research paper is available here. Their intro video is down after the break.

Thanks [ethan] for the tip!

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Literary Camouflage For Your Router

What is suspicious about the books in the image above? Is it that there is no bookend? How about the radio waves pouring out of them? [Clay Weiland] does not like the way a bare router looks in the living room, but he appreciates the coverage gained by putting it in the middle of his house. He added a layer of home decorating camouflage in the form of some second-hand book covers to hide the unsightly bit of tech.

There isn’t a blog post or video about this particular build anywhere. The photos were submitted to our tip line as-is with the note that a table-saw is involved. We can safely infer that book covers are stripped of their pages and filled with wooden blanks painted white and stuck together to look like a cluster of literature. The takeaway from this example is that our tech does not have to be hidden away like a secret, or disrupt the decor, it can be placed as functionally as possible without sacrificing Feng Shui.

If hiding behind books piques your interest, try a full-fledged version, or this smooth operator.

Thank you, [George Graves], for encouraging people to use our tip line.

Cheap Stuff To Hack: A Router With An SDR For $13

The history of consumer electronics is littered with devices that are relatively uninteresting at first, but become spectacular platforms for hardware exploitation once a few select people figure out how everything ticks. The Linksys WRT54G was just a router until someone figured out how to put a complete Linux system on them. Those RTL-SDR dongles were just for capturing over the air TV until someone realized they were actually a software-defined radio. The CueCat was just dot-com boom marketing garbage until… well, we picked up a lot of CueCats regardless.

Now there’s a new device sitting on the shelves at Walmart just waiting for some Linux hackers to have a go. It’s the Tzumi MagicTV, a device that allows you to watch over-the-air television on your phone. What’s inside? It’s a WiFi router, an RTL-SDR, and a battery pack in one tiny package. The best part? It costs $13, and apparently Walmart is just blowing them out.

Right now, there aren’t too many details on what’s going on inside the Tzumi MagicTV box, however, the discussion over on the RTLSDR subreddit has revealed enough to give us a good idea of what’s going on. The router inside the MagicTV is a TP-Link TL-WR703N, the exact same WiFi router that took the WRT54G’s place as the king of hackable routers a few years ago. The SDR chip is the same as the Astrometa DVB-T2, one of the common TV tuners on-a-stick. Other than that, there are TX and RX pins on the board, SSH is open, no one knows the password, but as of this writing, a few people are putting John the Ripper to work trying to break into this box.

What is the end goal of cracking this Linux box wide open? Well, it’s a WiFi router and an SDR, so if you want to make your own Flightaware ADS-B logger, that could be on the table. Of course, you could actually use it for its intended purpose and pull down over-the-air TV to your local network, but that seems so pedestrian after getting root on a $13 box from Walmart.

Thanks [Adam] for the tip!

Building The Perfect Home Router

When a favorite piece of hardware dies, it’s fairly common to experience a bit of dread. The thought that now you’ll have to go through the process of getting a replacement for the device can be very troubling, and is fraught with difficult questions. Is the hardware still available? Has it been made obsolete by something else in the time you’ve had it? But while it can be a hassle, there’s no question you can come out the other side better than you went in. Sometimes it takes the passing of an old piece of gear for you to really embrace what’s possible with the latest and greatest.

That’s exactly what happened to [Tyler Langlois]. When his trusty home router finally gave up the ghost, he was left with a couple of options. He could get another consumer router, upgrade to a enterprise-level model, or take the road less traveled and build his own router to his exacting specifications. Since you’re reading about it on Hackday, we’ll give you one guess as to which door he went through.

The blog post [Tyler] has written up about the saga of building his own router is an incredible resource for anyone who might be thinking of taking the plunge into DIY networking. From selecting the proper hardware to the nuances of getting all of the software packages installed, this is an absolute treasure trove. At the beginning of the post he mentions that the post shouldn’t be considered a comprehensive guide, but considering we’ve seen commercial hardware that wasn’t documented this well, we’d have to respectfully disagree on that point.

Some elements of his homespun may come as something of a surprise. For one, [Tyler] bucked the hive mentality and determined the Raspberry Pi simply wasn’t up to the task due (at least in part) to the single 100 Mbps network interface. He ended up going with an ESPRESSObin, a relatively niche Linux SBC that features an onboard gigabit switch in addition to a fairly hefty spec sheet. He also decided to forgo WiFi entirely, and leave the intricacies of wireless networking to a standalone access point from Ubiquity.

A router is often overlooked as just another piece of consumer kit sitting around the house, but it’s actually an excellent place to flex your creative and technical muscle. From adding a remote display to converting it into a mobile battle tank, there’s a lot more you can do with your router than stare at the blinkenlights.