Hackaday Links: September 8, 2019

September 8, 2019 by Dan Maloney 7 Comments

We start this week with very sad news indeed. You may have heard about the horrific fire on the dive boat Conception off Santa Cruz Island last week, which claimed 33 lives. Sadly, we lost one of our own in the tragedy: Dan Garcia, author of the wildly popular FastLED library. Dan, 46, was an Apple engineer who lived in Berkley; his partner Yulia Krashennaya died with him. Our community owes Dan a lot for the work he put into FastLED over the last seven years, as many an addressable LED is being driven by his code today. Maybe this would be a good chance to build a project that uses FastLED and add a little light to the world, courtesy of Dan.

In happier news, the biggest party of the hardware hacking year is rapidly approaching. That’s right, the 2019 Hackaday Superconference will be upon us before you know it. Rumor has it that there aren’t that many tickets left, and we haven’t even announced the slate of talks yet. That’s likely to clean out the remaining stock pretty darn quickly. Are you seriously prepared to miss this? It seems like a big mistake to us, so why don’t you hop over and secure your spot before you’re crying into your Club-Mate and wondering what all the cool kids will be doing in November.

Of course one of the highlights of Superconference is the announcement of the Hackaday Prize winner. And while we naturally think our Prize is the best contest, that doesn’t mean there aren’t others worth entering. MyMiniFactory, the online 3D-printing community, is currently running a “Design with Arduino” competition that should be right up the alley of Hackaday readers. The goal is simple: submit a 3D-printed design that incorporates Arduino or other electronics. That’s it! Entries are accepted through September 16, so you’ve still got plenty of time.

Sometimes you see something that just floors you. Check out this tiny ESP32 board. It doesn’t just plug into a USB port – it fits completely inside a standard USB Type A jack. The four-layer board sports an ESP32, FTDI chip, voltage regulator, an LED and a ceramic antenna for WiFi and Bluetooth. Why would you want such a thing? Why wouldn’t you! The board is coming soon on CrowdSupply, so we hope to see projects using this start showing up in the tipline soon.

Here’s a “why didn’t I think of that?” bench tip that just struck us as brilliant. Ever had to probe a board to trace signal paths? It’s a common enough task for reverse engineering and repairs, but with increasingly dense boards, probing a massive number of traces is just too much of a chore. Hackaday superfriend Mike Harrison from “mikeselectricstuff” makes the chore easier with a brush made from fine stainless wires crimped into a ring terminal. Attached to one probe of a multimeter, the brush covers much more of the board at a time, finding the general area where your trace of interest ends up. Once you’re in the neighborhood you can drop back to probing one pad at a time. Genius! We’d imagine a decent brush could also be made from a bit of coax braid too.

Another shop tip to wrap up this week, this one for woodworkers and metalworkers alike. Raw materials are expensive, and getting the most bang for your buck is often a matter of carefully laying out parts on sheet goods to minimize waste. Doing this manually can be a real test of your spatial relations skills, so why not automate it with this cut list optimizer? The app will overlay parts onto user-defined rectangles and snuggle them together to minimize waste. The program takes any units, can account for material lost to kerfs, and will even respect grain direction if needed. It’s built for wood, but it should prove useful for sheet metal on a plasma cutter, acrylic on a laser, or even PCBs on a panel.

The Ultimate Guide To Artisan USB Cables

September 4, 2019 by Tom Nardi 45 Comments

If you’ve gone through the trouble of building your own customized mechanical keyboard, the last thing you want to do is plug it into your computer with some plebeian USB cable from the local electronics shop. Your productivity, nay livelihood, depends on all those 1s and 0s being reproduced with the crisp fidelity that’s only possible with a high-end USB cable. Anything less would be irresponsible.

Or at least, that’s what the advertising on the back of the package would say if we tried to sell the custom USB cables built by [Josef Adamčík]. But alas, he’s decided to give away all the details for free so that anyone can build their own delightfully overengineered USB cables. Do you need a paracord USB cable with GX12 aviation connectors in the middle? Of course not. But you still want one, don’t you?

As [Josef] admits in his blog post, there’s nothing particularly special about what he’s doing here. If you can splice wires together, you can build your own bespoke USB cables. But what attracted us to his write-up was the phenomenal detail he goes into. Every step is clearly explained and includes a nice, well-lit, photo to illustrate what he’s doing. Honestly, when the documentation for soldering some USB connectors onto a wire looks this good, there’s no excuse why more substantial projects get little more than a few blurry shots.

Of course, even for those of us who are no stranger to the ways of the soldering iron, there’s likely a few ideas you can pull from this project. We particularly liked his tip for taping the USB connector to the workbench while soldering it rather than trying to get it to stay in a vise, and his method for adding a coil the cable with a wooden jig and a heat gun is definitely something to file away for future use.

Then again in an era where even the lowly-USB cable can potentially be a security threat, or simply not live up to published specifications, rolling your own might not be such a bad idea.

Uncovering The Echo Dot’s Hidden USB Port

August 15, 2019 by Tom Nardi 62 Comments

If you upgraded to Amazon’s latest Echo Dot, you might have been surprised to find that the diminutive voice assistant had shed its USB port. Earlier models of the Dot used a garden variety micro USB port for power, which hackers eventually figured out also provided a helpful way to snoop around inside the device’s firmware. The fact that the USB port was deleted on the latest Echo Dot in favor of a simple barrel connector for power was seen by some as a sign that Amazon was trying to keep curious owners out of their hardware.

But as [Brian Dorey] shows, all they did was put a bump in the road. While they removed the external USB connector, the traces for it are still on the board waiting to be accessed. Even better, it turns out the USB data lines are connected to the test points located on the bottom of the Dot. All you need is a simple breakout that will connect through the existing opening in the device’s case, and you’ve got your USB port back.

So what can you do with USB on the Echo Dot? Well, not much right now. [Brian] found that the Dot shows up as a Mediatek device under Linux using lsusb, and fastboot can see it and even confirms the presence of a locked bootloader. It’s going to take some work from the community to see how deep this particular rabbit hole goes.

Even if you’re not interested in restoring its USB port, [Brian] has uncovered a wealth of fascinating hardware information about the Echo Dot during his deep-dive. He’s mapped out many of the test points located throughout the device’s PCBs, and found a few interesting points that might be worth further investigation. For example, he found that driving one of the pins high would trigger the Dot to mute its microphones; which could be useful for anyone looking to cover Alexa’s ears.

[Brian] first cracked open the Echo Dot last month, after scoring one for cheap during Amazon’s Prime Day sale. It looks like he’s making fairly rapid progress on unraveling the mysteries of this popular gadget, and we’re very interested in seeing where this research takes us.

Millenium Falcon HID: Get Unity To Talk To Teensy

August 15, 2019 by Inderpreet Singh 11 Comments

Here’s one that proves a hardware project can go beyond blinking LEDs and dumping massive chunks of data onto a serial console. Those practices are fine for some, but [dimtass] has found a more elegant hack for a more civilized age. His 3D Millennium Falcon model gets orientation data from his IMU as an an HID device.

The hardware involved is an MPU6050 6-axis sensor that is interfaced with a Teensy 3.2 board. [dimtass] documents his approach to calibrating the IMU going a bit further by using a Python script to generate offsets. We’ve advocated using Jupyter notebooks in the past and this is a good example of Jupyter plotting the data and visualizing the effect of the offsets in a second pass.

When in action, the Teensy reads IMU data and sends it over a USB RAW HID interface. For the uninitiated, HID transfers are more reliable than USB CDC transfers (virtual serial port) because they use smaller data chunks per event/transaction and usually don’t require special drivers. On the computer side, [dimtass] has written a small application that gets the IMU values over the RAW HID and then provides it to the visualization application.

A 3D Millennium Falcon model is rendered in Unity, the popular open source game development engine. Even though Unity has an API, this particular approach is more OS specific using a shared-memory technique. The HID application writes to a file (/tmp/hid-shared-buffer) which is then read by Unity to make orientation changes to the rendered model.

[dimtass] provides lots of details on the tools used to bring his project to life and it can be a great starting point for more projects that need interfacing sensors with a visualization system. We have seen ways to turn a person’s head into a joystick and if you need a deeper dive into Unity, look no further.

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KVM Foot Switch In A Few Steps

August 12, 2019 by Kristina Panos 6 Comments

[Radishmouse], despite the handle, is not a mouse guy. Give him a keyboard and he will get around just fine in any OS or program. As it is, he’s got a handful of ThinkPads, each running a different OS. He wanted to be able to switch his nice mechanical keyboard between two laptops without the hassle of unplugging and replugging the thing. His solution: a DIY KVM foot switch.

He’s been learning about electronics and 3D design, and this problem was the perfect opportunity to dig in and get his hands dirty. After learning enough about the USB protocol and switches to figure out what had to happen, he made a prototype from a pâte tub. Though undeniably classy, this vessel would never survive the rigors of foot-stomping in feline territory. Fortunately, [radishmouse] has also been learning about 3D design. After some trial and error, he came up with a sturdy, curvy 3D-printed two-piece enclosure. We particularly like the blocks built into the bottom piece that shore up the USB ports.

There are lots of reasons to build input controls for those under-utilized appendages at the ends of your legs. You could control your ‘scope with a probe in each hand, or use a foot switch to relocate an inconvenient power button.

Via [r/functionalprint]

A SuperCap UPS

August 5, 2019 by Brian McEvoy 61 Comments

If you treat your Pi as a wearable or a tablet, you will already have a battery. If you treat your Pi as a desktop you will already have a plug-in power supply, but how about if you live where mains power is unreliable? Like [jwhart1], you may consider building an uninterruptible power supply into a USB cable. UPSs became a staple of office workers when one-too-many IT headaches were traced back to power outages. The idea is that a battery will keep your computer running while the power gets its legs back. In the case of a commercial UPS, most generate an AC waveform which your computer’s power supply converts it back to DC, but if you can create the right DC voltage right to the board, you skip the inverting and converting steps.

Cheap batteries develop a memory if they’re drained often, but if you have enough space consider supercapacitors which can take that abuse. They have a lower energy density rating than lithium batteries, but that should not be an issue for short power losses. According to [jwhart1], this quick-and-dirty approach will power a full-sized Pi, keyboard, and mouse for over a minute. If power is restored, you get to keep on trucking. If your power doesn’t come back, you have time to save your work and shut down. Spending an afternoon on a power cable could save a weekend’s worth of work, not a bad time-gamble.

We see what a supercap UPS looks like, but what about one built into a lightbulb or a feature-rich programmable UPS?

Control Your Web Browser Like It’s 1969

July 23, 2019 by Dan Maloney 14 Comments

Imagine for a moment that you’ve been tasked with developing a device for interfacing with a global network of interconnected devices. Would you purposely design a spring-loaded dial that can do nothing but switch a single set of contacts on and off from 1 to 10 times? What kind of crazy world would we have to live in where something like that was the pinnacle of technology?

Obviously, such a world once existed, and now that we’ve rolled the calendar ahead a half-century or so, both our networks and our interfaces have gotten more complex, if arguably better. But [Jan Derogee] thinks a step backward is on order, and so he built this rotary phone web browser. The idea is simple: pick up the handset and dial the IP address of the server you want to connect to. DNS? Bah, who needs it?

Of course there is the teensy issue that most websites can’t be directly accessed via IP address anymore, but fear not – [Jan] has an incredibly obfuscated solution to that. It relies on the fact that many numbers sound like common phrases when sounded out in Chinese, so there end up being a lot of websites that have number-based URLs. He provides an example using the number 517, which sounds a bit like “I want to eat,” to access the Chinese website of McDonald’s. How the number seven sounding like both “eat” and “wife” is resolved is left as an exercise to the reader.

And here we thought [Jan]’s rotary number pad was of questionable value. Still, we appreciate this build, and putting old phones back into service in any capacity is always appreciated.

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