Month: March 2018

HairIO: An Interactive Extension Of The Self

March 29, 2018 by 19 Comments

Most of what we see on the wearable tech front is built around traditional textiles, like adding turn signals to a jacket for safer bike riding, or wiring up a scarf with RGB LEDs and a color sensor to make it match any outfit. Although we’ve seen the odd light-up hair accessory here and there, we’ve never seen anything quite like these Bluetooth-enabled, shape-shifting, touch-sensing hair extensions created by UC Berkeley students [Sarah], [Molly], and [Christine].

HairIO is based on the idea that hair is an important part of self-expression, and that it can be a natural platform for sandboxing wearable interactivity. Each hair extension is braided up with nitinol wire, which holds one shape at room temperature and changes to a different shape when heated. The idea is that you could walk around with a straight braid that curls up when you get a text, or lifts up to guide the way when a friend sends directions. You could even use the braid to wrap up your hair in a bun for work, and then literally let it down at 5:00 by sending a signal to straighten out the braid. There’s a slick video after the break that demonstrates the possibilities.

HairIO is controlled with an Arduino Nano and a custom PCB that combines the Nano, a Bluetooth module, and BJTs that drive the braid. Each braid circuit also has a thermistor to keep the heat under control. The team also adapted the swept-frequency capacitive sensing of Disney’s Touché project to make HairIO extensions respond to complex touches. Our favorite part has to be that they chalked some of the artificial tresses with thermochromic pigment powder so they change color with heat. Makes us wish we still had our Hypercolor t-shirt.

Nitinol wire is nifty stuff. You can use it to retract the landing gear on an RC plane, or make a marker dance to Duke Nukem.

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A High Speed, Infinite Volume 3D Printer

March 29, 2018 by 22 Comments

One of the most interesting developments in 3D printing in recent memory is the infinite build volume printer. Instead of a static bed, this type of printer uses a conveyor belt and a hotend set at an angle to produce parts that can be infinitely long in one axis, provided you have the plastic and electricity. For this year’s Hackaday Prize, [inven2main] is exploring the infinite build volume design, but putting a new spin on it. This is a printer with a conveyor belt and a SCARA arm. The goal of this project is to build a printer with a small footprint, huge build volume, no expensive rails or frames, and a low part count. It is the most capable 3D printer you can imagine using a minimal amount of parts.

Most of the documentation for this build is hanging around on the RepRap forums, but the bulk of the work is already done. The first half of this build — the SCARA arm — is well-traveled territory for the RepRap community, and where there’s some fancy math and kinematics going on, there’s nothing too far out of the ordinary. The real trick here is combining a SCARA arm with a conveyor belt to give the project an infinite build volume. The proof of concept works, using a conveyor belt manufactured out of blue painter’s tape. These conveyor belt printers are new, and the bed technology isn’t quite there, but improvements are sure to come. Improvements will also be found in putting a small crown on the rollers to keep the belt centered.

All the files for this printer are available on the Gits, and there are already a few videos of this printer working. You can check those out here.

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Ask Hackaday: Is Your Clock Tied To Mains Frequency?

March 29, 2018 by 162 Comments

Earlier in March we heard about a quirk of the interconnected continental European electricity grid which caused clocks to lose about six minutes so far this year. This was due to a slight dip in the mains frequency. That dip didn’t put anything out of commission, but clocks that are designed to accumulate the total zero-crossings of the power grid frequency of 50 Hz don’t keep accurate time when that frequency is, say 49.985 Hz for an extended period of time.

An interesting set of conversations popped up from that topic. There were several claims that modern alarm clocks, and most devices connected to mains, no longer get their clock timing from mains frequency. I’ve looked into this a bit which I’ll go into below. But what we really want to know is: are your alarm clocks and other devices keeping time with the grid or with something else?

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Super-Blue CNC Part Fixturing

March 29, 2018 by 20 Comments

Simple clamps are great if you need to keep the pressure on two parallel surfaces, but if you have an irregular plane, or you need to cut through it, clamps are not the correct tool. The folks at [NYC CNC] feature a video with a clever hack borrowing from other disciplines. Painters tape is applied to the top of a level mounting surface in the machine and then burnished. The same is done to the bottom of the workpiece. Superglue is drizzled between the tape layers and pressed together so now the stock is held firmly below the toolhead.

Some parts are machined in the video, which can be seen below, and the adhesion holds without any trouble. One of the examples they cut would be difficult to hold without damage or stopping the machine. The accepted wisdom is that superglue holds well to a slightly porous surface like tape, but it doesn’t like do as well with smooth surfaces like metal. Removing residue-free tape at the end of a cut is also cleaner and faster than glue any day.

If you have yet to cut your teeth, you can watch our very own Elliot Williams getting introduced to CNC machines or a portable machine even a child can use.

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It’s Raining Chinese Space Stations: Tiangong-1

March 29, 2018 by 50 Comments

China’s first space station, Tiangong-1, is expected to do an uncontrolled re-entry on April 1st, +/- 4 days, though the error bars vary depending on the source. And no, it’s not the grandest of all April fools jokes. Tiangong means “heavenly palace”, and this portion of the palace is just one step of a larger, permanent installation.

But before detailing just who’ll have to duck when the time comes, as well as how to find it in the night sky while you still can, let’s catch up on China’s space station program and Tiangong-1 in particular.

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Dumb Down Your Xiaomi Smart Lamp With A Custom Firmware

March 29, 2018 by 42 Comments

Undoubtedly, the ESP8266’s biggest selling point is its WiFi capability for a ridiculously low price. Paranoid folks probably await the day its closed-source firmware bits will turn against humanity in a giant botnet, but until then, hobbyists and commercial vendors alike will proceed putting them in their IoT projects and devices. One of those devices is the Yeelight desk lamp that lets you set its color temperature and brightness via mobile app.

[fvollmer] acquired such a lamp, and while he appreciated its design and general concept, he wasn’t happy that it communicates with external servers. So he did the only reasonable thing and wrote his own firmware that resembles the original functionality, but leaves out the WiFi part. After all, the ESP8266 has still a lot to offer in its core essence: a full-blown 32-bit microcontroller with support for the most common, hobbyist-friendly SDKs.

The lamp’s color temperature and brightness are set with a rotary encoder / push button combo switch, and the LEDs themselves are controlled via PWM. All things considered, it’s a rather straightforward endeavour, for which [fvollmer] chose the standalone C SDK. And in the end, it’s not like he’s unreasonably cautious to keep some control over his household items.

Eavesdropping On A VGA Monitor’s Conversations

March 29, 2018 by 28 Comments

Did you ever wonder what your monitor and your computer are talking about behind your back? As it turns out, there’s quite a conversation going on while the monitor and the computer decide how to get along, and sniffing out VGA communications can reveal some pretty fascinating stuff about the I²C protocol.

To reverse engineer the configuration information exchanged between a VGA monitor and a video card, [Ken Shirriff] began by lopping a VGA cable in two. The inside of such cables is surprisingly complex, with separate shielding wires for each color and sync channel and a host of control wires, all bundled in multiple layers of shielding foil and braid to reduce EMI. [Ken] identified the clock and data lines used for the I²C interface and broke those out into a PocketBeagle for analysis using the tiny Linux machine’s I²C tools.

With a Python script to help decode the monitor’s Extended Display Identification Data (EDID) data, [Ken] was able to see everything the monitor knows about itself — manufacturer, serial number, all the supported resolution modes, and even deprecated timing and signal information left over from the days when CRTs ruled the desktop. Particularly interesting are the surprisingly limited capabilities of a VGA display in terms of color reproduction, as well as [Ken]’s detailed discussion on the I²C bus in general and how it works.

We always enjoy these looks under the hood that [Ken] is so good at, and we look forward to his reverse engineering write-ups. His recent efforts include a look at core memory from a 50-year old mainframe and reverse engineering at the silicon level.