Friday Hack Chat: Tenaya Hurst From Arduino

May 10, 2017 by Mike Szczys 7 Comments

Join us this Friday at noon PDT for a Hack Chat with Tenaya Hurst of Arduino. If you’ve been one of the big Maker Faires over the last few years (or innumerable other live events) and stopped by the Arduino area you’ve probably met Tenaya. She is the Education Accounts Manager for Arduino and loves working with wearable electronics.

Come and discuss maker education and the role Arduino is playing in getting our students excited about electronics, and STEAM education in general. Tenaya will also be discussing a new wearable tech kit she’s been working on. We hope to see the gear in person at Bay Area Maker Faire next week.

Here’s How To Take Part:

Our Hack Chats are live community events on the Hackaday.io Hack Chat group messaging.

Log into Hackaday.io, visit that page, and look for the ‘Join this Project’ Button. Once you’re part of the project, the button will change to ‘Team Messaging’, which takes you directly to the Hack Chat.

You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.

Hacking The Thotcon 0x8 Badge

May 10, 2017 by John Baichtal 12 Comments

[Kenjo] attended Chicago’s Thotcon this past week and has started hacking the convention badge and detailing what he learned. Thotcon’s badge, designed by [Jedha] and programmed by [John Wallis] of Workshop 88, is packed with the requisite electronic hardware and cryptic clues. There are four NeoPixel LEDs, three pots, and a micro USB, all run by an ATmega32u4.

The stock firmware is a game called tesserHack, a maze game using the three pots for navigation. You can also connect via USB to play through the serial console, and this version includes a map view and help menu.

[Kenjo] who previously hacked the Thotcon 0x6 badge, accidentally deleted the stock firmware on this year’s badge, so he used a Bus Pirate as an ISP to burn the Arduino boot loader back on, and has started mapping out the pots and LEDs. If you’re interested in helping out, check out the project on Hackaday.io. [Thanks, gigawatts]

How A Hacker Remembers A PIN

May 10, 2017 by Elliot Williams 98 Comments

If you have more than a few bank cards, door-entry keycodes, or other small numeric passwords to remember, it eventually gets to be a hassle. The worst, for me, is a bank card for a business account that I use once in a blue moon. I probably used it eight times in five years, and then they gave me a new card with a new PIN. Sigh.

How would a normal person cope with a proliferation of PINs? They’d write down the numbers on a piece of paper and keep it in their wallet. We all know how that ends, right? A lost wallet and multiple empty bank accounts. How would a hacker handle it? Write each number down on the card itself, but encrypted, naturally, with the only unbreakable encryption scheme there is out there: the one-time pad (OTP).

The OTP is an odd duck among encryption methods. They’re meant to be decrypted in your head, but as long as the secret key remains safe, they’re rock solid. If you’ve ever tried to code up the s-boxes and all that adding, shifting, and mixing that goes on with a normal encryption method, OTPs are refreshingly simple. The tradeoff is a “long” key, but an OTP is absolutely perfect for encrypting your PINs.

The first part of this article appears to be the friendly “life-hack” pablum that you’ll get elsewhere, but don’t despair, it’s also a back-door introduction to the OTP. The second half dives into the one-time pad with some deep crypto intuition, some friendly math, and hopefully a convincing argument that writing down your encrypted PINs is the right thing to do. Along the way, I list the three things you can do wrong when implementing an OTP. (And none of them will shock you!) But in the end, my PIN encryption solution will break one of the three, and remain nonetheless sound. Curious yet? Read on.

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Measuring Walking Speed Wirelessly

May 10, 2017 by Lewin Day 9 Comments

There are a lot of ways to try to mathematically quantify how healthy a person is. Things like resting pulse rate, blood pressure, and blood oxygenation are all quite simple to measure and can be used to predict various clinical outcomes. However, one you may not have considered is gait velocity, or the speed at which a person walks. It turns out gait velocity is a viable way to predict the onset of a wide variety of conditions, such as congestive heart failure or chronic obtrusive pulmonary disease. It turns out, as people become sick, elderly or infirm, they tend to walk slower – just like the little riflemen in your favourite RTS when their healthbar’s way in the red. But how does one measure this? MIT’s CSAIL has stepped up, with a way to measure walking speed completely wirelessly.

You can read the paper here (PDF). The WiGate device sends out a low-power radio signal, and then measures the reflections to determine a person’s location over time. Alone, however, this is not enough – it’s important to measure the walking speed specifically, to avoid false positives being triggered by a person simply not moving while watching television, for example. Algorithms are used to separate walking activity from the data set, allowing the device to sit in the background, recording walking speed data with no user interaction required whatsoever.

This form of passive monitoring could have great applications in nursing homes, where staff often have a huge number of patients to monitor. It would allow the collection of clinically relevant data without the need for any human intervention; the device could simply alert staff when a patient’s walking pattern is indicative of a bigger problem.

We see some great health research here at Hackaday – like this open source ECG. Video after the break.

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LED Tail Lights For Improved Motorcycle Visibility

May 10, 2017 by Lewin Day 32 Comments

Motorcycles are hard to see at the best of times, so riders are often concerned with making themselves as visible as possible at all times. [Josh] wanted to do this by creating a custom tail light for his Ducati 749.

The tail light is based around SMD LEDs, mounted in acrylic to diffuse the light. The construction is beautiful, using custom PCBs and carefully machined acrylic to match the lines of the bike.

As far as warning lights go, a brighter light will be more obvious in the day time, but could actually hinder visibility at night by blinding other road users. To this end, [Josh] built the tail light around an ATtiny 45, which could be programmed with various routines to optimise the light level depending on ambient conditions. Another feature is that the light’s brightness pulses at high frequency in an attempt to attract the eye. Many automakers have experimented with similar systems. The ATtiny controls the lights through a PCA9952 LED controller over I2C. This chip has plenty of channels for controlling a bunch of LEDs at once, making the job easy.

Overall, it’s a very tidy build that lends a very futuristic edge to the bike. We’ve seen [Josh]’s work in this space before, too – with this awesome instrument display on a Suzuki GSX-R.

3D-Printed Tiger Lopes With The Help Of A Motor

May 9, 2017 by John Baichtal 9 Comments

[Greg Zumwalt], master of 3D-printed mechanisms, has published his Saber 2 project as well as an assembly Instructable telling you how to put it together.

Saber 2 is a 3D-printed gear-and-cam saber-toothed tiger that can be motorized to show an excellent loping movement. It’s 14” long and 10” tall and consists of 108 components of which 34 are unique parts, and it all moves with the help of a 6 VDC 60 RPM gearmotor. With threaded PLA rods to keep it all together, and tapped holes to secure the rods, one imagines the printer would have to be pretty finely tuned and leveled for the parts to move as elegantly as you see in the video.

Hackaday readers might recall [Greg]’s 3D-printed projects such as his balloon-powered engine as well as his toy car also powered by balloons.

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Monoprice Select Mini Gets Smooth

May 9, 2017 by Al Williams 19 Comments

We’ve had a love affair with the Monoprice Select Mini since it came out. The cheap printer has its flaws, though. One of them is that the controller is a bit opaque. On the one hand, it is impressive that it is a 32-bit board with an LCD. On the other hand, we have no way to modify it easily other than loading the ready-built binaries. Want to add bed leveling? Multiple fans? A second extruder and mixing head? Good luck, since the board doesn’t support any of those things. [mfink70] decided the controller had to go, so he upgraded his Mini with a Smoothie board.

On the plus side, the Smoothie board is also a 32-bit board with plenty of power and expansion capability. On the downside, it costs about half as much as the printer does. Just replacing the board was only part of the battle. [mfink70] had to worry about the steppers, the end stops, and a few other odds and ends.

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