Pool Playing Robot Destined For Trouble In River City

May 10, 2017 by Dan Maloney 15 Comments

You’d think pool should be an easy game for a robot to play, right? It’s all math — geometry to figure out the angles and basic physics to deal with how much force is needed to move the balls. On top of that, it’s constrained to just two dimensions, so it should be a breeze.

Any pool player will tell you there’s much, much more to the game in real life, but still, a robot to play pool against would be a neat trick. As a move toward that goal, [BVarv] wisely decided on a miniature mockup of a pool-playing robot, and in the process reinvented the pool table itself. Realizing that a tracked or wheeled robot would have a tough time maneuvering around the base of a traditional pool table, his model pool table is a legless design that looks like something from IKEA. But the pedestal support allows the robot to be attached to the table and swing around in a full circle, and this allowed him to work through the kinematics as shown in the charming stop-action video below.

[BVarv] has gotten as far as motion control on the swing axis, as well as on the arms that will eventually hold the cue. He plans overhead image analysis for identifying shots, and of course there’s the whole making it full-size thing to do. We’d love to play a game or two against a bot, so we hope he gets there. In the meantime, how about a little robo-air hockey?

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Hackaday Prize Entry: Modular Rail Lighting

May 10, 2017 by James Hobson 6 Comments

When operating any kind of hydroponic farming, there are a number of lighting solutions — few of them inexpensive. Originally looking for an alternative to the lighting of IKEA’s expensive hydroponics system, [Professor Fartsparkle] and their colleague prototyped a rail system that allows clip-on LED boards for variable lighting options.

Taking inspiration from wire and track lighting systems, the key was the 5mm fuse holders mounted on the bottom of the LED boards. Snipping off their stopping clip makes them easy to install and remove from the mounting rails. The rails themselves double as power conduits for the LED boards, but keeping them out of the way is easily done with the variety of 3D printed hangers [Professor Fartsparkle] has devised. Lighting is controlled by a potentiometer on the power injection board, as well as any home automation control via an ESP8266.

[Professor Fartsparkle] asserts that the boards can be slid along the rails without any noticeable flickering, but they do suffer from heat dissipation issues. That aside, the prototype works well enough that the 3W LEDs can be run at half power.

This is an ingenious — and cheap — workaround for when sunlight isn’t an option, but you are still looking for a solution capable of automation.

Designing For Fab: A Heads-Up Before Designing PCBs For Professional Assembly

May 10, 2017 by Sonya Vasquez 55 Comments

Designing pcbs for assembly is easy, right? We just squirt all the footprints onto a board layout, connect all the traces, send out the gerbers and position files, and we’re done–right?

Whoa, hold the phone, there, young rogue! Just like we can hack together some working source code with variables named after our best friends, we can also design our PCBs in ways that make it fairly difficult to assemble.

However, by following the agreed-upon design specs, we’ll put ourselves on track for success with automated assembly. If we want another party to put components on our boards, we need to clearly communicate the needed steps to get there. The best way to do so is by following the standards.

Proper Footprint Orientation

Now, for a moment, let’s imagine ourselves as the tip of a vacuum pickup tool on a pick-and-place machine. These tools are designed to pick up components on the reel from their centroid and plunk them on their corresponding land pattern. Seems pretty straightforward, right? It is, provided that we design our footprints knowing that they’ll one day come face-to-face with the pick-and-place machine.

To get from the reel to the board, we, the designers, need two bits of information from out part’s datasheet: the part centroid and the reel orientation.

The part centroid is an X-Y location that calls out the center-of-mass of the part. It basically tells the machine: “pick me up from here!” As designers, it’s our responsibility to design all of our footprints such that the footprint origin is set at the part’s centroid. If we forget to do so, the pick-and-place will try to suck up our parts from a location that may not stick very well to the package, such as: the corner.

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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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