Robot Foosball Will Kick Your Butt If You Play Slowly


Sometimes we find a project that is so far outside of our realm of experience, it just makes us sit back and think “wow”. This is definitely one of those projects. [Saba] has created a Robotic Foosball set that learns.

[Saba Khalilnaji] is a recent engineering graduate from UC Berkeley, and his passion is robotics. After taking an Artificial Intelligence class during his degree (you can take it online through edX!), he has decided to dabble in AI by building this awesome robot Foosball set.

His “basic” understanding of machine learning includes a few topics such as Supervised Learning, Unsupervised Learning and Reinforcement Learning. For this project he’s testing out a real-world application of Reinforcement Learning using the Markov Decision Process or MDP for short. At an extremely top level description it works by programming an agent to learn from the consequences of its actions in a given environment. There are a set of states, actions, probabilities for given state and action, and rewards for specific state and action sets.

Before we butcher the explanation anymore, check out his blog for more information — and watch the following video.

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Sound Card Tachometer Rises From the Junkbox


We love writing up projects that re-use lots of old parts. In fact, we save the links and use them as defense when our significant other complains about the “junk” in the basement. No, that tactic hasn’t ever worked, but we’re going to keep trying. Case in point, [Wotboa] needed a non-contact tachometer. There are plenty of commercial products which do just that. After consulting his parts bin, [wotboa] realized he had everything he needed to hack out his own. An IR break beam sensor from an old printer was a perfect fit in an aluminum tube. With the outer shell removed, the emitter and detector were mounted in the nylon shell of an old PC power supply connector, effectively turning them pair into a reflective sensor. To amplify the circuit, [wotboa] used a simple 2n2222 transistor circuit. The key is to keep the voltage seen by the sound card the range of a line level signal. This was accomplished by adding a 2.2 Megohm resistor in line with the output. [wotboa] drew his schematic in eagle, and etched his own PCB for the project. Even the tachometer’s case came from the parts bin. An old wall wart power supply gave up its shell for the cause, though [wotboa] is saving the transformer for another project.

For sensing, [wotba] used [Christian Zeitnitz's] Soundcard Oscilloscope software.  Measuring the RPM of the device under test is simply a matter of determining the frequency of the signal and multiplying by 60. A 400 Hz signal would correspond to a shaft turning at 24,000 RPM. The circuit performs well in the range of RPM [wotboa] needs, but using a sound card does have its limits. The signals on the scope look a bit distorted from the square waves one would expect. This is due to the AC coupled nature of sound cards. As the signal approaches DC, the waveform will become more distorted. One possible fix for this would be to remove the AC coupling capacitor on the sound card’s input. With the capacitor removed, an op amp buffer would be a good idea to prevent damage to the sound card.

[Via Instructables]

Using SDR to Read Your Smart Meter


[BeMasher] was dissatisfied with the cost of other solutions to read his smart meter, so he made a project to read it himself using an rtl-sdr dongle.

Using his hacking and reverse engineering skills along with a $20 RTL-SDR dongle, [BeMasher] wrote rtlamr to automatically detect and report the consumption information reported by smart meters within range. Though designed for his Itron C1SR, [BeMasher] claims that any electronic receiver transmitter (ERT) capable smart meter should work.

[BeMasher]‘s Itron C1SR smart meter broadcasts both interval data and standard consumption in the 915MHz ISM band using a Manchester encoded, frequency hopping spread spectrum protocol. [BeMasher] used the RTL-SDR dongle to do the signal capture and analysed the resulting signal in software afterwards. [BeMasher] did a great job of going through the theory and implementation of analysing the resulting data capture, so be sure to check it for an in-depth analysis.

If the RTL-SDR dongles are too limited for you taste, you might want to check out some hacker friendly SDRs with a little more punch.

Hackaday Meetup with [Chris Gammell]


Update: We have it figured out. We’re bringing the awesome at The Blind Donkey in Pasadena, CA at 6pm this evening. Stop in with your hardware and your war stories. Chris Gammell, Mathieu Stephan, and I can’t wait to talk Arduino hardware hacking with you!

I’m getting to meet all kinds of cool people in person this year, and so can you! Well… if you happen to be in Pasadena, California on Wednesday after work and have nothing better to do. [Chris Gammell] — well-known for The Amp Hour and Contextual Electronics – and I are both going to be in town. We’re meeting up for a beer and thought we’d invite you along for the fun.

Details are scarce right now. I’m not sure of time or place (other than Pasadena area) so make sure you follow @Hackaday on Twitter and watch for the #HaD_meetup tag Wednesday afternoon for the details. We’ll also update the Hackaday Projects event page at the time. I’ll bring along some swag; you’d better cart along a piece of hardware to show off in return for a t-shirt or stickers. You’re on your own for food and beverages at this one.

Wondering what I meant about meeting lots of cool people? In addition to the nearly 500 awesome readers who showed up at The Gathering, I met [Brian] and [Eliot] for the first time.

Hexapod Robot Terrifies Humans and Wallets


[Kevin] brings us Golem, his latest robot project. Golem is crafted not of clay and stone like his namesake, but of T6 Aluminum and Servos. We don’t have a banana for scale, but Golem is big. Not [Jamie Mantzel's] Giant Robot Project big, but at 2.5 feet (76.2 cm) in diameter and 16 lbs (7.3 Kg), no one is going to call Golem a lightweight. With that kind of mass, standard R/C servos don’t stand much of a chance. [Kevin] pulled out all the stops and picked up Dynamixel MX64 servos for Golem’s legs. Those servos alone propelled the Golem’s costs well beyond the budget of the average hobbyist. Kevin wasn’t done though. He added an Intel NUC motherboard with a fourth generation i5 processor, a 120 Gigabyte solid state drive, and 8 Gigbytes of Ram.  Sensing is handled by gyros, accelerometers, and an on-board compass module. We’re assuming from the lack of a GPS that Golem will mainly see indoor use. We definitely like the mini subwoofer mounted on Golem’s back. Hey, even robots gotta have their tunes.

Golem is currently walking under human control via a Dualshock 3 controller paired via bluetooth. [Kevin's] goal is to use Golem to learn Robotic Operating System (ROS). He’s already installed ubuntu 13.04 and is ready to go. [Kevin] didn’t mention a vision system, but based on the fact that some of his other robots use the Xtion pro live, we’re hopeful. We can’t wait to see Golem’s first autonomous steps.

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Retrotechtacular: Hacking Mother Nature’s North Temperate Regions

…because they’ll tickle your insides! Seriously, don’t eat them if you happen to parachute alone into wilderness and must survive without firearms or equipment like our protagonist here. This 1955 US Navy-produced gem of a training film will show you how to recognize, procure, and prepare many kinds of nutritious plant, insect, and animal life commonly found between 45° and 70° north latitude.

While you hone your large game hunting skills, you can tide yourself over with all kinds of things that will just sit there ready to be plucked for your nourishment: many berries and fruits, nuts, moss, lichens, and the inner bark of several kinds of trees is edible. Sate your taste for savory with grubs, termites, or grasshoppers. When in doubt, eat what the birds and small animals are eating, but stay away from mushrooms. It’s too hard to distinguish the poisonous varieties.

Many edible things are found in and around bodies of water. Game such as deer, ducks, and birds are attracted to water and make their homes near it. Various kinds of traps made from twigs and vegetation will outwit rabbits and squirrels. You can fashion a bow and arrow in order to kill large quadrupeds like deer, elk, and ram. It’s best to aim for the head, neck, or just behind the shoulders as these are the most vulnerable areas.

Once you have killed a large animal, prepare it for cooking by draining its blood and removing its entrails. There are many ways to cook your spoils of survival, and most of them involve cutting the meat into small pieces first. Hopefully, you have some basic tools for starting fires.

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US Government Screws Up Terrorist Watchlist, Few Surprised


It looks like [Dave Jones] got himself on a US government watch list. We don’t mean [Dave L. Jones], awesomesauce electronic wizard and host of eevblog, though. Some three-letter agency is just looking at someone named [David Jones]. Is this going to screw over our Aussie friend? You betcha.

[Dave] bought a few things through Element 14 that he would later pick up at their Sydney warehouse. When he got there, he discovered the parts were ‘on hold’. Out of curiosity, he asked what the holdup was and discovered his name was flagged on a US government watch list.

If you’re keeping score, this is an Australian citizen buying stuff from an Australian subsidiary of a UK company, and being told ‘no’ by the US government.

The folks behind the counter at the Element 14 warehouse were extremely helpful, clearing the hold and getting [Dave]‘s parts in just a few minutes. This has, apparently, been going on for a while; [Dave] recalled a few times when orders showed up a few days late with the Farnell/Element 14 people apologizing with the word ‘hold’ in there somewhere.

Of course this means it’s possible for someone working at the Element 14 warehouse to clear one of these US government holds, and even if they don’t the order will still go through in a day or two. Government efficiency at its best.

At the time of this writing, [David Bowie], the singer for The Monkees, the creator of Grand Theft Auto, and the British author famous for perpetual motion machines were unavailable for comment. -ed.