Real Time Video Anonymizer

May 19, 2015 by 39 Comments

If you’re wondering, Cornell is just like every other university in one respect: the grad students are starving, and wherever there is free food, students circle like vultures. The engineering and CS departments have a mailing list alerting people to free food, but a more automated solution was desired. The first web cam ever was used to notify grad students if a coffee pot was full, but Cornell shot down this idea on the basis of privacy concerns.

It’s final project time for [Bruce Land]’s courses, and a project by [Ferian Chen] and [Sean Ogden] solved the privacy concerns of a webcam in a kitchen. It’s a real-time video anonymizer, that can also be used to livestream ransom demands if you’re so inclined.

There are actually two parts to this project. The first part pixellates faces and any other skin tone, just like you’d see on a true crime TV show. This part of the project was based on an FPGA-based face detection project. ‘Skin’ pixels are defined as having a difference between the red and green channels within a certain range. With the right lighting, it works very well.

You can identify someone with their voice, too, so [Ferian] and [Sean] also made efforts to disguise hungry student’s voices as well. This was done with a phase vocoder that changes the pitch of someone’s voice, but not the spectral characteristics. The result should have been an audio channel that can’t be pinned down to one person, but is still recognizable as speech. The audio processing didn’t work as intended, with noticeable artifacts in the output. There’s still some work to be done, and now that [Ferian] and [Sean] aren’t checking the kitchen every ten minutes, the might have the time to do it.

An Open Source, DIY Digitizer

May 19, 2015 by 29 Comments

When you look at the current methods of scanning 2D and 3D objects available today, you’re basically looking at an imaging process. Either you take a picture of a 2D object, or you grab a blob of point clouds with a 3D scanner and make a 3D object that way. It wasn’t always like this – real, hardware 3D digitizers were used all the way back in the 70s, and touch probes are standard equipment on high-end CNC machines.

[Nikolaj Møbius] needed a way to record points in physical space, and not wanting to deal with the problems of images, he made an open source DIY digitizer. It’s basically a laser cut arm with rotary encoders at each joint. By reading the rotary encoders with an Arduino, [Nikolaj] can digitize a few points on a workpiece – just enough to make a bracket, or find the critical dimensions of a part.

It’s a great tool for when you need a little more information than a set of calipers can provide, and a great example of some ancient tech made useful again.

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Hackaday Prize Entry: Density Altitude Gauge

May 18, 2015 by 16 Comments

Despite what extraordinarily overpowered quadcopters suggest, the air pressure of whatever a flying machine flys at is extremely important. Pressure is dependent on altitude and temperature, and there are hundreds of NTSB investigations that have concluded density altitude – pressure altitude corrected for nonstandard temperature variations – was the reason for a crash. Normally density altitude is computed through a slide rule or a flight computer, with the pilot entering in altitude and temperature, but somehow accidents still happen. For his entry to The Hackaday Prize, [Neil McNeight] is building an automated density altitude calculator to automate the process entirely.

Instead of having a pilot enter the altitude and temperature into a flight computer manually, [Neil]’s device grabs the current altitude from a GPS unit, and reads the temperature with a tiny sensor acquired from SparkFun. With just a little bit of math, this device will spit out the altitude an airplane or ‘copter thinks it’s at.

While the FAA won’t allow instruments that are cobbled together on a breadboard, this does have a few applications in the RC world. There are extremely high performance racing quadcopters out there now, and knowing how the craft will perform before flying it will save a few props.

The 2015 Hackaday Prize is sponsored by:

An Introduction To Valve’s Tracking Hardware

May 18, 2015 by 42 Comments

[Alan Yates] brought a demo of Valve’s new VR tech that’s the basis of the HTC Vive system to Maker Faire this year. It’s exceptionally clever, and compared to existing VR headsets it’s probably one of the best headtracking solutions out there.

With VR headsets, the problem isn’t putting two displays in front of the user’s eyes. The problem is determining where the user is looking quickly and accurately. IMUs and image processing techniques can be used with varying degrees of success, but to do it right, it needs to be really fast and really cheap.

[Alan] and [Valve]’s ‘Lighthouse’ tracking unit does this by placing a dozen or so IR photodiodes on the headset itself. On the tracking base station, IR lasers scan in the X and Y axes. By scanning these IR lasers across the VR headset, the angle of the headset to the base station can be computed in just a few cycles of a microcontroller. For a bunch of one cent photodiodes, absolute angles and the orientation to a base station can be determined very easily, something that has some pretty incredible applications for everything from VR to robotics.

Remember all of the position tracking hacks that came out as a result of the Nintendo Wii using IR beacons and a tracking camera? This seems like an evolutionary leap forward but in the same realm and can’t wait to see people hacking on this tech!

Tin Spider Is 13-foot Rideable Strandbeest

May 18, 2015 by 28 Comments

Arguably our best find at Bay Area Maker Faire this year was the Tin Spider built by [Scott Parenteau]. He constructed the 13-foot tall vehicle to take with him on his very first trip to Burning Man back in 2012. There’s very little information available online so we were excited that [Scott] spent some time speaking with us on Saturday.

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Vintage Microammeter Now Tells Temperature

May 18, 2015 by 10 Comments

[Craig] sent in this tip about a simple hack he built to convert an old analog micro-ammeter into a thermometer using a few parts. There’s a certain charm to retro analog meters, and there was enough space inside the old meter to accommodate the tiny breadboarded circuit and the three AA batteries to convert it into a cool looking centerpiece which is useful too!

He used the 3-pin MCP9700 analog temperature sensor connected to a LTC1541 – a combined comparator, op-amp and band gap reference voltage all rolled into one package. The thermometer displays 1uA per degree Celsius, has an output of 1mV per degree Celsius for external temperature monitoring / data logging, and draws just about 20uA. While the build itself is pretty simple, [Craig] took the time to walk through every design decision he made in the video after the break. This starts with the design for his circuit, and  moves on to the selection of parts and their values. The video is a must-watch for anyone wanting to learn more about precision op-amp based designs.

The three batteries will drain over time, and a circuit like this one requires a stable reference voltage. That is taken care by the bandgap reference voltage from the LTC1541. This eliminates the use of additional voltage regulators, and allows the circuit to work from 4.5V down to about 3.3V. Check the video after the break to listen to [Craig] describe how it works. We’re not sure how quickly it responds to changes in ambient temperature since the sensor is enclosed inside the meter, so maybe some vents at the back, or bringing out the sensor might be a good idea.

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Ask Hackaday: The Internet Of Things And The Coming Age Of Big Data

May 18, 2015 by 67 Comments

Samsung has thrown its hat into the Internet of Things ring with its ARTIK platform. Consisting of three boards, each possesses a capability proportional to their size. The smallest comes in at just 12x12mm, but still packs a dual core processor running at 250MHz on top of 5 MB flash with bluetooth.  The largest is 29x39mm and sports a 1.3GHz ARM, 18 gigs of memory and an array of connectivity. The ARTIK platform is advertised to be completely compatible with the Arduino platform.

Each of these little IoT boards is also equipped with Samsung’s Secure Element. Worthy of an article on its own, this crypto hardware appears to be built into the processor, and supports several standards. If you dig deep enough, you’ll find the preliminary datasheet (PDF) to each of these boards. It is this Secure Element thing that separates the ARTIK platform from the numerous other IoT devices that have crossed our memory banks, and brings forth an interesting question. With the age of the Internet of Things upon us, how do we manage all of that data while keeping it secure and private?

What is The Internet of Things?

These kind of terms get thrown around too much. It was just the other day I was watching television and heard someone talk about ‘hacking’ their dinner. Really? Wiki defines the IoT as –

“a network of physical objects or “things” embedded with electronics, software, sensors and connectivity to enable it to achieve greater value and service by exchanging data with the manufacturer, operator and/or other connected devices.”

Let’s paint a realistic picture of this. Imagine your toaster, shower head, car and TV were equipped with little IoT boards, each of which connects to your personal network. You walk downstairs, put the toast in the toaster, and turn on the TV to catch the morning traffic. A little window pops up and tells you the temperature outside, and asks if you want it to start your car and turn on the air conditioning. You select “yes”, but not before you get a text message saying your toast is ready. Meanwhile, your daughter is complaining the shower stopped working, making you remind her that you’ve programmed it to use only so much water per shower, and that there is a current clean water crisis in the country.

This is the future we all have to look forward to. A future that we will make. Why? Because we can. But this future with its technical advancements does not come without problems. We’ve already seen how malicious hackers can interfere with these IoT devices in not so friendly ways.

Is it possible for our neighbor’s teenage kid to hack into our shower head? Could she turn our toaster on when we’re not home? Or even start our car? Let’s take this even further – could the government monitor the amount of time you spend in the shower? The amount of energy your toaster uses? The amount of time you let your car idle?

Clearly, the coming age of the Internet of Things doesn’t look as nice when we lose the rose colored glasses. The question is how do we shape our future connected lives in a way that is secure and private? If closed source companies like Samsung get their IoT technology into our everyday household items, would you bet a pallet of Raspberry Pi’s that the government will mine them for data?

This, however, does not have to happen. This future is ours. We made it. We know how it works – down to the ones and zeros. There is no fate, except that which we make. Can we make the coming IoT revolution open source? Because if we can, our community will be able to help ensure safety and privacy and keep our personal data out of the government’s hands. If we cannot, and the closed source side of things wins, we’ll have no choice but to dig in and weed out the vulnerabilities the hard way. So keep your soldering irons sharp and your bus pirates calibrated. There’s a war brewing.