Face tracking with an Android device

This Android device can recognize faces and move to keep them in frame. It’s a proof of concept that uses commonly available parts and software packages.

The original motivation for the project was [Dan O’s] inclination to give the OpenCV software a try. OpenCV is an Open Source Computer Vision package that takes on the brunt of the job when it comes to discerning meaning from images. To give the phone the power to move he designed and printed his own mounting brackets for the phone and a couple of hobby servos. An IOIO board connects to the Android device in order to control the motors. On the software side all [Dan] needed to do was write some code to interface the output of the OpenCV face tracking modules with the input of the IOIO. See the finished project demonstration after the jump.

This system can easily be implemented with other hardware, like this Arduino-based version we looked at earlier in the year.

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Mirage 2.0 Lights up the desert with 4,024 LEDs

Registering a mutant vehicle at the Burning Man Department of Mutant Vehicles (DMV) is rough. To be allowed to operate at night, wacky rolling creations have to have a certain degree of lighting presence. This keeps vehicles  from blending into the scenery. Unfortunately Mirage 1.0 was built specifically with this in mind,  using reflective surfaces to turn a van into a semi-invisible shiny slab. Not even EL wire, an illuminated dance floor, and spot lights could placate the DMV. The solution? Wrap the entire friggen vehicle in a netting of 4,000 LEDs! Take that officials!

Most of the hardware is Phillips display stuff, digital LED fixture controllers are used to interpret HDMI data and then pipe out color data to addressed chains. All this mapping and addressing means that the entire setup functions like a 168×24 pixel monitor.  Split chains of LEDs also happen to allow the crew to operate the doors and get in and out of the vehicle.

The underlying car was built on the same sort of principal that hid the wheels of  Skywalker’s landspeeder, only in this case the idea was to cover an entire car with mylar and mirror. An interesting side effect of this mirror wrapping is that a sheen of desert dust helps reflect the ambient LED light quite well, blurring pixel colors together. It sort of makes us wonder about picking up a bucket of Mylar for some of our spaced out displays.

The Mirage crew has plans for next year, and have videos of several ideas on the site (portions of the test videos are NSFW).  Check out the video of Mirage 2.0 in action after the jump! Thanks [erland]!

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Arduino parking lot attendant

Here’s an automatic parking gate for toy cars. There’s no need to press a button, the electronics detect the presence of a vehicle on either side of the gate, raising it after verifying that the lot is not already full. It’s the same idea as counting how many people enter a room in order to switch the lights but the hardware is just a bit different.

The system is controlled by a pair of sensors in the paper which serves as the parking lot. There are three sheets of heavy stock, the top and bottom both have aluminum foil on them, with the center layer  as a separator. There are holes cut in the separator where the hash marks are seen above. By adding a little pressure to the car when you drive it up to the gate this completes a circuit instructing the Arduino that there’s a vehicle in position.

You can see a demonstration, as well as the guts of the build, in two videos after the break.

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Singing pumpkins

This Halloween table will sing a sweet serenade to spook your guests. Each of the animatronic pumpkins were quite easy to build, but you may end up spending a bit more time choreographing the performance.

Inside each Jack-o-lantern you’ll find a custom Arduino compatible board called a Minion board. These include a wireless connection which lets the system sync with the computer playing the audio. The pumpkins are fake, which means that can be reused year after year (unlike our LED matrix inside a real pumpkin). The mouth is connected to a servo with a short piece of bent wire, allowing it to flap along with the words of a song. You can see a performance of the Ghostbusters theme in the clip after the break.

A custom GUI was written in C# to aid in the choreography. It handles the playback of the song, with a few buttons that can be used to record the light and mouth effects. This ‘recording’ is then used to drive the pumpkins during a performance.

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Repairing a junked signal generator

We must be walking past the wrong dumpsters because we certainly haven’t encountered equipment like this just waiting to be salvaged. [Shahriar] found an HP 8648C Synthesized Signal Generator while he was ‘dumpster diving’ and set out to fix the malfunctioning lab equipment. He posted a 1-hour video on the project, which you can find embedded after the break. The actual fix happens in the first half, the rest of the video is spent testing the resurrected device.

The back corner of the case has been dented, which may be the reason this has been thrown out. When it is first powered it emits an unpleasant screeching noise and the user interface doesn’t do anything. [Shahriar] says he recognizes the sound as a malfunctioning switch-mode power supply. Sure enough, when disconnected from the main board it still makes the noise. It turns out there’s a huge electrolytic capacitor the size of a stack of poker chips which has come loose from the PSU board. When it’s resoldered the device fires up as expected.

Now how are we going to find a digital capture oscilloscope that just needs to have its PSU reassembled?

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7400 project encrypts and decrypts data

[Nakul], [Nikilesh], and [Nischal] just finished posting about their entry in the 2012 Open 7400 Logic competition. It’s an encryption system based entirely on 7400 logic chips. The device operates on 8-bit binary numbers, which limits its real-world applications. But we bet they learned a lot during the development process.

The encryption algorithm is based on a the concept of cellular automaton. This is a something with which we’re already familiar having seen many Conway’s Game of Life projects around here. What we’re not familiar with is this particular wing of the concept called ‘Rule 30‘. It works well with this project because a complex pattern can be generated from simple beginnings.

After conceptualizing how the system might work the team spent some time transferring the implementation to the chips they had available. The end result is a quartet of chip-packed breadboards and a rat’s nets of wires, but the system is capable of both encrypting and decrypting data.

Controlling a robot with your mind

For [Ern]’s MEng group project, his group had to develop a robotics platform capable of achieving some end goal. Because innovation is a large part of the grade, [Ern] convinced his team members to work with a brain controlled interface and build a mind controlled robotics platform.

For wont of having an easy build, [Ern] and his team chose a Lynxmotion Tri-Track robot capable of moving around the classroom while receiving commands from a computer. The mind-control portion of the build comes from a NeuroSky MindWave Mobile, a cheap and fairly open EEG system that reads alpha, beta, and delta waves generated by a user’s brain and sends that data over to a computer for processing.

After a bit of testing that included an Arduino to move the robot forward if the MindWave’s ‘attention’ value was over 60%, [Ern] and his team looked for a way to implement multi-directional control.

In order to get the robot moving left, right, and backwards in addition to moving forwards, the team looked at the included ‘blink detection’ abilities of the MindWave to cycle through a few commands. This technique turned out to be far too sensitive – the blink detection of the MindWave is simply too good. To get around that problem, the team used the signal strength of the received EEG signals. The theory being when a user blinks their eyes, the EEG contacts will move slightly, degrading the signal received by the hardware.

The team finally got a reasonable mind-controlled robot up and working, as demonstrated in the video after the break. Check out how each blink allows [Ern] and his colleagues to cycle through driving modes. Pretty neat for controlling something with your mind.

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