An Attempt To Replace Multiple RFID Cards With A Single Hacked-together Tag

January 21, 2013 by 31 Comments

It’s kind of a convoluted title, but [Hudson’s] attempt to replace multiple HID Prox cards with one AVR chip didn’t fully pan out. The project started when he wanted to reduce the number of RFID access cards he carries for work down to just one. The cards use the HID Proximity protocol which is just a bit different from the protocols used in most of the hobby RFID projects we see. He ended up taking an AVR assembly file that worked with a different protocol and edited it for his needs.

The device above is the complete replacement tag [Hudson] used. It’s just an AVR ATtiny85 and a coil made of enameled wire. The coil pics up current from the card reader’s magnetic field, and powers the chip through the leakage on the input pins (we’ve seen this trick a few times before). The idea he had was to store multiple codes on the device and send them all in a row. He was able to get the tag to work for just one code, but the particulars of the HID Prox reader make it difficult if not impossible to send multiple codes. The card must send the same code twice in a row, then be removed from the magnetic field before the reader will poll for another combination.

Video-based Radar For Your Car

July 9, 2012 by 28 Comments

[Gustaf] has been playing around with machine vision for a while and sent in his latest project in on our tip line. It’s a video based car radar system that can detect cars in a camera’s field of vision while cruising down the highway.

Like [Gustaf]’s previous experiments with machine vision where he got a computer to recognize and count yellow cylinders and green rectangles, the radar build uses ADABoost and the AForge AI/Machine Vision C# framework. [Gustef] used an evolutionary algorithm to detect the presence of a car in a video frame, first by selecting 150 images of cars from a pre-recorded video, and the another 1,850 images were selected by a computer and confirmed as a car by a human eye.

With 2000 images of cars in its database, [Gustaf]’s machine vision algorithm is able to detect a car in real-time as he drove down a beautiful Swedish highway. In addition to overlaying a rectangle underneath each car in a video frame and an awesome  Terminator-style HUD in the upper right corner, [Gustaf] also a distance display above the hood of his car.

It’s an awesome build that makes us wonder if [Gustef] is building an autonomous car. Even if he’s not, it really makes us want to install a video HUD in our whip, just to see this in action.

Burning Man 2011: Peter Hudson’s Charon Strobe Sculpture

September 16, 2011 by 20 Comments

Here at Hackaday the only thing we like better than giant whirling artistic desert based contraptions are interactive giant whirling artistic desert based contraptions. [Peter Hudston]’s Charon is no exception. Known for his strobe sculptures [Peter] has returned from a two year hiatus with possibly one of the craziest and nightmarish sculptures found on the deep playa. The work features a gigantic spinning wheel that has posed human skeletons mounted on it’s inner edge. Onlookers can pull a series of 6 rope pairs which cause the wheel to rotate rapidly. When the rope pullers are coordinated enough to get the wheel spinning at the right speed, a strobe is activated revealing the skeleton’s animation.

I wandered over to this thing one night after hearing the local buzz about the piece.  The towering wheel was spinning away as the rope pullers of the moment tried desperately to get the strobe to activate, every couple of minutes or so somebody would try and coordinate the pulling only to confuse things.  From my perspective it seemed to be very difficult to get the right speed, and the pullers had to yank the rope practically to the ground. During the short time I was watching the piece (jaw to the floor) the strobe activated once or twice and honestly it was completely worth the effort. To see what this monster looks like in action check out the video after the jump.

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HUD For Real Life Capture-the-flag

February 11, 2010 by 27 Comments

If you’ve played any of the Splinter Cell games you’ll remember the PDA that [Sam Fisher] carried around with him.  What if you could have one of your own when playing capture-the-flag? [Brad] has created the ZephyrEye as an electronic command and communications device for real-life games.

Each player carries around their own unit. The ZephyrEye has a GPS module, Xbee module, LCD screen, and control buttons. This allows a player to setup one of several different games, map out the game field including base locations and flag locations, and monitor a time limit and scoring. Other players can join the game in progress. The best part? The GPS modules report tracking to each handheld and act as radar for your team and the enemy team. We’ve got a couple of demo videos after the break.

Words can’t describe how delighted this would have made us back in the day. We don’t play outside with the other neighborhood kids anymore (insert dirty-old-man joke here) but that might change just because of this device. We may end up joining [Barney Stinson] for some amazingly awesome laser-tag games after all.

[Brad’s] posted hardware information and source code so that you can use to throw together a dozen or so units. We think the next version should incorporate a wearable display.

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Nightvision Car Heads Up Display

December 17, 2007 by 18 Comments


[alti] wants night vision for his car, so he picked up a nightmax night vision camera that has a built in LCD. The plan is to mount the display so that it will reflect off the windshield of his car to create a simple HUD. Unfortunately the image gets reflected from the inside and outside of the windshield. The discussion in the forum is getting pretty lengthy, but it’s an interesting project.

Celebrating Pi Day With A Ghostly Calculator

March 14, 2024 by No comments

For the last few years, [Cristiano Monteiro] has marked March 14th by building a device to calculate Pi. This year, he’s combined an RP2040 development board and a beam-splitting prism to create an otherworldly numerical display inspired by the classic Pepper’s Ghost illusion.

The build is straightforward thanks to the Cookie board from Melopero Electronics, which pairs the RP2040 with a 5×5 matrix of addressable RGB LEDs. Since [Cristiano] only needed 4×5 LED “pixels” to display the digits 0 through 9, this left him with an unused vertical column on the right side of the array. Looking to add a visually interesting progress indicator for when the RP2040 is really wracking its silicon brain for the next digit of Pi, he used it to show a red Larson scanner in honor of Battlestar Galactica.

With the MicroPython code written to calculate Pi and display each digit on the array, all it took to complete the illusion was the addition of a glass prism, held directly over the LED array thanks to a 3D-printed mounting plate. When the observer looks through the prism, they’ll see the reflection of the display seemingly floating in mid-air, superimposed over whatever’s behind the glass. It’s a bit like how the Heads Up Display (HUD) works on a fighter jet (or sufficiently fancy car).

Compared to his 2023 entry, which used common seven-segment LED displays to show off its fresh-baked digits of Pi, we think this new build definitely pulls ahead in terms of visual flair. However, if we had to pick just one of [Cristiano]’s devices to grace our desk, it would still have to be his portable GPS time server.

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The Cockpit Voice Recorder Controversy

January 31, 2024 by 74 Comments

Every time there’s a plane crash or other aviation safety incident, we often hear talk of the famous “black box”. Of course, anyone these days will tell you that they’re not black, but orange, for visibility’s sake. Plus, there’s often not one black box, but two! There’s a Flight Data Recorder (FDR), charged with recording aircraft telemetry, and a Cockpit Voice Recorder (CVR), designed to record what’s going on in the cabin.

It sounds straightforward enough, but the cockpit voice recorder has actually become the subject of some controversy in recent times. Let’s talk about the basics of these important safety devices, and why they’re the subject of some debate at the present time.

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