Reusing An Old Pacemaker As A Flash Timer

pacemaker-flash-timer

Most people use pacemakers to, you know, keep their heart pumping at a steady rhythm. [David Prutchi] on the other hand has found a pretty novel use for some of the old pacemakers he has in his collection.

We really had no idea that pacemakers had uses outside the world of medicine, but [David] has taken advantage of their reliability in one of his favorite hobbies – high speed photography. In a darkened room, he set up an infrared barrier which feeds its signal to the atrium input of an old pacemaker. The signal is relayed through the ventricular output, which then fires his camera’s flash.

The pacemaker allows [David] to set an “AV” delay, which is the interval between when the atrium input receives an electrical impulse and when that signal is repeated from the ventricular output. This allows him to finely tune how much time elapses from when a drop of milk breaks the IR barrier to when his flash actuates.

We think this is a pretty cool way to reuse an old pacemaker, but check out the shots he has captured and judge for yourself.

Sound-reactive EL Wire Box Makes Gift Giving Awesome

sound-reactive-el-wire-display

[Jonathan Thomson] was ruminating on EL wire displays and decided that most he has seen are boring, static fixtures or installations that simply flash EL wire on and off at a fixed rate. He thought that EL wire has far more potential than that, and set off to build something more exciting. Using a graphic equalizer T-shirt, with which we’re sure you are familiar, he put together a slick, sound-reactive EL wire display.

He started off by removing the EL panel and inverter from the aforementioned T-shirt, separating the display into two pieces. He set aside the panel and focused on wiring up the inverter’s ribbon cable to a set of EL wire strands he picked up for the project. Once he had everything hooked up, he put a design together on a cardboard box, which he intended to use for wrapping Christmas presents. With the holiday behind him, [Jonathan] broke down his original display and constructed another to offer up some fun birthday wishes.

While the EL inverter was originally built to display sounds detected by an onboard mic, [Jonathan] added a 3.5” stereo jack to his so that he can feed audio directly into the display using an MP3 player.

Continue reading to see the EL display in action, and be sure to check out his writeup if you are looking to spice up your gift giving this year.

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Tool Box Light Dimmer Helps Out A Friend, Offers Up Design Tips

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[miceuz] has a friend that works as a theatre technician, and in the course of his job he often needs to jigger with various stage components while shows are in progress. As you can imagine, the lighting situation is far from ideal, so he asked [miceuz] to build him an adjustable lighting solution for his tool box.

The circuit itself is relatively straightforward, using an ATMega88 to provide the PWM required for dimming and color control. Input is taken from three different sources, a rotary encoder for color selection, a pot for brightness control, and a button to turn the light strip on and off.

[miceuz] says that while project came together pretty easily, it still presented some issues along the way which provide some useful design reminders for beginners (and some veterans) alike.

First and foremost: debounce, debounce, debounce. [miceuz] forgot this mantra and made a mad dash to add capacitors to his design after etching the PCB to ensure that his inputs were not bouncing all over the place. He also noted that one should always be sure to read the ADCL before the ADCH register when decoding ADC data. His final observation is that using thick traces is the best policy whenever possible – he ran into a lot of issues with traces detaching during assembly, which he had to rework with wire and solder.

In the end, his friend was happy with the result, and [miceuz] is a better hacker for having worked through his issues. What sorts of important/useful lessons have you learned through the course of your projects? Be sure to share them with us in the comments.

Automating The Shutdown Of APC UPS Devices

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[Ishan Karve] works in some bizarro world where the building management demands that all servers and Uninterruptible Power Supplies be shut down at the end of each evening. While inconceivable to most systems admins, he has no recourse but to comply. This means that his employees need to turn things off before they leave for the day, and since they often work up to 15 hours a day, waiting for Windows server to shut down seems like an eternity.

Being the good manager he is, [Ishan] decided to build a device that handles the clean shutdown of their servers and UPS for them. An Arduino board serves as the brains of the device, communicating with and issuing shutdown commands to the UPS over a serial port. The Arduino is also connected to the office network, enabling it to send ARP requests to the servers in order to determine when they have completely shut down for the day. In order to protect against an accidental shutdown due to network connectivity issues, [Ishan] added an RTC module to the mix so that the Arduino does not issue shutdown commands until at least 8 pm.

Instead of waiting around for Windows to do its thing, [Ishan’s] employees can take off once they start the server shutdown process, knowing that they are totally compliant with their landlord’s crazy requests.

Power Wheels Jeep Makes An Awesome R/C Car

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[Will] from RevoltLab wrote in to share part one of a cool project he is working on right now, a remote-controlled mobile rocket launcher. Before you run off and call the Department of Homeland Security, he says that the launcher will be used for personal hobby rockets, which are typically considered mostly harmless.

The first part of the build is mostly concerned with obtaining a Power Wheels car and tweaking it to be driven remotely. After stripping out most of the odds and ends out of a Barbie Jeep he found via Craigslist, he added a small hobby servo under the dashboard to actuate the pedal. A larger (and much more expensive) servo was attached to the Jeep’s steering bar, allowing [Will] to easily turn the wheels with the flick of a switch.

With the mechanical bits out of the way, he installed an R/C receiver and took to the streets lawn with his creation.

The car seems to handle pretty well, and although the price of the components quickly start to add up, we’d be more than happy to spend that kind of cash for an R/C car that size!

Continue reading to watch a short video of the Jeep in action, and be sure to check Revolt Labs’ site often to follow [Will’s] progress.

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Rainbow Machine Livens Up Any Photograph

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[Shameel Arafin, Sean McIntyre, and Reid Bingham] really dig rainbows. Going by the moniker the “RainBroz”, the trio built a portable display that can be used to add cool light painting effects to pictures.

The group brings their Rainbow Machine all over the place, including parties, gatherings, and random spots on the street. Anyone is welcome to have their picture taken with the Rainbow machine, and each subject is given a card with a URL on it, so that they can check out their picture whenever they please.

The display consists of addressable RGB LED strips and an Arduino from Adafruit, along with the associated support mechanisms for moving the LEDs. The real magic is carried out by the LPD8806 light painting library, also from Adafruit, which enables the RainBroz to create all sorts of images with little fuss.

As you can see in the video below, the Rainbow Machine seems to get a pretty warm reception from just about everyone, even people grabbed right off the street. It looks simple enough to build, so why not put one together for your next gathering?

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[Alex] Shows Us What Happens When Dance Dance Revolution Meets Simon

ddr-simon

[Alex] was digging through his closet and came upon an old PS2 game pad for Dance Dance Revolution. He hated the idea of throwing it out just slightly more than the idea of playing DDR again, so he decided to find a way to reuse it.

He was a big fan of the game Simon (aka Genius) as a kid and thought that the DDR pad would make a novel interface for the classic game. Using the PS2XLib by [Bill Porter], which allows an Arduino to easily communicate with a PS2 controller, [Alex] put his Simon replica together in no time flat.

He painted an empty ice cream container with the classic Simon colors, installing a small LED under each quadrant, then wrote the game’s code.

As you can see in the video below, his version of the game works nicely, and forces you to actually get up and move a bit, which we like.

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