Heart-shaped Heart Simulator

July 27, 2013 by 12 Comments

Heart

A few years ago, [Addie] over at Tymkrs put together a spooky little Halloween project: a small Propeller board that emulates the electrical signals in a heart. As a cardiac nurse, she thought her project could use a little improvement, and after two years she’s finally done. It’s a heart-shaped board that simulates electrical signals moving through the heart.

There are several key areas that conduct electrical signals through the heart – the sinoatrial node, atrioventricular node, and bundle branches all work like players in an orchestra to keep a heart beating like it should. If something goes wrong with one of these, the heart goes into tachycardia or fibrillation – not good, by any measure. [Addie]’s board simulates all the different ways a heart can go wrong with LEDs standing in for the electrical signals in a real heart. The name of the game here is to look at the LEDs and tell what state the heart is in.

The PCB heart is just one part of [Addie]’s heart simulator. The simulated heart can also plug into a neat little heart-shaped project box wired up with a solenoid, LCD display, headphone jack, and other electronics to turn this electronic heart into a complete study tool for heart rhythms. The nurses in [Addie]’s unit love the thing, and it looks like [Addie] might have a real cardiac training tool on here hands here.

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10-drive Microserver Is The Clown Car Of The Computer Case World

July 27, 2013 by 55 Comments

ten-drive-itx-clown-car

[Coke Effekt] wanted to push his server’s storage limits to a higher level by combining ten 3 TB drives. But he’s not interested in transitioning to a larger case in order to facilitate the extra hardware. It only took a bit of hacking to fit all the storage in a mini-ITX case.

His first step was to make a digital model of his custom drive mount. This uses two 3D printed cages which will each hold five drives mounted vertically. To keep things cool the two cages are bolted to a 140mm fan. The connections to the motherboard also present some issues. He uses a two-port SATA card which plays nicely with port multipliers. Those multiplier boards can be seen on the bottom of the image above. The boards are mounted using another 3D printed bracket. Each breaks out one of the SATA ports into five connections for the drives.

[Thanks Pat]

Retrotechtacular: A Tour Of WLW, A 500,000 Watt Radio Transmitter

July 26, 2013 by 61 Comments

retrotechtacular-wlw-transmitter-tour

This is an overview of a 500,000 Watt radio transmitter site. It’s one of the slides shared in a guided video tour of the transmitter’s hardware. The radio station — whose call sign was WLW — called itself the Nation’s Station because of its ability to reach so much of the country.

It operated at the 500 kW level starting back in the 1930’s. The technology at the time meant that there were a lot of challenges involved with transmitting at this level of power. It took 750 kW input to achieve the 500 kW output. To reach that the station had a set of AC motors in the basement generating the 4500 Amps at 33 Volts DC needed to power the transmitter to heat each filament. Obviously there was a lot of heat generated at the same time. The system was water-cooled. An elaborate network of Pyrex pipes carried distilled water to and from the tubes to handle the heat dissipation.

The video tour lasts about thirty minutes. It’s just packed with interesting tidbits from the experts leading the tour so add it to your watch list for some geeky entertainment over the weekend.

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CNC Router Built With 80/20 Rail

July 26, 2013 by 32 Comments

There’s still quite a bit of machining that goes into a CNC mill build of this size. But using 80/20 brand extruded rail optimizes most of the build process into tasks manageable by the average basement hacker. That’s not to say that we think [Jim] is average. He took this mill from start to finish in just two weeks.

He picked up the set of three ball screws on eBay for $180. Two of them drive the X axis with the third moving the cutter assembly along the Y axis. The X axis travels along a set of precision rails instead of precision rods. He machined his own mounting plates to which those are attached. For now he’s not running the motors at full speed because the vibration starts to make the table shake. He may end up bolting the base to the floor once all is said and done.

We see this extruded rail used all over the place. We could highlight some other mill builds or 3d printers, but instead we think you’ll enjoy an extruded rail robotic bass guitar.

Oh, one last thing. We’re not against a bit of pandering. Below you can see the mill cutting out the Hackaday logo:

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Building An Internal Combustion Engine From Hardware Store Parts

July 26, 2013 by 69 Comments

[MacGyver] [Lou Wozniak] is on a mission to build an internal combustion engine using only hardware store parts. What you see above is his third attempt at it. Depending on your hardware store this may have ventured outside of what they sell because [Lou] switched over to using gasoline. But the first two attempts were powered by a propane torch fuel canister.

Unfortunately it still isn’t running. But the demo below makes us think that he’s really close. Timing is always touchy and that seems to be what is causing the problems. He makes use of a lot of plumbing fixtures. At the right you can see the parts (including a peanut butter jar) which make his carburetor with a valve pointing straight up as the choke. The fuel and air mixture moves down through the pipe to the cylinder and valve assembly where it is ignited by the black grill igniter module. His custom cut plywood gear moves with the fly-wheel. It triggers his improvised spark plug by using a bit of wire to pull on the leaf switch.

We feel like he’s so close to getting this up and running. If you have any advice on where he might be going wrong [Lou] welcomes your input.

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Geometry Class Just Got Augmented

July 26, 2013 by 26 Comments

ruler

Just about every engineer needs to take a drawing class, but until now we surprisingly haven’t seen electronics thrown into rulers, t-squares, and lead holders. [Anirudh] decided to change that with Glassified. It’s a transparent display embedded in a ruler that is able to capture hand drawn lines. These physical lines can be interacted with or measured, turning a ruler into a bridge between a paper drawing and a digital environment.

For the display, [Anirudh] mounted a transparent TOLED display with a digitizer input into a ruler. The digitizer captures the pen strokes underneath the ruler, and is able to interact with the physical lines, either to calculate the length and angle of lines, or just to bounce a digital ball inside a hand-drawn polygon.

There’s no word on how this display is being driven, or what kind of code is running on it. [Anirudh] said he will have some schematics and code available up on his website soon (it’s a 404 right now).

Defcon Presenters Preview Hack That Takes Prius Out Of Driver’s Control

July 26, 2013 by 66 Comments

hacking-control-of-a-prius

This one’s a treasure trove of CAN bus hacks that will scare the crap out of an unsuspecting driver — or worse. [Charlie Miller] and [Chris Valasek] are getting ready to present their findings, which were underwritten by DARPA, at this year’s Defcon. They gave a Forbes reporter a turn in the driver’s seat in order to show off.

You’ve got to see the video on this one. We haven’t had this much fun looking at potentially deadly car hacking since Waterloo Labs decided to go surfing on an Olds. The hacks shown off start as seemingly innocent data tweaks, like misrepresenting your fuel level or displaying 199 mph on the speedometer while the car is standing still. But things start to get interesting when they take that speed readout from 199 down to zero instantly, which has the effect of telling the car you’ve been in a crash (don’t worry, the airbags don’t fire). Other devilish tricks include yanking the steering wheel to one side by issuing a command telling the car to park itself when driving down the road. Worst of all is the ability to disable the brakes while the vehicle is in motion. Oh the pedal still moves, but the brake calipers don’t respond.

The purpose of the work is to highlight areas where auto manufacturers need to tighten up security. It certainly gives us an idea of what we’ll see in the next Bond film.

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