MobilECG Goes Open Source

February 23, 2014 by 13 Comments

After a failed crowdfunding campaign, MobilECG has gone open source. MobilECG is a medical grade 12 lead electrocardiograph. A 12 lead system is quite a bit more complex than some of the ECG systems we have featured in the past.  [Péter], the founder and designer of the device attempted to fund it through an Indiegogo campaign. While MobilECG is relatively cheap, medical certifications are not. The campaign didn’t reach its goal of $230,000 USD. [Péter] tried again with a grass-roots donation round at his website. That round also fell short of [Péter’s] goal to keep working on the project. Rather than let his hard work go to waste, [Péter] has made the decision to release his hardware and software to the community. The hardware is licensed under CERN OHL v1.2. The software is released under the humorously named WTFPL.

While we’re not ECG experts, the basic hardware design appears to be sound. MobileECG is based around the Texas Instruments ADS1278 octal analog to digital converter. Two AVR microcontrollers are used, an ATTiny24, and an ATUC64. The analog design incorporates such niceties as lead off detection and defibrillator protection. It should be noted that there are some known bugs in the design, [Péter] mentions he can be contacted with questions. The software seems to be in an early state, and would require quite a bit of work to get it to a final design. While we do wish [Péter] had better luck with his campaign, we’re always glad to see designs released into the open source community.

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Workbench With Built-In Solder Fume Extractor

February 23, 2014 by 19 Comments

Solder

There’s nothing quite like getting an eye full of solder fumes, but when it comes to solder fume extraction, the most common solution take up a whole lot of work area. Here’s a very clever solder fume extractor that doesn’t get in the way, and can be perfectly positioned over the acrid brimstone of a soldering station.

The build consists of a cheap bathroom vent fan built into the back of the workbench feeding into a long PVC pipe that blows the exhaust to the floor a few feet away. The fan is controlled by a simple wall switch, but the intake is where this build really shines. It’s a series of hard, flexible plastic segments that allow the intake to be precisely oriented above the work piece, or wherever it’s most convienent to suck solder fumes from.

This solder fume extractor is just a part of a really amazing electronics workbench. A lot of thought went into this workspace, from threaded inserts in the work surface to mount a panavise to an amazingly thoughtful equipment rack for computers, monitors, and other assorted heavy equipment.

via Hacked Gadgets

Vintage DACs And A Raspberry Pi

February 23, 2014 by 25 Comments

DAC

Before the days of iPod docks in every conceivable piece of audio equipment, most devices were actually built very well. Most shelf top equipment usually came with well designed circuits using quality components, and late 90s CD players were no exception. [Mariosis] heard of some very nice DACs found in some of these units and decided to take one out for a spin. He’s using a Raspberry Pi to play audio with the DAC found in a late 90s Kenwood CD player.

After fortune favored a CD player with a dead drive on [Mariosis]’ workbench, he dug up the service manual and found some interesting chips – a PCM56 DAC, a little bit of logic, and an SM5807 oversampling chip that does all the conversion for the DAC.

This oversampling chip uses an I2S – not I2C – bus to carry the data from the CD to the DAC. There is, of course, an I2S driver for the Raspi, but the first attempts at playing audio didn’t result in anything. It turned out there was a problem with what the oversampler expected – the ‘standard’ I2S signal delays the data one tick behind the LRCLK signal.

There are two ways to fix this problem: programming a kernel driver, or building some custom logic to fix the problem. Obviously breaking out some flip-flops and NOR gates was the cooler option, giving [Mariosis] a great sounding stereo with a vintage DAC.

[Dino] Brings The Waterproof Fire

February 22, 2014 by 33 Comments

firestarter

For many of our parents, grandparents, and great grandparents, the things we consider hacking, making, and doing weren’t just for fun. They were important skills that could help one survive. This week [Dino] shows us something his dad taught him: waterproof fire starters. The trick is paraffin wax. [Dino] starts by melting down some wax in a pot. He then dips strips of newspaper in the liquid wax. Several strike anywhere matches also get the wax treatment, are then placed on the newspaper. The newspaper and matches are rolled up into a tight bundle, which is itself dipped in wax several times.

The resulting small bundle of waxed newspaper and matches is safe and easy to carry in pocket or backpack. It also becomes the perfect wet fire starter. The “newspaper shell” is torn off into strips of waxed paper, which burns slowly and allows the tinder and wood to catch. [Dino] demonstrates his pioneering skills by starting a fire at the end of the video. When the inevitable zombie apocalypse hits, we definitely want [Dino] at the Hackaday compound.

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Remote Controlled Lawn Mower Lets You Sit Back And Enjoy The Show

February 22, 2014 by 39 Comments

“Its hard to find people that actually WANT to mow their lawn.” A more true statement has never been made. [Kurt’s] project turns an old lawn mower into a remote control lawn mower.

The first step of this build is to replace the front drive wheels with mini-bike tires which have built-in gear tooth sprockets. The rear wheels were then replaced with large caster wheels. The 12-24V DC motors and gear boxes used come from National Power Chair. While we have seen more complicated RC lawn mowers before, this project is a great way to get started. All that [Kurt] wanted was to make lawn mowing more fun, we believe that he has succeeded. This thing is very mobile and can turn on a dime. Check out the demo video after the break.

What’s next? Add a GPS, a Raspberry Pi, and a few other odds and ends. Tie it together with some clever programming and you will have your own autonomous lawn mower. Have you already created a completely autonomous lawn mower? Let us know!
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Breadboardable WS2812 LEDs

February 22, 2014 by 21 Comments

LED

Hackaday sees a ton of projects featuring the WS2812 series of digitally controllable RGB LEDs, in the form of bare chips, RGB LED strips, or some form of Adafruit’s NeoPixels. All these WS2812 LED products have one thing in common – they’re chip LEDs, making some projects difficult to realize. Now there’s a new member of the WS2812 family – a through-hole LED version – that should be available through the usual sources sometime later this year.

The key difference between these and the usual WS2812 LEDs is the packaging; these are 8mm LEDs with pins for power, ground, data in, and data out. With the preexisting libraries, this 8mm LED should work just the same as any other WS2812 LED.

Aside from a through-hole package, these new LEDs are very diffuse and aren’t as blinding as the normal chip LEDs. If you want to pick up a few of these LEDs, they’re available here, 13 LEDs for $15. There’s a lot of potential here for RGB LED cubes, something we hope to see sooner rather than later.

DIY Ceiling Rack Keeps Your Bikes Out Of The Way

February 22, 2014 by 22 Comments

bikke lift

Need to optimize some space in your garage? Why not build a ceiling mounted winch-assisted bicycle rack!

[Mathieu] already has a rather spacious garage, but wanted to make it even more organized. He built the bicycle rack out of 1″ square aluminum tubing, and it’s all bolted together (no welding required!). The bikes sit in aluminum U-channels to be secured in place. The entire rack is hinged off of the back wall, and a pulley system using a little ATV winch raises and lowers the rack for easy access to the bikes.

It’s currently powered off a 12V motorcycle battery, which he plans to add a trickle charger to — that being said, it has lasted for more than 6 months and he still hasn’t had to recharge it! He threw together a little control circuit featuring two relays (up and down) and a 2 channel remote control. The motor is a little slow, but it does the job quite well. If he wanted to get it going a bit faster, he could probably double the voltage to allow for a quicker movement — since it’s only on for short periods of time it should be okay. Seeing hacks like this has us wondering just how many winch-driven extras you could build into a single abode.

Check out the following video of it in action!

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