Battery Desulfator

July 5, 2009 by Eliot 30 Comments

mini-d

Hack a Day favorite [Mikey Sklar] is back with a new project. Mini-D is a battery desulfator. If a 12V lead-acid battery sits with a voltage below 12.3V, sulfur crystals will begin to form on the lead plates. This crystal growth increases the internal resistance and eventually makes the battery unusable. A battery desulfator sends high frequency pulses through the battery to create a resonance that will break up the crystals. On a 60lb automotive battery, it will take approximately three weeks to completely desulfate. You can find schematics plus a dozen lines of code for the ATmega169 on his site. Embedded below is a video where he explains the device and other techniques like load testing.

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Capacitive Discharge Spot Welder Update

July 5, 2009 by Eliot 22 Comments

welder

It seems one of our commenters took great umbrage with [PodeCoet] not documenting his capacitive discharge cutting properly. [PodeCoet] had been waiting till he got the full spot welder working before publishing, but he’s expedited the work after all our whining. Check out his full writeup of the device in its current state. It uses a 1Farad audio cap for storage. A dsPIC monitors all of the voltage sources and regulates charging. A nice touch is the tactile switch on the electrode.

Home Power Monitoring

July 5, 2009 by Eliot 25 Comments

powermonitor

Reader [john] finished up his home power monitor over the holiday weekend. It uses a pair of current transducers clamped onto the mains. These output 0-3V and are read by the Arduino’s ADC. The Arduino averages samples over a 20 second period, calculates power used, and uploads it using an Ethernet Shield. The shield can’t do DNS lookups, so he uses a WRT54G to negotiate with the remote webserver. He admits that the system could be more accurate; it can’t detect small loads like wall warts. He also says that money could be saved by talking serial to the router instead of over ethernet. Here are the current usage charts.

You can find many power monitor projects like this in out Home Hacks category.

Wireshark 1.2.0 Available

June 29, 2009 by Eliot 10 Comments

wireshark

Everyone’s favorite packet sniffer has a new stable release. Wireshark 1.2.0 has a slew of new features. They’ve included a 64-bit Windows installer and improved their OSX support. A number of new protocols are recognized and filter selection autocompletes. One of the more interesting additions is the combined GeoIP and OpenStreetMap lookups. We’re excited about this new release as Wireshark has proven an indispensable tool in the past for figure out exactly what was going on on our network.

[via Lifehacker]

OTTO, Beat Slicing Interface

June 29, 2009 by Eliot 12 Comments

otto

Create Digital Music has a great post on [Luca De Rosso]’s OTTO. Built as part of his masters’ thesis, it’s a unique tangible music interface. You load a sample into the software which displays it on the instrument surface. The user can then manipulate the sample using various hardware inputs while watching the LED representation. The device uses just one Arduino for the display and inputs. It works with Max/MSP and is designed to give the performer only the information they truly need. You can find more pictures of the device on Flickr and a picture of the guts on CDM. Embedded below is the ‘Getting Started’ video that shows it in use.

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IDisplay, Webcam Multitouch

June 26, 2009 by Eliot 32 Comments

[youtube http://www.youtube.com/watch?v=mlLY0zic7u0%5D

Embedded above is an interesting multitouch demo by [Lahiru]. The goal of the project was to find an easy way to retrofit current LCDs for multitouch. Instead of using infrared or capacitive recognition, it uses a standard webcam mounted overhead. To calibrate, you draw polygon around the desktop screen as the webcam sees it. The camera can identify the location of markers placed on the screen and their color. iDisplay can also recognize hands making the pinch motion and sends these as touch events via TUIO, so it works with existing touch software. It’s written in C++ using OpenCV for image processing with openFrameworks as the application framework.

[via NUI Group]

Bus Pirate Preorders Open

June 25, 2009 by Eliot 45 Comments

buspirate

Update, Saturday July 4th, 2009: All preorders are closed.

We’re excited to announce our partnership with the folks at Seeed Studio (home of the excellent Seeeduino) to put the Bus Pirate v2go into production! The preorder period ends July 3rd. The price is $30 including worldwide shipping. The board pictured above is a hand soldered prototype, but the ones sold by Seeed are completely factory assembled.

This is the first officially produced piece of Hack a Day hardware. Depending on its success, we’ll be able to put many future designs into production. Read more about the Bus Pirate in our latest How-to. Thank you for your support!

***Update, Monday June 29, 2009: Wow, your support has been overwhelming! Thank you! There have been more orders for the Bus Pirate than we ever imagined. As of this update, there’s a few (12) Bus Pirates left in the Seeed preorder. After that, we’ve exhausted the supply of PIC24FJ64GA002s available in Shenzhen. If you’ve already placed your order nothing changes, the manufacturing process has already begun and your Bus Pirate will ship ASAP.

After the first preorder is filled, Seeed will start a new preorder. The second preorder will be delayed until more PIC24FJ64GA002s are delivered, about 4 to 6 weeks. This order should ship about 6 to 8 weeks after July 3, 2009, but we’ll try our best to get it out sooner. Thank you again for your support!