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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[Michael] has a keypad in his previous car’s door and he missed it enough to hack one into his Dodge Caliber. He bought a Ford keypad and mounted it inside his door with some custom electronics. He started with an Arduino nano to receive and authenticate button presses. This then splices into wires in the door that control the door lock. The program has a 5-digit code to unlock the door, but simply pressing 1 twice will lock the doors. He also implemented a lockout feature to prevent people from brute-forcing the combination. Although it isn’t wireless, it’s significantly simpler.

[thanks Michael]

The EVIC is a computer controlled internal combustion engine, utilizing a cam less solenoid actuated valve system. In addition to intake and exhaust valve control, the processor also handles ignition timing. With dynamic valve timing, it is possible to make an engine more efficient. Where a classic combustion engine would wastefully burn fuel, the EVIC can skip power cycles which are not needed. By increasing the valve duration, the CPU enables easy starting. The latest is the EVIC Mk3 which adds an exhaust valve sensor, and 3:1 solenoid leverage. There is a photo gallery with several EVIC engines. The Mk2 Twin is demonstrated in the video embedded below.

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[Hazard] wanted a full color POV display for his bike wheel. Adafruit’s SpokePOV is single color and Monkeylectric’s original version didn’t display images. He also balked at the cost and decided to manufacture his own version. It uses 16 RGB LEDs on a single layer board he manufactured himself. It’s an entirely through-hole design to make assembly easy. It uses a hall effect sensor to synchronize the image display. The two main components are an ATmega328p microcontroller, which should make it Arduino compatible, and a TLC5940 PWM LED driver. It’s a very well documented build and certainly a good looking effect.

[via adafruit]

[Bill2009] has made some nice progress on a control panel for his motorcycle over at the arduino.cc forums.  It can show speed, tachometer readings for the wheel and engine, as well as indicate the current gear. He reads the square wave coming off of his tachometer input and pulses from a reed switch mounted on the wheel to calculate all this. To top it all off he can monitor the data via a Bluetooth module attached to the board, which is much better than trying to balance a laptop on your knees while cruising down the highway.  He is working on getting the size down so that he can mount the whole assembly inside of his motorcycle. He also plans to add new software features like wind resistance calculations and0 to 60mph timing.

[Hazard] is designing this open source POV system for bikes. With the recent release of Monkey Electric’s m464q, [Hazard] was inspired. He found the price tag of roughly $2,000 to be way too much though. He is designing his own and taking us along for the trip. He hasn’t quite reached the Monkey Electric level of features, but he does have image display and simple animation. He encourages others to join him in improving the design. He notes that the image on the back side of the wheel is mirrored, so text would be backwards. Maybe he can pick some tips up from this old project.

[Soren Coughlin-Glaser] runs a mobile photobooth in the Portland area. It’s built inside of an electric Volkswagen bus. The conversion to electric hasn’t been easy though. He’s spent most of the last few months rebuilding it after an electrical fire. Last fall he installed a 9 inch electric motor from Hi-Torque Electric after his smaller one blew up. We really like this project and look forward to seeing it back on the road… once he replaces his stripped transmission coupler.

[via Boing Boing Gadgets]

After making a few units for the new Discovery t.v. show called Weaponizers, [Jeremy] decided to release this video showing how to modify a golf cart for radio control. The radio and controller are basic off the shelf R/C gear, running some linear actuators.
[thanks Divide]

[fibra] has been slowly building a custom controller for his motorcycle. It’s an automated chain oiling system that varies application based on RPM. The LCD can show wheel RPM, voltage, time, date, air, and engine temperature. A separate driver board has a MOSFET for controlling the oiling valve. The real gold here is the attention to detail. He built a one off circuit board. The case is laser cut acrylic that he then shaped. The box is molded smoothly into the original instrument cluster using epoxy. It’s excellent work that could be mistaken for a commercial product.

GM, in an effort to make their cars slightly more eco friendly, added a feature that puts your car in 4th gear when cruising along in 1st under certain conditions. This is apparently despised by many owners. I is despised so much, that you can buy a commercial product to disable it. That product costs between $20 and $40. Jalopnik has posted a simple solution to disable this feature for under $7 .  All you need is a replacement plug and a resistor. It’s really pretty simple.

[Avi Aisenberg] sent us his final project for ece 4760.  His team built and OBD-II data interface. Even though OBD-II is an industry standard, each manufacturer has implemented it differently. This is where this project shines. They have built it to be capable of talking to any of them. Not only that, but it has a nice backlit LCD screen for diagnosing issues without having to go back to your computer and downloading the data. If you really don’t need all the bells and whistles, you can make one for roughly $15. They even have an OBD-II app for the iPhone.

[Matthew] sent us his group’s final project, where they built a nice GPS logging system. Not only can it simply log the GPS coordinates on a predetermined interval, it can also be triggered to make an entry by a wireless device. In this example, they use a camera. This allows them to then upload all the GPS information and pictures to places like Google Earth.

They are using an ATmega644, with an LCD, SD card, and GPS unit. They had to do a little hacking on their camera to add the wireless transmitter, which triggers the logger. You can see not only the cost break down and source code for the project, but also a map with lots of geotagged photos. This is the kind of thing we can almost see as a standard item in the future.

We posted a story about someone doing some APRS tracking recently. This is old news to some, but new fresh stuff for others. If you want to build your own tracker, here’s a great writeup on one.  The WhereAVR is low cost, low power and has plenty of I/O.  With all of the schematics and PCB files available on his site, you should be able to get one working in quickly. He does need a little help building a nice simple configuration tool to work in windows, anyone want to volunteer?

We really wish we had a little more information on the construction of this, but [Jeff] made this APRS tracker several years ago. APRS, or Automatic Packet Reporting System is a system where shortwave radios put out small packets of data that are uploaded to a database available via the web. This specific one is relaying GPS data so his family can see where they are located. With current phones, you might think this is antiquated, but he notes that he took this through New Mexico and was able to transmit his position even when there was zero cell phone coverage.