Why spend time etching circuit boards and applying solder masks when all you really need is a rollerball pen and some paper? That’s what University of Illinois professors [Jennifer Lewis and Jennifer Bernhard] were asking when they set off to research the possibility of putting conductive ink into a standard rollerball pen. The product of their …
New conductive ink allows circuit prototyping with a pen and paper
Tweeting home alarm system
Instructables user [willnue] wanted to build a DIY Tweeting alarm system from the ground up, but reconsidered after taking a close look at the scope of such a project. He settled on using an off the shelf security system, taking care of the Twitter interface on his own. He bought a GE 45142 Wireless alarm …
DIY servo activated door lock with capacitive touch keypad
Since he was a kid [Giorgos Lazaridis] has always loved the idea of having an electronic door locking mechanism, and now that he has the means, he’s decided to construct one for securing the door to his apartment. He calls the project “simple and cheap”, though we’re not sure about the first part. Taking a …
Google Android ADK Bluetooth wireless communications
Once the Google ADK was announced, the team over at [ElectFreaks] jumped right in and started experimenting to see what they could do with the new Arduino/Android interface. While the ADK was great for allowing the two devices to interact over a USB connection, they felt that the system would be far better if it …
A doorbell loud enough to wake the dead
[Ed Nauman] runs a machine shop, which we imagine can be quite loud at times. Sick of never hearing the doorbell when he was busy working on things, he decided that the solution to his problem was a new doorbell…an incredibly loud doorbell. His Really Loud Doorbell (RLD for short) is actually a pretty simple …
Tesla coil bullet-time photography
One thing we can all probably agree on is that Tesla coils are one part high-voltage electricity and two parts pure awesome. [Rob Flickenger] thinks so too, and he built a pretty nice one in his workshop some time ago. He took a bunch of pictures showing off the coil’s capabilities, but he thought that …
Giant POV tube for light painting
When you really want your feelings known, we always say that bigger is better. [Gavin Smith, aka The Mechatronics Guy] must come from the same school of thought, because there’s absolutely no mistaking what he is trying to say with his latest project. Inspired by this WiFi signal painter we featured a while back, the …
Teensy AVRs used in penetration testing
While some people know that you should be wary of USB drives with unknown origins, the same care is rarely, if ever exercised with USB peripherals. The security firm Netragard recently used this to their advantage when performing a penetration test at a client’s facility. When the client ruled out the use of many common …
Tweeting bird feeder keeps a picture record of all visitors
If you weren’t aware, Adafruit Industries is sponsoring the “Make it Tweet” contest over at Instructables, and this Twitter-enabled bird feeder is [quasiben’s] entry into the competition. His bird feeder not only sends messages to Twitter, it also sends a picture of each bird to Twitpic. The feeder itself is a standard off the shelf …
Keep all eyes on your kegerator with this light up gauge cluster
A few years back [Evan] built a kegerator from a mini fridge and was quite happy with his new beer chiller. Like many of us do, he started thinking up ways in which he could improve the project as soon as it was completed. While it took a couple of years, he recently got around to …
