If you have ever forgotten your computer password after a long weekend or maybe you can remember it but just can’t seem to type it correctly, [Thomas] has a project for you. It’s a physical key that locks and unlocks your PC.
So how does it work? The heart of the project is an Arduino Leonardo. You may recall that this board is a bit different from the preceding Arduinos as it can enumerate on a host computer as a Human Interface Device (HID), such as a keyboard or mouse. The Arduino sketch continually reads an input pin using an internal pull-up resistor to make it logic high with the key switch connecting the signal to ground. When the Arduino sees the pin change from high to low, it sends out a keyboard command consisting of the Windows Key and “L”, which is the keyboard shortcut for locking the computer.
When the physical key is turned again, the Arduino sees the pin change back to a high state and it again emulates a keyboard but this time enters your password. You do have to include your password in the Arduino sketch for this to work. In addition, there are two LED’s wired up to show if the computer is locked or not, but you’ll be able to tell pretty quick when trying to get back to work.
Continue reading “Physical Keys Not Just For Doors Anymore, Now Available For Windows”
Here’s a clever use of a webcam and some facial recognition software — They call it Happy ++ and it will DJ [Pharrell’s] Happy according to how much you’re smiling (or not at all!).
It’s another project to come out of MIT’s Media Lab for a spring event this year by [Rob, Dan & Javier]. The facial tracking software was re-used from an older project, the MIT Mood Meter, which was a clever installation that had several zones on campus tracking the apparent “happiness” of the students walking by.
To create the program they’ve split up the song Happy into its various components. Drums, vocals, band, and the full mix. As the webcam recognizes a smile, it records the intensity, which in turn turns up the vocals and band. If no smiling is present there is only a drum beat. Continue reading “Smile Meter Reacts to Your Expressions With Pharrell’s Happy”
At home, [Daniel] has an extremely powerful dual quad-core Xeon system with ECC RAM that he uses for heavy lifting tasks – compiling, CUDA processing, and actual computing. Of course the electric bill for running this box all the time would be crazy, so Wake on LAN it is. There’s only one problem: for some reason, the BIOS doesn’t have Wake on LAN. The solution, of course, was a microcontroller system that would listen for the magic WoL packet and turn the computer on when it was received. This project eventually turned into a great case mod with an integrated LCD that powers the computer up over Ethernet, shows the current running processes, CPU and memory usage, and is an excellent use of a TI dev board.
The dev board in question is a TI Sitara AM355x starter kit that runs Linux, has two Ethernet ports and a touch sensitive LCD, and more than enough power to handle something as simple as a system monitor. To power on his monster computer from the dev board, [Daniel] is using a LED on the board, an inverter, a ULN2003 driver chip, and a relay connected to the computer’s power button. It’s not exactly a masterpiece of craftsmanship, but the dev board looks good mounted in the case, and from the videos below, it’s a great way to get system information embedded right into a computer case.
Continue reading “Wake On LAN With A Dev Board”
[Evan] was perusing his local thrift store when he found a beautiful IBM Model M 122-key keyboard made in 1987.
“This is my keyboard, there are many like it, but this one is mine.”
~The Typist’s Creed
In [Evan’s] case, this might actually be the only one like it still in use today. An idea formed in his head. What if he took this ancient keyboard, gave it a USB driver, and customized the keys on a hardware level to do exactly what he wanted.
The first step was converting it to USB. He’s using a Teensy 2.0 mostly because it is super inexpensive, and its able to act as a USB HID device. In addition to wiring up the keyboard to the Teensy he’s also added foot pedals that connect via 1/8″ stereo plugs — these kind of act like extra mouse buttons, allowing him to scroll through galleries left to right, add page breaks, and other macros to increase efficiency.
Continue reading “Laser Etching Brings New Life To An IBM Keyboard”
[Frank] knows how important backups are for data security, but his old method of plugging a hard drive in to take manual backups every so often is not the most reliable or secure way of backing up data. He realized he was going to need a secure, automated solution. He didn’t need a full-sized computer with a ton of power; why waste electricity for something so simple? His solution was to use a Raspberry Pi as the backup computer.
The main problem he faced with the Pi was finding a way to make it rack mountable. [Frank] started with an empty 1U server case. He then had to bend a few metal plates in order to securely mount the backup drive into the case. A couple of small rubber pads help dampen any vibrations caused by the hard drive.
The computer power supply was able to put out the 12V needed for the hard disk, but not the 5V required to run the Pi. [Frank’s] solution was to use an LM2596 based switching supply to turn the 12V into 5V. He soldered the power supply wires directly to the Pi, thinking that a USB plug might vibrate loose over time. Mounting the Pi to the computer case should have been the trickiest part but [Frank] made it easy by simply gluing the Pi’s plastic case to the inside of the computer case. When all was said in done, the backup server pulls 29W under full load, 9W with the disk spinning, and only about 2W in an idle state.
On the software side of things, [Frank’s] backup box uses bash shell scripts to get the job done. The Pi connects to his main server via VPN and then the bash scripts use rsync to actually collect the files. The system not only saves backups every night, but also keeps week old backups just in case. If you are really paranoid about your backups, try hooking up a custom battery backup solution to your Pi. If a Pi just isn’t doing it for you, you can always try one of many other methods.
Power supplies are essential for at home tinkering and electronics hacking. Unfortunately, they’re really quite expensive, and a bit out of reach for most hobbyists. Computer ATX power supplies are a cheap alternative, although they usually tend to lack the features of real bench power supplies… unless you hack yours like [Mark Schoonover]!
When [Mark] set out on this project he wanted to use as many recycled components as possible, but still come up with an extremely functional bench top power supply. He snagged a 500W ATX power supply from one of his kid’s old desktop PC’s, grabbed some old wall-warts for individual current limited supplies (apparently ATX PSU’s don’t have 5V rails anymore?), and put it all into a nice big project box.
He’s even thrown in a voltage regulator with current metering and a nice set of 7-segment displays!
Continue reading “Not Your Typical ATX Power Supply Hack”
[Tasos] sent us this tip about the custom battlestation he’s been working on for his Internet café. (Greek; Translated). The desk started from humble enough beginnings: a simple frame from what appears to be MDF with cabinets to secure the PCs. The goal with this build was to provide an aesthetically pleasing and user-friendly construction. [Tasos] was dissatisfied with the limitations posed by off-the-shelf monitor mounts, so he fabricated his own, more adjustable alternatives, through which he ran the necessary cords.
[Tasos] gave each monitor stand a thorough sanding, priming and painting for a finished result that exudes metallic perfection, then he attached a large pushbutton for booting the computer and some LEDs to provide soft backlight. Under the hood, [Tasos] fitted the PCs’ innards into a custom enclosure of sorts. Though he’s yet to provide full details on this part of the construction, we suspect more images are forthcoming. You can find more details in his forum post.