When [Tom] got tired of the large size of his Microsoft Comfort Curve 2000 keyboard, he decided to hack a recently acquired Apple Adjustable Keyboard for use with Windows. After removing the ancient ADB based control board from the Apple keyboard, he was able to map the keys and transplant the Microsoft keyboard’s USB control board into the Apple keyboard. After soldering the control board into the keyboard with old IDE cables, all that was left was to add some diodes to prevent ghost key presses, and the keyboard hack was complete. [Tom] offers a spreadsheet of the results of his key mapping on his site, and while you’re there be sure to check out his other projects, like his DIY Proton Pack that he made for Halloween last year.
Every year [Len Bales] designs and builds a new clock. His 2006 clock runs on the classic Intel 8008 microprocessor. The design is definitely not for the faint of heart, but he includes all code, diagrams and a good description on his site. The project is an interesting look into the not-so-distant past of computing. While the function of the project is a clock, it is actually a fully programmable 8008 computer running at 500khz with 16k of memory space and 4io ports. [Len] also links a lot of useful 8008 resources for anyone wanting to tackle a project of their own.
Over at SpriteMods, [sprite_tm] realized that a microcontroller could be used as a boost converter to power itself. A boost converter steps up voltage from a battery by switching the output of a coil. First, it is tied to ground so a magnetic field can build up in the coil. It is then released as a higher voltage than the input. Normally dedicated chips do this at an incredibly high frequency, but the PWM signal from an AVR works well enough. This can be used in low-power situations where space is an issue.
Here is a classic project used to increase wireless signal strength. Cantennas focus using a waveguide very much like a magnifying glass focuses light. [Robert] made a Natural Light beer cantenna, pictured in the upper left. His approach used three beer cans, a paper towel holder, and a shower curtain rod. On the tipline, he noted a signal boost from 11Mbps to 54Mbps. This is certainly something we can hack together if our room lacks adequate signal. Read about parabolic and seeking versions after the break.
This tiny bot wants to go inside your body. That’s right, it was designed to travel through veins. The little bot has no on board propulsion system. It is controlled by a magnet outside the body. See those little spines? Those straighten out to keep the bot in place when it isn’t supposed to move. Creepy right? In all the articles we’ve seen on this bot, there aren’t any details about what actually is on board. They mention adding a camera in the near future, but why are they calling it a robot? Surely there’s something cool in that little body. This is a quite practical application of a project we covered recently. Commenters weren’t impressed with the external control system, likening it to the old vibrating football player game. Well, here’s where it could be usefull.
We would like you to meet PR2. Made by Willow Garage, PR2 is a platform for research into robotic programming. The bot itself is simple compared to some of the humanoid bots we see, but its behavior is quite complex. In the video above, you see PR2 completing milestone 2 of its development. This includes navigating an office with closed doors and plugging itself into a standard wall outlet for a charge. We’re especially fond of the “wiggle”. You can hear some of the developers talk more about PR2 and its completion of milestone 2 in the video after the break.
Giving us a chance to break out the TLAs, [Blair] sent in his latest hack where he embedded an RGB LED into his EeePC to display twitter, pidgin, and email notifications. It is based around the ATtiny45, and requires very few additional parts. He based the project on a foundation of work laid by [Dennis Schulze] on notifications and the work of [Dave Hillier] that used V-USB, a library for implementing USB on AVRs. The entire circuit was done freehand and crammed inside the netbook. He says that it is a lot easier to see notifications, even when the laptop is shut.
[Maarten] told us about a C64 USB keyboard that was modified to be used as a standard input device. An interesting aspect of the project is the use of V-USB (formerly known as AVR-USB). V-USB is a software only approach to slow speed USB HID. In essence this is a two fold mod, The C64 keyboard is patched to a PC, and an off the shelf AVR is software-hacked to bit bang the USB communications. The author notes an initial problem with multiple key presses that was later corrected in the application. For the other side of the spectrum, we had covered the C64 twittering client, and a commodore 64 laptop.
Ferrite beads (L1 in the photo) filter high frequency power supply noise by converting it into a tiny amount of heat. Power supply noise can cause various problems for many parts, especially in analog audio and display circuits.
Ferrite beads are simple, but choosing one can be confusing because they’re not commonly used by hobbyists. Most designs will still work if you omit the ferrite bead(s), but beads are so cheap there’s no reason to sacrifice the added reliability they provide. We describe how we pick ferrite beads for our projects after the break.
Here’s an interesting WiiMote based project. [Mans] is a tennis fan, though a bit out of practice. With the tennis season coming to a rather climactic end, he got excited and wanted to brush up on his skills. He found the toss part of his serve to be very sloppy. Being a hacker, the first thing he thought was that there must be some way of tracking and graphing his toss so that he could improve it in an intelligent and controlled manner. The WiiMote seemed a perfect fit for this. Only a small modification was necessary, an external button wired to the internal “-” button. This switch is active while he’s holding the ball, and inactive when the ball is released. In this manner, he can track and chart his toss to find out exactly where he needs improvement. He uses [Johnny Chung Lee]’s code, with a small but unspecified modification to write the accelerometer data to a text file.
As he points out, this could be very usefull for any repetitive movement. Whith accelerometers getting cheaper and cheaper, there’s nothing stopping you from using multiple ones either. Imagine a golf rig to analyze your swing, Maybe a boxing rig that measured your hip twist and arm extension, or possibly a yoyo glove to tell you if your flick needs some help. Great job [Mans].
[Chris] wrote in to tell us about this project he did while living in the dorms. He built a system to automate his dorm room door. It handles unlocking and opening/closing the door via iPhone, secret knock, and even the key. The lock/knob portion is handled by a servo while the opening/closing action is hydraulic. After living with it for a year, he says that it never gets old, but there were a few bugs. Apparently it would randomly open in the middle of the night sometimes. If you’re interested in doing something like this, but not damaging the door, maybe you should check out the RFID dorm door lock project.
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.
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.
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.
