Monitoring the status of a unisex bathroom

Years ago, someone at [Chuck]’s job came up with the brilliant solution of an indicator to display if the unisex bathroom is currently vacant, a men’s bathroom, or a women’s bathroom. The old system worked well, but [Chuck] thought it would be a great idea to display the current status of the bathroom on the large TV in the office, saving his coworkers from getting up only to wait in line until the bathroom became vacant.

Like the previous paper sign, [Chuck]’s build has three statuses: a men’s room, a women’s room, and vacant with a manual dial that is turned whenever someone is entering or leaving. The new build vastly improves on the paper-based indicator by using a laser cut indicator on a rotary switch.

The electronics are dead simple; just an XBee and a Explorer USB board. Whenever the switch state is changed, the XBee sends a bit of data off to a mac mini and displays the status on the office TV. It may be funny to our immature sense of humor, but it’s still a very nice project.

Converting a manual camera lens to use motorized zoom and focus

[Guy] wrote in to share this motorized camera lens project he recently finished. He really loved the zoom lens, but since both zoom and focus are manually controlled, he sometimes had trouble getting both set to the right place in time to take the shot. With modern DSLR cameras which allow video capture, he also wants to have the option of a smooth zoom that is always in focus. The solution was to add motors to the rings and control them with a Wii classic controller.

This hack really shines when it comes to the add-on hardware. He has some beautifully made rings which wrap around the focus and zoom rings on the lens. They are then held in place by a timing belt. These belts have teeth which key into the gears on a pair of servo motors. From there it’s a snap to drive the motors with an Arduino, connecting to the Wii controller with a breakout connector. You can see [Guy] showing off the build in the clip after the break.

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Controlling Raspberry Pi expansion pins with a web interface

For the lucky few who have a Raspberry Pi board in their hands, you can now use the GPIO pins as a web interface (German, google translation). [Chris] is turning this magical board is turning a small device that can play 1080p video into something that can blink LEDs via the web.

The build started with an example of driving GPIO pins under Linux. [Chris] cobbled together a bit of PHP and Javascript on the Raspberry pi. Whenever he goes to the website hosted on the Pi, he’s greeted with the status and direction of a couple of expansion IO pins.

On a semi-related note, [Tony] is building a GPIO MIDI interface for his Pi. Yes, he could just get a USB to MIDI adapter and call it a day, but this is a far more professional looking solution to all the MIDI goodness the RasPi will deliver. If you’ve got any info on other RasPi breakout boards you’ve seen, send them in on the tip line.

Building a prosthetic leg from scratch

[Radek] from Poland sent in a neat video of a bionic prosthetic leg he made for one of his patients. Even though [Radek] says it’s a ‘prototype of a prototype,’ we’d have to agree with him that it’s a very neat build that could provide inexpensive motorized prosthetic legs to amputees in the future.

[Radek] has been working on his project for about two years now, after building the motor and electronics by hand. The leg is powered by 1.5 kilogram battery pack – no details on the chemistry of the batteries, but [Radek] says it will last 12 hours on one charge. There are also small vibration sensors in the leg for a bit of feedback, and a few switches so the knee joint can be operated by the stump.

If you’re wondering where [Radek] got the proper tools and materials to make a carbon fiber prosthesis, he works for Carbon Prosthetics where builds simple prosthetic devices. His bionic leg creation looks really cool, and he says the final product will be much less expensive than the very high-end bionic prosthetic legs.

[Radek] was kind enough to share some more videos and a few pictures of his robotic prosthetic leg; you can check those out after the break.

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Arduino Uno BIOS flasher

We’ve seen the Arduino used to flash BIOS chips several times now. But these hacks are almost always the result of a bad flash. This time around [GNUtoo] is interested in putting a tool in your hands which can be used to flash Coreboot to your motherboard. His offering uses the Arduino Uno, but there are several other hardware options covered as well.

The firmware makes use of the serprog-duino library which was crafted at writing to flash memory chips. On the computer side of things the flashrom package pushes the BIOS image to the Arduino. The nice thing is the flashrom is a common packge in Linux repositories so it’s probably just an apt-get away.

The process isn’t fast, taking about ten minutes to program a 1 Mb chip. But if you’re just interested in loading an open source BIOS alternative this is easy to set up.