Laptop Keyboard EL Panel Backlight


[nullpointr] wanted a backlit keyboard for his Asus Transformer Prime so that it would be a bit easier to use in low-light situations. He considered a few different options and ended up adding electroluminescent panels behind the keys.

Those paying close attention might wonder why we called this a laptop in the title. Well, it’s a tablet with a keyboard dock and that’s a mouthful. This actually really helps to simplify the modifications because the motherboard and other bits are all in the screen portion of the device. EL panels are also a nice choice because you can cut them to size and they still function. With a bit of case work, three panels were made to fit side-by-side.

The part that just isn’t going to make it in the original enclosure is the inverter that drives the panels. It’s the black box to the left. [nullpointr] added a USB-form-factor jack to the side of the case that allows the inverter to be disconnected quite easily. This way the Transformer Prime can still go with him on the road, it just won’t light up unless he also hauls around that add-on.

Way way back we saw someone do this with fiber optics and an LED. Unfortunately that project link seems to be dead so we figure it’s about time someone revisited the concept.

Tips and Tricks for the C Pre-processor

C Pre-processor

The C pre-processor can help you write more concise, easy to follow code. It can also let you create a tangled ball of macros and #defines. [s1axter] wrote up a guide on how to use the pre-processor and keep your sanity.

We’ve seen some neat hacks with the C pre-processor, such as a full adder implementation, but this focuses on more practical usages. First, [s1axter] explains what the pre-processor does with your code by writing simple macros. Next up is arguments, and usage of ‘##’ directive for metaprogramming. Finally, we get a good explanation of why you need to worry about scope when using macros, and how to safe code by using ‘do {} while()’ statements.

If you’re into embedded programming, this guide will help you understand some of the more complex pre-processor techniques out there. It’s helpful for making your code clearer, and abstracting away hardware dependencies in a few lines of code.

Making Use of the Trancend WiFi SD Card


[CNLohr] spends most of his time on the Internet, but sometimes real life drags him away from his keyboard. These “vacations”, as he calls them, don’t have a good Internet connection and forces him to rely on flaky cell phone connections that go up and down at the drop of a hat. Figuring this would be a great opportunity for some hardware hacking, [CNLohr] came up with an ‘Internet-o-mometer’ – a device powered by a Trancend WiFi SD card that uses an 8×8 LED display to show the current status of his phone’s Internet connection.

This build uses the Trancend WiFi SD card motherboard we’ve seen before. When the card boots, it tries to connect to his phone’s WiFi connection.  When it connects, a green smiley face is displayed on the LED matrix. When a whole lot of files are downloaded or, more specifically, the ping to is more than 4 seconds, a red frowny face indicates the Internet connection is down.

In other Trancend WiFi SD card news, a whole lot of people including [Dan Krause] (thanks for the tip) have been working on a complete replacement OS for these neat little cards. Right now the OS is in very rough shape, but there is a pre-built system available should anyone want to experiment. [CNLohr] is also working on a compact, double-sided version of his SD card motherboard and we’ll be happy to feature a link to his Tindie store when he sends that in.

Artificial Leg Comes with a Normal Gait!


Did you know over 50% of amputees take at least one fall per year due to limited prosthetic mobility? That compares to only about a third of all elderly people over the age of 65!

[Professor Mo Rastgaar] and his PhD student [Evandro Ficanha] set out to fix that problem, and they have come up with a microprocessor controlled prosthetic foot capable of well, to put it bluntly, walking normally.

Working with a scientist from the Mayo Clinic, the pair have created a prosthesis that uses sensors to actively adjust the ankle to create a normal stride. Commercially available prosthetics can do this as well, but can only adjust the foot in an up-down motion, which is fine — if you only plan on walking in a straight line. In addition to having an ankle that can also roll side-to-side and front-to-back based on sensor feedback, they have also moved the control mechanism up the leg using a cable-driven system, which lightens the foot making it easier to use.

We find the test apparatus almost as interesting as the prosthesis itself. The researchers had to come up with a way to measure the performance of the prosthesis when used to walk in an arc. The solution was the turn-table treadmill seen above.

If you have time, check out the video demonstration on the main article’s page which covers the leg and the treadmill build.

[via Reddit]

Fail of the Week: [Caleb's] Phosphorescent CD Player


When [Caleb Kraft] was in full production for Hackaday he pumped a pile of awesome videos. But not every project worked out. He’s been a fan of the Fail of the Week posts, and sent in his own recollection of a project gone wrong. Above you can see his phosphorescent CD player. He prototyped the project in May of last year but technical issues and looming deadlines meant it never saw the light of day. We’ll fill you in on his fail after the jump.

Editor’s note: We need more tips about your own failure! There are a handful of submissions left in our reserves, but to keep this topic as a weekly column we need help tracking down more failed projects. Please document your past failures and send us a link to the write-up. If you don’t have a blog to post it on you may do what [Caleb] has done and email us directly. Remember to include any images and links to video which you may have.

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Interactive Boozeshelf is its own Dance Party


[Jeremy] refused to settle on your typical alcohol storage options, and instead created the Boozeshelf. Like most furniture hacks, the Boozeshelf began as a basic IKEA product, which [Jeremy] modified by cutting strips of wood to serve as wine glass holders and affixing the front end of a wine rack at the base to store bottles.

In its standard operating mode the Boozeshelf lies dark and dormant. Approaching it triggers a cleverly recessed ultrasonic sensor that gently illuminates some LEDs, revealing the shelf’s contents. When you walk away, then lights fade out. An Arduino Mega running [Jeremy's] custom LEDFader library drives the RGB LED strips, which he wired with some power MOSFETS to handle current demands.

[Jeremy] didn’t stop there, however, adding an additional IR receiver that allows him to select from three different RGB LED color modes: simple crossfading, individual shelf colors (saved to the on-board EEPROM), or the festive favorite: “Dance Party Mode.” Stick around after the break to see [Jeremy] in full aficionado attire demonstrating his Boozeshelf in a couple of videos. Considering blackouts are a likely result of enjoying this hack, we recommend these LED ice cubes for your safety.

[Read more...]

SparkFun Ponders Women in STEM Fields


Tuesday was [Ada Lovelace] day and to recognize it SparkFun posted an article about women in their workforce and the STEM initiative. [Ada Lovelace] is credited with forging a path for women in mathematics and computing. The STEM acronym represents a movement to get more of America’s students into Science, Technology, Engineering, and Mathematics fields in order to keep up with the rest of the developed world. But part of the issue includes drastically increasing the interest of young women in these fields and their access to it. The thing is, I feel the same way about the community at Hackaday.

Obviously some of the biggest names in the hobby electronics and engineering enthusiast industry are women. The name that seems to top lists is always [Limor Fried] who you may know better as [Lady Ada]. She founded Adafruit industries. But there are couple of other notables that stick out in our minds. [Jeri Ellsworth] has been huge name around here forever. Just this week Hackaday was celebrating the Kickstarter for her latest project. [Becky Stern] has had a ton of awesome project featured, mostly in conjunction with her work at Adafruit but her knitting machine hack when she was with MAKE has always stuck out in our minds. And of course, there’s [Quinn Dunki] who has long been building her own 6502 computer from the ground up (Incidentally we’re running a Guest Rant from her at midday on Friday).

What I’m missing is the grass-roots hacks from women. I know they’re out there because I see them at monthly meetings at the local hackerspace. We featured [Caroline's] bathymetric book, and [Robin]‘s collaboration that produced solar powered supercap jewelry. Both are members of Sector67.

So I call for all Hackaday readers to make this a friendly environment for anyone who wants to participate. If you’re a female reader who has been lurking around rather than sending in links to your gnarly hacks please take the plunge and send us a tip! If your female friends have awesome projects, offer to help them document it for a feature. You may not have thought of it, but sharing your projects makes you a role model for young readers.

By trade I’m an orchestra musician — a field that was completely closed off to women until well into the last century. While gender equality hasn’t been reached in all orchestras, the Regional Orchestras I have and do play with, show equal representation of gender throughout. Let’s make the same thing happen with STEM!