Hack a Day

Hydrogen peroxide – the same stuff you can pick up from a drug store or beauty supply store – is one of those very interesting chemicals that belongs on every maker’s cabinet. At concentrations of about 30%, it’s perfect for etching PCB boards, and at even higher concentrations – about 70% – it can be used as rocket fuel. Unfortunately for the home hacker, it’s very difficult and expensive to obtain peroxide in concentrations above 3% or so. That’s alright with [Charlie], though, because he’s come up with a way to concentrate peroxide and measure the concentration once he’s done.

There are a few YouTube videos of kitchen chemists concentrating peroxide by heating it on a stove to just under 100°C. Because hydrogen peroxide boils at 150°C, they’re simply boiling off the water and increasing the concentration of peroxide. This is a qualitative method, and you’ll never know what concentration you’re getting. [Charlie] rigged up a small-scale with a pipette to measure the weight of his concentrated peroxide per unit of volume, giving him the density of his concoction and thus the concentration.

We have to note that concentrated peroxide is dangerous stuff, but the results of [Charlie]‘s lab work aren’t much more dangerous than what hair stylists work with every day. If you’re going for high-test peroxide, good job, that’s awesome, but do be aware of the risks.

Home automation has existed in one form or another for quite some time, but we thought this take on controlling lights was quite interesting.  Instead of having a menu of lights that you can turn on and off, this Android app lets you point your phone at the device and turn it on or of. Undoubtedly similar to how [Darth Vader] controls his lights at home.

Although the really technical details of this project aren’t listed, this setup reads the compass and GPS output of the Android device to figure out where it’s pointed in space. Combined with a script that understands the layout of the room, and an [X10] automation controller, it’s able to control lights accurately.

Be sure to check out the video of this device in action, or check out [Mike]‘s [Project Rita] blog to see the other interesting projects that he’s working on!

Sometimes you need a power supply that can be thrown into the back of a car and taken into the field. [BadWolf] didn’t want to take his bench supply, so he whipped up this very portable power supply made from a computer PSU. To ruggedize his build a little, he put it in a 50 caliber ammo can making it more than able to handle the roughest field work.

While not a proper adjustable power supply, this ammo can is more than capable of delivering a whole lot of current in a number of different voltages. There are a few bells and whistles – a ‘plugged in’ and ‘on’ light, as well as a few very cool looking toggle switches that are sure to arouse the suspicions of unsuspecting bystanders.

[BadWolf] kept all the safety features built-in to the computer PSU, so this ammo box power supply is still protected from short circuits, and over-current, making it much safer than its appearance belies. It’s also a great example of what can be done if you don’t have a proper bench supply, so we’ve got to tip our hat to [BadWolf] for that.

By now you might have a bit weary of your small and inexpensive TV tuner dongle software defined radio. Yes, using a USB TV dongle is a great introduction to SDR, but it has limited bandwidth, limited frequency range, and can’t transmit. Enter the bladeRF, the SDR that makes up for all the shortcomings of a USB dongle, and also serves as a great wireless development platform.

The bladeRF is able to receive and transmit on any frequency between 300 MHz and 3.8 GHz. This, along with a powerful FPGA, ARM CPU, and very good ADCs and DACs makes it possible to build your own software defined WiFi adapter, Bluetooth module, ZigBee radio, GPS receiver, or GSM and 4G LTE modem.

It’s an impressive bit of kit, but it doesn’t exactly come cheap; the bladeRF is available on the Kickstarter for $400. The folks behind the bladeRF seem to be doing things right, though, and are using their Kickstarter windfall for all the right things like a USB vendor ID.

There’s a video of two bladeRFs being used as a full duplex modem. You can check that out after the break.

[Heinrich Laue] was kind of a latecomer to the fake guitar playing video game phenomenon. He played Frets on Fire — an open source clone of the game — on PC and eventually bought a copy of Guitar Hero World Tour. But playing on the keyboard was a drag. Instead of buying a controller he built his own hacked Guitar Hero controller from a scrapped keyboard and a toy guitar.

The plastic toy he started with was screwed together. This is a really nice since it’s almost impossible to open toys that have been welded together. There was plenty of room inside for all his components and even some space to run the wires.

He started the electronic portion of the build by tracing out the keyboard matrix to figure out which solder pads he could tap into. The strum bar uses a door hinge with buttons on either side of it. When you move it back and forth it hits the buttons, with the spring mechanism in each returning it back to center. The fret buttons are keys from the keyboard, but the switches uses were pulled from a few computer mice. But the real innovation comes into play when he added the Star Power tilt sensor and whammy bar. Follow the link above to find out how he did it.

Here’s a Raspberry Pi hack that adds web control using PHP and MySQL. As you can see in the image, it serves up a webpage (using the Apache2 server) which allows you to change the state of the GPIO pins. It’s not super-complicated, but it is nice to see a step-by-step guide for installing and configuring the package.

Web interface GPIO control is one of the features we loved about the Adafruit Web IDE. But this offering is loaded completely from the RPi (the Adafruit package uses cloud based code) and utilizes the tools most Linux network admins will be used to. A MySQL database manages the connection between GUI commands and GPIO modification. The webpage is served up by a PHP script which takes care of polling and changing database values. Configuration requires a new database, plus the username and password which has access to it.

This glove controller let you play a musical game. The challenge is to perform the correct wrist motions at the right tempo to play the intro to the song Where is my Mind by the Pixies. This is demonstrated in the video clip after the break.

We often see flex sensors used on the fingers of glove projects, but this one does it all with an accelerometer. That module, along with the Piezo buzzer used for playback are affixed to the small breadboard on the back side of his hand. Rubber bands connect the Arduino to his third and forth fingers. The tempo and rhythm are pre-programmed but the tone generated is based on the gravity reading at the start of each note. If you don’t have your hand positioned correctly the wrong tone will be played.

The code was published in link at the top. It would be fun to see this altered as a hacked Simon Says game.

These geeky Superbowl decorations glow thanks to the EL panel hack which [Becky Stern] created. It’s almost impossible to make out in this image, but the EL panels have been applied to the surface of the helmet. On the San Francisco helmet you can just make out the black connector and cord at the bottom of the F.

El panels are a lot like EL wire (but they’re flat) in that the phosphors are excited when connected to a high voltage AC supply. You can cut the panels into shapes without a problem. The technique used here is to create a black vinyl mask to go over the top of the panel. This makes cutting the panel a lot easier.

The mask sticker is made on a vinyl cutter. [Becky] is a master at using the vector tool as you can see in the video after the break. She outlined each team logo with paths to create a file which the cutter can use. From there it took several tries to get the sticker just right as the curve of the helmet distorts the logos just a bit. Once it was dialed in she stuck the vinyl on the El panel and cut around the perimeter.

The Adafruit team sure loves to use electroluminescent accents.

This hack could be titled ‘Exercise or Starve’. [Charalampos] needed some motivation to become more active. There’s a device called a FitBit tracker (black and blue on the left) which records your activity and submits it to a web interface. You get daily goals and can earn badges. But those stinking badges didn’t motivate him. He decided he needed something that would really get him off of the couch. So he hacked the FitBit to cut power to his refrigerator. Not meeting his goals will eventually result in a stinky mess and no dinner.

It’s a bad idea to cut power to the icebox. But we see this merely as a proof of concept. He’s using the Belkin WeMo networked outlet. Other than some security issues we discussed on Thursday this is a very simple way to control devices from your server. [Charalampos'] implementation uses the FitBit API to check his activity and drives the outlet accordingly.

Here’s a demonstration which proves you don’t really need special tools to populate a surface mount PCB. We’ve seen this board before, it’s the glass PCB server which [Cnlohr] developed and demonstrated by connecting the real world to Minecraft. It’s a tiny board and we were happy to have the chance to see his method for populating the parts before reflow soldering.

In the video after the break [Cnlohr] starts by dispensing a glob of solder pasted from its storage container. He mentions that as long as you store the stuff in the refrigerator it’s rather easy to work with. Because most of his projects are single boards it’s not worth it to have a solder stencil produced. Instead he picks up a bit of the solder glob on the end of a toothpick and applies it to each pad.

This isn’t really as bad as it sounds. The fine pitch TQFP footprints can just be dragged with a bit of the paste. After this application — which took around seven minutes — he grabs some tweezers (not the vacuum type) and begins placing each component. If he missed some paste he’ll discover it in this step and add where necessary. The last step is a trip through his toaster oven.

[via Reddit]

Before beginning his day, [Richard] needs to decide whether he should ride his bike to work or take the London tube. All the information to make that decision is available on the Internet – the current weather report, and the status of the subway lines and stations he’d be taking. The problem, though, is all these pieces of information are spread out in multiple places. [Richard]‘s solution to this was to make a bicycle barometer that pulls data from these places and makes the decision to ride a bike or the tube for him.

[Richard]‘s barometer is built around a nanode and an old clock he found at a flea market. The nanode queries the UK’s weather bureau and the London underground’s line and station status. All the variables under consideration are weighted; if it’s snowing, the output is much more likely to decide on the tube than if there was a slight drizzle.

It’s a really cool build that certainly makes a great use of the publicly accessible APIs made available by the London underground. You can check out a video of the barometer after the break.

The Federal Trade Commission really doesn’t like robocalls and other telephone solicitors selling you vinyl siding or home security upgrades. The FTC is even offering $50,000 to anyone who can do away with these robocalling telemarketers, and [Alex] looks like he might just claim the prize. He developed The Banana Phone, a device that eliminates those pesky telemarketers.

The basic idea of the Banana Phone is requiring callers to enter a four-digit pass code (played via text to speech over a relevant song to prevent a bot from getting through) before connecting them to the main line. Once a caller has been verified as human, their number is added to a white list so they won’t have to listen to [Raffi] every time they call.

The Banana Phone uses off-the-shelf parts  including a Raspberry Pi and a phone/Ethernet adapter with the total build cost under $100. You can check out a demo of the Banana Phone in action after the break starting at about 2:25.

Startup accelerator Y Combinator and Upverter are joining forces to run a hardware hackathon. This event aims to encourage hardware hackers to get together and design new products in a twelve hour sprint. Startups including Pebble, Octopart, and Lockitron will also be participating.

It’s a free event, and the winning teams will get their design manufactured. Participants will retain the rights to their designs, get free professional Upverter accounts, and have the chance to chat with some of the Y Combinator partners. This makes it a great opportunity for people looking to create their own hardware startup.

The event takes place on February 23rd at the Y Combinator offices in Mountain View, CA. Registration is open until February 8th. If you’re in the Bay Area and do hardware, you should check this event out.