Hackaday Links: Sunday, July 21st, 2013

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Adafruit tears down a set of brainwave cat ears. They’re made by Necomimi and use your brain waves to adjust a pair of plush cat ears on the headgear.

If your desktop computer is sitting on the floor you may have damaged USB dongles by hitting them with your knees. [Megacier] prevents this from happening again by building a flexible dongle link.

Can anyone help [Brian Benchoff] find a datasheet for this International Rectifier 92-O350 so he can fix up his old VT100 terminal?

Here’s a quick example of how to graph data from a Raspberry Pi on the sen.se cloud service.

Have some extra fun with your oscilloscope by displaying any image. This set of conversions starts with a picture and ends with an audio file that will draw it on the scope’s screen.

You’ve probably already heard that the Sikorsky Prize for human powered helicopter has been claimed. If you didn’t see any footage of the flight now’s your chance. [Thanks Adam]

Simple Looking Antique Internet Radio Has A Lot Under The Hood

rpi-internet-radioAt first glance you might not even notice that this 1934 radio has been altered. But close study of the tuning dial will tip you off that changes have been made. It still scrolls through stations just like the original. But it’s not a wheel with some numbers on it. The rotary motion is an effect produced by an LCD screen.

This is the second time we’ve seen one of [Florian Amrhein’s] Internet radio projects. The first used guts from a Laptop paired with an Arduino to pull everything together. This time he’s chosen to wield a Raspberry Pi board. It feeds a USB sound card for a bit better quality. A small amplifier board us used to power one large speaker behind the original grill of the radio.

Check out the demo video to see that radio dial in action. It’s delightful that he went to the trouble to emulate a rotating disc to keep with the theme of the project.

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The Most Advanced Microwave You’ll Ever Own

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Voice activation, one-touch cooking, web controls, cooking settings based on UPC… have you ever seen a microwave with all of these features? We sure haven’t. We thought it was nice that ours have a reheat button with three different settings. But holy crap, what if you could actually program your microwave to the exact settings of your choice? You can, if you let a Raspberry Pi do the cooking.

This hack run deep and results in a final product with a high WAF. Nathan started by taking apart his old microwave. He took pictures of the flexible sheets that make up the control button matrix in order to reverse engineer their design. This led him to etch his own circuit board to hook the inputs up to a Raspberry Pi board and take command of all the appliance’s other hardware. Because it also drives the seven segment display you’ll never see the wrong time on this appliance again. It’s set based on NTP.

We mentioned you can tweak settings for a specific food. The best way of doing this is shown in the demo video. The web interface is used to program the settings. Recalling them is as simple as using the barcode reader to scan the UPC. Amazing.

Now you can keep that old microwave working, rather than just scraping it for parts.

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Web Based Automation Courtesy Of Raspberry Pi

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This project is a great example of the Raspberry Pi’s ability to eclipse Arduino when it comes to interaction. [Fall Deaf] mentions that he used to use an Arduino board with an Ethernet shield to add extensible interactivity to his project. But this one, which is a home automation lamp project, uses a Raspberry Pi instead. The concepts end up being very similar. But the cost of the hardware is less and the coding work is arguably orders of magnitude easier.

Don’t get us wrong, the hardware is fundamentally different. When you move from Arduino to RPi you lose some I/O pins and the low level control of them isn’t quite as straight-forward. But you also don’t have to program the thing in C. The Linux kernel handles the low level control which means you can write your scripts using Python. Because Python is an interpreted language the testing and debugging is much faster — no need to flash new code, just run the script again.

This project used the RPi GPIO to drive a strip of LEDs which use the WS2801 protocol. The board includes a NIC which makes it a snap to use as a web server. The smart phone controls seen above are served up from the Pi using jQuery. Right now there’s a cord running out of the lamp. But there should be plenty of room to use a screw-in outlet adapter and to hide the RPi and its PSU inside.

The board still has enough juice to drive other automation features too, like acting as a web radio server.

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Bolstering Raspberry Pi HDMI With A Current Regulator

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We’ve never tried using an HDMI to VGA converter with Raspberry Pi. We heard they were expensive and have always just used HDMI out (although DVI would be just as easy). Apparently if you have a VGA converter that isn’t powered the RPi board may output unstable video due to lack of current from the connector. [Orlando Cosimo] shows how to fix the problem with a few inexpensive components.

Just this morning we saw a portable PSU using an LM317. This project uses the same part, but in a different way. [Orlando] uses three resistors in parallel to make the LM317 behave like a current regulator (as opposed to a voltage regulator) which will output about 550 milliamps. Input voltage is pulled directly from the 5V line of the microUSB port. The output is injected into the HDMI connector. This will boost the amount of juice available to the unpowered VGA converter, stabilizing the system.

There are a lot of other power hacks out there for the RPi. One of our favorites is pulling the stock linear regulator in favor of a switch mode regulator.

[via Dangerous Prototypes]

Hackaday Links: Sunday, June 30th, 2013

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The race is on to squeeze cycles out of an 8MHz AVR chip in order to better drive the WS2811 LED protocol.

[Asher] doesn’t want to buy charcoal aquarium filters if he can just build them himself. He filled a couple of plastic drink bottles with charcoal, cut slots in the sides, and hooked them up to his pump system. A gallery of his work is available after the break.

Is the best way to make microscopic sized batteries to 3d print them? Harvard researchers think so. [Thanks Jonathan and Itay]

The Ouya gaming console is now available for the general public. [Hunter Davis] reports that the Retrode works with Ouya out-of-the-box. If you don’t remember hearing about it, Retrode reads your original cartridge ROMs for use with emulators.

Making a cluster computer out of 300 Raspberry Pi boards sounds like a nightmare. Organization is the key to this project.

Hackaday alum [Jeremy Cook] is working on an animatronic cigar box. Here he’s demonstrating it’s ability to listen for voice commands.

A Kelvin clips is a type of crocodile clip that has the two jaws insulated from each other. [Kaushlesh] came up with a way to turn them into tweezer probes.

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RF Wireless Kernel Module For Raspberry Pi, BeagleBone And Others

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If you’ve done any wireless work with hobby electronics you probably recognize this part. The green PCB is an RFM12B wireless board. They come in a few different operating bandwidths, the 433 MHz is probably the most common. They’re super easy to interface with a small microcontroller but what about an embedded Linux board? That is the focus of this project, which builds a kernel driver for the RF module.

You can get your own RFM12B for a few bucks. They’re quite versatile when paired, but a lot of inexpensive wireless consumer goods operate on this band so the board can be used to send commands to wireless outlets, light fixtures, etc. [Georg] has been working with the BeagleBone, BeagleBone Black, and Raspberry Pi. His software package lets you build a kernel module to add an entry for the device into the /dev directory of a Linux system. So far the three boards listed are all that’s supported, but if you have five I/O pins available it should be a snap to tailor this to other hardware.

Wondering what else you can do with the setup? This will get the receiving end of a text-messaging doorbell up and running in no time.

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