Hackaday Links: December 6, 2015

[Camus] had it all wrong. After a few hundred years of rolling a stone up a mountain, Sisyphus would do what all humans would do: become engrossed in novelty. The stone would never reach the summit, but it could roll off some pretty sweet ramps. That mountain goat that ticked him off a few decades ago? If Sisyphus let go right now, the stone would probably take that goat out. Sisyphus, like all of us, would be consumed in meaningless novelty. One must imagine Sisyphus happy.

The pumpkin spice must flow. It’s the holidays and for a lot of us that means copious amounts of baked goods. How about an edible sandworm? It looks like something close to a cinnamon roll.

This December’s Marie Claire – whatever that is, I have no idea – features haute circuits. These circuit boards are the work of [Saar Drimer] and Boldport, makers of fine circuit board art. We’ve seen his work a number of times featuring squiggly traces and backlit panels. This seems to be the first time Boldport and the entire idea of PCB art has infiltrated the design world. He also does puzzles.

Raspberry Pi cases simply do not look cool. There’s ports coming out everywhere, and plastic really doesn’t look that great. You know what does look great? Walnut. [Karl] made a few of these out of walnut, MDF and solid aluminum. He’s thinking he might bring this to market, you can check out his webzone here.

Self-driving cars being sold right now! That’s an eBay link for a DARPA Grand Challenge vehicle, a heavily modified Isuzu VehiCross loaded up with computers, a laser scanner, camera, and connected to actuators for steering, brake, pedals, and shifter.

A few years ago, a snowboarding company realized they could use YouTube as a marketing device. They made some really cool projects, like a snowboard with battery-powered heaters embedded in the core of the board (yes, it works). There’s only so many different snowboards you can build, so they turned to surfboards. In fact, they turned to cardboard surfboards, and last week they made a cardboard electric guitar in the Fender custom shop. It’s a completely understandable linear progression from A to B to I don’t know what kind of glue they’re using.

Why 100 Watt eBay LEDs Are Not Your Friends

LEDs are amazing things. As time marches on, they are being used in more and more lighting applications – everything from household bulbs to automotive headlights. But the push for smaller, cheaper, and brighter LEDs seems to have hit a snag for some of the less reputable manufactures.

Case in point, [bigclivedotcom] has been testing of some 100 Watt LEDs from eBay. When these LEDs work correctly, they put out a face-melting beam of light that you wouldn’t dare looking into (picture the scene from Raiders of the Lost Ark). They also have some unusual specs for an LED, like running on 30 Volts – and that’s a lot compared to the forward voltage of most LEDs at around 2.5 volts@20 mA.

So what gives? Well many of these high-wattage LEDs use a string of several LEDs in series. And as [bigclivedotcom] points out, this can be a real problem when a few of the LEDs begin to fail and act more like a low value resistor than a typical LED. In the videos after the break you can see [bigclivedotcom] test the LEDs to get a better look and what’s happening and why.

Continue reading “Why 100 Watt eBay LEDs Are Not Your Friends”

PID Controlled Glue Gun

Internals of a glue gun controlled with a PID controller

Hot glue falls into the same category of duct tape and zip ties as a versatile material for fixing anything that needs to be stuck together. [Ed]’s Bosch glue gun served him well, but after a couple of years the temperature regulation stopped working. Rather than buying a new one, he decided to rip it apart.

With the old temperature regulation circuit cooked, [Ed] looked around for something better on eBay. He came across a cheap PID temperature controller, and the Frankengluegun was born.

A thermocouple, affixed with some kapton tape and thermal paste, was used to measure the temperature of the barrel. Power for the glue gun was routed through the PID controller, which uses PWM to accurately controller the temperature. All the wiring could even be routed through the original cord grips for a clean build.

Quality glue guns with accurate temperature control are quite pricey. This solution can be added on to a glue gun for less than $30, and the final product looks just as good.

Building a custom interface for surplus HF radios

[PRC148] picked up a Motorola Micom radio from eBay. These are US State Department surplus, but apparently the 125 Watt HF units are top-of-the-line at a tenth of the sticker price. The one hangup is that they’re headless; you can’t control them without additional hardware. But the Internets are often kind to the hobbyists, and this is no exception. You can get software to run the radio from a PC thanks to the Micom Yahoo Group. [PRC148] took that software as an example and built his own stand-alone interface. [Cached version of the page]

The head unit is an Arduino driving a four-line LCD display and a rather large array of buttons. The forum thread linked above shows his humble beginnings on a breadboard. During the project [PRC148] learned a lot of skills to end up with what you see above. Hiding behind the reused bezel is a PCB he designed in Eagle CAD and etched himself. It allowed him to cram the tactile switches close enough to work with the button overlay on this keypad.

UPDATE: The traffic from this feature took down the forum hosting the content. They requested that we do not link to them because of this. A cached version without images can be found above thanks to [Termm].

$3 adds sweet tunes to your project

It’s a fun time to design your own MP3 player, lovingly adding in features to a meticulously crafted user interface. But sometimes you just want a quick and cheap way to add music to a project. [Jeff Ledger] will show you how to do just that using some knock-off hardware from overseas. Instead of a proper breakout board — which can cost a bundle — he used a generic MP3 player acquired for $3 from an eBay seller.

Cracking open the case you’ll see that you actually get a lot for your triad of Washingtons. We know, it may be of questionable quality (see this feature about cheap PSU problems) but we’re not building mission critical hardware now are we? Inside is a rechargeable Lithium battery for use with another project, and a chip-on-board device with attached SD card slot, audio jack, and USB port. The battery inputs are used to solder the MP3 pcb to the power rails on your project. To control the playback, just make connections to the button pads as [Jeff] describes in his post. It sounds like this will work with any MP3 player which runs at either 3.3V or 5V.

Exposing some fake electronics with too-good-to-be-true prices

[Giorgos Lazaridis] needed an AC adaptor for his Canon PowerShot camera. He hit eBay and was excited to find this branded adaptor for just five bucks! It works and, even though it would sometimes reboot his camera if the cord was twisted around in the jack, he was satisfied that it did what it was supposed to.

That is, until one day he observed some very peculiar behavior while taking pictures of a PIC circuit he was prototyping. When holding the camera and putting his other hand near the breadboard one of the status LEDs in his circuit began flashing sporadically. If he was using the camera with batteries instead of the adapter this didn’t happen.

His first instinct was to hook up the adapter to his oscilloscope and see what is happening on the power bus. The signal is incredibly noisy. Shockingly so. [Giorgos] cracked open the case to see what is going on with the power supply circuit inside. You simply must view the video after the break to see the horror-show he found. The board is poorly soldered, components are not properly seated in their footprints, and our favorite is when [Giorgos] points out a squiggly trace which takes the place of the smoothing inductors.

Have you documented your own fake electronic hardware finds? We’d love to hear about them. Continue reading “Exposing some fake electronics with too-good-to-be-true prices”

How to be a dinosaur for Christmas

Well, this metal suit might not make you a dinosaur, but it would be perfectly possible for you to play one on your computer. Retailing on eBay for a mere $2,397.99 OBO (plus Freight for a 350 pound box), this device was made and used for the motion capture of Ugobe’s Pleo Robot. With the right external components (no word on what those are), it would be perfectly possible to get this suit up an going back on Motion Capture as all the onboard electronics are included. This setup would be perfect for anyone planning an animated dinosaur movie that needs some reference movements, or for any mad scientist engineer who needs a control rig for a 40 story robotic dino of death. The possibilities are endless!

[eBay via Engadget]