Month: May 2012

Hackaday Links: May 21, 2012

May 21, 2012 by 12 Comments

Turning anything into a touch sensor

Makey Makey is a small board with a USB plug and bunch of contact points for alligator clips. Plug the Makey into your computer and attach just about anything to the contacts, and you can make anything into a video game controller, a keyboard, a piano, or pretty much anything you can imagine. If [Sprite_tm] copied it, you know it has to be cool.

RepRaps will finally cost a million dollars

The Pentagon is throwing money at 3D printers. It’s “only” $60 Million the DoD is putting into 3d printer research, but hopefully our most brilliant researchers will help refine some of the ‘unsolved problems’ – like metal and circuit printing – the 3D printer community is facing.

Getting started with FPGAs

[Tim] found a neat little $40 FPGA board aimed right at the hobby hacker. The good news: It’s compatible with Arduino shields, and it’s very cheap. The bad news: it only has 1280 logic cells, so you probably won’t be emulating CPUs on this thing. If anyone has a teardown / project with this board, send it in.

Improving a Bluetooth dongle with a bit of wire

Unsurprisingly, the extremely cheap Bluetooth dongle [Mike] bought on eBay didn’t have great reception or range. No problem, because you can just replace the internal antenna with a piece of wire cut to length. Now bluetooth devices are recognized instantly, and there are no Bluetooth ‘dead spots’ around [Mike]’s computer.

Come to France, make stuff

The Toulouse Hackerspace is having a little shindig this coming weekend (May 25-27) featuring a conference, workshop, concerts and performances. If you’re in the area, drop on by,

Hackit: Leap Motions New Motion Sensor

May 21, 2012 by 73 Comments

The big news circulating this morning is of the Leap Motion sensor that will be hitting the market soon. They claim that their sensor is ~100 more accurate than anything else on the market right now. Check out the video to see what they mean (there’s another at the link). This is pretty impressive.  You can see the accuracy as they use a stylus to write things. If you’ve played with the Kinect, you know that it is nowhere near this tight. Of course, the Kinect is scanning a massive space compared to the work area that this new sensor works in.  The response time looks very impressive as well, motions seem to be perfectly in sync with the input. We’re excited to play with one when we get a chance.

Continue reading “Hackit: Leap Motions New Motion Sensor” →

3d Printing A Mini Lathe

May 21, 2012 by 21 Comments

While browsing on one of our regularly visited sites, RobotsDreams, we found this interesting little video. Here, [Sublime] is showing off his 3d printed mini lathe. In the video he mentions that all the files are available for download so you could make one for yourself, but there were unfortunately no links. A quick bit of googling and we found some more information.  We found the project on Thiniverse, though reading through the comments it seems that [Sublime] no longer uses Thingiverse. You can now find the files on his GitHub account to make your own.

The design seems very solid and looks like it could handle some basic jobs. As [Sublime] points out in the video below, you already know what parts are going to wear out fast and can simply print a few extras to have on hand.  While that may seem somewhat wasteful, he also points out that he’s using PLA which is compostable and much easier to recycle.

Continue reading “3d Printing A Mini Lathe” →

Light Trikes Allow You To Pedal For Your Life

May 21, 2012 by 2 Comments

Unfortunately, none of our writers are located in California this year. This means that we weren’t able to go to the Bay Area MakerFaire and see the cool stuff for ourselves. We have been following along on the web though and a few projects have caught our eye. The rig you see above is a physical controller for a game that was inspired by the classic Tron light cycle. The gameplay is pretty obvious, you pedal the trike to go and turn the handlebars to turn your light tricycle. The hardware seems fairly simple, they’re using an arduino to collect information from the bike, then sending that through NetLab hub, a cross platform toolkit for taking data from a micro controller and feeding it to flash.  We think they did a fantastic job on the presentation, this actually looks like fun to play.

For some reason though, we want them to build a level that looks like the Stanley Hotel.

Continue reading “Light Trikes Allow You To Pedal For Your Life” →

Getting Great Bootlegs With The BootlegMIC

May 21, 2012 by 28 Comments

Go to any concert, show, or basement band practice, and you’ll find someone recording a bootleg. While these live recordings are sometimes fairly high quality, bootlegs recorded with a cell phone usually sound terrible. The guys over at Open Music Labs have a great solution to these poor quality recordings that only needs a few dollars worth of parts.

The project is called bootlegMIC. It’s a simple modification of an electret microphone – the same type of mic found in cellphones and bluetooth headsets – that allows for some very high quality recording in very noisy environments. According to the open music labs wiki, the modification is as simple as cutting a few traces on the PCB in an electret mic and soldering on a cap and a few resistors.

An electret mic contains a small JFET to amplify the signal coming from the microphone diaphragm; the specific JFET is selected by the manufacturer to ensure the microphone has the right gain and response. Usually these JFETs are chosen with the expectation of a relatively quiet environment, and trying to record a concert only results in a ton of distortion. By putting a resistor between the source of the JFET and ground of the microphone, it’s possible to reduce this distortion.

The circuit is easy enough to solder deadbug style, and should work with most cellphones. The guys at Open Music Lab were able to get their mic working with an iPhone, but they’re still working on figuring out the Android mic input. There’s a great demo video showing the improvement in audio quality; you can check that out after the break.

Continue reading “Getting Great Bootlegs With The BootlegMIC” →

The Pi Pad

May 20, 2012 by 40 Comments

In the world of electronics we have impedance; the combination of all forces which oppose the flow of electric current. Often times we have circuits with different impedances, 50 ohms for RF, or 75 for cable TV. It’s pretty important to use the right coax in these circuits, else you’ll be wondering why your RG-58 antenna feed line doesn’t give you anything good to watch.

It’s pretty important to match impedances when connecting different circuits. Apart from the obvious flaws such as a 50 ohm load blowing up a 300 ohm amplifier, there are subtler things such as signal reflection and destructive interference which might just be enough to break whatever it is your playing with. RF mosfets are not cheap! But how could we match impedances? Well we could always use a transformer, but those are rather expensive and bulky. What if we only have a box of resistors to play with? Continue reading “The Pi Pad” →

IPhone Charger Teardown Shows Astounding Miniaturization.

May 20, 2012 by 24 Comments

There’s no question that Apple has their industrial design down pat; comparing a cell phone charger made by Blackberry or Motorola to the tiny 1-inch-cube Apple charger just underscores this fact. [Ken Shirriff] posted a great teardown of the Apple iPhone charger that goes through the hardware that makes this charger so impressive.

Like most cell phone chargers and power supplies these days, Apple’s charger is a switching power supply giving it a much better efficiency than a simple ‘transformer, rectifier, regulator’ linear power supply. Inside the charger, mains power is converted to DC, chopped up by a control IC, fed into a flyback transformer and converted into AC, and finally changed back into DC, and finally filtered and sent out through a USB port.

The quality of the charger is apparent; there’s really no way this small 1-inch cube could be made any smaller. In fact, if it weren’t for the microscopic 0402 SMD components, it’s doubtful this charger could be made at all.

Comparing the $30 iPhone charger of a cheap (and fake) iPhone charger, the budget charger still uses a flyback transformer but there are serious compromises of the safety and quality. The fake charger doesn’t use a power supply controller IC and replaces the four bridge diodes for a single diode to rectify the AC; a very efficient cost-cutting measure, but it does lead to a noisier power supply.

There’s also the issue of safety; on the Apple charger, there is a (relatively) huge physical separation of  ~340 VDC and your phone. With the off-brand charger, these circuits are separated by less than a millimeter – not very safe, and certainly wouldn’t be UL approved.

It’s worth pointing out that [Ken] compares a similar $7 Samsung charger favorably to the $30 Apple charger. Both are functionally identical, but Apple also has their  marketing down pat, to say the least.

Tip ‘o the hat to [George] for sending this in.

EDIT: In case a 1-inch cube wasn’t impressive enough, check out the euro version of the iPhone/iPad charger. It supplies 1A @ 5V, and isn’t much thicker than the USB port itself. Thanks [Andreas] for bringing this to our attention. If anyone wants to do a teardown of the euro version, send it in on the tip line.