Outlet Charging Station Retrofitted With The Guts Of A WiFi Router

November 20, 2012 by Mike Szczys 1 Comment

While wandering around the aisles of his local electronics store this Westinghouse USB charging station caught [James’] eye. He sized it up and realized it would make the perfect enclosure for a small WiFi router. And so began his project to turn a TP-Link TL-WR703N into a DIY Pwn Plug.

The basic idea is to include hidden capabilities in an otherwise normal-looking device. For instance, take a look at this ridiculously overpriced power strip that also happens to spy on your activities. It doesn’t sound like [James] has any black hat activities planned, but just wanted an interesting application for the router.

He removed the original circuit board from the charging station to make room for his own internals. He inserted a cellphone charger to power the router, then desoldered the USB ports and RJ-45 connector for the circuit board to be positioned in the openings of the case. He even included a headphone jack that breaks out the serial port. There’s a lot of new stuff packed into there, but all of the original features of the charging station remain intact.

More Continuous Wave Radar Fun

November 20, 2012 by Mike Szczys 5 Comments

[Gregory Charvat] continues to have a great time testing out radar systems. He and a friend have pointed the radar out the garage door and are using it to see who can reach a high running velocity.

The last time we looked in on [Greg’s] work he had acquired an old police radar unit and wired it up to use with a laptop. The hardware he’s working with now is a lot more bulky and we don’t think it will be hitting the road with him anytime soon (although it is on wheels). The video after the break starts off which an overview of the test system which is mounted in a waist-high rack. He illustrates how Labview is monitoring the radar inputs and then moves on to show off the hardware which is actually harvesting the data. The box is quite versatile, able to run five different systems and includes a slew of different connector types.

Continue reading “More Continuous Wave Radar Fun” →

[Jeri] Uses Light Bulbs In An Oscillator

November 18, 2012 by Brian Benchoff 37 Comments

Way back when [Ms Ellsworth] was a kid, she kept seeing the same circuit over and over again in her various op-amp books. It was a Wien bridge oscillator, a small circuit that outputs a sine wave with the help of a light bulb. Now that [Jeri] is much wiser, she decided to play around with this strange oscillator and found it’s actually pretty impressive for, you know, a light bulb.

The interesting portion of the Wien bridge is the gain portion of the circuit. It’s just a simple resistor divider, with a light bulb thrown in on one of its legs. When the current increases, this causes the light bulb to warm up (not enough to glow, though). When the temperature increases, the resistance in the light bulb increases, making the oscillator reach an equilibrium.

It’s a clever setup, but what about swapping out a resistor in place of the light bulb? In the video, [Jeri] tries just that, and it’s a mess. Where the light bulb circuit is amazingly stable with very, very low distortion, the resistor circuit looks like a disaster on the scope with harmonics everywhere.

A very cool build that would be perfect for an audio synth, but as [Jeri] says in her YouTube comments, “This doesn’t have enough distortion for indie bands.”

Continue reading “[Jeri] Uses Light Bulbs In An Oscillator” →

Building A Thermal Imaging Sensor From Scratch

November 12, 2012 by Brian Benchoff 45 Comments

[youtube=http://www.youtube.com/watch?v=pIb1scnD67o&w=470]

[Rob] lives in a 100-year-old house, and with these antique lath and plaster walls and old window frames comes a terrible amount of drafts. The usual way to combat this energy inefficiency is with a thermal imaging camera, a device that overlays the temperature of an object with a video image. These cameras are hideously expensive so [Rob] did what any of us would do and built his own.

The build centers around a Melexis MLX90620 far infrared thermopile that can be had for about $80. Basically, this sensor is a very, very low resolution camera (16×4 pixels) that senses heat instead of light. By sticking this sensor on a breadboard with an Arduino Mini and WiFly network adapter, [Rob] is able to pull the data down from the IR sensor to his iPhone and overlay it on the feed from the camera.

The result, as seen in the video above, is a low-resolution but still very useful thermal imaging camera, perfect for looking for cold drafts in an old house or tracking down [Arnie] just like a Predator.

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

Netduino Gets A Huge Upgrade

November 9, 2012 by Brian Benchoff 12 Comments

The Netduino, a dev board built around the .NET Micro framework with the goal of being compatible with Arduino shields just got a huge upgrade.

The new Netduino Plus 2 features an upgraded STM32 ARM Cortex-M4 uC running at 168 MHz, improving on the original Netduino’s ARM7 running at 47 MHz. In addition to some more processing power, the STM32-based microcontroller has twice the RAM and six times as much Flash memory. Also, Ethernet (10Mbps), a MicroSD card port, and of course compatibility with all Arduino shields – including the new Arduino ‘Revision C’ boards for the Leonardo – remains intact.

In keeping with the design goals of the Netduino, the new board uses the .NET Micro Framework running under Windows. It looks like OS X and Linux users won’t be left out in the cold for long, though; there’s a project to port the .NET Micro stuff over to Mono.

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

Building Your Own Fusion Drive

November 5, 2012 by Mike Szczys 46 Comments

We missed the original announcement, but Apple unveiled more than just the iPad Mini at their last event. They’ve got a new storage system called Fusion Drive which is supposed to combine the access speeds of solid state with the storage density of platter drives. When you look just under the surface what you’re really seeing is a disc drive with grossly enlarged cache in the form of an SSD drive. How about moving from the 64 MB or so of cache seen on many large hard drives today to something like 64GB?

Well you don’t have to wait for Apple to do it. [Patrick Stein] gave it a shot using command line tools to combine an SSD with a physical drive. Sure, it’s not an all-in-one solution, but it is a pretty good proof. The linchpin that will really make it possible is a low-level driver that can handle the caching on the SDD, while ensuring that the data eventually makes it to the platter for long-term storage.

[via Engadget]

[Jeri] Shows Off A Delta Sigma ADC

November 5, 2012 by Brian Benchoff 56 Comments

[Jeri] has had a bear of a time moving up to Valve Software, but electron microscope is safely in her garage (!) and her electronics lab is slowly taking shape. Since she can’t bring out the real-life gravity gun she’s working on, she decided to show off a one-bit ADC that uses just a flip-flop to sample an analog waveform into digital data.

By toggling the clock input of a 74xx74 (or any flip-flop, really) and feeding the complimentary output to back into the data input, [Jeri] can get an output that is a 50% duty cycle feeding into the input of the chip. Adding an audio input to this data input with 10k pot to this feedback loop will cause the duty cycle to change in relation to the analog input, making a one-bit ADC.

As with any electronic shortcut, there are a few drawbacks: the clock cycle feeding into the flip-flop has to be pretty fast; at least a few dozen kilohertz if you’re sampling audio. Still, if you don’t have a free ADC pin, or you’d just like to build a bitcrushing guitar pedal, it’s a very simple (and cheap) way to get analog into a digital micro.

Continue reading “[Jeri] Shows Off A Delta Sigma ADC” →