University Attempts To Break 3D Printing World Record

April 5, 2014 by James Hobson 83 Comments

lulz

LeTourneau University attempted to set a 3D printing Guinness World Record yesterday. They had 50 3D printers print the same thing at the same time. Impressive? Kind of, but not really.

LulzBot — our favorite 3D printer company — saw this and thought “that’s cute — we run over 50 printers a day on a normal basis!”. So just for lulz, they decided to film a little counter-record video featuring 109 LulzBot 3D printers running simultaneously.

To be honest, we kinda feel sorry for LeTourneau University — but it looks like LulzBot really takes the cake here. The university has a really cool policy for their engineering students though — all incoming freshmen students are required to build their own 3D printer for school. Whoa! To be honest it is a really cool way to force you to get out of your comfort zone and learn a bit about several different engineering disciplines.

To follow along the discussion and status of the record, a thread is going on over at 3Dprintboard.com. Stick around to see the video of LulzBot’s drool worthy server racks filled with identical printers.

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Super Mario On A Human-Machine-Interface!

April 5, 2014 by James Hobson 3 Comments

super mario

Getting Super Mario to work on your TI-83 calculator is almost a rite of passage for young geeks, so we really liked this project where [Chad Boughton] managed to get it running on a PLC’s HMI screen instead!

He’s using a Danfoss DP600LX microcontroller with an HMI display along with a CAN bus joystick. This kind of equipment is typically used to control hydraulic systems, as well as display sensor data — [Chad] was curious to see if he could do animation with it as well — it looks like he’s succeeded! The funny thing is we’ve seen those “joysticks” before and it’s cool to see them used for something like this — like [Chad] said, they’re normally used for actuating hydraulic and pneumatic cylinders.

Stick around after the break to see Mario eat some mushrooms.

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Gesture Recognition Using Ultrasound

April 5, 2014 by Will Sweatman 27 Comments

SAMSUNG

You’d be hard pressed to find a public restroom that wasn’t packed full of hands free technology these days. From the toilets to the sinks and paper towel dispensers, hands free tech is everywhere in modern public restrooms.

The idea is to cut down on the spread of germs. However, as we all know too well, this technology is not perfect. We’ve all gone from sink to sink in search of one that actually worked. Most of us have waved our hands wildly in the air to get a paper towel dispenser to dispense, creating new kung-fu moves in the process. IR simply has its limitations.

What if there was a better way? Check out [Ackerley] and [Lydia’s] work on gesture recognition using ultrasound. Such technology is cheap and could easily be implemented in countless applications where hands free control of our world is desired. Indeed, the free market has already been developing this technology for use in smart phones and tablets.

Where a video camera will use upwards of 1 watt of power to record video, an ultrasound device will use only micro watts. IR can still be used to detect gestures, as in this gesture based security lock, but lacks the resolution that can be obtained by ultrasound. So let us delve deep into the details of [Ackerley] and [Lydia’s] ultrasound version of a gesture recognizer, so that we might understand just how it all works, and you too can implement your own ultrasound gesture recognition system.

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Open Source Power Line Communication

April 5, 2014 by Eric Evenchick 40 Comments

Since we all have wires running throughout our houses to provide mains power, there’s a number of devices that piggyback on mains lines for communication. For his thesis project, [Haris Andrianakis] developed his own power line communication system.

The basic principle of the system is to inject a signal onto the power lines at a much higher frequency than the 50 or 60 Hz of the AC power itself. Using both active and passive filters, the signal can be separated from the AC power and decoded. This system uses frequency-shift keying to encode data. This part is done by a ST7540 modem that’s designed for power line applications. The modem is controlled over SPI by an ATmega168 microcontroller.

[Haris]’ write up goes into detail about some of the challenges he faced, and how to protect the device from the high voltages present. The final result is a remote display for a weigh scale, which communicates over the power line. Schematics, PCB layout, and software are all available.

The Mobile Phone PixelSWaLL

April 5, 2014 by James Hobson 12 Comments

As much as we hate to admit it, smart phones have become somewhat of a disposable item in today’s society. People upgrade their phones constantly and simply chuck their old ones. Of course, there’s plenty of things you can do with slightly out of date phones… Here’s one we haven’t seen before — a wireless multi-phone display!

It’s called the PixelSWaLL, and according to the author, his software can control up to 240 Android devices! To run this demo with just 9 phones, he’s using an old Apple Macbook running Windows 7 bootcamp, which sends the display info using an old Telmex router. Each phone or tablet runs the Android terminal application using Eclipse ADT which renders OpenGL in real-time. The server application was made with Delphi 7 and uses the DSPack library to read video files in order to send them over UDP via Indy 10. It’s a bit of a mouthful to explain, but the resulting display array is pretty cool!

Time to start collecting phones…

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Bike Pedals In Both Directions, Gets You To Your Destination AND Back

April 5, 2014 by Rich Bremer 48 Comments

[punamenon2] has built an interesting bike that moves forward regardless if it is pedaled forward or backwards! What? Yes, you read that correctly. Pedal forward or backwards and the bike goes forward. This project started off as any old cruiser with a free-wheeling rear hub. To pull off this mod a second free-wheel and sprocket had to be added to the current wheel assembly. One free-wheel and sprocket set is used when pedaling forward, the other set is used when pedaling in reverse. There is also a new chain tensioner that serves to not only keep the chain taut but also allows for the chain to change directions which ultimately allows this novel idea to work.

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Taking Pictures With A DRAM Chip

April 5, 2014 by Eric Evenchick 65 Comments

This picture was taken by using a DRAM chip as an image sensor (translated). A decapped 64k DRAM chip was combined with optics that could focus an image onto the die. By reading data out of the DRAM, the image could be constructed.

DRAM is the type of RAM you find on the RAM cards inserted into your motherboard. It consists of a massive array of capacitors and transistors. Each bit requires one transistor and one capacitor, which is quite efficient. The downside is that the memory needs to be refreshed periodically to prevent the capacitors from discharging.

Exposing the capacitor to light causes it to discharge faster. Once it has discharged past a certain threshold, the bit will flip from one to zero. To take a picture, ones are written to every bit in the DRAM array. By timing how long it takes a bit to flip from one to zero, the amount of light exposure can be determined. Since the DRAM is laid out in an array, each bit can be treated as a pixel to reconstruct the image.

Sure, modern CCDs are better, cheaper, and faster, but this hack is a neat way to totally re-purpose a chip. There’s even Turbo Pascal source if you’d like to recreate the project.

Thanks to [svofski] for the tip.