NYC Resistor Gets A PDP-11/34

May 18, 2014 by 40 Comments

PDP-11/34 NYCR

[Trammel Hudson] and NYC Resistor have gotten their hands on some old computing iron in the form of a PDP-11/34.  The PDP-11 is a 16 bit minicomputer made by Digital Equipment Corporation (DEC). Various incarnations of the PDP-11 were sold from the 1970’s all the way into the 1990’s. NYC Resistor’s model is has a label dating it to 1983.

The PDP was found in an old storage unit in the Bronx. Moving several racks of equipment across the city is no small feat, but NYC Resistor members have it done it so many times they’ve got it down to a science.

Once power is applied, a stock PDP won’t actually do anything until the boot loader is keyed in from the CPU front panel. Thankfully this particular PDP-11 had its boot instructions printed on a label on the CPU. NYCR’s machine also includes an M9312 “bootstrap / Unibus terminator” board, which allows the machine to boot at the push of a button.

The team connected the racks, terminals, and drives. Carefully following the instructions, they actually got their PDP to boot up! Their next step is to start reading in some of the old tapes that came with the machine. We’re all waiting with bated breath to see what “digitized monkey brains” contains. Once the machine is fully functional, we hope they get it on the internet and load up The Hackaday Retro Edition.

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Firmware For Cheap Bluetooth Modules

May 18, 2014 by 43 Comments

Ibluetoothf you’ve ever built anything with a microcontroller, some sort of sensor, and a connection to the outside world, you’re probably wondering how those places in China can pump out cheap electronics for a mere percentage of what it costs you to pull a DIY. It’s not just volume – it’s engineering; if something has Bluetooth, you find a Bluetooth module with a built-in microcontroller so you can write firmware to it.

The BC417 is the System on Chip found in the very popular BlueCore4-Ext Bluetooth module featuring 8Mbits of Flash (75% of which is used for Bluetooth related stuff), somewhere around 12 kB of RAM, with everything run in a virtual machine. [pfalcon] wrote an extremely experimental firmware for this device that allows anyone to create a wireless sensor node for peanuts. These devices are almost as cheap as a bare ATMega, so the possibilities are interesting, to say the least.

At this point, the hardest part of putting custom firmware on these devices is programming them. For that, [Elastic Sheep] comes to the rescue with a parallel port to SPI interface. There’s also a firmware dumper and some breakout boards available. These modules are pretty cheap, and the pitch isn’t too bad, so you might be able to etch your own boards should you want to experiment a little.

Thanks [Peter] for sending this in.

Hacking An Old Parallel Port Webcam To Work With A Gameduino 2

May 18, 2014 by 8 Comments

connecting parallel port web camera to gameduino 2

[Andrew] couldn’t pass up a 20ish year old parallel port based webcam he saw on the shelf at a thrift store. It’s a Connectix QuickCam and was the first webcam that did not require a separate video input card to interface with your computer. Due to this feature, the webcam was extremely popular, so popular that Logitech ended up buying Connectix and marketing the camera for themselves.

It’s tough to find a newer computer that still has a parallel port, but using an old computer wasn’t [Andrew]’s plan anyways. After thinking about it, he decided to try to get the camera’s image to display on a Gameduino 2.

The hardware list is fairly minimal. The cam’s parallel connector is plugged straight into STM32 Nucleo development board by way of several jumpers. The Gameduino 2 is connected to the dev board and a USB to PS/2 adapter was made to power the camera.

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Hyperspectral Imaging With A DSLR

May 18, 2014 by 12 Comments

It’s a relatively simple task to find evidence of helium by just looking at the sun; all you need is a prism, diffraction grating, and a web cam. DIY spectrometers have been around for ages, but most of them only produce a spectrum, not a full image complete with spectral data. Now it’s possible to take an image of an object, complete with that objects spectra using a DSLR, some lenses, a PVC pipe, and the same diffraction grating from your DIY interferometer.

The idea behind a hyperspectral imager is to gather the spectral data of each pixel of an image. The spectral data is then assembled into a 3D data cube, with two dimensions dedicated to the image, and the third dimension used to represent wavelength. There are a surprising number of applications for this technique, ranging from agriculture and medicine to some extremely creepy surveillance systems.

The authors of this paper (freakin’ huge PDF) used a piece of PVC pipe, three camera lenses, a diffraction grating, and a small paper aperture to construct their hyperspectral imager. Images are captured using a standard, multi exposure HDR method, assembling the raw data from the camera into a hyperspectral image with MATLAB.

There’s a ton of awesome info in the PDF, covering how the authors calibrated their system for different lighting conditions, interpreted the RGGB Bayer sensor in the camera, and a few examples of what kind of image can be constructed with this kind of data. That’s a recommended read, right there.

Thanks [Yannick] for the tip.

A Raspi Ambilight With HDMI Input

May 18, 2014 by 19 Comments

With the Raspberry Pi now most famously known as a $30 media PC, it only makes sense that the best uses for the GPIO pins on the Pi are used for an Ambilight. [Great Scott Labs] put up a great video on using the Pi as a uniquely configurable Ambilight with Hyperion and just about any video input imaginable.

This isn’t the first Ambilight clone [Great Scott] has put together, but for the first version the Ambilight functioned only under Raspbian and not any random HDMI input. The new version solves this by using an HDMI splitter box, feeding into an HDMI to composite converter, and finally into a USB composite capture dongle attached to the Raspi.

With the software in the instructions, the Raspi effectively mirrors the video coming from the video capture dongle. The Pi is running Hyperion to control a strip of WS2801 RGB LEDs, making the back of any TV glowey and blinkey.

Since [Great Scott] is using a component video signal as an input, the adapters necessary to have any device work with this Ambilight are readily available. We’d honestly like to see this build working with the old Commodore disk access screen border going nuts, so be sure to send that in if you ever get that working.

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A Ring Of Colored Pencils

May 17, 2014 by 16 Comments

Colored Pencil Ring

[Peter] proved he has equal parts prowess, patience, and perseverance with this colored pencil ring (imgur link). The ring is made from a cross-section of several colored pencils. The idea seems simple. The build process IS simple. As always though, the devil is in the details.

[Peter] started with a cheap pack of colored pencils. They have to be hexagonal pencils, as round ones won’t work well for this build. [Peter] used two nails to align the  pencils, and medium thickness Cyanoacrylate glue to bond them together. Cyanoacrylate (aka super glue) is a very strong but inflexible bond. We’re curious if a different adhesive might have worked better for this task.

Once the block of glued pencils was dry, [Peter] drilled a hole approximately his ring size. He used a band saw to cut a rough ring blank around the hole, then headed to the wood lathe. He mounted the ring with a jam chuck, which is a piece of wood turned to an interference fit with the workpiece. The problem was that the jam chuck cracked the ring as it was being installed. [Peter] was able to glue the ring back together, and turn it down on his lathe.

Click past the break for more on [Peter’s] ring.

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carbon nanotube being turned into aerogel sheet

Artificial Muscles Use Carbon Nanotube Sheets

May 17, 2014 by 46 Comments

Light as air, stronger than steel and more flexible than rubber. Sound like something from the next installment of the Iron Man series? [Tony Stark] would certainly take notice of this fascinating technology. Fortunately for us, it does not come from the studios of Hollywood, but instead the halls of the NanoTech Institute at the University of Texas.

Professor [Ray Baughman] and his team of scientists at the NanoTech Institute have developed a type of artificial muscle through a process of making aerogel sheets by growing carbon nanotubes in a forest like structure. Think of a vertical bamboo forest, with each bamboo stem representing a single carbon nanotube. Now imagine that the individual bamboo stems were connected together by much smaller horizontal threads. So that if you dislodge the bamboo and began to pull, the threads would pull the others, and you would get this sheet-like structure.

These aerogel sheets of carbon nantubes have some truly science fiction like properties. They can operate from 1,600 degrees centigrade to near absolute zero. If you inject a charge, each nanotube will be repulsed from one another, expanding some 220% of the sheet’s original size. Your muscles do this at roughly 20 – 40%. Stick around after the break for a video demonstration of these carbon nanotube aerogel sheets being made and demonstrated.

Thanks to [Steven] for the tip!

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