Vintage 8mm Camera Now Powered By Raspberry Pi

March 16, 2016 by Jenny List 20 Comments

If you are a lover of the aesthetic of vintage photography and Instagram’s filters don’t quite cut it for you, then there are plenty of opportunities even in this post-film age to sample the real thing. Plastic lens cameras from the former Soviet Bloc countries or the Pacific rim are still in production, and you can still buy 35mm and 120 roll film to put in them.

You can even still buy 8mm film for your vintage movie camera, but it’s rather pricey. [Claire Wright] is a young film maker who had an old 8mm camera and really wanted that analog film feel to her work, and she and her father solved this problem by using the 8mm camera’s lens in front of a Raspberry Pi camera sensor. Since an 8mm film frame is 4.5mm x 3.3mm and the Pi camera sensor size is 3.76mm x 2.74mm, it’s quite a good fit.

Their first prototype had a custom case which concealed the Pi camera behind the lens on rails taken from an old CD-ROM drive, and had an HDMI screen on top and a pistol grip to make it portable. An external thumb screw allowed the camera to be positioned in the focal plane.

A further refinement has stepper motor driven focus driven from an Adafruit motor drive HAT. The software is simply the standard Pi camera utilities. To demonstrate the system, she made a short video about how it came to be, and took the camera on a road trip to Austin, Texas. She tells us a local 3D print shop is working on a 3D model to replicate the camera, but sadly as yet there are no resources for the Hackaday crowd to examine.

Her video is below. She has certainly captured the feel of an 8mm film very well. If the SUVs were replaced by cars with more chrome in her Mainstreet America, you might almost be there in the 1950s.

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Tiny Raspberry Pi Shield For High-Quality RF Signals

March 16, 2016 by Dan Maloney 18 Comments

Among its many tricks, the Raspberry Pi is capable of putting clock signals signal out on its GPIO pins, and that turns out to be just the thing for synthesizing RF signals in the amateur radio bands. What [Zoltan] realized, though, is that the resulting signals are pretty dirty, so he came up with a clever Pi shield for RF signal conditioning that turns a Pi into a quality low-power transmitter.

[Zoltan] stuffed a bandpass filter for broadband noise, a low-pass filter for harmonics, and a power amplifier to beef up the signal a bit into a tiny shield that is cleverly engineered to fit any version of the Pi. Even with the power amplifier, the resulting transmitter is still squarely in the realm of QRP, and the shield is optimized for use as a WSPR beacon on the 20-meter band. But there’s plenty of Pi software available to let hams try other modes, including CW, FM, SSB, and even SSTV, and other signal conditioning hardware for different bands.

Yes, these are commercially available products, but even if you’re not in the market for a shield like this, or if you want to roll your own, there’s a lot to learn from [Zoltan]’s presentation at the 2015 TAPR Digital Communications Conference (long video below). He discusses the difficulties encountered getting a low-profile shield to be compatible with every version of the Pi, and the design constraints that led to the decision to use SMT components.

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A $5 Graphics Card For Homebrew Computers

March 14, 2016 by Brian Benchoff 39 Comments

While not very popular, building a homebrew computer can be a fun and rewarding process. Most of the time, though, the video capabilities of these computers is as bare bones as it can get – running headless, connected to a terminal. While this is an accurate reproduction of the homebrew computers of the 1970s and 80s, there’s a lot to be said about a DIY computer with an HDMI-out port.

[spencer] built a Z-80-based homebrew computer a few years ago, and while connecting it to a terminal was sufficient, it was a build that could use a little more pizzazz. How did he manage to stuff a terminal in a tiny project box? With everyone’s favorite five dollar computer, the Raspberry Pi Zero.

The computer [spencer] built already had serial inputs, outputs, power, and ground rails – basically, a serial port. The Raspberry Pi also has TX and RX pins available on the 40-pin header, and with a stupidly simple board that [spencer] whipped up in KiCad, he could plug a Pi into the backplane of his homebrew computer. A few setup scripts, and a few seconds after turning this computer on [spencer] could mash a keyboard and wail away on some old school BASIC.

This isn’t a use case that is the sole domain of the Pi Zero. A Parallax Propeller chip makes for a great video terminal with inputs for PS/2 keyboards and mice. A largish AVR, with the requisite NTSC video library, also makes for a great video interface for a homebrew computer. The Pi Zero is only five dollars, though.

The Raspberry Pi Zero contest is presented by Hackaday and Adafruit. Prizes include Raspberry Pi Zeros from Adafruit and gift cards to The Hackaday Store!
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A Pi Powered Recording Studio

March 13, 2016 by Brian Benchoff 48 Comments

In the mid-90s, you recorded your band’s demo on a Tascam cassette tape deck. These surprisingly cheap four-track portable studios were just low tech enough to lend an air of authenticity to a band that calls itself, ‘something like Pearl Jam, but with a piano’. These tape decks disappeared a decade later, just like your dreams of being a rock star, replaced with portable digital recording studios.

The Raspberry Pi exists, the Linux audio stack is in much better shape than it was ten years ago, and now it’s possible to build your own standalone recording studio. That’s exactly what [Daniel] is doing for our Raspberry Pi Zero contest, and somewhat predictably he’s calling it the piStudio.

Although the technology has moved from cassette tapes to CompactFlash cards to hard drives, the design of these four-track mini recording studios hasn’t really changed since their introduction in the 1980s. There are four channels, each with a fader, balance, EQ, and a line in and XLR jack. There are master controls, a few VU meters, and if the technology is digital, a pair of MIDI jacks. Since [Daniel] is using a Raspberry Pi for this project, he threw in an LCD for a great user interface.

As with all digital recorders, the money is in the analog to digital converters. [Daniel] is using a 24-bit, 216kHz, four-channel chip, Texas Instruments’ PCM4204. That’s more than enough to confuse the ears of an audiophile, although that much data will require a hard drive. Good thing there will be SATA.

Although you can buy an eight-channel solid state recorder for a few hundred dollars – and [Daniel] will assuredly put more than that into this project, it’s a great application of a ubiquitous Linux computer for a device that’s very, very useful.

The Raspberry Pi Zero contest is presented by Hackaday and Adafruit. Prizes include Raspberry Pi Zeros from Adafruit and gift cards to The Hackaday Store!
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Birthday Celebrations The Pi Way

March 13, 2016 by Jenny List 3 Comments

The William Gates Building concourse packed with Pi enthusiasts

On a damp and cold Saturday in early March the Cambridge University Computer Laboratory threw open its doors to the Raspberry Pi community. The previous Monday had been the fourth (or first, if you are a leap year pedant!) birthday of the little single-board computer, and last weekend saw its official birthday celebration.

The festivities took the form of an exhibition floor with both traders and community show-and-tell exhibits, plus a packed schedule of workshops and talks. With the Raspberry Pi 3 launch only a few days before there were no surprise announcements of exciting new hardware, but it did provide a good networking opportunity for the Pi community and a chance to test the state of the Raspberry Pi nation.

The most obvious first impression at the event was that it was one that catered for a diverse range of ages and ability groups. Side-by-side with parents and their children were educators, and the maker community. The range of exhibits was therefore slanted somewhat towards a younger age range with games and interactive exhibits, and there was more than a slight educational flavour to the event. This was entirely in keeping with the Foundation’s objectives, and since it is events like these that are inspiring the Hackaday readers of the next decade, a very welcome sight. Join us after the break for a look at all that was happening at the event.

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One Man’s Quest To Spend Less TIme In The Basement

March 12, 2016 by Brian Benchoff 45 Comments

[Lars] has a second floor apartment, and the washing machines and clothes dryers are in the basement. This means [Lars] has spent too much time walking down to the basement to collect his laundry, only to find out there is 15 minutes left in on the cycle. There are a few solutions to this: leave your load in the washer like an inconsiderate animal, buy a new, fancy washer and dryer with proprietary Internet of Things™ software, or hack together a washer and dryer monitoring solution. We all know what option [Lars] chose.

Connecting a Pi to the Internet and serving up a few bits of data is a solved problem. The hard part is deciding which bits to serve. Washers and dryers all have a few things in common: they both use power, they both move and shake, they make noise, and their interfaces change during the wash cycle. [Lars] wanted a device that could be used with washers and dryers, and could be used with other machines in the future. He first experimented with a microphone, capturing the low rumble of a washer sloshing about and a dryer tumbling a load of laundry. It turns out an accelerometer works just as well, and with a sensor securely fastened to a washer or dryer, [Lars] can get a pretty good idea if it’s running or not.

With a reliable way to tell if a washer or dryer is still running, [Lars] only had to put this information on his smartphone. He ended up using PushBullet, and quickly had an app on his phone that told him if his laundry was done.

Digital Zoetrope Powered By Pi

March 11, 2016 by Jenny List 2 Comments

A zoetrope is a charming piece of Victoriana, a device that gives the sensation of a moving image by exposing its successive frames through slits in a rotating drum. [Brian Corteil] however is not content with a mere 19th century parlour amusement, he’s connected twelve OLED displays to a Raspberry Pi and mounted them on a circular platform with a rotary encoder to make a fully digital zoetrope.

Connecting 12 SPI devices to the Pi was always going to be something of a challenge, because only two CS lines are provided. [Brian] has a rather elegant solution to this problem, he’s daisy-chained his displays to form a shift register in which each image is passed to the next display on a rotational increment.

His resulting zoetrope sits on a laser-cut frame which rotates over an encoder disc which looks to be made from printed paper. It is still something of a work in progress, but he has plans to record video on the Pi camera for immediate playback on his creation. You can take a look at his code for the zoetrope on GitHub.

This isn’t the first zoetrope we’ve covered here at Hackaday, or even the first digital one. We’ve seen a couple of 3d-printed ones, and one featuring laser-cut images captured with a Kinect. But it’s a good piece of work, and has the promise of more to come if his camera plans come to fruition. Continue reading “Digital Zoetrope Powered By Pi” →