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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Making Dumb Robots Evolve

March 14, 2016 by Brian Benchoff 32 Comments

Evolution is a fact of life, except in Kansas. It is the defining characteristic of life itself, but that doesn’t mean a stupid robot can’t evolve. For his entry into the Hackaday Pi Zero contest, [diemastermonkey] is doing just that: evolution for robots built around microcontrollers and a Raspberry Pi.

[diemastermonkey]’s project is a physical extension to genetic algorithms. Just like DNA and proteins have no idea what they’re actually doing, microcontrollers don’t either. Instead of randomly switching up base pairs and amino acids, [diemastermonkey]’s project makes random connections pins depending on the values of those pins.

The potential of these crappy, randomly programmed robots is only as good as the fitness function, and so far [diemastermonkey] has seen some surprising success. When putting these algorithms into a microcontroller connected to a tilting table mechanism and a PIR sensor, the robot eventually settled on a bit of code that would keep a ball in motion. You can check out the video of that below.

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 $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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Wifi Enabled Center Speaker

March 12, 2016 by Gerrit Coetzee 2 Comments

[Ronald] has been improving his audio set-up for a while now, his latest revision culminating in this WiFi enabled center channel speaker. It all started with feature creep as you can see in this direct quote, “Being an engineer, I couldn’t stop here, not now that I had a way of adding more features…”

He had purchased a new amplifier for his system, but was irritated that the loudness setting would re-enable itself every time he switched inputs. First he thought he might just have a little board that intercepted the signals from his remote and tacked on the loudness off signal. It occurred to him that it would be even cooler if he could control it from his computer or phone. So he opened the case on his new amp and discovered an i2c break-out. We can guess how it went after that.

In version 2.0 he kept most of his work from 1.0, but wanted to simplify the set-up and build it all into a center speaker unit since an amplifier and two speaker cabinets takes up too much room. He fit a similar set-up as before in the center speaker casing, but added a touch screen and a few other improvements. Though, strangely, he ran into some problems upgrading to the Raspberry Pi 2.0 and had to revert.

The final result is very nice, though obviously not done. As the engineer’s mantra goes, “If it ain’t broke, it doesn’t have enough features yet.”