Every year at Superconference, Editor-in-Chief Mike Szczys gets the chance to talk about what we think are the biggest, most important themes in the Hackaday universe. This year’s talk was about science and technology, and more importantly who gets to be involved in building the future. Spoiler: all of us! Hackaday has always stood for the ideal that you, yes you, should be taking stuff apart, improving it, and finding innovative ways to use, make, and improve. To steal one of Mike’s lines: “Hackaday is an engine of engagement in engineering fields.”
We all know CERN as that cool place where physicists play with massive, superconducting rings to smash atoms and subatomic particles to uncover secrets of matter in the Universe. To achieve this aim, they need to do a ton of research in other areas, such as development of special particle detectors.
While such developments are essential to the core research needs of the Centre, they also lead to spinoff applications for the benefit of society at large. One such outcome has been the Medipix Collaborations – a family of read-out chips for particle imaging and detection that can count single photons, allowing X-rays and gamma rays to be converted to electrical signals. It may not be possible for us hackers to get our hands on these esoteric sensors, but these devices are pretty interesting and deserve a closer look. Medipix sensors work like a camera, detecting and counting each individual particle hitting the pixels when its electronic shutter is open. This enables high-resolution, high-contrast, noise hit free images – making it unique for imaging applications.
Some months back, CERN announced the first 3D color X-ray of a human made possible using the Medipix devices. The result is a high-resolution, 3D, color image of not just living structures like bones, muscular tissues and vessels, but metal objects too like the wrist watch, seen in the accompanying photograph. The Medipix sensors have been in development since the 1990’s and are presently in their 4th “generation”. Each chip consists of a top semiconducting sensor array, made from gallium arsenide or cadmium telluride. The charge collected by each pixel is transported to the CMOS ASIC electronics via “bump bonds”. The integration is vertical, with each sensing pixel connected via the bump bond to an analog section followed by a digital processing layer. Earlier versions were limited, by technology, in their tiling ability for creating larger matrices of multiple sensors. They could be abutted on three sides only, with the fourth being used for on-chip peripheral logic and wire-bond pads that permit electronic read-out. The latest Medipix4 Collaboration, still under some development, eliminates this short coming. Through-silicon-via (TSV) technology provides the possibility of reading the chips through copper-filled holes that bring the signals from the front side of the chip to its rear. All communication with the pixel matrix flows through the rear of the chip – the peripheral logic and control elements are integrated inside the pixel matrix.
The Analog front end consists of a pre-amplifier followed by a window discriminator which has upper and lower threshold levels. The discriminator has four bits for threshold adjustment as well as polarity sensing. This allows the capture window to be precisely set. The rest of the digital electronics – multiplexers, shift registers, shutter and logic control – helps extract the data.
Further development of the Medipix (Tech Brief, PDF) devices led to a separate version called Timepix (Tech Brief, PDF). These new devices, besides being able to count photons, are capable of two additional modes. The first mode records “Time-Over-Threshold”, providing rough analog information about the energy of the photon. It does this by counting clock pulses for the duration when the signal stays above the discrimination levels. The other mode, “Time of Arrival”, measures arrival time of the first particle to impinge on the pixel. The counters record time between a trigger and detection of radiation quanta with energy above the discrimination level, allowing time-of-flight applications in imaging.
Medipix3 pixel schematic
Timepix2 pixel schematic
Besides medical imaging, the devices have applications in space, material analysis, education and of course, high energy physics. Hopefully, in a few years, hackers will lay their hands on these interesting devices and we can get to know them better. At the moment, the Medipix website has some more details and data sheets if you would like to dig deeper. For an overview on the development of such single photon detectors, check out this presentation from CERN – “Single X-Ray Photon Counting Systems: Existing Systems, Systems Under Development And Future Trends” (PDF).
We missed [iliasam’s] laser text projector when it first appeared, perhaps because the original article was in Russian. However, he recently reposted in English and it really caught our eye. You can see a short video of it in operation, below.
The projector uses raster scanning where the beam goes over each spot in a grid pattern. The design uses one laser from a cheap laser pointer and a salvaged mirror module from an old laser printer. The laser pointer diode turned out to be a bit weak, so a DVD laser was eventually put into service. A DVD motor also provides the vertical scan which is just a slight wobble of a mirror. A Blue Pill CPU provides all the smarts. You can find the code on GitHub.
In 1899, you might have been forgiven for thinking the automobile was only a rich-man’s toy. A horseless carriage was for flat garden pathways. The auto was far less reliable than a horse. This was new technology, and rich people are always into their gadgets, but the automobile is a technology that isn’t going to go anywhere. The roads are too terrible, they don’t have the range of a horse, and the world just isn’t set up for mechanized machines rolling everywhere.
This changed. It changed very quickly. By 1920, cars had taken over. Industrialized cities were no longer in the shadow of a mountain of horse manure. A highway, built specifically for automobiles, stretched from New York City to San Francisco. The age of the automobile had come.
And here we are today, in the same situation, with a technology as revolutionary as the automobile. People say self-driving cars are toys for rich people. Teslas on the road aren’t for the common man because the economy model costs fifty thousand dollars. They only work on highways anyway. The reliability just isn’t there for level-5 automation. You’ll never have a self-driving car that can drive over mountain roads in the snow, or navigate a ball bouncing into the street of a residential neighborhood chased by a child. But history proves time and time again that people are wrong. Self-driving cars are the future, and the world will be unrecognizable in thirty years. There’s only one problem: we’re not calling them the right thing. Self-driving cars should be called ‘cryptocybers’.
Fritzing is a very nice Open Source design tool for PCBs, electrical sketches, and schematics for designers and artists to move from a prototype to real hardware. Over the years, we’ve seen fantastic projects built with Fritzing. Fritzing has been the subject of books, lectures, and educational courses, and the impact of Fritzing has been huge. Open up a book on electronics from O’Reilly, and you’ll probably see a schematic or drawing created in Fritzing.
However, and there’s always a however, Fritzing is in trouble. The project is giving every appearance of having died. You can’t register on the site, you can’t update parts, the official site lacks HTTPS, the Twitter account has been inactive for 1,200 days, there have been no blog posts for a year, and the last commit to GitHub was on March 13th. There are problems, but there is hope: [Patrick Franken], one of the developers of Fritzing and the president of the PCB firm Aisler which runs the Fritzing Fab, recently gave a talk at FOSDEM concerning the future of Fritzing. (That’s a direct FTP download, so have fun).
Lasers work by emitting light that is “coherent” in that it doesn’t spread out in a disorganized way like light from most sources does. This makes extremely focused beams possible that can do things like measure the distance from the Earth to the Moon. This behavior isn’t just limited to electromagnetic waves, though. [Gigs] via [CodeParade] was able to build a device that produces a tightly focused sound wave, essentially building an audio laser.
Curiously enough, the device does not emit sound in the frequency range of human hearing. It uses a set of ultrasound speakers which emit a “carrier wave” in the ultrasound frequency. However, with a relatively simple circuit a second signal in the audible frequency range is modulated on top of it, much the same way that an AM radio broadcast has a carrier wave with an amplitude modulated signal on top of it. With this device, though, the air itself acts in a nonlinear way and demodulates the signal, producing the modulated signal as audible sounds.
There are some interesting effects of using this device. First, it is extremely directional, so in order to hear sound from the device you would need to be standing directly in front of it. However, once the ultrasound beam hits a solid object, the wave is instantly demodulated and reflected from the object, making it sound like that object is making the sounds and not the device. It’s obvious that this effect is hard to experience via video, but it’s interesting enough that we’d like to have one of our own to try out. It’s not the only time that sound waves and electromagnetic waves have paired up in interesting ways, either.
There’s an old joke that all you need to fix TVs is a cheater, a heater, and a meter. If you don’t remember, a cheater was a cord to override the interlock on TVs so you could turn them on with the back removed. Of course, in real life, pro repair techs always had better equipment. In 1939 that might have meant the Supreme Vedolyzer which combined a meter, a ‘scope, and a wavemeter all in one device. [Mr Carlson] acquired one that was in fair shape and made a few videos (see below) of the teardown and restoration.
[Mr Carlson] wasn’t restoring this as an art project, by the way. He plans on using it, so he was less concerned with authenticity and more worried about usability. That led him to do things like remove the input jacks and replace them with BNCs. The video series is a bit of a time investment. Part one is about 82 minutes long! But if you are interested in old gear, this is a chance to peer inside an unusual specimen.
Some months back, CERN announced 
The Analog front end consists of a pre-amplifier followed by a window discriminator which has upper and lower threshold levels. The discriminator has four bits for threshold adjustment as well as polarity sensing. This allows the capture window to be precisely set. The rest of the digital electronics – multiplexers, shift registers, shutter and logic control – helps extract the data.
