A More Open Raspberry Pi Camera Stack With Libcamera

May 11, 2020 by Roger Cheng 15 Comments

As open as the Raspberry Pi Foundation has been about their beloved products, they would be the first to admit there’s always more work to be done: Getting a Pi up and running still requires many closed proprietary components. But the foundation works to chip away at it bit by bit, and one of the latest steps is the release of a camera stack built on libcamera.

Most Linux applications interact with the camera via V4L2 or a similar API. These established interfaces were designed back when camera control was limited and consisted of a few simple hardware settings. Today we have far more sophisticated computational techniques for digital photography and video. Algorithms have outgrown dedicated hardware, transforming into software modules that take advantage of CPU and/or GPU processing. In practice, this trend meant bigger and bigger opaque monolithic pieces of proprietary code. Every one a mix of “secret sauce” algorithms commingling with common overhead code wastefully duplicated for each new blob.

We expect camera makers will continue to devise proprietary specialties as they seek a competitive advantage. Fortunately, some of them see benefit in an open-source framework to help break up those monoliths into more manageable pieces, letting them focus on just their own specialized parts. Leveraging something like libcamera for the remainder can reduce their software development workload, leading to faster time to market, lower support cost, and associated benefits to the bottom line that motivates adoption by corporations.

But like every new interface design borne of a grandiose vision, there’s a chicken-and-egg problem. Application developers won’t consume it if there’s no hardware, and hardware manufacturers won’t implement it if no applications use it. For the consumer side, libcamera has modules to interop with V4L2 and other popular interfaces. For the hardware side, it would be useful to have a company with wide reach who believes it is useful to open what they can and isolate the pieces they can’t. This is where the Raspberry Pi foundation found a fit.

The initial release doesn’t support their new High-Quality Camera Module though that is promised soon. In the short term, there is still a lot of work to be done, but we are excited about the long term possibilities. If libcamera can indeed lower the barrier to entry, it would encourage innovation and expanding the set of cameras beyond the officially supported list. We certainly have no shortage of offbeat camera sensor ideas around here, from a 1-kilopixel camera sensor to a decapped DRAM chip.

[via Hackster.io]

A Raspberry Pi Video Intercom System

April 27, 2020 by Orlando Hoilett 5 Comments

When it comes to hacks, we’re always amazed by the aesthetic of the design as much as we are by the intricacies of the circuit or the cleverness of the software. We think it’s always fun to assemble projects that were just sort of rigged up in our shop really quickly and made to just work, without worrying about much else. But, when you really invest time in the aesthetics and marry form with function, the results are always one to marvel at.

That’s what the engineers over at [Hacker Shack] did with their Raspberry Pi-based video intercom system over on Hackster. Now we’ve seen RPi doorbell projects here on Hackaday before, but it’s the implementation of a full-duplex video intercom system that makes [Hacker Shack’s] project really stand out. (Unless you want to be a bit more secretive). They used a Raspberry Pi 3 Model B with an off-brand Pi camera, but the R Pi branded camera will also work just fine. Couple the camera with a very crisp LCD display, microphone, and speaker and you’re good to go! Continue reading “A Raspberry Pi Video Intercom System” →

This Camera Captures Piezo Inkjet Micro-Drops For DIY Microfluidics

April 15, 2020 by Donald Papp 6 Comments

In microfluidics, there are “drop on demand” instruments to precisely deposit extremely small volumes (pico- or nano-liters) of fluid. These devices are prohibitively expensive, so [Kyle] set out to design a system using hobbyist-level parts for under $1000. As part of this, he has a fascinating use case for a specialized camera: capturing the formation and shape of a micro-drop as it is made.

There are so many different parts to this effort that it’s all worth a read, but the two big design elements come down to:

Making the microdrop using a piezo element
Ensuring the drop is made correctly, and visually troubleshooting

Working prototype. The piezo tube is inside the blue piece at the top. The camera is to the right, and the LED strobe is on the left.

It’s one thing to make an inkjet element in a printer work, but it’s quite another to make a piezoelectric element dispense arbitrary liquids in a controlled, repeatable, and predictable way. Because piezoelectric elements force liquid out with a mechanical motion, different liquids require different drive signals and that kind of experimentation requires a way to see what is going on, hence the need for a drop observation camera.

[Kyle] ended up taking the lens assembly from a cheap USB microscope and mating it to his Korukesu C1 USB Camera with a 3D printed assembly. Another 3D printed enclosure doubles as a lightbox, holding the piezo tube in the center with the LED strobe and camera on opposite sides. The whole assembly had a few false starts, but in the end [Kyle] seems pretty happy with his results. The device is briefly described at a high level here. There are some rough edges, but it’s a working system.

Inkjet technology has been around for a long time (you can see a thirty-plus year old inkjet printer in action here) but it’s worth mentioning that not all inkjet heads are alike. Most inkjet printer heads operate thermally, which means a flash of heat vaporizes some ink to expel a micro-drop. These heads aren’t very suitable for microfluidics because not only do they rely on vaporizing the liquid, but they also don’t work well with anything other than the ink they’re designed for. Piezoelectric print heads are less common, but are more suited to the kind of work [Kyle] is doing.

Classic Leica Film Camera Turns Digital

April 10, 2020 by Bryan Cockfield 36 Comments

While there’s still a market for older analog devices such as vinyl records, clocks, and vacuum-tube-powered radio transmitters, a large fraction of these things have become largely digital over the years. There is a certain feel to older devices though which some prefer over their newer, digital counterparts. This is true of the camera world as well, where some still take pictures on film and develop in darkrooms, but if this is too much of a hassle, yet you still appreciate older analog cameras, then this Leica film camera converted to digital might just attract your focus.

This modification comes in two varieties for users with slightly different preferences. One uses a Sony NEX-5 sensor which clips onto the camera and preserves almost all of the inner workings, and the aesthetic, of the original. This sensor isn’t full-frame though, so if that’s a requirement the second option is one with an A7 sensor which requires extensive camera modification (but still preserves the original rangefinder, an almost $700 part even today). Each one has taken care of all of the new digital workings without a screen, with the original film advance, shutters, and other HIDs of their time modified for the new digital world.

The finish of these cameras is exceptional, with every detail considered. The plans aren’t open source, but we have a hard time taking issue with that for the artistry this particular build. This is a modification done to a lot of cameras, but seldom with so much attention paid to the “feel” of the original camera.

Thanks to [Johannes] for the tip!

[Ben Krasnow] Rolls Old School Camera Out For Photolithography

March 26, 2020 by Dan Maloney 14 Comments

In a time when cameras have been reduced to microchips, it’s ironic that the old view camera, with its bellows and black cloth draped over the viewscreen for focusing, endures as an icon for photography. Such technology appears dated and with no application in the modern world, but as [Ben Krasnow] shows us, an old view camera is just the thing when you want to make homemade microchips. (Video, embedded below.)

Granted, the photolithography process [Ben] demonstrates in the video below is quite a bit upstream from the creation of chips. But mastering the process on a larger scale is a step on the way. The idea is to create a high-resolution photograph of a pattern — [Ben] chose both a test pattern and, in a nod to the season, an IRS tax form — that can be used as a mask. The camera he chose is a 4×5 view camera, the kind with lens and film connected by adjustable bellows. He found that modifications were needed to keep the film fixed at the focal plane, so he added a vacuum port to the film pack to suck the film flat. Developing film has always been magical, and watching the latent images appear on the film under the red light of the darkroom really brings us back — we can practically smell the vinegary stop solution.

[Ben] also steps through the rest of the photolithography process — spin coating glass slides with photoresist, making a contact print of the negative under UV light, developing the print, and sputtering it with titanium. It’s a fascinating process, and the fact that [Ben] mentions both garage chip-maker [Sam Zeloof] and [Justin Atkin] from the Thought Emporium means that three of our favorite YouTube mad scientists are collaborating. The possibilities are endless.

Continue reading “[Ben Krasnow] Rolls Old School Camera Out For Photolithography” →

The Drone That Can Play Dodgeball

March 23, 2020 by Rich Hawkes 10 Comments

Drones (and by that we mean actual, self-flying quadcopters) have come a long way. Newer ones have cameras capable of detecting fast moving objects, but aren’t yet capable of getting out of the way of those objects. However, researchers at the University of Zurich have come up with a drone that can not only detect objects coming at them, but can quickly determine that they’re a danger and get out of the way.

The drone has cameras and accompanying algorithms to detect the movement in the span of a couple of milliseconds, rather than the 20-40 milliseconds that regular quad-copters would take to detect the movement. While regular cameras send the entire screens worth of image data to the copter’s processor, the cameras on the University’s drone are event cameras, which use pixels that detect change in light intensity and only they send their data to the processor, while those that don’t stay silent.

Since these event cameras are a new technology, the quadcopter processor required new algorithms to deal with the way the data is sent. After testing and tweaking, the algorithms are fast enough that the ‘copter can determine that an object is coming toward it and move out of the way.

It’s great to see the development of new techniques that will make drones better and more stable for the jobs they will do. It’s also nice that one day, we can fly a drone around without worrying about the neighborhood kids lobbing basketballs at them. While you’re waiting for your quadcopter delivered goods, check out this article on a quadcopter testbed for algorithm development.

Hackaday Links: March 22, 2020

March 22, 2020 by Dan Maloney 23 Comments

Within the span of just two months, our world of unimaginable plenty and ready access to goods manufactured across the globe has been transformed into one where the bare essentials of life are hard to find at any price. The people on the frontline of the battle against COVID-19 are suffering supply chain pinches too, often at great risk to their health. Lack of proper personal protective equipment (PPE), especially face masks, is an acute problem, and the shortage will only exacerbate the problem as healthcare workers go down for the count. Factories are gearing up to make more masks, but in the meantime, the maker and hacker community can pitch in. FreeSewing, an open-source repository of sewing patterns, has a pattern for a simple face mask called the Fu that can be made quickly by an experienced threadworker. Efficacy of the masks made with that pattern will vary based on the materials used, obviously; a slightly less ad hoc effort is the 100 Million Mask Challenge, where volunteers are given a pattern and enough lab-tested materials to make 100 face masks. If you know how to sew, getting involved might make a difference.

As people around the world wrap their heads around the new normal of social distancing and the loss of human contact, there’s been an understandable spike in interest in amateur radio. QRZ.com reports that the FCC has recorded an uptick in the number of amateur radio licenses issued since the COVID-19 outbreak, and license test prep site HamRadioPrep.com has been swamped by new users seeking to prepare for taking the test. As we’ve discussed, the barrier for entry to ham radio is normally very low, both in terms of getting your license and getting the minimal equipment needed to get on the air. One hurdle aspiring hams might face is the cancellation of so-called VE testing, where Volunteer Examiners administer the written tests needed for each license class. Finding a face-to-face VE testing session now might be hard, but the VEs are likely to find a way to adapt. After all, hams were social distancing before social distancing was cool.

The list of public events that have been postponed or outright canceled by this pandemic is long indeed, with pretty much everything expected to draw more than a handful of people put into limbo. The hacking world is not immune, of course, with many high-profile events scuttled. But we hackers are a resourceful bunch, and the 10th annual Open Source Hardware Summit managed to go off on schedule as a virtual meeting last week. You can watch the nearly eight-hour livestream while you’re self-isolating. We’re confident that other conferences will go virtual in the near-term too rather than cancel outright.

And finally, if you’re sick of pandemic news and just want some escapist engineering eye candy, you could do worse than checking out what it takes to make a DSLR camera waterproof. We’ve honestly always numbered cameras as among the very least waterproof devices, but it turns out that photojournalists and filmmakers are pretty rough on their gear and expect it to keep working even so. The story here focuses (sorry) on Olympus cameras and lenses, which you’ll note that Takasu-san only ever refers to as “splash-proof”, and the complex system of O-rings and seals needed to keep water away from their innards. For our money, the best part was learning that lenses that have to change their internal volume, like zoom lenses, need to be vented so that air can move in and out. The engineering needed to keep water out of a vented system like that is pretty impressive.