Author: Dan Maloney

3373 Articles

Interesting Optical Journey Results In Hybrid Viewfinder For Smartphones

December 12, 2022 by 5 Comments

Fair warning: if you ever thought there was nothing particularly interesting with optical viewfinders, prepare to have your misconception corrected by [volzo] with this deep-dive into camera-aiming aids that leads to an interesting hybrid smartphone viewfinder.

For most of us, the traditional optical viewfinder is very much a thing of the past, having been supplanted by digital cameras and LCD displays. But some people still want to frame a photograph the old-fashioned way, and the optical principles that make that possible are actually a lot more complicated than they seem. [volzo]’s blog post and video go into a great deal of detail on viewfinder optics, so feel free to fall down that rabbit hole — it’s worth the trip. But if you’d rather cut to the chase, the actual viewfinder build starts at about the 23:00 mark in the video.

The design is an interesting combination of lenses and beamsplitters that live in a 3D-printed enclosure. The whole thing slips over one end of a smartphone and combines an optical view of the scene that corresponds to the camera’s field of view with a small digital overlay from the phone’s screen. The overlay is quite simple: just some framing gridlines and a tilt indicator that’s generated by a little Android app. But it’s clear that much more information could be added now that [volzo] has all the optical issues sorted out.

We appreciate this deep dive into something that appears to be mundane and outdated, which actually proves to be non-obvious and pretty interesting. And if you have any doubt about the extreme cleverness of the camera engineers of yore, look no further than this sort-of solar-powered camera from the 1960s.

Continue reading “Interesting Optical Journey Results In Hybrid Viewfinder For Smartphones” →

Battery Engineering Hack Chat

December 12, 2022 by 7 Comments

Join us on Wednesday, December 14 at noon Pacific for the Battery Engineering Hack Chat with Dave Sopchak!

Of all the things driving technology forward, you’d have to say that the ability of chip makers to squeeze more complex circuits than ever onto silicon has to rank right up there. And while that’s no doubt true, it only tells a part of the story. For our money, though, the advancements in battery technology over the last 30 years or so are the real champ, because without compact, cheap, energy-dense batteries, almost none of the cool stuff we see today, from smartphones to electric vehicles, would be practical.

Battery technology has come a long way from the days when carbon-zinc and nickel-cadmium cells were kings. New chemistries, better materials and methods, and engineering improvements have all contributed to incredibly powerful, incredibly compact batteries that make applications nobody could have thought of just a few decades ago possible.

join-hack-chatDave Sopchak has been in the thick of battery engineering since taking a doctorate in electrochemistry from Case Western Reserve. Since then he has worked at several fuel cell start-ups, and is now working on a lithium-air battery that sounds really interesting. We’ve asked him to help us wrap up the 2022 Hack Chat series with a discussion on battery engineering, with a focus on upcoming technologies and advancements that could really put some power in your pocket.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, December 14 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

Hackaday Links Column Banner

Hackaday Links: December 11, 2022

December 11, 2022 by 13 Comments

“They paved paradise and put up a parking lot.” That might be stretching things a bit, especially when the “paradise” in question is in New Jersey, but there’s a move afoot to redevelop the site of the original “Big Bang Antenna” that has some people pretty upset. Known simply as “The Horn Antenna” since it was built by Bell Labs in 1959 atop a hill in Holmdel, New Jersey, the antenna was originally designed to study long-distance microwave communications. But in 1964, Bell Labs researchers Arno Penzias and Robert Wilson accidentally discovered the microwave remnants of the Big Bang, the cosmic background radiation, using the antenna, earning it a place in scientific history. So far, the only action taken by the township committee has been to authorize a study to look into whether the site should be redeveloped. But the fact that the site is one of the highest points in Monmouth County with sweeping views of Manhattan has some people wondering what’s really on tap for the site. A petition to save the antenna currently has about 3,400 signatures, so you might want to check that out — after all, you don’t know what you’ve got ’til it’s gone.

Continue reading “Hackaday Links: December 11, 2022” →

Properly Pipe Laser Light Around With Homebrew Fiber Couplings

December 9, 2022 by 7 Comments

It’s a rare person who can pick up a cheap laser pointer and not wield it like a lightsaber or a phaser, complete with sound effects. There’s just something about the “pew-pew” factor that makes projecting a laser beam fun, even if it’s not the safest thing to do, or the most efficient way to the light from one place to another.

We suspect that [Les Wright] has pew-pewed his way through more than a few laser projects in his lab, including his latest experiments with fiber coupling of lasers. The video below is chock full of tips on connecting cheap communications-grade fiber assemblies, which despite their standardized terminations aren’t always easy to use with his collection of lasers. Part of the challenge is that the optical fiber inside the cladding is often very small — as few as 9 microns. That’s a small target to hit without some alignment help, which [Les] uses a range of hacks to accomplish.

The meat of the video demonstrates how to use a cheap fiber fault locator and a simple optical bench setup to precisely align any laser with an optical fiber. A pair of adjustable mirrors allow him to overlap the beams of the fault locator and the target laser precisely. The effects can be interesting; we had no idea comms-grade fiber could leak as much light through the cladding as this, and the bend-radius limits are pretty dramatically illustrated. [Les] teases some practical sensing applications for this in a follow-up video, which we’re looking forward to.

Looking for more laser fun with your remaining eye? Check out [Marco Reps] teardown of a 200-kW fiber laser.

Continue reading “Properly Pipe Laser Light Around With Homebrew Fiber Couplings” →

Audio Amp Puts VFDs To Work In An Unusual Way

December 8, 2022 by 14 Comments

It’s safe to say that most projects that feature a VFD emphasize the “D” aspect more than anything. Vacuum fluorescent displays are solid performers, after all, with their cool blue-green glow that’s just the right look for lots of retro and not-so-retro builds. But that doesn’t mean there aren’t applications that leverage the “V” aspect, such as this nifty audio preamp using VFDs as active components.

The inspiration behind [JGJMatt]’s build came from the Korg Nutube line of VFD-based low-voltage dual-triode vacuum tubes. Finding these particular components a little on the expensive side, [JGJMatt] turned to the old standby DM160 VFD indicator tube, which is basically just a triode, to see how it would fare as an amp. The circuit takes advantage of the low current and voltage requirements of the VFDs — the whole thing runs from a USB boost converter — by wedging them between a 2N3904 input stage and a 2N2007 MOSFET output. There’s a mix of SMD and through-hole components on the custom-etched PCB, with a separate riser card to show off the VFDs a little bit through the front panel of the 3D printed case.

All in all, we find this little amp pretty cool, and we love the way it puts a twist on the venerable VFD. We’ve seen similar VFD amps before, but this one’s fit and finish really pays off.

Rotary Dial Number Pad Is The Perfect Prank For Retro-Phone Enthusiast

December 5, 2022 by 10 Comments

We’re not sure about the rest of you, but to us, a keyboard without a number pad all the way over to the right just seems kind of — naked? We might not be accountants, but there’s something comforting about having the keypad right there, ready for those few occasions when you need to enter numbers more rapidly than would be possible with the row of number keys along the top of the keyboard.

What we are sure about, though, is that rapid numeric keying is not what this rotary dial numpad keyboard is all about. In fact, it’s actually an April Fool’s prank [Squidgeefish] played on a retro-phone-obsessed coworker, and it worked out pretty well. Starting with an old telephone dial from what must be an exceptionally well-stocked parts bin, [Squidgeefish] first worked out the electrical aspects of interfacing the dial with a cheapo mechanical keyboard. It turns out that there’s a lot of contact bounce in those old dials, leading to some software hacks to keep the Arduino happy.

There was also a little hackery needed to stuff a USB hub into the keyboard, as well as literal hacking of the keyboard’s PCB. A 3D printed enclosure allows the rotary dial to nestle into the place where the regular numpad would be, and it looks pretty good. We also like forcing the issue by replacing the entire row of number keys with a single massive prank key.

While this was all for fun, there are a couple of cool tips here, like chucking a bit of printer filament in a Dremel tool to stir-weld parts together. And even though we’ve seen that parametric keycap generator before, it is pretty cool to see it in action.

Hackaday Links Column Banner

Hackaday Links: December 4, 2022

December 4, 2022 by 25 Comments

Well, this is embarrassing! Imagine sending a multibillion-dollar rover to an ancient lakebed on Mars only to discover after a year of poking around at the rocks that it might not actually have been a lake after all. That seems to be the impression of Jezero Crater that planetary scientists are forming after looking at the data coming back from Perseverance since it nailed the landing in what sure as heck looked like a dried-up lake, complete with a river delta system. A closer look at the sediments Perseverance has been sampling reveals a lot of the mineral olivine, which on Earth is rare near the surface because it readily reacts with water. Finding lots of olivine close below the surface of Jezero suggests that it either wasn’t all that watery once upon a time, or that what water was there was basically ice cold. The results are limited to where the rover has visited, of course, and the nice thing about having wheels is that you can go somewhere else. But if you were hoping for clear signs that Jezero was once a lake teeming with life, you might have to keep waiting.

In other space news, we have to admit to taking NASA to task a bit in the podcast a couple of weeks back for not being quite up to SpaceX’s zazzle standards with regard to instrumenting the SLS launch. Yeah, a night launch is spectacular, but not having all those internal cameras like the Falcon has just sort of left us flat. But we should have been more patient, because the images coming back from Artemis 1 are simply spectacular. We had no idea that NASA attached cameras to the solar panels of the Orion spacecraft, which act a little like selfie sticks and allow the spacecraft to be in the foreground with Earth and the Moon in the background. Seeing Earth from lunar distance again for the first time in 50 years has been a real treat, and getting our satellite in the frame at the same time is a huge bonus.

Continue reading “Hackaday Links: December 4, 2022” →