Printed Film Camera Gets 10 Seconds Out Of A 35mm Roll

December 17, 2022 by Jenny List 17 Comments

When the British budget electronics brand Amstrad released their first budget VHS camcorder in the mid 1980s, they advertised it as making a filmmaker out of everyone. Now everyone truly is a filmmaker of sorts with their always-handy mobile phones, even though possessing a camera does not give you the talent of Steven Spielberg.

Such easy access to video hasn’t dimmed the allure of old-style film though, and there is a band of enthusiasts who seek out the older medium. [Joshua Bird] is one, and he’s produced a rather special 3D printed camera that can capture short videos on a standard roll of 35mm camera film. The downside is that, at the going rate, filming your masterpiece comes out to approximately $600 USD for each 10 minutes of footage. Better keep that dense exposition to a minimum.

The two most important mechanisms in a movie camera are the shutter and the film advance. The first is a disc that spins once a frame with an arc-shaped aperture over a section of it to let the light through, while the second is a hook that engages with the film once a frame after the shutter aperture has passed, to advance it to the next frame. Designing these to work in printed form is no easy task, and [Joshua] takes the reader through the various twists and turns in their development. Beyond that he takes a novel approach to a through-the-lens viewfinder, eschewing a split prism for an angled mirror on the shutter disk.

With each frame taking a fraction of the 35mm frame it’s clear from the video below that this doesn’t deliver the highest quality image. But that’s not the point of a device like this, above all it’s a working movie camera that he made himself. Since some of us have interests in that direction, dare we say we’re envious? Meanwhile, this isn’t the first 3D printed movie camera we’ve brought you.

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Citizen-Driven Network Monitors Public Service Radio For Natural Disaster Alerts

December 17, 2022 by Dan Maloney 12 Comments

Time is of the essence in almost every emergency situation, especially when it comes to wildfires. A wind-driven fire can roar across a fuel-rich landscape like a freight train, except one that can turn on a dime or jump a mile-wide gap in a matter of seconds. Usually, the only realistic defense against fires like these is to get the hell out of their way as soon as possible and make room for the professionals to do what they can to stop the flames.

Unfortunately, most people living in areas under threat of wildfires and other natural disasters are often operating in an information vacuum. Official channels take time to distribute evacuation orders, and when seconds count, such delays can cost lives. That’s the hole that Watch Duty seeks to fill.

Watch Duty is a non-profit wildfire alerting, mapping, and tracking service that provides near-real-time information to those living in wildfire country. Their intelligence is generated by a network of experienced fire reporters, who live in wildfire-prone areas and monitor public service radio transmissions and other sources to get a picture of what’s going on in their specific area. When the data indicate an incident is occurring, maps are updated and alerts go out via a smartphone app. Reporters have to abide by a strict code of conduct designed to ensure the privacy of citizens and the safety of first responders.

While Watch Duty’s network covers a substantial area of California — the only state covered so far — there were still a significant number of dead zones, mostly in the more remote areas of the Sierra Nevada Mountains and in the northern coastal regions. To fill these gaps, Watch Duty recently launched Watch Duty Echo, which consists of a network of remote listening posts.

Each station is packed with RTL-SDR receivers that cover a huge swath of spectrum used by the local fire, law enforcement, EMS agencies — any organization likely to be called to respond to an incident. In addition, each station has an SDR dedicated to monitoring ADS-B transponders and air band frequencies, to get a heads-up on incidents requiring aerial support. The listening posts have wideband discone antennas and a dedicated 1090-MHz ADS-B antenna, with either a cellular modem or a Starlink terminal to tie into the Watch Duty network.

Hats off to the folks at Watch Duty for putting considerable effort into a system like this and operating it for the public benefit. Those who choose to live close to nature do so at their own risk, of course, but a citizen-driven network that leverages technology can make that risk just a little more manageable.

DIY Square Guitar Is Anything But

December 17, 2022 by Kristina Panos 3 Comments

One of the greatest things about this place is how y’all constantly feed off of each other. And while this isn’t exactly an example of that, it’s pretty darn close — we feature a square guitar build one day, and get a tip about another way different and perhaps more functional one the next.

[Craig Lindley] had no idea of his luthier powers until an email from StewMac inspired him to build his own guitar. Rather than strip a perfectly good axe or two for all the parts, he bought the hardware and a pre-made neck, and built the body himself. The Bo Diddley-inspired boxy body is an ice cream sandwich of sapele, inlaid with white ash around the perimeter which is quite the classy look. Speaking of looks, [Craig] worried that all-gold hardware would be too flashy, but we think it looks great.

Not hard-mode enough for you? Well, here’s a guitar made from scratch, (more or less). If you’d rather have more of a teaching guitar, behold this LED-laden axe.

Yesterday’s Future Is Brighter Today

December 17, 2022 by Elliot Williams 31 Comments

The demoscene never ceases to amaze. Back in the mid-80s, people wouldn’t just hack software to remove the copy restrictions, but would go the extra mile and add some fun artwork and greetz. Over the ensuing decade the artform broke away from the cracks entirely, and the elite hackers were making electronic music with amazing accompanying graphics to simply show off.

Looked at from today, some of the demos are amazing given that they were done on such primitive hardware, but those were the cutting edge home computers at the time. I don’t know what today’s equivalent is, with CGI-powered blockbusters running in mainstream cinemas, the state of the art in graphics has moved on quite a bit. But the state of the old art doesn’t rest either. I’ve just seen the most amazing demo on a ZX Spectrum.

Simply put, this demo does things in 2022 on a computer from 1982 that were literally impossible at the time. Not because the hardware was different – this is using retro gear after all – but because the state of our communal knowledge has changed so dramatically over the last 40 years. What makes 2020s demos more amazing than their 1990s equivalents is that we’ve learned, discovered, and shared enough new tricks with each other that we can do what was previously impossible. Not because of silicon tech, but because of the wetware. (And maybe I shouldn’t underestimate the impact of today’s coding environments and other tooling.)

I love the old demoscene, probably for nostalgia reasons, but I love the new demoscene because it shows us how far we’ve come. That, and it’s almost like reverse time-travel, taking today’s knowledge and pushing it back into gear of the past.

Say The Magic Word, And The TinySA Goes Ultra

December 17, 2022 by Al Williams 15 Comments

We’ve looked at the TinySA spectrum analyzer in the past. However, the recent Ultra edition offers an increase in range from 800 MHz to 6 GHz. How does it work? [IMSAI Guy] tells us in a recent video that you can watch below. In addition to an increased frequency range, the new device offers a larger display and enhancements to the signal generator and bandpass filtering. It also has an optional LNA. All this, of course, is at a price since the Ultra sells at a little more than twice the original unit’s price. Still, $120 or so for a 6 GHz spectrum analyzer isn’t bad.

For some reason, you have to put a passcode in to enable the Ultra mode, although the passcode appears to be common knowledge and available on the device’s wiki. You can presume they could, at some point, make this feature or others require a paid passcode, but for now, it is just a minor inconvenience. Reminds us of a certain oscilloscope that’s become quite popular in our community.

One thing you should be aware of, however, is that the Ultra mode uses a mixer to downconvert the incoming signal to the ordinary 800 MHz range. That means, as you can see in the video, that the local oscillator puts out some signal at the input. The level is relatively low, but still something to be aware of if you are trying to make a precision measurement.

The video compares the device to an HP 8591E spectrum analyzer. It tops out at 1.8 GHz and runs about $2,500 new. Even on eBay, you can expect to pay between $500 and $1000 for one of these. The results seem to be comparable, for the most part.

We looked at the device’s predecessor back in 2020. We also did a full-blown review a little bit later.

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Differential Swerve Drive Is Highly Maneuverable

December 17, 2022 by Lewin Day 17 Comments

There are a variety of wheel designs out there that can provide for rotation and translation in various directions. The differential swerve drive, though, as demonstrated by [WildWillyRobots], uses regular wheels on a complex mount to achieve impressive directional flexibility.

The design uses a regular round wheel mounted on an axle, which has a gear on one end. This allows the wheel to be driven. The wheel and axle is mounted upon a circular carrier, which is then fitted with a pair of surrounding gears on bearings. Differentially driving these gears changes the way the drive behaves. With both gears driven in the same direction, the wheel rotates on its vertical axis to point in different directions. If both gears are driven in opposite direction, the wheel itself is driven. Relatively varying the speed of both gears allows the direction and drive of the wheel to be controlled. The result is a wheel that can rotate to any angle, and then be driven forwards or backwards as well.

Fitting a set of these wheels to a robot creates a highly maneuverable platform. As a bonus, it doesn’t have the drawback of poor grip that is common with various omniwheel-type designs.

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Kids’ Jukebox Based On Arduino With RFID

December 16, 2022 by Bryan Cockfield 10 Comments

Consumer electronics aimed at young children tend to be quite janky and cheap-looking, and they often have to be to survive the extreme stress-testing normal use in this situation. You could buy a higher quality item intended for normal use, but this carries the risk of burning a hole in the pockets of the parents. To thread the needle on this dilemma for a child’s audiobook player, [Turi] built the Grimmboy for a relative of his.

Taking its name from the Brothers Grimm, the player is able of playing a number of children’s stories and fables in multiple languages, with each physically represented by a small cassette tape likeness with an RFID tag hidden in each one. A tape can be selected and placed in the player, and the Arduino at the center of it will recognize the tag and play the corresponding MP3 file stored locally on an SD card. There are simple controls and all the circuitry to support its lithium battery as well. All of the source code that [Turi] used to build this is available on the project’s GitHub page.

This was also featured at the Arudino blog as well, and we actually featured a similar project a while ago with a slightly different spin. Both are based on ideas from Tonuino, an open source project aimed at turning Arduinos into MP3 players. If you’re looking to build something with a few more features, though, take a look at this custom build based on the RP2040 microcontroller instead.