Building An Army Of Faux Cameras In The Name Of Art

August 10, 2021 by Tom Nardi 9 Comments

After taking mental note of the number of surveillance cameras pointed at him while standing in line at the local Home Depot, [Mac Pierce] was inspired to create A Scanner Darkly. The art installation uses beams of light projected by mock security cameras to create a dot-matrix character display on the opposing wall, which slowly blinks out US surveillance laws and regulations.

[Mac] has put together an extensive behind the scenes look at how he created A Scanner Darkly, which among other things covers the incredible time and effort that went into producing the fifteen identical cameras used to project the 3×5 grid. Early on he decided on 3D printing each one, as it would give him complete control over the final result. But given their considerable size, it ended up taking 230 hours and 12 kilograms of PLA filament to print out all the parts. It took a further 55 hours to sand and paint the camera housings, to make sure they didn’t actually look like they’d been 3D printed.

Internally, each camera has an off-the-shelf LED flashlight that’s had its power button rigged up to an ESP8266. Once they’ve been manually pointed to the appropriate spot on the wall, [Mac] can turn each camera’s spotlight on and off over WiFi. Rather than rely on the gallery’s infrastructure, all of the cameras connect to the ESP32 M5Stack that serves as the central controller via ESP-Now.

From there, it was just a matter of writing some code that would load a text document from the SD card, convert the current character into a 3×5 array, and then command the appropriate cameras to turn their lights on or off. [Mac] has not only provided the STL files for the 3D printed camera, but the client and server Arduino code to control the lights. Combined with his excellent documentation, this makes A Scanner Darkly something of a viral art piece; as anyone with the time and appropriate tools can either duplicate the installation or use it as a base for something new.

While some will no doubt argue that [Mac] could have completed this project far faster had he just modified some commercial dummy cameras, it’s important to remember that as an artist, he had a very specific look in mind for A Scanner Darkly. This project is a perfect example of how a creator’s passion can take an idea to new heights, and we think the end result proves it’s worth the time and sweat to put in the extra effort.

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This Week In Security: Fail2RCE, TPM Sniffing, Fishy Leaks, And Decompiling

July 30, 2021 by Jonathan Bennett 10 Comments

Fail2ban is a great tool for dynamically blocking IP addresses that show bad behavior, like making repeated login attempts. It was just announced that a vulnerability could allow an attacker to take over a machine by being blocked by Fail2ban. The problem is in the mail-whois action, where an email is sent to the administrator containing the whois information. Whois information is potentially attacker controlled data, and Fail2ban doesn’t properly sterilize the input before piping it into the mail binary. Mailutils has a feature that uses the tilde key as an escape sequence, allowing commands to be run while composing a message. Fail2ban doesn’t sanitize those tilde commands, so malicious whois data can trivially run commands on the system. Whois is one of the old-school unix protocols that runs in the clear, so a MItM attack makes this particularly easy. If you use Fail2ban, make sure to update to 0.10.7 or 0.11.3, or purge any use of mail-whois from your active configs. Continue reading “This Week In Security: Fail2RCE, TPM Sniffing, Fishy Leaks, And Decompiling” →

Vintage Monochromator Makes Monochromatic Light, Mechanically

July 27, 2021 by Donald Papp 25 Comments

A monochromator is an optical instrument that permits only a narrow selection of wavelengths to be transmitted from a source, and the particular model [Doug] obtained renders visual light monochromatic by way of a mechanically-adjusted system of mirrors and diffraction gratings that allows only the selected wavelength to pass. The big dial is how the operator selects the desired wavelength, and is labeled in ‘mu’ (or milli-micro), but [Doug] helpfully points out the more modern term for that is nanometers.

LCD monitor viewed through a monochromator set to pass red wavelength only, showing that images remain intact.

How does it work? Light enters the device via an opening at the base, and only the selected wavelength exits from the top. The dial’s range is from 450 nm to 640 nm (representing violet-blue to red), which [Doug] demonstrates by shining a white LED flashlight into the unit and showing how only green, red, or blue will exit from the top depending on the setting of the dial.

An interesting side note is that with this particular device, images can be rendered monochromatic but otherwise remain intact. [Doug] demonstrates this by viewing a small section of his LCD monitor through the device, as shown in the photo he managed to capture.

It’s an interesting piece of vintage equipment that shows what is possible with passive optical components and a clever mechanical design. These devices are therefore entirely manually-operated tools (at least until someone sticks a stepper motor to the adjustment dial to create an automated scanner, that is.)

The Devil Is In The Details

July 3, 2021 by Elliot Williams 28 Comments

If you’ve taken a physics class, you’ve doubtless heard tales of mythical beasts like the massless string, the frictionless bearing, and the perfect sphere. And if you’re designing something new, it’s not always wrong to start by thinking in terms of these abstractions, just to get the basic framework laid and a first-order handle on the way things go. But once you start building, you’d better be ready to shed your illusions that a 6 mm peg will fit into a 6 mm hole.

Theory and practice are the same thing, in theory. But as soon as you step into practice, your “weekend build” can easily turn into a 500-hour project, full of hurdles, discoveries, experimentation, and eventual success. I’m not going to rehash [Scott Rumschlag]’s project here — you should really watch his detailed video — but suffice it to say that when building a sub-millimeter precision 3D measuring device, bearings do have friction and string does have non-zero mass, and it all matters.

When you start working on a project that “looked good on paper” or for whatever reason just doesn’t turn out as precisely as you’d wished, you could do worse than to follow [Scott’s] example: start off by quantifying your goals, and then identify where every error along the way accumulates to keep you from reaching them. Doing precise work isn’t easy, but it’s not impossible either if you know where all the errors are coming from. You at least have a chain of improvements that you can consider, and if you’ve set realistic goals, you also know when to stop, which is almost as important.

And if anyone out there has an infinite sheet of perfectly conductive material, I’m in the market.

Hackaday Podcast 123: Radioactive Rhinos, Wile E. Coyote Jetpack, Radio Hacks 3-Ways, And Battery Welders On The Spot

June 18, 2021 by Dan Maloney No comments

Hackaday’s Mike Szczys is taking a bit of vacation this week, so Elliot is joined by Staff Writer Dan Maloney to talk about all the cool hacks and great articles that turned up this week. Things were busy, so there was plenty to choose from, but how would we not pick one that centers around strapping a jet engine to your back to rollerskate without all that pesky exercise? And what about a light bulb that plays Doom – with a little help, of course. We’ll check out decals you can make yourself and why the custom keyboard crowd might want to learn that skill, learn about the other “first computer”, and learn how a little radiation might be just what it takes to save an endangered species.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (55 MB or so.)

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A Massive Modular Smartwatch To Match Your Sci-Fi Fantasies

June 11, 2021 by Danie Conradie 15 Comments

Modern smart watches have some incredible features, but they still don’t stack up to what science fiction promised us, both in size and capabilities. Fortunately, [Zack Freedman] has set out to change that with the Singularitron, a modular wearable computer that is less Apple Watch and more Pip-Boy.

The most striking features of this monstrosity is its size and the out-of-production four-line VFD display. The inputs consist of a row of large RGB-illuminated buttons and a rotary encoder mounted at an angle to curve around the wearers arm. On the inside are a pair of PCBs with an integrated Teensy 3.2, BLE module, motion processing module, haptic driver and power circuitry drawing from a removable 18650 battery. The armband is from a commercial wrist mounted barcode scanner which attaches to the Singularitron with a quick-detach mount.

A major feature of the Singularitron is its modularity. Arrayed around its edges are four slots with spring-loaded contacts for add-on modules. Modules have access to the SPI and I2C busses, two GPIO pins, 3.3 V and 5 V lines. Each module also contains an EEPROM chip to store the module’s ID and any configured settings, allowing modules to be hot swapped and automatically recognised. [Zack] has created a number of modules, like a laser pointer, environmental sensor, OLED display and a Teensy 4.0 to blink an LED. When a module is plugged or inserted, a series of randomly generated status messages flash across the display, thanks to an awesome little library which we are absolutely copying for our own projects. Ironically, keeping the time is one of the Singularitron weak points, since [Zack] wasn’t able to fit a backup battery inside, so the time needs to be reset when the battery dies. Maybe a module with an RTC and backup battery is the perfect solution. Continue reading “A Massive Modular Smartwatch To Match Your Sci-Fi Fantasies” →

Automated Sentry Turret For Your Secret Lab

June 6, 2021 by Danie Conradie 1 Comment

There are few things as frustrating when you’re trying to get some serious hacking done than intruders repeatedly showing up without permission. [All Parts Combined] has the solution for you, with a Kinect-based robotic sentry turret to keep them at bay.

The system consists of a Microsoft Kinect V2 connected to a PC, which runs an app to do all the processing, and outputs the targeting information to an Arduino over serial. The Arduino controls a simple 2-axis servo mount with an electric airsoft gun zip-tied to it. The trigger switch is replaced with a relay, also connected to the Arduino.

The Kinect V2 comes with SDKs that really simplify tracking human movement, and outputs the data in an easy-to-use format. [All Parts Combined] used the SDK in Unity, which allows him to choose which body parts to track. He added scripts that detect a few basic gestures, issues voice commands, and generates the serial commands for the Arduino. The servo angles are calculated with simple geometry, using XY coordinates of the target received from the SDK, and the known distance between the Kinect and turret. When an intruder enters the Kinect’s field of view it immediately starts aiming at the intruder’s heart, issues a “Hands Up!” command, and tells the intruder to leave. If the intruder doesn’t comply, it starts an audible countdown before firing. [All Parts Combined] also added a secret disarming gesture (double hand pistols), which turns the turret into an apologetic comrade. All it needs is a Portal-inspired enclosure.

It’s a fun project that illustrates how the Kinect can make complex computer vision tasks relatively simple. Unfortunately the V2 is no longer in production, having been replaced by the more expensive, developer focused Azure Kinect. We’ve covered several Kinect-based projects, including a 3D room scanner and a robotic basketball hoop.

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