Acoustic Engine Harnesses The Power Of Sound

February 21, 2025 by Dan Maloney 33 Comments

If you think sonic booms from supersonic aircraft are a nuisance, wait until the sky is full of planes propelled by up-scaled versions of this interesting but deafening audio resonance engine.

Granted, there’s a lot of work to do before this “Sonic Ramjet” can fly even something as small as an RC plane. Creator [invalid_credentials] came up with the idea for a sound-powered engine after listening to the subwoofers on a car’s audio system shaking the paint off the body. The current design uses a pair of speaker drivers firing into 3D printed chambers, which are designed based on Fibonacci ratios to optimize resonance. When the speakers are driven with a low-frequency sine wave, the chambers focus the acoustic energy into powerful jets, producing enough thrust to propel a small wheeled test rig across a table.

It’s fair to ask the obvious question: is the engine producing thrust, or is the test model moving thanks to the vibrations caused by the sound? [invalid_credentials] appears to have thought of that, with a video showing a test driver generating a powerful jet of air. Downloads to STL files for both the large and small versions of the resonating chamber are provided, if you want to give it a try yourself. Just be careful not to annoy the neighbors too much.

Thanks to [cabbage] for the tip via [r/3Dprinting].

Decompiling Sonic Runners

August 22, 2023 by Matthew Carlson 7 Comments

Usually, when you hear about games being decompiled and rebuilt, the games are often decades-old relics, loving and saved from the ravages of time. [MattKC] recently set out to decompile the 2015 game Sonic Runners.

The game was a 2D endless runner released on mobile platforms. Despite getting praise for the gameplay, it received mixed reviews for the pop-up ads and pay-to-play elements. A little over a year later, the game was discontinued. However, the game required a constant online connection, so once the servers were offline, it rendered the over five million downloads unplayable.

A team of developers worked to reverse engineer the server, and with a little bit of binary hacking, the client could be patched to connect to a community-hosted server instead. However, as phones with notched displays came out and suggestions for improvements stacked up, the community realized a new client would bring immense benefits. Compared to many decompilation projects, Sonic Runners was pretty easy as it uses Unity, which means most of the code is in C#. Unfortunately, the build of Unity used by the game is from 2012, meaning many of the tools designed for much later versions of Unity were inoperable.

However, one native code library called UnmanagedProcess was designed to confuse reverse engineering efforts. The library handled AES encryption and communication with the server. Luckily, the library was a later addition, and earlier versions of its functions still lingered in the C# code. Since an open source server already existed, it was trivial to validate the changes. Additionally, all the shaders were in OpenGL Shading Language (GLSL), which meant rewriting them in High-Level Shading Language (HLSL) and checking that they matched the original GLSL when building for Android.

Now the client has new game modes, no ads, and a proper offline mode. The community continues adding new features and refining the game, which is very satisfying. If you’re curious about reverse engineering, [Matthew Alt] can help you get started.

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A two picture montage of a boy wearing a sonic the hedgehog costume with LEDs in them. The left picture is at night with the boy wearing sunglasses and a face mask with the sonic costume head piece lit up. The right picture is during the day with the boy wearing a face mask, holding a plastic pu mpkin bucket for candy and wearing a lit up sonic the hedgehog costume in the front yard of a house.

LEDs Put New Spin On A Sonic The Hedgehog Costume

November 26, 2022 by Abe Connelly 1 Comment

[Wentworthm] couldn’t say no to his son’s plea for a Sonic the Hedgehog costume for Halloween but also couldn’t resist sprucing it up with LEDs either. The end result is a surprisingly cool light up Sonic the Hedgehog costume.

After some experimentation, [Wentworthm] ordered two costumes and ended up mixing and matching the head piece of one with the body suit of the other. For the head, [Wentworthm] created six 3D printed “quills” that had slots for the WS2812B LED strips to slide into and diffuse out the sides, with each quill sliding into the folds of the Sonic head “spikes”. Sewn strips of cloth were used to house the LED strips that were placed down the sides of the costume. An additional 3D printed switch housing was created to allow for a more robust interface to the two push buttons to activate the LEDs. An Arduino Nano, soldered to a protoboard, was used to drive the LED strips with a USB battery pack powering the whole project.

[Wentworthm] goes into more detail about the trials and errors, so the post is definitely worth checking out for more detail on the build. Halloween is always a great source of cool costumes and we’ve featured some great ones before, like a light up crosswalk costume to making a giant Gameboy colour costume.

Video after the break!

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This Week In Security: Secure Boot Bypass, Attack On Titan M, KASLR Weakness

August 19, 2022 by Jonathan Bennett 9 Comments

It’s debatable just how useful Secure Boot is for end users, but now there’s yet another issue with Secure Boot, or more specifically, a trio of signed bootloaders. Researchers at Eclypsium have identified problems in the Eurosoft, CryptoPro, and New Horizon bootloaders. In the first two cases, a way-too-flexible UEFI shell allows raw memory access. A startup script doesn’t have to be signed, and can easily manipulate the boot process at will. The last issue is in the New Horizon Datasys product, which disables any signature checking for the rest of the boot process — while still reporting that secure boot is enabled. It’s unclear if this requires a config option, or is just totally broken by default.

The real issue is that if malware or an attacker can get write access to the EFI partition, one of these signed bootloaders can be added to the boot chain, along with some nasty payload, and the OS that eventually gets booted still sees Secure Boot enabled. It’s the perfect vehicle for really stealthy infections, similar to CosmicStrand, the malicious firmware we covered a few weeks ago.
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Don’t Trust Your Ears For The Freshest Chips

May 20, 2020 by Brian McEvoy 11 Comments

We hear fables of how to restore the crispness to your crisp and the crackle to your crackers, but they are more hot air than some of the methods. We found one solution that has some teeth though, and it doesn’t require any kitchen appliances, just a pair of headphones. Keep reading before you mash potato chips into your Beats. [Charles Spence] co-authors a paper with [Massimiliano Zampini] titled The Role of Auditory Cues in Modulating the Perceived Crispness and Staleness of Potato Chips. It’s a mouthful, so folks refer to it as the “Sonic Chip Experiment,” which rolls off the tongue. The paper is behind paywalls, but you can find it if you know where to look.

The experiment puts participants in some headphones while they eat Pringles, and researchers feed them different sound waves. Sometimes the sound file is a recording of crackly chewing, and other times it is muffled mastication. The constant was the Pringles, which are a delight for testing because they are uniform. Participants report that some chips are fresher than others. This means we use our ears to help judge consumable consistency. Even people who knew all about the experiment report they can willingly fool themselves with the recordings.

What other foods would benefit from the augmented crunch, and which ones would suffer? If shapely food is your jam, we have a holy cookie which is probably best enjoyed with your eyes. If you prefer your Skittles organized by color, we have you covered.

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Sonic The Self-Balancing Robot: Face-Plants And The Challenges Of Sensor Integration

February 26, 2020 by Danie Conradie 2 Comments

Watching a child learn to run is a joyous, but sometimes painful experience. It seems the same is true for [James Bruton]’s impressive Sonic the Self-Balancing robot, even with bendable knees and force sensitive legs.

We covered the mechanical side of the project recently, and now [James] has added the electronics to turn it into a truly impressive working robot (videos after the break). Getting it to this point was not without challenges, but fortunately he is sharing the experience with us, wipe-outs and all. The knees of this robot are actuated using a pair of motors with ball screws, which are not back drivable. This means that external sensors are needed to allow the motors to actively respond to inputs, which in this case are load cells in the legs and an MPU6050 IMU for balancing. The main control board is a Teensy 3.6, with an NRF24 module providing remote control.

[James] wanted the robot to be able to lean into turns and handle uneven surfaces (small ramps) without tipping or falling over. The leaning part was fairly simple (for him), but the sensor integration for uneven surfaces turned out to be a real challenge, and required multiple iterations to get working. The first approach was to move the robot in the direction of the tipping motion to absorb it, and then return to level. However, this could cause it to tip over slightly larger ramps. When trying to keep the robot level while going over a ramp with one leg, it would go into wild side-to-side oscillations as it drops back to level ground. This was corrected by using the load cells to dampen the motion.

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Sonic The Hedgehog Self-Balancing Robot Can Bend At The Knees

January 31, 2020 by Danie Conradie 4 Comments

Building your own self-balancing robot is a rite of passage for anyone getting into the field of robotics. Master of robots, [James Bruton] has been there, done that, and collected a few T-shirts. Now he’s building a large Sonic the Hedgehog self balancing robot that can bend at the knees and hip, allowing it to lean while turning and handle uneven terrain. Check out the first video embedded after the break.

Standing about 1 m tall, the robot is inspired by Boston Dynamic’s box handling bot, Handle. It’s “skeleton” consists of 20×20 aluminium extrusions, bolted together using a bunch of 3D printed fittings in the signature blue and red of Sonic. The wheels and tyres are also 3D printed, and driven by brushless motor via a toothed belt. The knee/hip mechanism is actuated using a ball screw, also driven by a brushless motor.

[James] intends to implement an active shock absorption system into the leg mechanism, using the same technique he tried on his OpenDog robot. It works by bolting a load cell onto one of the leg extrusion to sense when it flexes under load, and then actuating the knee mechanism to absorb the force. His first version of the system on OpenDog used PWM signals to send the load cell data to the main controller, but the motors on the legs induced enough noise in the signal wires to make it unusable. He has since started experimenting with the CAN bus protocol, which was specifically designed to work reliably in noisy systems like modern automobiles. If he gets it working on the two legs of this Sonic robot, he plans to also implement it on the quadruped OpenDog.

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