Everything Makes Sound If You Try Hard Enough

Speaker cone materials can be a deep rabbit hole ranging from inexpensive paper to kevlar. We’ve all cut apart, or blown out, the cheapies to see their inner workings, but the exotic material list does not stop at audiophile-quality models. It can include mirrors, microwave ovens, and a European hacker’s forehead. Video also after the break. In addition to the speakers with expensive elements, there are sound-generating transducers with no cones. These are sometimes called surface speakers, and they vibrate something, anything, to make a sound. At their cores, they have many of the same parts, and making a surface speaker from a traditional speaker is not difficult.

The first step is to find a raw speaker, one with no crossover components, possibly from a garage sale or from a set your spouse insists are outdated, ugly, and better off as firewood. Power specifications should not change since we will be using the same solenoid, and that means your amplifier can follow the speakers back from the dead. The video provides step-by-step instructions, and the goal is to create a module with a moving shaft, but the range must be limited so it cannot be pushed back into the speaker or pulled away, both could destroy it. Once you have that, go around and make everything noisy. Don’t use this on pets or children, but spouses are fair game.

We would love to see a chip bender experiment with different speaker mediums to add an extra layer of complexity, but for the rest of us, bone conduction is already a real thing, and if you enjoy impractical speakers, you are not the only one with your head in the clouds.

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This Week In Security: Signal, WhatsApp, Oauth Fishing, And More State-Sponsored Attacks

A bug was recently fix in Signal that allowed a caller to force a call connection without any user interaction on the receiving side. We’ve seen this sort of problem in other chat applications, most recently the Zoom debacle.

The Signal client uses the same function to connect an outgoing call as an incoming call. This bit of code re-use allows a malicious client to initiate a call, and then send the “Accept Call” message. Because of the code re-use, this message triggers the same code as the accept call button on the receiving side. It’s as if the attacker uses reverse psychology to trick the other client into connecting.

It seems this bug only affected the Android client, and didn’t trigger a video call. It’s unclear whether the bug was discovered and exploited before it was fixed, but now that it has been announced, be sure to get Signal up to date. Continue reading “This Week In Security: Signal, WhatsApp, Oauth Fishing, And More State-Sponsored Attacks”

Sending An ESP32 Into Space

Just two weeks ago, the crew from the International Space Station released a photo of their nine crew members – an odd number considering that the facility only has space to house six astronauts at a time. In fact, the crew had just gathered for a celebratory dinner before three of the astronauts were to return home. The new astronauts joining including Hazza Al Mansouri, the first astronaut from the United Arab Emirates (who has since returned from his mission), as well as astronaut Jessica Meir and cosmonaut Oleg Skripochka.

Amidst the excitement over the upcoming 10 (!) spacewalks in the next three months, there’s also been some cool developments in the open source space, with one of the first ESP32s launched into space.

[Nico Maas] from the Microgravity User Support Center (MUSC) at DLR (German Aerospace Center) worked on an experiment launched by MORABA (Mobile Rocket Base) at DLR. The launch site was at the Esrange Space Center in Kiruna, Sweden, with the mission launching on June 13, 2019 at 4:21 am local time.

The experiment – APEX (Advanced Processors, Encryption, and Security Experiment) was onboard the ATEK / MAPHEUS-8, mission, rising to an altitude of 240km into space and returning back to earth after six minutes of microgravity.

[via AIP]
The goal of the research was to develop an off-the-shelf computer with a more powerful system for high-speed sensors and image acquisition than the Microchip ATmega328P, the current standard. The flight test measured the speed of the system as well as stress testing its ability to handle compute-intensive tests.

The main board included two ESP32s and a Raspberry Pi Zero W, running resinOS / balenaOS, an operating system designed to run parallel Docker containers and optimized for IoT fleet management.

Prior to the experiment, the standard for on-board computers for use in CubeSats was the ATmega/Arduino-based ARDUSAT. Since it was first made available for use in CubeSats in 2013, the performance has become limited, with improvements needed to perform higher throughput data sampling or operations requiring more computational power.

It’s also cool to note that the system, built using a 3D-printed holder, survived the re-entry (reaching up to 20.6g) with hardly a scratch.

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CPU Showdown For Pancakes

If you ask people how they rate as a driver, most of them will say they are better than average. At first, that seems improbable until you realize one thing: people judge themselves by different criteria. So Sally thinks she’s a good driver because she goes fast. Tom’s never had a wreck. Alice never gets lost. You can see the same effect with CPUs. Some are faster or have more memory bandwidth or more instruction issues per cycle. But [Andrew] and [Scharon] at Tom’s Hardware wanted to do the real test of a CPU. How well can it cook pancakes? If you want to know, see the video below.

While your CPU might be great for playing video games, it has a surprisingly small cooking surface, so the guys needed a very small pan. The pan had grooves in it, so they slathered it with thermal grease. We doubt that’s food-grade grease, either. Continue reading “CPU Showdown For Pancakes”