Day: July 26, 2019

Cheap Speakers Sound Great In A Proper Enclosure

July 26, 2019 by 31 Comments

It’s possible to pick up a low-cost set of speakers for a few dollars, but by and large, you don’t get a lot of quality for your money. Expect a small pair of drivers, with tinny sound and ugly noises from the enclosure’s cheap materials. [JSK-koubou] has shown us, however, that these speakers can become so much more.

The internal structure helps improve the frequency response.

In this case at least, the basic speaker drivers and electronics inside were passable. Harvesting these, the builder then proceeds to create a stunning pair of tuned wooden enclosures for the speakers. This is achieved with a routing template, large blocks of wood and plenty of elbow grease.

The internal structure makes a huge difference to the bass response of the speakers, allowing them to far more faithfully recreate the music under test. Thanks to the artisan-level craftsmanship, the final product is stunning to look at, too. It’s impressive just how well a cheap pair of drivers can perform with a proper enclosure, and of course, there’s nothing to stop an even better set of drivers being installed, either.

When building your own speakers, your creativity is the limit. Video after the break.

Continue reading “Cheap Speakers Sound Great In A Proper Enclosure” →

This Week In Security: Selfblow, Encryption Backdoors, Killer Apps, And The VLC Apocalypse That Wasn’t

July 26, 2019 by 18 Comments

Selfblow (Don’t google that at work, by the way) is a clever exploit by [Balázs Triszka] that affects every Nvidia Tegra device using the nvtboot bootloader — just about all of them except the Nintendo Switch. It’s CVE 2019-5680, and rated at an 8.2 according to Nvidia, but that high CVE rating isn’t entirely reflective of the reality of the situation. Taking advantage of the vulnerability means writing to the boot device, which requires root access, as well as a kernel flag set to expose the boot partitions to userspace. This vulnerability was discovered as part of an effort by [Balázs] and other LineageOS developers to build an open source bootloader for Nvidia Tegra devices.

The Tegra boot process is a bit different, having several stages and a dedicated Boot and Power Management CPU (BPMP). A zero-stage ROM loads nvtboot to memory and starts it executing on the BPMP. One of the tasks of nvtboot is to verify the signature of the next bootloader step, nvtboot-cpu. The file size and memory location are embedded in the nvtboot-cpu header. There are two problems here that together make this vulnerability possible. The first is that the bootloader binary is loaded to its final memory location before the signature verification is performed. The code is written to validate the bootloader signature before starting it executing on the primary CPU, so all is well, right? Continue reading “This Week In Security: Selfblow, Encryption Backdoors, Killer Apps, And The VLC Apocalypse That Wasn’t” →

Installing Android On Your Nintendo Switch, Because Why Not?

July 26, 2019 by 19 Comments

In a continuing trend of ‘but does it run Android?’, enterprising folk over at the XDA-Developers forum have found a way to get LineageOS (the successor to CyanogenMod) installed and running on the Nintendo Switch using Switchroot source code. Promising to release the necessary files to replicate this effort has obviously made other people at XDA-Developers forum as well as on Reddit rather excited.

As for the question of ‘why?’, one has to remember that internally the Nintendo Switch is an Nvidia Tegra X1-based system with a Maxwell GPU, making it definitely one of the nicer ARM-based portable systems out there if one wants to do some Android-based gaming. Even better, the entire Nvidia Shield TV-derived ROM runs from the SD card, so just popping out this SD card is sufficient to return to playing Switch games.

Currently a few nagging issues still have to be worked out with this ROM, such as touchscreen issues, sleep mode not working, auto-rotation not working as communication with the sensor needs to be figured out, and so on. This should make it clear that it won’t be a production ready piece of software, but definitely something that should be used at your own risk.

While it shouldn’t harm the Switch, one should probably not try it on a Switch one cares deeply about. Just in case.

HDMI From Your Arduino

July 26, 2019 by 29 Comments

Creating a video signal from a computer, a job that once required significant extra hardware, is now a done deal with a typical modern microcontroller. We’ve shown you more NTSC, PAL, and VGA projects than you can shake a stick at over the years. Creating an HDMI video signal however is not so straightforward. It’s not a loosely defined analogue standard but a tightly controlled digital one upon which the clever hacks that eke full colour composite video from a single digital I/O pin will have little effect. Surely creating them from a simple microcontroller will be impossible! Not according to [techtoys], who has created an Arduino shield that creates an HDMI output from an SPI control input.

At its heart are two interesting integrated circuits that give us a little bit of insight into creating graphics at this level. First up is an RA8876 MIPI TFT controller which is a full graphics engine that produces a digital RGB output, followed by a CH7035B HDMI encoder that produces an HDMI output from the RGB. This combination of chips is particularly interesting one, because the RA8876 supports a variety of different interfaces that between them should be able to talk to most microcontrollers. In the Arduino world the only other HDMI options come via the use of an FPGA.

This is a project that seems to have been around for a couple of years, but which is still an active one. The classic Arduino shield form factor may now seem a little past its zenith, but as this board shows it’s still capable of being used for interesting new applications.

Thanks [th_in_gs] for the tip.