Building A Motion Capture Suit On The Cheap

July 19, 2020 by Zoe Skyforest 5 Comments

Motion capture is a technology used in many films, particularly the animated variety. It makes giving characters realistic movements a cinch, as they’re all based on those of a real person. [Checkered Bug] worked with a middle school group who were looking to get started, so he whipped up a capable rig on a budget.

The rig is based around a chest unit that connects out to several satellite units placed at points on the body. Each unit contains a Bosch IMU which is used to measure the acceleration and rotation of the user’s various body parts. The data is fed back to an Arduino Mega, where it’s then passed to a PC running Blender. Motion sequences can be recorded live in Blender, or saved to an SD card and imported later. Files are available on Github for those keen to recreate the project.

It’s a tidy setup that does good motion capture on a low budget. Such a rig would have been inordinately expensive back in the day, but can now be whipped up for just a few hundred dollars. We’ve seen other motion capture systems before, too. Video after the break.

Continue reading “Building A Motion Capture Suit On The Cheap” →

The Real Story: How Samsung Blu Ray Players Were Bricked

July 19, 2020 by Zoe Skyforest 84 Comments

In June, many owners of Samsung Blu Ray players found that their devices were no longer usable. Stuck in a boot loop, speculation was rife as to the cause of the issue. Now it seems that the issue has become clear – a badly formatted XML file may be responsible for the problems (via The Register).

The problem stems from the logging system that stores user data and passes it back to Samsung over the Internet. Which data is logged and sent back is managed by an XML file which contains the policy settings that control this behaviour. According to a source known only as ~~“Gary”~~ “Gray”, the XML file posted on Samsung’s servers on June 18 featured a malformed list element. This caused a crash in the player’s main software routine, leading the player to reboot.

The failure was exacerbated by the fact that the XML file is parsed very early in the boot sequence, even before checking for firmware updates or a new XML file. This has prevented Samsung from rolling out an update or fix over the air, and is why the player gets stuck in a loop of continuous reboots.

Reportedly, the file can be found at this URL, though is now an updated version that shouldn’t brick players. Samsung have had to resort to a mail-in repair scheme, wherein technicians with service tools can manually remove the offending XML file from the player’s storage, allowing it to boot cleanly once again. While this shows our initial assumptions were off the mark, we’re glad to see a solution to the problem, albeit one that requires a lot of messing around.

[Thanks to broeckelmaier for the tip!]

Faux Radar Uses Ultrasound & Python

July 18, 2020 by Zoe Skyforest 25 Comments

Radars are simply cool, and their portrayal in movies and TV has a lot to do with that. You get a sweet glowing screen that shows you where the bad guys are, and a visual representation of your missiles on their way to blow them up. Sadly, or perhaps thankfully, day to day life for most of us is a little less exhilarating. We can make do with a facsimile of the experience instead.

The project consists of an Arduino Uno outfitted with an ultrasound module that can do basic range measurements on the order of tens of centimeters. The module is then placed on a servo and scanned through a 180 degree rotation. This data is passed back to a computer running a Python application, which plots the results on a Plan Position Indicator, or PPI – the sweeping display we’re all so familiar with.

While it’s unlikely you’ll be using such a setup to engage bandits, it could prove as a useful module for robot navigation or similar applications. We’ve seen ultrasonic transducers used for exactly that. Video after the break.

Continue reading “Faux Radar Uses Ultrasound & Python” →

Techniques For Making Complex Carbon Fibre Tube Parts

July 18, 2020 by Zoe Skyforest 19 Comments

Many a hacker spent their high school years picking up a few new skills in workshop classes. Whether it be woodworking, welding, or the patient, delicate skill of technical drawing, they’ve been a mainstay of secondary education for decades. However, composites are new enough that they aren’t a major feature of the curriculum. For those wishing to fill in a few gaps, [Easy Composites] have some great videos on carbon fibre techniques.

The video in question concerns the manufacture of a complex cross-section tube part, but these techniques can also apply to more complex hollow sections, like a bike frame, for example. Starting with a mold, the first step is to cut a rough template. This is then used to lay down the first layer of pre-preg carbon fibre material, and a more accurate template is made. The rest of the steps involve the production of a secure lap joint between subsequent layers, and how to properly use vacuum bag techniques on hollow parts.

It’s a useful primer on the basics of producing hollow carbon fibre parts with prepreg material. We’ve featured composites before, with this bulletproof armor a particularly good example. Video after the break.

Continue reading “Techniques For Making Complex Carbon Fibre Tube Parts” →

USB Flash Drive Reveals Strange SD Card Heart

July 17, 2020 by Zoe Skyforest 41 Comments

Many a hacker has dug an old flash drive out of the bottom of a backpack, and peeled apart the damaged plastic case to look inside. More often then not, you’d expect to see some SMD chips on a PCB along with a few passives, an LED and a USB port. [Gough] found something else entirely, and documented it for the interested public.

Inside the Comsol 8GB USB stick, [Gough] found an entire microSD card. One might be led to think this is a card reader and microSD masquerading as a normal flash drive, but the reality is far different. Instead, the drive contains a Flash memory controller which addresses the microSD card as raw NAND, through test points normally covered up on consumer-grade cards. The drive appears to be manufactured from factory second microSD cards that don’t pass the normal tests to be onsold to the public.

Armed with software obtained through spurious channels, [Gough] is able to dive deeper into the guts of the flash drive. The engineering tools allow the card to be optimised for capacity or speed, and different levels of error correction. It’s even possible to have the flash drive emulate a U3 CD ROM drive for OS installs and other purposes.

It’s a great dive into how USB drives work on a low level, and how the firmware and hardware work together. We’ve seen other flash drive hacks before too – like this simple recovery trick!

Hyundai Makes Push Towards Fuel Cell Trucking

July 16, 2020 by Zoe Skyforest 102 Comments

Hyundai has begun shipping fuel-cell based heavy duty trucks to face off against battery-electric trucks in the commercial hauling market.

Battery electric vehicles, more commonly known as electric cars, have finally begun to take on the world in real numbers. However, they’re not the only game in town when it comes to green transportation. Fuel cells that use tanks of hydrogen to generate electricity with H₂O as the main byproduct have long promised to take the pollution out of getting around, without the frustrating charge times. Thus far though, they’ve failed to make a major impact. Hyundai still think there’s value in the idea, however, and have developed their XCIENT Fuel Cell truck to further the cause. Continue reading “Hyundai Makes Push Towards Fuel Cell Trucking” →

RC Car Becomes Useful Little Mower

July 7, 2020 by Zoe Skyforest 16 Comments

When we think of lawn mowers, our first thought is of heavy, rusty old machines that take the best part of an afternoon to get started. Of course, there’s always another way, as [Mark] ably demonstrates with his own build.

Beginning from an unconventional starting point, [Mark] chose a remote control car, of the type that can flip and drive in both orientations. Having lost the controller, he started by ripping out the original electronics. In its place, an ESP32 receives signals from a FlySky RC receiver, and runs the drive motors with a Sparkfun Monster Motor Shield. Another channel on the receiver is hooked up directly to a drone speed controller driving a brushless motor, outfitted with a sawblade to cut the grass.

It’s a small platform, and one that ordinarily you might doubt could do the job. However, for [Mark]’s purposes, the rig works just fine, and has been doing good work for the last two years! We’ve seen mowers hacked before too, like this autonomous rig out in the wild. Video after break.