Author: Al Williams

4504 Articles

Hybrid Supercapacitors Are — Well — Super

March 14, 2020 by 39 Comments

Kurt.energy is promoting a new line of hybrid supercapacitors. By itself, that wouldn’t be very newsworthy, but the company claims these graphene-based supercapacitors merge the best features of both supercapacitors and lithium-ion batteries. Based on technology from a company called Shenzhen Toomen New Energy, the capacitors are optimized for either high energy or high power. They can reportedly charge and discharge 10-20 times faster than lithium-ion batteries. Of course, we’ve heard wild claims surrounding graphene capacitors before and, so far, they haven’t seemed very credible.

In addition to high performance, the company claims the capacitors are safe from overcharging, short circuit, and other safety issues that plague batteries. The devices are said to operate — including charging — from -40C to 80C. You can see a video from the company, below.

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Hearing Aid Reads Your Mind

March 13, 2020 by 16 Comments

If you’ve ever seen an experienced radio operator pull a signal out of the noise, or talked to someone in a crowded noisy restaurant, you know the human brain is excellent at focusing on a particular sound. This is sometimes called the cocktail party effect and if you wear a hearing aid, this doesn’t work as well because the device amplifies everything the same. A German company, Fraunhofer, aims to change that. They’ve demonstrated a hearing aid that uses EEG sensors to determine what you are trying to hear. Then it uses that information to configure beamforming microphone arrays to focus in on the sound you want to hear.

In addition to electronically focusing sound, the device stimulates your brain using transcranial electrostimulation. A low-level electrical signal tied to the audio input directly stimulates the auditory cortex of your brain and reportedly improves intelligibility.

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Retrotechtacular: Mobile Phones 1940s Style

March 13, 2020 by 24 Comments

We think of the mobile phone — well, what we would call a cell phone — as something fairly modern. Many of us can still remember when using a ham radio phone patch from your parked car would have people staring and murmuring. But it turns out in the late 1940s, Bell Telephone offered Mobile Telephone Service (MTS). It was expensive and didn’t work as well as what we have now, but it did let you make or receive calls from your automobile. After the break, you can see a promotional film about MTS.

The service rolled out in St. Louis in the middle of 1946. The 80-pound radios went in the trunk with a remote handset wired to the dashboard. At first, there were only 3 channels but later Bell added 29 more to keep up with demand. An operator connected incoming and outbound calls and if three other people were using their mobile phones, you were out of luck.

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Plastic Cleanup Via Retrobrighting

March 13, 2020 by 31 Comments

If you work on old radios, electronics is only one of the skills you need. The other is wood or metal working to restore the cabinets and chassis. However, more recent electronics have plastic and old plastic tends to turn yellow. [Odd Experiments] shows how to whiten plastic using a UV light source, aluminum foil, and hydrogen peroxide. Generally, ABS is the plastic at fault, especially those mixed with bromine as a fire retardant. You can see the results in the video below.

Note the peroxide in use was 12% — much stronger than what’s probably in your medicine cabinet. That’s usually only 3% solution, although you can get different strengths including some over 30% if you shop. However, if you search you’ll find that people have used 12%, 6%, and even 3% successfully, although we’d imagine it takes more time with 3%.

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MessagePack Is A More Efficient JSON

March 12, 2020 by 50 Comments

It is an age-old problem, that of having some data you want to store somewhere, and later bring it back. How do you format the data? Custom file formats are not that hard, but if you use an existing format you can probably steal code from a library to help you. Common choices include XML or the simpler JSON. However, neither of these are very concise. That’s where MessagePack comes in.

For example, consider this simple JSON stanza:

{"compact":true, "schema":0}

This is easy to understand and weighs in at 27 bytes. Using MessagePack, you’d signal some special binary fields by using bytes >80 hex. Here’s the same thing using the MessagePack format:

 
0x82 0xA7 c o m p a c t 0xC3 0xA6 s c h e m a 0x00

Of course, the spaces are there for readability; they would not be in the actual data stream which is now 18 bytes. The 0x82 indicates a two-byte map. The 0xA7 introduces a 7-byte string. The “true” part of the map is the 0xC3. Then there’s a six-byte string (0xA6). Finally, there’s a zero byte indicating a zero.

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An RF Engineer’s FPGA Learning Journey

March 12, 2020 by 3 Comments

[KF5N] admits he’s not a digital design engineer; he’s more into the analog RF side of things. But he’s recently taken on a project to communicate between a Ubuntu box and an Intel MAX10 FPGA. He did a presentation at a recent ham radio convention about what he’d learned and how you could get started.

The video talks a lot about the Intel (used to be Altera). However, the nearly 40 minute video after the break isn’t a step-by-step tutorial so even if you are interested in other devices, you’ll probably enjoy watching it. If you’ve programmed even one FPGA, this video likely won’t hold your interest — you aren’t the target audience. However, at about 00:31 he does recommend some books and some very inexpensive FPGA boards, so it’s not a total wash.

[KF5N] talks about what an FPGA is and how it’s different from a microcontroller. He also recommends Cornell’s [Bruce Land’s] course materials. He wasn’t a big fan of the online courses he tried. Of course, since he’s using an Intel chip, he also recommended the Intel courses. A lot of the video covers how to save on getting a development board. The Cornell class calls for a $250 board that is pretty powerful. That’s also pretty expensive, so he recommends a lighter version for about $85.

He also talks about the toolchain and his project to interface to his Linux box. He wound up with an SPI interface that ran up to 30 MHz. He also talks about using Julia to build a driver to talk to the interface on the PC side.

We didn’t notice him mentioning our own FPGA bootcamp, although he did mention projects on Hackaday.io. If you want to see a similar video but with open source tools, [David Williams] did a talk at Superconference that gives the same kind of overview but with Yosys and other related tools.

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Java On GPUs And FPGAs

March 11, 2020 by 48 Comments

There was a time when running a program on an array of processors meant that you worked in some high-powered lab somewhere. Now your computer probably has plenty of processors hiding in its GPU and if you have an FPGA, you have everything you need to make something custom. The idea behind TornadoVM is to modify OpenJDK and GraalVM to support running some Java code on parallel architectures supported by OpenCL. The system can utilize multi-core CPUs, GPUs (NVIDIA and AMD), Intel integrated GPUs, and Intel FPGAs.

If you want to try your hand at accelerated Java, there are some docker containers to get you started fast. There’ are also quite a few examples, such as a computer vision application.

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