Swiss Cheese Metamaterial Is An Analog Computer

May 3, 2019 by Al Williams 17 Comments

If you have had trouble with ordinary calculus, you may not be pleased to hear about “photonic calculus” — a recent idea from [Nader Engheta] of the University of Pennsylvania. The idea is that materials with certain properties could manipulate an electromagnetic wave in a way to solve a specific mathematical equation. [Engheta] proposed this idea back in 2014 and recently announced that he and his team have a demonstration device that proves the concept. The analog computer is about twice the size of an airplane’s tray table and made of CNC-shaped polystyrene. It solves Fredholm integral equations of the second kind.

The analog computer uses microwaves for the input and the polystyrene acts as a dielectric full of air holes. The team likens its structure to that of Swiss cheese. The shape is generated through an inverse design process which builds the shapes from known solutions to the equations. That means a particular set of shapes will do one specific equation. The equation could, for example, model the sound volume in a concert hall. You can encode certain parameters in the input wave and the output would specify the volume at different locations. However, a change to the actual equation would require a new set of plastic pieces.

The computation is very fast. Using microwaves, the answer comes out in a few hundred nanoseconds — a speed a conventional computer could not readily match. The team hopes to scale the system to use light which will speed the computation into the picosecond range. Creating a new optical analog computer could be similar to how we burn a CD or DVD today.

Analog computers predate digital ones by a lot. We really want to build one like [Bill Schweber’s]. Then again, we wouldn’t mind finding a Donner 3500 at a hamfest, either.

Full Earth Disc Images From GOES-17 Harvested By SDR

May 3, 2019 by Richard Baguley 10 Comments

We’ve seen lots of hacks about capturing weather images from the satellites whizzing over our heads, but this nicely written how-to from [Eric Sorensen] takes a different approach. Rather than capturing images from polar satellites that pass overhead a few times a day, this article looks at capturing images from GOES-17, a geostationary satellite that looks down on the Pacific Ocean. The fact that it is a geostationary satellite means that it captures the same view all the time, so you can capture awesome time-lapse videos of the weather. Continue reading “Full Earth Disc Images From GOES-17 Harvested By SDR” →

Add A Bit Of Soviet-Era Super-Computing To Your FPGA

May 3, 2019 by Maya Posch 11 Comments

The MESM-6 project is focused on bringing the 1960s Soviet BESM-6 computer to the modern age of FPGAs and HDLs. At the moment the team behind this preservation effort consists out of [Evgeniy Khaluev], [Serge Vakulenko] and [Leo Broukhis], who are covering the efforts on the Russian-language project page.

The BESM-6 (in Russian: БЭСМ-6, ‘Bolshaya Elektronno-Schetnaya Mashina’ or ‘large electronic computing machine’) was a highly performing Soviet super computer that was first launched in 1968 and in production for the next 19 years. Its system clock ran at 9 MHz using an astounding number of discrete components, like 60,000 transistors and 170,000 diodes, capable of addressing 192 kB of memory in total. Of the 355 built, a few survive to this day, with one on display at the London Science Museum (pictured above). Many more images and information can be found on its Russian Wikipedia page.

For those not gifted with knowledge of the Russian language, the machine-translated summary reveals that the project goal is to make a softcore in SystemVerilog that is compatible with user mode BESM-6, using the same Pascal compiler as originally used with that system. Further goals include at least 24 kB of data memory, 96 kB of command memory and the addition of modern peripherals such as SPI and I2C.

The system is meant to be integrated with the Arduino IDE, using the Pascal compiler to make it highly accessible to anyone with an interest in programming a system like this. Considering the MIT license for the project, one could conceivably use a bit of Soviet-era computing might in one’s future FPGA efforts.

If after watching the BESM-6 video — included below — you feel inspired to start your own Soviet-computing project, we’d like to wish you luck the Russian way: Ни пуха ни пера!

Continue reading “Add A Bit Of Soviet-Era Super-Computing To Your FPGA” →

Play Tetris On A Transistor Tester, Because Why Not?

May 3, 2019 by Bryan Cockfield 4 Comments

[Robson] had been using the same multimeter since he was 15. It wasn’t a typical multimeter, either. He had programmed it to also play the Google Chrome jumping dinosaur game, and also used it as a badge at various conferences. But with all that abuse, the ribbon cable broke and he set about on other projects. Like this transistor tester that was just asking to have Tetris programmed onto its tiny screen.

The transistor tester is a GM328A made for various transistor testing applications, but is also an LCR meter. [Robson]’s old meter didn’t even test for capacitance but he was able to get many years of use out of that one, so this device should serve him even better. Once it was delivered he set about adding more features, namely Tetris. It’s based on an ATmega chip, which quite easy to work with (it’s the same chip as you’ll find in the Arduino Uno but [Robson’s] gone the Makefile route instead of spinning up that IDE). Not only did he add more features, but he also found a mistake in the frequency counter circuitry that he fixed on his own through the course of the project.

If you’ve always thought that the lack of games on your multimeter was a total deal breaker, this project is worth a read. Even if you just have a random device lying around that happens to be based on an ATmega chip of some sort, this is a good primer of getting that device to do other things as well. This situation is a fairly common one to be in, too.

Continue reading “Play Tetris On A Transistor Tester, Because Why Not?” →

Low Power Weather Station Blows The Competition Away

May 3, 2019 by Bryan Cockfield 10 Comments

Building a weather station isn’t too tall of an order for anyone getting into an electronics project. There are plenty of plans online, and you can even put your station on Weather Underground if it meets certain standards. These usually have access to a reliable source of power, though, and like any electronics project can get challenging quickly once it needs to work reliably in a remote location. The weather station from [Tegwyn☠Twmffat] has met this challenge though, and has been working reliably for three years now.

Getting that sort of reliability from any circuit that has to be powered by an unreliable source (solar, wind, etc.) and a battery is quite a challenge. Not only do you need to sort out the power management and make sure that you can get enough sun in the winter for your application, but you’ll need to do some extreme low power modifications to your circuitry as well. This weather station accomplishes all of that, helped by using LoRa for communication, and also comes complete with a separate hardware watchdog timer that can reboot the weather station if it loses power or hangs up for some reason.

If you’ve been looking for a weather station to build, this is a great place to start. [Tegwyn☠Twmffat] also goes through the assembly of the weather station, complete with a guy-wire-supported platform to mount it on. There are other weather stations out there too, if you need even more ideas about saving power in remote areas.

New Part Day: Lynxmotion Smart Servos

May 3, 2019 by Roger Cheng 33 Comments

Anyone who shops for robotics kits would have come across a few designed by Lynxmotion. They’ve been helping people build robots since 1995, from robot arm kits to hexapod chassis and everything in between. We would expect these people know their motors, so when they launched their own line of servo motors called Lynxmotion Smart Servos (LSS), it is worth spending a bit of time to look over what they offer.

While these new devices have a PWM mode compatible with classic remote control servos, unleashing their full power requires bidirectional communication over a serial bus. We’ve previously given an overview of three serial bus servos already on the market for comparison. A quick look at the $68-$100 price tags listed on Lynxmotion’s parent company RobotShop made it clear they do not intend to compete on price, so what interesting features do these new kids on the block have?

Digging into product documentation found some great details. Acceleration and deceleration rates are adjustable, which can help with smoother robot movement. There’s also an adjustable level of “stiffness” that adds some “give” (compliance) so a robot won’t have to be as stiff as… well, a robot!

Mechanically, the most interesting internal component is the magnetic position sensor. They are far more precise than potentiometers, but more importantly, they allow positioning anywhere within full 360 degrees. Many other serial bus servos are constrained to positions within an arc less than 360 degrees leaving a blind spot.

An interesting quirk of the LSS offerings is that the serial communication protocol uses human-readable text characters, so sending a number 255 means transmitting a three byte string ‘2’, ‘5’, and ‘5’ instead of single byte 0xFF. This would make debugging our custom robot code far easier, at the cost of reduced bandwidth efficiency and loss of checksum for detecting communication errors. It’s a trade-off that some robot builders would be happy to make, but others might not.

Externally, these servos have bountiful mounting options including some we didn’t know to ask for. Historically Lynxmotion kits have used a wide variety of servo mounting brackets, so they are motivated to make mechanical integration easy. The most novel offering is the ability to bolt external gears to the servo body. A set of 1:3 gears allow for gearing the servo up or down, or you can use a set of 1:1 gears for a compact gripper.

As you’d expect of servos in this price range, they all have metal gears, but they also have the ability to power the motor directly from a battery pack (a 3 cell lithium polymer is recommended). There are additional features, like an RGB LED for visual feedback, which we didn’t cover here so dig into the documentation for more. We look forward to seeing how these interesting little actuators perform in future robotics projects.

Hackaday Podcast 017: Are Cheap Microcontrollers Worth It? Android On Your Bike. Plus Food Printers And Coffee Bots

May 3, 2019 by Mike Szczys 5 Comments

Join Editors Mike Szczys and Elliot Williams as they recount a week of fascinating hacks. We take a good look at the PMS150C, a microcontroller that literally costs pennies but can only be flashed once. SNES emulators have a new trick up their sleeves to make low-def a lot less low, and you retro enthusiasts will either hate or love the NES zapper chandelier. Elliot’s enamored by a bike computer running Android core, and both Mike and Elliot delve into the food hacking scene, be it meat, chocolate, coffee, or of course frosting!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)