Year: 2021

Build Your Own HV Capacitors

November 11, 2021 by 28 Comments

Finding high voltage capacitors can be tricky. Sure, you can buy these capacitors, but they are often expensive and hard to find exactly what you want. [RachelAnne] needed some low-value variable capacitors that would work at 100 kV. So she made some.

Instead of fabricating the plates directly, these capacitors use laminations from a scrap power transformer. These usually have two types of plates, one of which looks like a letter “E” and the other just like a straight bar. For dielectric, the capacitors use common transparency film.

Continue reading “Build Your Own HV Capacitors” →

Motorcycle Rally Computer Goes Open Source

November 11, 2021 by 6 Comments

Motorcycle rally racing is a high-speed, exciting, off-road motorsport that involves zipping across all types of terrain on two wheels. While riding, it’s extremely important for riders to know what’s coming up next —  turns, straightaways, stream crossings, the list goes on. Generally, this is handled by a roadbook — a paper scroll that has diagrams of each turn or course checkpoint, along with the distances between them and any other pertinent information. Of course, this needs to be paired with a readout that tells you how far you’ve traveled since the last waypoint so you’re not just guessing. This readout usually takes the form of a rally computer, a device that can display speed, distance traveled, and course heading (and some of the fancier ones have even more data available).

A roadbook with commercially-available rally computers

Frustrated with the lackluster interface and high cost associated with most rally computers on the market, [Matias Godoy] designed his own back in 2017, and was quick to realize he had a potential product. After several iterations he brought his idea to market with a small initial run, which sold out in a few hours!

He then took some time to reflect on the successful campaign. He decided that rather than continue to churn out units, he would open-source the design to make it available to everybody and see what the community could come up with. He published all of his design files to GitHub, and wrote up a wonderful blog post documenting the entire design process, from inspiration and early prototypes to his decision to go open source.

[Matias]’s project, the Open Rally Computer (formerly the Baja Pro) packages neatly in a CNC-machined case and features a nice high-visibility LCD display, a built-in GPS receiver, and an ergonomic handlebar-mounted remote. The data is crunched by an ESP32 microcontroller, which also allows for WiFi-enabled OTA updates. The end result is a beautiful and useful device that was clearly designed with great care. Love the idea but not a rally racer? If street bikes are more your thing then fear not because there’s an open source digital dashboard out there for you too.

So. What’s Up With All These Crazy Event Networks Then?

November 11, 2021 by 21 Comments

As an itinerant Hackaday writer I am privileged to meet the people who make up our community as I travel the continent in search of the coolest gatherings. This weekend I’ve made the trek to the east of the Netherlands for the ETH0 hacker camp, in a camping hostel set in wooded countryside. Sit down, connect to the network, grab a Club-Mate, and I’m ready to go!

Forget the CTF, Connecting To WiFi Is The Real Challenge!

There no doubt comes a point in every traveling hacker’s life when a small annoyance becomes a major one and a rant boils up from within, and perhaps it’s ETH0’s misfortune that it’s at their event that something has finally boiled over. I’m speaking of course about wireless networks.

While on the road I connect to a lot of them, the normal commercial hotspots, hackerspaces, and of course at hacker camps. Connecting to a wireless network is a simple experience, with a level of security provided by WPA2 and access credentials being a password. Find the SSID, bang in the password, and you’re in. I’m as securely connected as I reasonably can be, and can get on with whatever I need to do. At hacker camps though, for some reason it never seems to be so simple.

Instead of a simple password field you are presented with a complex dialogue with a load of fields that make little sense, and someone breezily saying “Just enter hacker and hacker!” doesn’t cut it when that simply doesn’t work. When you have to publish an app just so that attendees can hook up their phones to a network, perhaps it’s time to take another look . Continue reading “So. What’s Up With All These Crazy Event Networks Then?” →

Rolling Your Own Long-Range IoT Sensor Network

November 11, 2021 by 7 Comments

Homebrew wireless sensors are nothing new around these parts: grab an ESP8266, hang a BME280 from the I2C pins, and you’re just a few lines of code away from joining the Internet of Things on your own terms. Builds like this are so cheap and easy that they make an excellent first project for folks looking to get into the electronics game, but what if you’re looking for something a bit more bespoke?

In that case, you could follow in the footsteps of [Discreet Mayor] and put together a custom modular architecture for long-range wireless sensors. The core of the system is a breakout board for the Texas Instruments SimpleLink CC1312 wireless MCU which features a simple 2×11 header connector. This allows the module to either be plugged into a larger board or have a small sensor PCB attached directly to it.

Rather than using WiFi or requiring some existing radio infrastructure, the boards automatically create a private network using the IEEE 802.15.4 standard at a range of up to 600 meters. A dedicated receiver isn’t necessary, to pull data off the network, one of the CC1312 boards simply gets connected to a computer through a simple FT232 adapter.

[Discreet Mayor] has already created a number of projects that use these custom radios for communication, from a pool monitoring system to a temperature sensor for the BBQ. That portable battery operated devices are able to use this common communications backbone just as well as mains powered static devices is a testament to the work that went into the firmware to make it as robust and efficient as possible.

Like the idea of long-range private networks, but less enthusiastic about having to come up with your own hardware? Not to worry. Over the summer, Espressif announced that they’re working on an ESP32 variant that includes support for IEEE 802.15.4. Just as soon as this chip shortage is over, we might even get to see the thing.

Quantum computer

Scientific Honesty And Quantum Computing’s Latest Theoretical Hurdle

November 11, 2021 by 25 Comments

Quantum computers are really in their infancy. If you created a few logic gates with tubes back in the 1930s, it would be difficult to predict all the ways we would use computers today. However, you could probably guess where at least some of the problems would lie in the future. One of the things we are pretty sure will limit quantum computer development is error correction.

As far as we know, every quantum qubit we’ve come up with so far is very fragile and prone to random errors. That’s why every practical design today incorporates some sort of QEC — quantum error correction. Of course, error correction isn’t news. We use it all the time on unreliable storage media or communication channels and high-reliability memory. The problem is, you can’t directly clone a qubit (a quantum bit), so it is hard to use traditional error correction techniques with qubits.

After all, the whole point to a qubit is we don’t measure it until the end of the computation which, like Schrödinger’s cat, seals its fate. So if you were to “read” a bunch of qubits to form a checksum or a CRC, you’d destroy their quantum nature in the process making your computer not very useful. You can’t even copy a bit to use something like triple redundancy, either. There seems to be no way to practically duplicate a qubit.

Continue reading “Scientific Honesty And Quantum Computing’s Latest Theoretical Hurdle” →

Trying And (Mostly) Failing To 3D Print A Hydrofoil

November 11, 2021 by 5 Comments

[Sam Barker] had a boring dingy that he wanted to spice up a bit, so he resolved to 3D print a hydrofoil wing for it so that it could fly across the water. (Video, embedded below.)

With a large wing designed and sliced into several pieces, and a total print time of 200 hours, [Sam] was ready to glue the foil wing together when he realized his scale was way off and the wings were far too large for his boat. With some hacking, [Sam] was able to use a single wing across the bottom of the ship. [Tom Stanton] came over to help with fiberglassing, and they were ready for a test.

As you might have guessed from the title, the test wasn’t particularly successful. Swapping the engine on the boat for a more potent motor gave the lift he needed in the front, but without a back foil, it was a wheelie rather than what [Sam] hoped for. Back at home, they printed a second wing and went back for a second test. The boat would start to lift out the water, but the shaft of the engine lifted out of the water, sending him back down. Unfortunately, a downpour cut the test short.

Not to be defeated entirely, [Sam] connected it to a much larger boat once the weather cleared and pulled his dingy along behind. To [Sam’s] credit, they did get some solid foiling, and the ship did lift out of the water until the wings sheared off from the stress. All in all, an entertaining story of engineering while racing against the weather.

We admire [Sam’s] ambition, and if you’re thinking about building a whole hydrofoil, we suggest starting with a smaller RC model and scaling up from there.

The Game Of Life Moves Pretty Fast, If You Don’t Use Stop Motion You Might Miss It

November 11, 2021 by 12 Comments

Munged Ferris Bueller quotes aside, Conway’s Game of Life is the classic cellular automata that we all reach for. The usual approach is to just iterate over every cell in the grid, computing the next state into a new grid buffer. [K155LA3] set out to turn that on its head by implementing Game Of Life in the hardware of an FPGA.

[K155LA3]’s version uses Chisel, a new HDL from the Berkley and RISCV communities. Under the hood, Chisel is Scala with some custom libraries that know how to map Scala concepts onto hardware. In broad strokes, Verilog and VHDL are focused on expressing hardware and then added abstraction on top of that over the year. Chisel and other newer HDL languages focus on expressing high-level general-purpose elements that get mapped onto hardware. FPGAs already map complex circuits and hardware onto LUTs and other slices, so what’s another layer of abstraction?

The FPGA chosen for this project is a Digilent Arty A7 with a VGA Pmod to turn the RGB444 into analog signals to actually display. What’s impressive about [K155LA3]’s implementation is just how fast it is. Even running at 60 frames per second it’s almost as fast as the monitor can handle. Of course, most computers lying around you could simulate a 60 x4 8 grid at 60 fps. Next, instead of connecting the grid logic to the 60 Hz VGA clock, he connects it to the 100 MHz board external oscillator. Now each pixel in each frame displayed contains over a million generations.

Unfortunately, even this small grid of 60×48 takes up 90% of the LUTs on the Artix-7. In the future, we’d love to see an even larger FPGA hardware implementation capable of handling grids that could hold whole computers in them. And naturally, this isn’t the first FPGA version of the Game Of Life here at Hackaday.