Home-Crafting A Motorcycle Throttle Hold

Cruise control is a common feature on automobiles, though less so in the motorcycle market. Given that continual throttle application on long rides can be a real pain in the wrist, many riders long for such a convenience. As a cheat solution, bolt-on locks that hold the throttle at a set position are available, though quality varies and generally they need to be activated by the throttle hand anyway. [Nixie] wanted a solution that would leave the right hand entirely free, and held, rather than locked, the throttle.

The device [Nixie] came up with is essentially a brake that fits inside the throttle handle and holds it in position. This is achieved with a mechanism that presses a pair of small brake shoes into the inside of the throttle, holding it from rotating back to neutral when the rider lets go. The brake is activated by a control on the left handlebar via a Bowden cable, allowing [Nixie] to activate the throttle hold on the highway and use the right hand to check pockets or simply rest.

It’s a tidy build, and [Nixie] does a great job of explaining the various design choices and the intricacies of the Bowden cable actuated mechanism. It’s anything but a one-size-fits-all build, but other enterprising machinists could certainly duplicate the design for other motorcycles without too many problems.

For those interested in more traditional cruise control, we’ve featured a teardown of a simplistic 90s Jeep system before. Video after the break.

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DevTerm Beats Cyberdeck Builders To The Punch

What makes a cyberdeck? Looking as though it came from an alternate reality version of the 1980s is a good start, but certainly isn’t required. If you’re really trying to adhere to the cyberpunk ethos, any good deck should be modular enough that it can be easily repaired and upgraded over time. In fact, if it’s not in a constant state of evolution and flux, you’ve probably done something wrong. If you can hit those goals and make it look retro-futuristic at the same time, even better.

Which is why the Clockwork DevTerm is such an interesting device. It ticks off nearly every box that the custom cyberdeck builds we’ve covered over the last couple years have, while at the same time being approachable enough for a more mainstream audience. You won’t need a 3D printer, soldering iron, or hot glue gun to build your own DevTerm. Of course if you do have those tools and the skills to put them to work, then this might be the ideal platform to build on.

With a 65% QWERTY keyboard and widescreen display, the DevTerm looks a lot like early portable computers such as the TRS-80 Model 100. But unlike the machines it draws inspiration from, the display is a 6.8 inch 1280 x 480 IPS panel, and there’s no pokey Intel 8085 chip inside. The $220 USD base model is powered by the Raspberry Pi Compute Module 3, and if you need a little more punch, there are a few higher priced options that slot in a more powerful custom module. Like the Waveshare Pi CM laptop we recently looked at, there’s sadly no support for the newer CM4; but at least the DevTerm is modular enough that it doesn’t seem out of the question that Clockwork could release a new mainboard down the line. Or perhaps somebody in the community will even do it for them.

Speaking of which, the board in the DevTerm has been designed in two pieces so that “EXT Module” side can be swapped out with custom hardware without compromising the core functionality of the system. The stock board comes with extra USB ports, a micro USB UART port for debugging, a CSI camera connector, and an interface for an included thermal printer that slots into a bay on the rear of the computer. Clockwork says they hope the community really runs wild with their own EXT boards, especially since the schematics and relevant design files for the entire system are all going to be put on GitHub and released under the GPL v3.

They say that anything that sounds too good to be true probably is, and if we’re honest, we’re getting a little of that from the DevTerm. An (CPU BLOBs aside!) open hardware portable Linux computer with this kind of modularity is basically a hacker’s dream come true, and thus far the only way to get one was to build it yourself. It’s hard to believe that Clockwork will be able to put something like this out for less than the cost of a cheap laptop without cutting some serious corners somewhere, but we’d absolutely love to be proven wrong when it’s released next year.

Remoticon Video: Making Microphones And Finding Sound

A yogurt lid and embroidery hoop are key components in building this microphone. It’s a super low tech, entry-level project to get into “found sound” and exactly what is needed to start hacking around in the audio world. This workshop presented by Helen Leigh and Robyn Hails shows you how to build a simple microphone and use it as the electronic gateway to all kinds of audio shenanigans.

Key to this build are the piezo element and an amp to process the signals it generates. All other materials are common around most households, but put them together as shown in this live hands-on seminar from the 2020 Hackaday Remoticon, and I think you’ll surprise yourself with how good the thing sounds!

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Space Is Radioactive: Dealing With Cosmic Rays

Outer space is not exactly a friendly environment, which is why we go through great lengths before we boost people up there. Once you get a few hundred kilometers away from our beloved rocky planet things get uncomfortable due to the lack of oxygen, extreme cold, and high doses of radiation.

Especially the latter poses a great challenge for long-term space travel, and so people are working on various concepts to protect astronauts’ DNA from being smashed by cosmic rays. This has become ever more salient as NASA contemplates future manned missions to the Moon and Mars. So let’s learn more about the dangers posed by galactic cosmic rays and solar flares. Continue reading “Space Is Radioactive: Dealing With Cosmic Rays”

A Portable Serial Terminal That Should Be From The 1970s

The humble standalone serial terminal might be long gone from the collective computing experience, but in the ghostly form of a software virtual terminal and a serial converter it remains the most basic fall-back and essential tool of the computer hardware hacker. [Mitsuru Yamada] has created the product that should have been made in the serial terminal’s heyday, a standalone handheld terminal using a 6809 microprocessor and vintage HP dot matrix LEDs. In a die-cast box with full push-button keyboard it’s entirely ready to roll up to a DB-25 wall socket and log into the PDP/11 in the basement.

Using today’s parts we might achieve the same feat with a single-chip microcontroller and a small LCD or OLED panel, but with an older microcomputer there is more system-building required. The 6809 is a wise choice from the 1970s arsenal because it has some on-board RAM, thus there’s no need for a RAM chip. Thus the whole thing is achieved with only a 2716 EPROM for the software, a 6850 UART with MAX232 driver  for the serial port, and a few 74 chips for glue logic, chip selects, and I/O ports to handle keyboard and display. There’s no battery in the case, but no doubt that could be easily accommodated. Also there’s not much information on the keyboard itself, but in the video below we catch a glimpse of its wiring as the box is opened.

The value in a terminal using vintage parts lies not only in because you can, but also in something that can’t easily be had with a modern microcontroller. These parts come from a time when a computer system had to be assembled as a series of peripherals round the microprocessor because it had few onboard, leading to a far more in-depth understanding of a computer system. It’s not that a 6809 is a sensible choice in 2020, more that it’s an interesting one.

By comparison, here’s a terminal using technology from today.

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Exploring Custom Firmware On Xiaomi Thermometers

If we’ve learned anything over the years, it’s that hackers love to know what the temperature is. Seriously. A stroll through the archives here at Hackaday uncovers an overwhelming number of bespoke gadgets for recording, displaying, and transmitting the current conditions. From outdoor weather stations to an ESP8266 with a DHT11 soldered on, there’s no shortage of prior art should you want to start collecting your own environmental data.

Now obviously we’re big fans of DIY it here, that’s sort of the point of the whole website. But there’s no denying that it can be hard to compete with the economies of scale, especially when dealing with imported goods. Even the most experienced hardware hacker would have trouble building something like the Xiaomi LYWSD03MMC. For as little as $4 USD each, you’ve got a slick energy efficient sensor with an integrated LCD that broadcasts the current temperature and humidity over Bluetooth Low Energy.

You could probably build your own…but why?

It’s pretty much the ideal platform for setting up a whole-house environmental monitoring system except for one detail: it’s designed to work as part of Xiaomi’s home automation system, and not necessarily the hacked-together setups that folks like us have going on at home. But that was before Aaron Christophel got on the case.

We first brought news of his ambitious project to create an open source firmware for these low-cost sensors last month, and unsurprisingly it generated quite a bit of interest. After all, folks taking existing pieces of hardware, making them better, and sharing how they did it with the world is a core tenet of this community.

Believing that such a well crafted projected deserved a second look, and frankly because I wanted to start monitoring the conditions in my own home on the cheap, I decided to order a pack of Xiaomi thermometers and dive in.

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SLA 3D Printed Vortex Cooled Rocket Engine

3D printing is an incredible tool for prototyping and development, but the properties of the materials can be a limiting factor for functional parts. [Sam Rogers] and colleagues at [AX Technologies] have been testing and developing a small liquid-fueled rocket engine and successfully used vortex cooling to protect a resin 3D printed combustion chamber. (Video, embedded below.)

Vortex cooling works by injecting oxygen into the combustion chamber tangentially, just inside the nozzle of the engine, which creates a cooling, swirling vortex boundary layer along the chamber wall. The oxygen moves to the front end of the combustion chamber where it mixes with the fuel and ignites in the center. This does not protect the nozzle itself, which only lasts a few seconds before becoming unusable. However, thanks to the modular design of the test engine, only the small nozzle section had to be reprinted for every test. While this part could be manufactured using a metal 3D printer, the costs are still very high, especially at this experimental stage. The clear resin parts also allow the combustion observed and more accurate conclusions to be drawn from every test.

This engine intended to be used as a torch igniter for a much larger rocket engine. Fuel is injected into the front of the combustion chamber, where a spark plug is located to ignite the oxygen-fuel mixture. The flow of the oxygen and fuel is controlled by two servo-operated valves connected to a microcontroller, which is mounted with the engine on linear rails. This allows the test engine to move freely, and push against a load cell to measure thrust. The spark is created before the valves are opened to prevent a delayed ignition, which can blow up the engine, and getting the valve sequence and timing correct is critical. Many iterations and destroyed parts later, the [AX Technologies] team achieved successful ignition, with a clear supersonic Mach diamond pattern in the exhaust.

This is just one more example of 3D printing and cheap electronics allowing impressive progress on a limited budget. Another example is [Joe Barnard]’s progress in getting a model rocket to land itself with a solid fuel engine. Companies and organisations have been using 3D printed components in rocket engines for a few years now, and we’ve even seen an open source version.