Custom Powerbank In Compact Form Factor

December 27, 2020 by 28 Comments

The wide availability and power density of 18650 lithium-ion cells have made them a good option for everything from electric cars to flashlights. [Theo] needed a new power source for his FPV drone goggles, so he designed his own power bank with a very compact charge controller.The narrow PCB slips in between the cells

While [Theo] could charge the batteries with an RC battery charger, he preferred the convenience of one with a standard 5V micro USB input, and wanted battery level indication to avoid having the FPV goggles die unexpectedly mid-flight. When four 18650 cells are held in a cube arrangement, a 8x8x65 mm gap is formed between the cells. In this space [Theo] was able to fit a custom PCB with a micro USB jack, 1.3 mm power jack, BQ25606 charge controller, TPS61085 boost converter, and ATtiny MCU with LED for battery level feedback. The charge controller also allows 5V devices to be charged via USB, while the boost converter outputs 9V via the 1.3mm jack for [Theo]’s FPV goggles. Everything fits inside a nice compact 3D printed enclosure.

The project was not without hiccups. After ordering and building the PCB he discovered some minor PCB layout mistakes, and realized the boost converted could only output 600mA at 9V, which was not enough for his more power-hungry googles. He plans to fix this in the next version.

We’ve seen custom power banks in quite a few shapes and sizes, including one that runs on power tool batteries (which probably also have 18650s inside) and one that has just about every output you could want, including AC and wireless QI charging.

Building A Smash Bros. Controller With Keyswitches

December 18, 2020 by 5 Comments

When it comes to competitive fighting games, having the right controller in your hands can make the difference between victory and defeat. Many tournaments have strict rules around controllers for this very reason. [Akaki Kuumeri] has recently put together a custom controller, aimed at maximising performance in Super Smash Brothers: Ultimate on the Nintendo Switch. (Video, embedded below.)

The build is assembled in an attractive 3D-printed body, made to be reminiscent of the original Nintendo Entertainment System controller. Inside, a cheap third-party Gamecube controller is used to interface with the console. Mechanical keyboard switches are used to replace the buttons and even the analog sticks, with a special modifier key that enables walking and running across the stage. This is pulled off with a handful of resistors emulating the intermediate position of the analog sticks, and makes pulling off advanced combos easier.

It’s a fun build, and we can imagine the precise digital key inputs having some benefits over analog controls. It also pays to note that such a build wouldn’t be as easy without the ready supply of mechanical key switches thanks to the custom keyboard subculture. We’ve seen these satisfying switches cropping up in many controller builds in recent times.

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Remoticon Video: How To Use Machine Learning With Microcontrollers

December 4, 2020 by 5 Comments

Going from a microcontroller blinking an LED, to one that blinks the LED using voice commands based on a data set that you trained on a neural net work is a “now draw the rest of the owl” problem. Lucky for us, Shawn Hymel walks us through the entire process during his Tiny ML workshop from the 2020 Hackaday Remoticon. The video has just now been published and can be viewed below.

This is truly an end-to-end Hello World for getting machine learning up and running on a microcontroller. Shawn covers the process of collecting and preparing the audio samples, training the data set, and getting it all onto the microcontroller. At the end of two hours, he’s able to show the STM32 recognizing and responding to two different spoken words. Along the way he pauses to discuss the context of what’s happening in every step, which will help you go back and expand in those areas later to suit your own project needs.

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Game Cartridges And The Technology To Make Data Last Forever

December 3, 2020 by 69 Comments

Game cartridges are perhaps the hardiest of all common storage schemes. Short of blunt traumatic force or application of electrical surges to the cartridge’s edge connectors, damaging a game cartridge is hard to do by accident. The same is also true for the data on them, whether one talks about an Atari 2006 cartridge from the late 1970s or a 1990s Nintendo 64 cartridge.

The secret sauce here are mask ROMs (MROM), which are read-only memory chips that literally have the software turned into a hardware memory device. A mask layer unique to each data set is used when metalizing the interconnects during chip fabrication. This means that the data stored on them is as durable as the processor in the game console itself. Yet this is not a technology that we can use in our own hobby projects, and it’s not available for personal long-term data storage due to the costs associated with manufacturing what is essentially a custom chip.

Despite its value as truly persistent storage, MROM has fallen out of favor over the decades. You may be surprised to find a lot of what’s currently used in the consumer market is prone to data corruption over time spans as short as one year to one decade depending on environmental conditions.

So what are we to do if we need to have read-only data that should remain readable for the coming decades?

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Prusa Mini Gets Custom Heavy Duty Enclosure

November 17, 2020 by 15 Comments

Still waiting on your Prusa Mini to arrive? Join the club. Between the incredible amount of interest in the inexpensive 3D printer and the COVID-19 pandemic, it can take months for the machine to arrive at your doorstep. But patient makers are finally taking delivery of their new printers, and as such the hacks and modifications are starting to trickle their way in.

First up is this gloriously over-engineered enclosure from [Build Comics]. While PLA and PETG usually print fine with nothing more exotic than a heated bed, trickier materials like ABS work best when the printer is enclosed as it helps maintain a consistent temperature. Plus it keeps any curious hands and paws a safe distance from the hot moving bits, and if things go really pear-shaped, can help contain smoke and flames.

The enclosure is made from welded steel square tube, wood, and fire-retardant fiber board. A hinged polycarbonate cover, taking the form of a four-sided cube, is lowered over the printer with some heavy-duty hinges that look like they were intended for a fence. To keep the cover from slamming back down, [Build Comics] came up with a simple locking mechanism that can easily be operated from the front or side of the enclosure. With the addition of a small temperature and humidity display, the conditions inside the chamber can easily be monitored.

But [Build Comics] didn’t stop there. He also rigged up a relay box that will cut power to the printer should the smoke detector mounted above it trip. While there’s no reason to think the Prusa Mini would suffer the same fate of earlier budget desktop 3D printers, but there’s certainly no harm in taking precautions.

Will you need to build a similar enclosure whenever your Prusa Mini shows up? Maybe not. But if you felt so inclined, at least now you’ve got plenty of images and details that can help you spin up your own solution.

Hello From The NearSpace

November 9, 2020 by 6 Comments

A key challenge for any system headed up into the upper-atmosphere region sometimes called near space is communicating back down to the ground. The sensors and cameras onboard many high altitude balloons and satellites aren’t useful if the data they collect can’t be retrieved. Often times, custom antennas or beacons are added to help. Looking at the cost and difficulty of the problem, [arko] and [upaut] teamed up to try and make a turn-key solution for any near-space enthusiast by building CUBEX, a wonderful little module with sensors and clever radio that can be easily reused and repurposed.

CUBEX is meant as a payload for a high-altitude balloon with a camera, GPS, small battery, solar cell, and the accompanying power management circuits. The clever bit comes in the radio back down. By using the 434.460 Mhz band, it can broadcast around a hundred miles at 10mW. The only hardware to receive is a radio listener (a cheap RTL USB stick works nicely). Pictures and GPS coordinates stream down at 300 baud.

Their launch was quite successful and while they didn’t catch a solar eclipse, their balloon reached an impressive 33698m (110,560ft) while taking pictures. Even though it did eventually splashdown in the Pacific Ocean, they were able to enjoy a plethora of gorgeous photos thanks to their easy and cost-effective data link.

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A Featherweight Direct Drive Extruder In A Class Of Its Own

November 5, 2020 by 39 Comments

Even a decade later, homebrew 3D printing still doesn’t stop when it comes to mechanical improvements. These last few months have been especially kind to lightweight direct-drive extruders, and [lorinczroby’s] Orbiter Extruder might just set a paradigm for a new kind of direct drive extruder that’s especially lightweight.

Weighing in at a mere 140 grams, this setup features a 7.5:1 gear reduction that’s capable of pushing filament at speeds up to 200 mm/sec. What’s more, the gear reduction style and Nema 14 motor end up giving it an overall package size that’s smaller than any Nema 17 based extruder. And the resulting prints on the project’s Thingiverse page are clean enough to speak for themselves. Finally, the project is released as open source under a Creative Commons Non-Commercial Share-Alike license for all that (license-respecting!) mischief you’d like to add to it.

This little extruder has only been around since March, but it seems to be getting a good amount of love from a few 3D printer communities. The Voron community has recently reimagined it as the Galileo. Meanwhile, folks with E3D Toolchangers have been also experimenting with an independent Orbiter-based tool head. And the Annex-Engineering crew has just finished a few new extruder designs like the Sherpa and Sherpa-Mini, successors to the Ascender, all of which derive from a Nema 14 motor like the one in the Orbiter. Admittedly, with some similarity between the Annex and Orbiter designs, it’s hard to say who inspired who. Nevertheless, the result may be that we’re getting an early peek into what modern extruders are starting to shape into: smaller steppers and more compact gear reduction for an overall lighter package.

Possibly just as interesting as the design itself is [lorinczroby’s] means of sharing it. The license terms are such you can faithfully replicate the design for yourself, provided that you don’t profit off of it, as well as remix it, provided that you share your remix with the same license. But [lorinczroby] also negotiated an agreement with the AliExpress vendor Blurolls Store where Blurolls sells manufactured versions of the design with some proceeds going back to [lorinczroby].

This is a clever way of sharing a nifty piece of open source hardware. With this sharing model, users don’t need to fuss with fabricating mechanically complex parts themselves; they can just buy them. And buying them acts as a tip to the designer for their hard design work. On top of that, the design is still open, subject to remixing as long as remixers respect the license terms. In a world where mechanical designers in industry might worry about having their IP cloned, this sharing model is a nice alternative way for others to both consume and build off of the original designer’s work while sending a tip back their way.

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