FIR Filters For Xilinx

May 18, 2021 by 7 Comments

Digital filters are always an interesting topic, and they are especially attractive with FPGAs. [Pabolo] has been working with them in a series of blog posts. The latest covers an 8th order FIR filter in Verilog.  He covers some math, which you can find in many places, but he also shows how an implementation maps to DSP slices in a device. Then to reduce the number of slices, he illustrates folding which trades delay time for slice usage.

Folding takes a multi-stage parallel multiplication and breaks it into fewer multiplications done over a longer period of time. This reuses slices to reduce the number required for high-order filters.

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Toolchanging Printers Get A Nozzle Hanky Like No Other

May 18, 2021 by 7 Comments

When it comes to toolchanging 3D printers, idle nozzles tend to drool. Cleaning out that nozzle goo, though, is critical before switching them into use. And since switching nozzles can happen hundreds of times per print, having a rock-solid cleaning solution is key to making crisp clean parts. [Kevin Mardirossian] wasn’t too thrilled with the existing solutions for cleaning, so he developed the Pebble Wiper, a production worthy nozzle wicking widget that’s wicked away nozzles thousands of times flawlessly.

With a little inspiration from [BigBrain3D’s] retractable purge mechanism, [Kevin] is first purging tools onto a brass brad. Rather than have filament extrude into free space, it collects into a small bloblike “pebble” that cools quickly into a controlled shape. From here, after one quick flick with a servo arm and a small wipe with a silicone basting brush, the nozzle is ready to use. The setup might sound simple, but it’s the result of thousands and thousands of tests with the goal of letting no residual ooze attach itself to the actual part being printed. And that’s after [Kevin] put the time into scratch-building his own toolchanging 3D printer to test it on first. Finally, he’s kindly made the files available online on Github for other hackers’ tinkering and mischief.

So how well does it work? Judging by the results he’s shared, we think spectacularly. Since adopting it, he’s dropped any sacrificial printing artefacts on the bed entirely and been able to consistently pull off stunning multimaterial prints flawlessly with no signs of residual nozzle drool. While toolchanging systems have been great platforms for hacking and exploration, [Kevin’s] Pebble Wiper takes these machines one step closer at hitting “production-level” of reliability that minimizes waste. And who knows? Maybe all those pebbles can be sized to be ground up, remade into filament, and respooled back into usable filament?

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Send Old-Fashioned Pager Messages With New-Fashioned Hardware

May 18, 2021 by 5 Comments

In a world of always-connected devices and 24/7 access to email and various social media and messaging platforms, it’s sometimes a good idea to take a step away from the hustle and bustle for peace of mind. But not too big of a step. After all, we sometimes need some limited contact with other humans, so that’s what [EverestX] set out to do with his modern, pocket-sized communication device based on pager technology from days of yore.

The device uses the POCSAG communications protocol, a current standard for pager communications that allows for an SMS-like experience for those still who still need (or want) to use pagers. [EverestX] was able to adapt some preexisting code and port it to an Atmel 32u4 microcontroller. With a custom PCB, small battery, an antenna, and some incredibly refined soldering skills, he was able to put together this build with an incredibly small footprint, slightly larger than a bottle cap.

Once added to a custom case, [EverestX] has an excellent platform for sending pager messages to all of his friends and can avoid any dreaded voice conversations. Pager hacks have been a favorite around these parts for years, and are still a viable option for modern communications needs despite also being a nostalgic relic of decades past. As an added bonus, the 32u4 microcontroller has some interesting non-pager features that you might want to check out as well.

Thanks to [ch0l0man] for the tip!

Making Minty Fresh Music With Markov Chains: The After Eight Step Sequencer

May 18, 2021 by 7 Comments

Step sequencers are fantastic instruments, but they can be a little, well, repetitive. At it’s core, the step sequencer is a pretty simple device: it loops through a series of notes or phrases that are, well, sequentially ordered into steps. The operator can change the steps while the sequencer is looping, but it generally has a repetitive feel, as the musician isn’t likely to erase all of the steps and enter in an entirely new set between phrases.

Enter our old friend machine learning. If we introduce a certain variability on each step of the loop, the instrument can help the musician out a bit here, making the final product a bit more interesting. Such an instrument is exactly what [Charis Cat] set out to make when she created the After Eight Step Sequencer.

The After Eight is an eight-step sequencer that allows the artist to set each note with a series of potentiometers (which are, of course, housed in an After Eight mint tin). The potentiometers are read by an Arduino, which passes MIDI information to a computer running the popular music-oriented visual programming language Max MSP. The software uses a series of Markov Chains to augment the musician’s inputted series of notes, effectively working with the artist to create music. The result is a fantastic piece of music that’s different every time it’s performed. Make sure to check out the video at the end for a fantastic overview of the project (and to hear the After Eight in action, of course)!

[Charis Cat]’s wonderful creation reminds us of some the work [Sara Adkins] has done, blending human performance with complex algorithms. It’s exactly the kind of thing we love to see at Hackaday- the fusion of a musician’s artistic intent with the stochastic unpredictability of a machine learning system to produce something unique.

Thanks to [Chris] for the tip!

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Do You Really Own It? Motorcycle Airbag Requires Additional Purchase To Inflate

May 18, 2021 by 218 Comments

If you ride a motorcycle, you may have noticed that the cost of airbag vests has dropped. In one case, something very different is going on here. As reported by Motherboard, you can pick up a KLIM Ai-1 for $400 but the airbag built into it will not function until unlocked with an additional purchase, and a big one at that. So do you really own the vest for $400?

Given the nature of the electronics and computer business lately, we spend a good bit of time thinking of what it means to own a piece of technology. Do you own your cable modem or cell phone if you aren’t allowed to open it up? Do you own a piece of software that wants to call home periodically and won’t let you stop it?  Sometimes it makes sense that you are paying for a service. But there have been times where, for example, a speaker company essentially bricks devices that could work fine on their own even though you — in theory — own the device.

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2021 Hackaday Prize Hack Chat; Join Us Live On Wednesday

May 18, 2021 by 1 Comment

Join us on Wednesday, May 19 at noon Pacific for the 2021 Hackaday Prize Hack Chat with Majenta Strongheart!

At this point last year, we probably all felt like we’d been put through a wringer, and that things would get back to normal any day now. Little did we know how much more was in store for us, and how many more challenges would be heaped on our plates. Everything that we thought would be temporary seems to be more or less permanent now, and we’ve all had to adapt to the new facts of life as best we can.

But we’re hackers, and adapting to new situations more often than not means making the world fit our vision. And that’s why the 2021 Hackaday Prize has adopted the theme of “Rethink, Refresh, Rebuild.” We want you to rethink and refresh familiar concepts across the hardware universe, and create the kind of innovation this community is famous for.

The 2021 Hackaday Prize will have it all. As in previous years, the Prize will have several specific challenges, where we set you to work on a creative problem. There will also be mentoring sessions available, $500 cash prizes for 50 finalists along the way, with $25,000 and a Supplyframe Design Lab residency awarded to the Grand Prize winner.

We know you’re going to want to step up to the challenge, so to help get you started, Majenta Strongheart, Head of Design and Partnerships at Supplyframe, will drop by the Hack Chat with all the details on the 2021 Hackaday Prize. Come prepared to pick her brain on how the Prize is going to work this year, find out about the mentoring opportunities, and learn everything there is to know about this year’s competition. It’s the Greatest Hardware Design Challenge on Earth, so make sure you get in on the action.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, May 19 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.
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Tiny DeLorean Made From Lighters Is A Total Gas

May 18, 2021 by 29 Comments

There’s making stuff out of trash, and then there’s mind-blowing stuff like this: a DeLorean built from four disposable cigarette lighters and various other bits and bobs like wire sheathing and cotton bud sticks. If it weren’t for the video evidence embedded below, we would have never believed that [Ank Creative] or anyone else could have turned boxy acrylic into the fastback time machine we all know and love.

Is the back window the most important detail? Maybe.

[Ank Creative] seems to have wasted no parts of the lighters, and even saved themselves a bit of trouble by using curved scraps to make the wheel wells. After installing the windshield, we certainly didn’t expect them to saw the thing in half, but how else are they going to put in the little seats and the steering column when the gull-wing doors aren’t real?

This build is all about unbelievable craftsmanship and deft but daring use of hand tools. Although this totally qualifies as an open source how-to video, you’d have to be quite the sorcerer to pull this one off. Zoom past the break (if you haven’t already) and check out this amazing build.

Disposable lighters are dirt cheap, but they get the job done and you can always see how much gas is left in the tank. On the other hand, a refillable lighter is just that, and if you build it yourself, you can make it actuate like a cap gun.

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