Making PCBs With A Vinyl Cutter

April 1, 2020 by 26 Comments

You might assume that you need a lot of expensive stuff to make your own PCBs, but that isn’t the case: you can do it with a vinyl cutter and a few common chemicals and tools. [Emiliano Valencia] has laid out the entire process. While we’ve seen plenty of make your own PCB guides before, this one goes a bit further as it covers using the vinyl cutter to make solder masks, so you can use it for surface mount designs.

The end result of the process that [Emilano] lays out is the tinyDice, a cute little electronic die that can fit on a keyring. The whole process is very well written up, and even experienced PCB makers will probably find a few useful tricks here.

The really interesting part for us was using the vinyl cutter to make three parts of the process: the etching mask, the solder mask that protects the traces and the solder stencil that applies the solder to the pads for surface mounting. Continue reading “Making PCBs With A Vinyl Cutter” →

A Digital Pitch Pipe Gets You In Tune

April 1, 2020 by 4 Comments

Some humans are blessed with perfect pitch, an ability that comes in handy when pursuing the musical arts. For many others though, a little help is often appreciated. A pitch pipe is a handy way to find the starting note of a performance, and [Isaac] decided to build his own in the digital realm.

The project is based on the Adafruit Circuit Playground express, which packs in all the peripherals needed right on board. The buttons are used to select the pitch required, with the LEDs used to display the selected note. Blue means flat, green means natural, and red means sharp. A 3D printed outer ring is clipped on to the board to denote the pitches for the user. To play the note, the user simply blows on the pitch pipe. The onboard MEMS microphone detects this and plays the note on the onboard speaker.

It’s a tidy little project that is a great way to get one’s feet wet with embedded programming and working with audio. We’ve seen the Circuit Express pop up before too, such as in this pizza-box DJ mixer. Video after the break.
Continue reading “A Digital Pitch Pipe Gets You In Tune” →

Impractical Switches For The Bored Maker

April 1, 2020 by 14 Comments

Cabin fever: the inability to socialize with other humans does weird things to the human brain. Then again some of us are born to stand out, and one such amazing maker, [Lee], is spending time making weird switches from basically anything.

So what would you consider weird? How about using a piece of pasta? How about using the conductivity of an empty sink? There is even an experiment with breakfast cereal, though we do not recommend it for production use. [Lee] continues to pour experiments into Twitter and recently has gotten some conductive tape. Stick some on a game joystick and you got yourself an instant switch on a switch.

These experiments prove that there is a lot you can do with the stuff you have around your house and the other end of the circuit doesn’t necessarily need to be a humble LED. You could get more interesting results with adding the likes of a microcontroller like an ATtiny. Coupling it with a DIY LED badge would be a great idea and we’d love to see what you come up with.

Stay Smarter Than Your Smart Speaker

April 1, 2020 by 56 Comments

Smart speakers have always posed a risk to privacy and security — that’s just the price we pay for getting instant answers to life’s urgent and not-so-urgent questions the moment they arise. But it seems that many owners of the 76 million or so smart speakers on the active install list have yet to wake up to the reality that this particular trick of technology requires a microphone that’s always listening. Always. Listening.

With so much of the world’s workforce now working from home due to the global SARS-CoV-2 pandemic, smart speakers have suddenly become a big risk for business, too — especially those where confidential conversations are as common and crucial as coffee.

Imagine the legions of lawyers out there, suddenly thrust from behind their solid-wood doors and forced to set up ramshackle sub rosa sanctuaries in their homes to discuss private matters with their equally out-of-sorts clients. How many of them don’t realize that their smart speaker bristles with invisible thorns, and is even vulnerable to threats outside the house? Given the recent study showing that smart speakers can and do activate accidentally up to 19 times per day, the prevalence of the consumer-constructed surveillance state looms like a huge crisis of confidentiality.

So what are the best practices of confidential work in earshot of these audio-triggered gadgets?

Continue reading “Stay Smarter Than Your Smart Speaker” →

Accurate Dispensing Of Toilet Paper Will Get Us Through The Crisis

April 1, 2020 by 51 Comments

As we enter our second week of official COVID-19-related lockdown where this is being written, it’s evident that there are some resources we will have to conserve to help get us through all this. Instead of just using all of something because we can nip out to the store and buy more, we have to look at what we’ve got and treat it as though it will have to get us through the next three months. It’s not always certain that on our infrequent trips to the supermarket they’ll have stocks of what we want.

This is the very last of the toilet paper in my local supermarket, on the 8th of March.
This is the very last of the toilet paper in my local supermarket, on the 8th of March.

A particular shortage has been of toilet paper. The news was full of footage showing people fighting for the last twelve-pack, and since early last month there has been none to be had for love nor money. To conserve stocks and save us from the desperate measures of having to cut the Daily Mail into squares and hang them on the wall, a technical solution is required. To this end I’ve created a computerised toilet roll dispenser which carefully controls the quantity of the precious sanitary product, in the hope of curbing its consumption to see us through the crisis.

In the midst of a full lockdown it’s difficult to secure immediate delivery of our usual maker essentials, so rather than send off for the controller boards I might have liked it has been necessary to make do with what I had. In the end I selected an older single board computer I had in a box under my bench. The Sinclair ZX81 has a single-core Z80 processor running at 3.25 MHz, dual-channel memory, a Ferranti GPU, and plenty of expansion possibilities from its black plastic case. I chose it because I could repurpose its thermal printer peripheral as a toilet paper printer, and because it has an easily wiped and hygienic membrane keyboard rather than a conventional one that could harbour germs.

Hardware wise I found I was fairly easily able to adapt a standard roll of Cushelle to the ZX printer, and was soon dispensing sheets with the following BASIC code.

10 REM TOILET PAPER PRINTER
20 FOR T=0 TO 44
30 LPRINT ""
40 NEXT T
50 LPRINT "---------- TEAR HERE -----------"

For now it’s working on the bench, but it will soon be mounted with a small portable TV as a monitor on the wall next to the toilet. Dispensing toilet paper will be as simple as typing RUN and hitting the ZX’s NEW LINE key, before watching as a sheet of toilet paper emerges magically from the printer. It’s the little hacks like this one that will be so useful in getting us through the crisis. After all, this Sinclair always has a square to spare.

Gold Cables Really Do Work The Best

April 1, 2020 by 88 Comments

As a writer, I have long harboured a dream that one day an editor will buy me a top-of-the-range audio analyser, and I can set up an audio test lab and write pieces debunking the spurious claims made by audiophiles, HiFi journalists, and the high-end audio industry about the quality of their products. Does that amp really lend an incisive sibilance to the broader soundstage, and can we back that up with some measurable figures rather than purple prose?

An Audio Playground You Didn’t Know You Had

An Audio Precision APx525 audio analyser.
An Audio Precision APx525 audio analyser. Bradp723 (CC-BY-SA 3.0)

Sadly Hackaday is not an audio magazine, and if Mike bought me an Audio Precision he’d have to satisfy all the other writers’ test equipment desires too, and who knows where that would end! So there will be no Hackaday audio lab — for now. But that doesn’t mean I can’t play around with audio analysis.

Last month we carried a write-up of a Supercon talk from Kate Temkin and Michael Ossmann, in which they reminded us that we have a cracking general purpose DSP playground right under our noses; GNU Radio isn’t just for radio. Once I’d seen the talk my audio analysis horizons were opened up considerably. Maybe that audio analyser wouldn’t be mine, but I could do some of the same job with GNU Radio.

It’s important to stress at this point that anything I can do on my bench will not remotely approach the quality of a professional audio analyser. But even if I can’t measure infinitesimal differences between very high-end audio circuitry, I can still measure enough to tell a good audio product from a bad one.

Continue reading “Gold Cables Really Do Work The Best” →

Fail Of The Week: How Not To Die Of Boredom During Isolation

April 1, 2020 by 26 Comments

They say you can’t actually die from boredom, but put a billion or so people into self-isolation, and someone is bound to say, “Hold my beer and watch this.” [Daniel Reardon]’s brush with failure, in the form of getting magnets stuck up his nose while trying to invent a facial touch reminder, probably wasn’t directly life-threatening, but it does underscore the need to be especially careful these days.

The story begins with good intentions and a small stack of neodymium magnets. [Daniel]’s idea for a sensor to warn one of impending face touches was solid: a necklace with magnetic sensors and wristbands studded with magnets. Sounds reasonable enough; one can easily see a compact system that sounds an alarm when a hand subconsciously crosses into the Danger Zone while going in for a scratch. Lacking any experience in circuits, though, [Daniel] was unable to get the thing working, so he started playing with the magnets instead. One thing led to another, and magnets were soon adorning his earlobes, and then his nostrils. Unfortunately, two magnets became locked on either side of his septum, as did two others meant to neutralize the pull of the first pair. So off [Daniel] went to the emergency department for a magnetectomy.

Of course it’s easy to laugh at someone’s misfortune, especially when self-inflicted. And the now-degaussed [Daniel] seems to be a good sport about the whole thing. But the important thing here is that we all do dumb things, and hackers need to be especially careful these days. We often work with sharp, pointy, sparky, toxic, or flammable things, and if we don’t keep our wits about us, we could easily end up in an ER somewhere. Not only does that risk unnecessary exposure to COVID-19, but it also takes medical resources away from people who need it more than you do.

By all means, we should be hacking away these idle hours. Even if it’s not in support of COVID-19 solutions, continuing to do what we do is key to our mental health and well-being. But we also need to be careful, to not stretch dangerously beyond our abilities, and to remember that the safety net that’s normally there to catch us is full of holes now.

Thanks to [gir.st] for the tip — you actually were the only one to send this in.