ESP32-S2 Hack Chat With Adafruit

May 4, 2020 by Dan Maloney 23 Comments

Join us on Wednesday, May 6 at noon Pacific for the ESP32-S2 Hack Chat with Limor “Ladyada” Fried and Scott Shawcroft!

When Espressif released the ESP8266 microcontroller back in 2014, nobody could have predicted how successful the chip was to become. While it was aimed squarely at the nascent IoT market and found its way into hundreds of consumer devices like smart light bulbs, hackers latched onto the chip and the development boards it begat with gusto, thanks to its powerful microcontroller, WiFi, and lots of GPIO.

The ESP8266 was not without its problems, though, and security was always one of them. The ESP32, released in 2016, addressed some of these concerns. The new chip added another CPU core, a co-processor, Bluetooth support, more GPIO, Ethernet, CAN, more and better ADCs, a pair of DACs, and a host of other features that made it the darling of the hacker world.

Now, after being announced in September of 2019, the ESP32-S2 is finally making it into hobbyist’s hands. On the face of it, the S2 seems less capable, with a single core and neither Bluetooth nor Ethernet. But with a much faster CPU, scads more GPIO, more ADCs, a RISC-V co-processor, native USB, and the promise of very low current draw, it could be that the ESP32-S2 proves to be even more popular with hobbyists as it becomes established.

To talk us through the new chip’s potential, Limor “Ladyada” Fried and Scott Shawcroft, both of Adafruit Industries, will join us on the Hack Chat. Come along and learn everything you need to know about the ESP32-S2, and how to put it to work for you.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, May 6 at 12:00 PM Pacific time. If time zones have got you down, 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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Hackaday Links: May 3, 2020

May 3, 2020 by Dan Maloney 7 Comments

In a sign of the times, the Federal Communications Commission has officially signed off on remote testing sessions for amateur radio licensing in the United States. Testing in the US is through the Volunteer Examiner Coordinator program, which allows teams of at least three Volunteer Examiners to set up in-person testing sessions where they proctor amateur radio licensing exams. The VEs take their jobs very seriously and take pride in offering exam sessions on a regular schedule, so when social distancing rules made their usual public testing venues difficult to access, many of them quickly pivoted to remote testing using teleconferencing applications. Here’s hoping that more VEs begin offering remote testing sessions.

Another aspect of life changed by COVID-19 and social distancing rules has been the simple pleasure of a trip to the museum. And for the museums themselves, the lack of visitors can be catastrophic, both in terms of fulfilling their educational and research missions and through the lack of income that results. To keep the flame alive in a fun way, Katrina Bowen from The Centre for Computing History in Cambridge has recreated her museum in loving detail in Animal Crossing: New Leaf. For being limited to what’s available in the game, Katrina did a remarkable job on the virtual museum; we especially like the Megaprocessor wallpaper. She even managed to work in that staple last stop of every museum, the gift shop.

To the surprise of few, “spatial computing” startup Magic Leap has announced that it is laying off half its workforce as it charts a new course. The company, which attracted billions in funding based on its virtual retinal display technology, apparently couldn’t sell enough of their Magic Leap One headsets to pay the bills. The company is swiveling to industrial users, which honestly seems like a better application for their retinal display technology than the consumer or gaming markets.

And finally, as if 2020 hasn’t been weird enough already, the Department of Defense has officially released videos of what it calls “unidentified aerial phenomena.” These videos, taken from the head-up displays of US Navy fighter jets, had previously been obtained by private parties and released to the public. Recorded between 2004 and 2015, the videos appear to show objects that are capable of extremely high-speed flight and tight maneuvers close to the surface of the ocean. We find the timing of the release suspicious, almost as if the videos are intended to serve as a distraction from the disturbing news of the day. We want to believe we’re not alone, but these videos don’t do much to help.

DJ Scratches Out Club Music With Tape, Not Turntables

April 30, 2020 by Dan Maloney 20 Comments

It goes without saying that not everyone has the same taste in music, and what sounds amazing to one person will be the next person’s noise. But even if you’re not into hip-hop and the whole DJ scene, it’s hard not to be impressed with what [Jeremy Bell] has done here with his homemade tape loop “scratching” rig.

Most people have probably seen a DJ in a club using dual turntables to scratch or “scrub” a vinyl record back and forth to create effects that add to the music. Part musician and part performance artist, DJs and “turntablists” tend to be real crowd-pleasers. [Jeremy]’s “ScrubBoard” uses a loop of 2″ audiotape, the kind recording studios once used for multitrack recordings. The loop is driven across a wide platen by a motor with a foot pedal control, which he can use to quickly reverse the direction of travel and control the speed of the tape. A pair of playback heads are wired into the amplifier and can be positioned anywhere on the sometimes moving, sometimes stationary tape. The sounds he can create are rhythmic, percussive, and at times frenetic, but they’re always interesting. Check it out in action in the video below.

This version of the ScrubBoard is far from the first [Jeremy] has built. You may recall his first prototype from our coverage in 2014; that one used just a few feet of 1/4″ tape fixed to a board. He was still able to get some great sounds from it, but this version should really change things for him.

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This Animatronic Mouth Mimics Speech With Servos

April 30, 2020 by Dan Maloney 12 Comments

Of the 43 muscles that comprise the human face, only a few are actually important to speaking. And yet replicating the movements of the mouth by mechanical means always seems to end up only partly convincing. Servos and linkages can only approximate the complex motions the lips, cheeks, jaw, and tongue are capable of. Still, there are animatronics out there that make a good go at the job, of which this somewhat creepy mechanical mouth is a fine example.

Why exactly [Will Cogley] felt the need to build a mechanical maw with terrifying and fairly realistic fangs is anyone’s guess. Recalling his lifelike disembodied animatronic heart build, it just seems like he pursues these builds for the challenge of it all. But if you thought the linkages of the heart were complex, wait till you see what’s needed to make this mouth move realistically. [Will] has stuffed this pie hole with nine servos, all working together to move the jaw up and down, push and pull the corners of the mouth, raise and lower the lips, and bounce the tongue around.

It all seems very complex, but [Will] explains that he actually simplified the mechanical design to concentrate more on the software side, which is a text-to-speech movement translator. Text input is translated to phonemes, each of which corresponds to a mouth shape that the servos can create. It’s pretty realistic although somewhat disturbing, especially when the mouth is placed in an otherwise cuddly stuffed bear that serenades you from the nightstand; check out the second video below for that.

[Will] has been doing a bang-up job on animatronics lately, from 3D-printed eyeballs to dexterous mechatronic hands. We’re looking forward to whatever he comes up with next — we think.

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Cheap Alternative Solvents For PCB Cleaning

April 29, 2020 by Dan Maloney 82 Comments

If you’re in the habit of using isopropyl alcohol to clean your PCBs after soldering, you probably have a nice big jug of the stuff stashed away. If you don’t, you’re probably out of luck, since the COVID-19 pandemic has pretty much cleared IPA out of the retail market. But don’t fret: depending on where you live, alternative PCB cleaning solutions may be as close as your nearest auto parts store.

[Steven]’s search for a cheaper and perhaps more readily available substitute for his usual dedicated flux cleaner lead him to try automotive brake cleaner on a few test boards. He suspected that they might contain acetone, which is prone to yield unfortunate results with solder resist and silkscreen on PCBs, so some tests were in order. The brand he tried was Normfest Bremsenreiniger MC-1, a German brand that according to its Safety Data Sheet contains only hydrocarbons like alkanes, butane, and propane. It did a fine job cleaning all but the crustiest rosin flux without collateral damage.

In the video below, [Steven] goes through a few more brands with similar results, and we were encouraged enough by his results to check brake cleaners made for the US market. Alas, almost all of the cheap and readily available aerosols have acetone as the principle ingredient, mixed in with methanol, ethanol, and assorted ingredients that together will probably make for a bad day. About the only US-sold brand without acetone that we could find was Keller-Heartt, which lists only naptha and ethanol on its SDS. There may be others, but make sure you test whatever you find.

Aerosol solvents aren’t the only way to clean a PCB, of course. Ultrasonic cleaners do a great job, and as [Steven] discovered, they’re generally safe for most components.

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Pi Cam Replaces Pinhole And Film For Digital Solargraphy

April 28, 2020 by Dan Maloney 29 Comments

Solargraph from a one-year exposure on film. Elekes Andor / CC BY-SA

Have you ever heard of solargraphy? The name tells you much of what you need to know, but the images created with a homemade pinhole camera and a piece of photographic film can be visually arresting, showing as they do the cumulative tracks of the sun’s daily journey across the sky over many months. But what if you don’t want to use film? Is solargraphy out of reach to the digital photographers of the world?

Not at all, thanks to this digital solargraphy setup. [volzo] searched for a way to make a digital camera perform like a film-based solargraphic camera, first thinking to take a series of images during the day and average them together. He found that this just averaged out the sun from the final image. His solution was to take a pair of photos at each timepoint — one correctly exposed to capture the scene, and one stopped way down to just capture the position of the sun as a pinprick of light. All the foreground images are averaged, while the stopped-down sun images are overlaid upon each other, producing the track of the sun across the sky. Add the two resulting images and you’ve got a solargraph.

To automate the process, [volzo] used a Raspberry Pi and a Pi-Cam fitted in a weatherproof 3D-printed box. A custom hat powers up the Pi every few minutes, which boots up and takes the two pictures. Sadly, the batteries only last for a couple of days, so those long six-month exposures aren’t possible yet. But [volzo] has made all the sources available, so feel free to build on his work. If you prefer to use a DSLR for the job, this Bluetooth intervalometer might help.

Citizen Science Hack Chat With Ben Krasnow

April 27, 2020 by Dan Maloney 4 Comments

Join us on Wednesday, April 29 at noon Pacific for the Citizen Science Hack Chat with Ben Krasnow!

For most of human history, there was no such thing as a professional scientist. Those who dabbled in “natural philosophy” were mainly men — and occasionally women — of privilege and means, given to spend their time looking into the workings of the world. Most went where their interest lay, exploring this facet of geology or that aspect of astronomy, often combining disciplines or switching to new ones as they felt like it. They had the freedom to explore the universe without the pressure to “publish or perish,” and yet they still often managed to pull back the curtain of ignorance and superstition that veiled the world for eons, at least somewhat.

In their footsteps follow today’s citizen scientists, a relatively small cohort compared to the great numbers of professional scientists that universities churn out year after year. But where these credentialed practitioners are often hyper-focused on a particular sub-field in a highly specialized discipline, the citizen scientist enjoys more freedom to explore the universe, as his or her natural philosopher forebears did. These citizen scientists — many of whom are also traditionally credentialed — are doing important work, and some are even publishing their findings in mainstream journals.
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