Get Inside A TCXO Clock Chip

August 9, 2017 by Elliot Williams 28 Comments

[Pete] wondered how real-time clock modules could be selling on eBay for $1.50 when the main component, the Maxim DS3231 RTC/TCXO chip, cost him more like $4 apiece. Could the cheap modules contain counterfeit chips?

Well, sure they could. But in this case, they didn’t, and [Pete] has the die shots to prove it. He started off by clipping the SOIC leads rather than desoldering — he’s not going to be reusing this chip after he’s cut it in half. Next was a stage of embrittling the case by heating it up with a lighter and dunking it in water. Then he went at it with sandpaper.

It’s cool. You can see the watch crystal inside, and all of the circuitry. The DS3231 includes a TCXO — temperature-corrected crystal oscillator — and it seems to have a bank of capacitors that it connects and disconnects depending on the chip’s temperature to keep the oscillator running at the right speed. [Pete] used one in an offline situation, and it only lost sixteen seconds over a year, so we’d say that they work fine.

If you’d like to know more about how crystals are used to keep time, check out [Jenny]’s excellent article. And if sixteen second per year is way too much for you, tune up your rubidium standard and welcome to the world of the time nuts.

Everything You Need To Know About Logic Probes

July 29, 2017 by Elliot Williams 43 Comments

We just spent the last hour watching a video, embedded below, that is the most comprehensive treasure trove of information regarding a subject that we should all know more about — sniffing logic signals. Sure, it’s a long video, but [Joel] of [OpenTechLab] leaves no stone unturned.

At the center of the video is the open-source sigrok logic capture and analyzer. It’s great because it supports a wide variety of dirt cheap hardware platforms, including the Salae logic and its clones. Logic is where it shines, but it’ll even log data from certain scopes, multimeters, power supplies, and more. Not only can sigrok decode raw voltages into bits, but it can interpret the bits as well using protocol decoder plugins written in Python. What this all means is that someday, it will decode everything. For free.

[Joel] knows a thing or two about sigrok because he started the incredibly slick PulseView GUI project for it, but that doesn’t stop him from walking you through the command-line interface, which is really useful for automated data capture and analysis, if that’s your sort of thing. Both are worth knowing.

But it’s actually the hardware details where this video shines. He breaks down all of the logic probes on his bench, points out their design pros and cons, and uses that basis to explain just what kind of performance you can expect for $20 or so. You’ll walk away with an in-depth understanding of the whole toolchain, from grabber probes to GUIs.
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Maywa Denki’s Nonsense Machines

July 26, 2017 by Elliot Williams 9 Comments

We just spent a few hours trying to figure out Japanese techno-performance-art-toy company [Maywa Denki]. As self-described “parallel-world electricians”, the small art collective turns out strange electro-mechanical instruments, creates bellows-powered “singing” sculptures, and puts on concerts/demos/lectures. And if you desperately need an extension cord in the shape of a fish skeleton, [Maywa Denki] has you covered. Writing about art is like dancing about economics, so first we’ll just drop a few of our favorites and let you decide.

On the serious art front are “nonsense machines” like SeaMoonsII and Wahha Go Go. The most iconic performance piece is probably the Pachi-Moku, a set of finger-snap-activated wooden gongs mounted on anime-style wings. And then there are “toys” like Mr. Knocky and the Otamatone, here demonstrated playing some DEVO.

There’s a lot going on here. The blue suits of the assembly-line worker, the back story as a small-electronics “company”, and the whole art-as-commodity routine is a put into contrast with the mad-inventor schtick make sense both as a reaction against conformist, corporatist postwar Japanese culture or as a postmodern hat-tip to the realities of the modern art scene. But mostly, what comes across is the feeling that [Novmichi Tosa], the “president” of [Maywa Denki] just loves to make crazy gizmos.

How else do you explain the gas-powered, chomping mouth-full-of-knives, Poodle’s Head?

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The End Of Arduino 101: Intel Leaves Maker Market

July 25, 2017 by Elliot Williams 81 Comments

This looks like the end of the road for Intel’s brief foray into the “maker market”. Reader [Chris] sent us in a tip that eventually leads to the discontinuation notice (PCN115582-00, PDF) for the Arduino 101 board. According to Intel forum post, Intel is looking for an alternative manufacturer. We’re not holding our breath.

We previously reported that Intel was discontinuing its Joule, Galileo, and Edison lines, leaving only the Arduino 101 with its Curie chip still standing. At the time, we speculated that the first wave of discontinuations were due to the chips being too fast, too power-hungry, and too expensive for hobbyists. Now that Intel is pulling the plug on the more manageable Arduino 101, the fat lady has sung: they’re giving up on hardware hackers entirely after just a two-year effort.

According to the notice, you’ve got until September 17 to stock up on Arduino 101s. Intel is freezing its Curie community, but will keep it online until 2020, and they’re not cancelling their GitHub account. Arduino software support, being free and open, will continue as long as someone’s willing to port to the platform.

Who will mourn the Arduino 101? Documentation was sub-par, but a tiny bit better than their other hacker efforts, and it wasn’t overpriced. We’re a little misty-eyed, but we’re not crying. You?

[via Golem.de]

Duocopter Does It With Two Fewer Propellers

July 25, 2017 by Elliot Williams 15 Comments

Quads are a great ‘copter design. The paired blades counteract each others’ torque, and varying the relative speeds of the four motors makes it easy to steer. But what if you could get by with fewer blades, substituting a significantly fancier control algorithm?

[Dirk Brunner]’s DuoCopter drone uses two propellers that counter-rotate, and it steers by increasing and decreasing the speed at which the blades rotate within a single revolution. Spinning faster on one side than the other makes it tilt. Saying this is one thing, but getting the real-time control algorithms up and running is another. From the video embedded below, it looks like [Dirk] has it working. (He also holds the world’s record for fastest quadcopter ascent, FWIW.)

Of course some of you out there won’t be satisfied until your ‘copter has only one propeller. Or maybe you’d prefer a third prop. Whatever your taste, we’re stoked to see people pushing the boundaries of copter design.

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RoGeorge Attacks A Pulse Meter

July 22, 2017 by Elliot Williams 2 Comments

The “Crivit Sports” is an inexpensive chest-strap monitor that displays your current pulse rate on a dedicated wristwatch. This would be much more useful, and presumably more expensive, if it had a logging option, or any way to export your pulse data to a more capable device. So [RoGeorge] got to work. Each post of the (so-far) three-part series is worth a read, not the least because of the cool techniques used.

In part one, [RoGeorge] starts out by intercepting the signals. His RF sniffer? An oscilloscope probe shorted out in a loop around the heart monitor. Being able to read the signals, it was time to decode them. Doing pushups and decoding on-off keyed RF signals sounds like the ideal hacker training regimen, but instead [RoGeorge] used a signal generator, clipped to the chest monitor, to generate nice steady “heartbeats” and then read the codes off the scope without breaking a sweat.

With the encoding in hand, and some help from the Internet, he tested out his hypothesis in part two. Using an Arduino to generate the pulses logged in part one, he pulsed a coil and managed to get the heart rates displayed on the watch.

Which brings us to part three. What if there were other secrets to be discovered? Brute-forcing every possible RF signal and looking at the watch to see the result would be useful, but doing so for 8,192 possible codes would drive anyone insane. So [RoGeorge] taught himself OpenCV in Python and pointed a webcam at the watch. He wrote a routine that detected the heart icon blinking, a sign that the watch received a valid code, and then transmitted all possible codes to see which ones were valid. Besides discovering a few redundant codes, he didn’t learn much new from this exercise, but it’s a great technique.

We’re not sure what’s left to do on the Crivit. [RoGeorge] has already figured out the heart-rate data protocol, and could easily make his own logger. We are sure that we liked his thorough and automated approach to testing it all, from signal-generator-as-heartbeat to OpenCV as feedback in a brute-force routine. We can’t wait to see what’s up next.

I Am An Iconoscope

July 19, 2017 by Elliot Williams 26 Comments

We’d never seen an iconoscope before. And that’s reason enough to watch the quirky Japanese, first-person video of a retired broadcast engineer’s loving restoration. (Embedded below.)

Quick iconoscope primer. It was the first video camera tube, invented in the mid-20s, and used from the mid-30s to mid-40s. It worked by charging up a plate with an array of photo-sensitive capacitors, taking an exposure by allowing the capacitors to discharge according to the light hitting them, and then reading out the values with another electron scanning beam.

The video chronicles [Ozaki Yoshio]’s epic rebuild in what looks like the most amazingly well-equipped basement lab we’ve ever seen. As mentioned above, it’s quirky: the iconoscope tube itself is doing the narrating, and “my father” is [Ozaki-san], and “my brother” is another tube — that [Ozaki] found wrapped up in paper in a hibachi grill! But you don’t even have to speak Japanese to enjoy the frame build and calibration of what is probably the only working iconoscope camera in existence. You’re literally watching an old master at work, and it shows.

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