Some of you may remember the SCiO, originally a Kickstarter darling back in 2014 that promised people a pocket-sized micro spectrometer. It was claimed to be able to scan and determine the composition of everything from fruits and produce to your own body. The road from successful crowdsourcing to production was uncertain and never free from skepticism regarding the promised capabilities, but the folks at [Sparkfun] obtained a unit and promptly decided to tear it down to see what was inside, and share what they found.
The main feature inside the SCiO is the optical sensor, which consists of a custom-made NIR spectrometer. By analyzing the different wavelengths that reflect off an object, the unit can make judgments about what the object is made of. The SCiO was clearly never built to be disassembled, but [Sparkfun] pulls everything apart and provides some interesting photos of a custom-made optical unit with an array of different sensors, various filters, apertures, and a microlens array.
It’s pretty interesting to see inside the SCiO’s hardware, which unfortunately required destructive disassembly of the unit in question. The basic concept of portable spectroscopy is solid, as shown by projects such as the Farmcorder which is intended to measure plant health, and the DIY USB spectrometer which uses a webcam as the sensor.
When you take an item with you on a camping trip and it fails, you are not normally in a position to replace it immediately, thus you have the choice of fixing it there and then, or doing without it. When his LED camping lantern failed, [Mark Smith] was in the lucky position of camping at a friend’s compound equipped with all the tools, so of course he set about fixing it. What he found shocked him metaphorically, but anyone who handles it while it is charging can expect the more literal variation.
The lamp was an LED lantern with built-in mains and solar chargers for its Ni-Cd battery pack, and a USB charger circuit that provided a 5 volt output for charging phones and the like. The problem [Mark] discovered was that the mains charger circuit did not have any mains isolation, being a simple capacitive voltage dropper feeding a rectifier. These circuits are very common because they are extremely cheap, and are perfectly safe when concealed within insulated mains-powered products with no external connections. In the case of [Mark]’s lantern though the USB charging socket provided that external connection, and thus access to a potential 120 VAC shock for anyone touching it while charging.
Plainly this lamp doesn’t conform to any of the required safety standards for mains-powered equipment, and we’re guessing that its design might have come about by an existing safe lamp being manufactured with an upgrade in the form of the USB charger. The write-up gives it a full examination, and includes a modification to safely charge it from a wall-wart or similar safe power supply. Definitely one to watch out for!
If you were wondering what the fault was with Mark’s lamp, it was those cheap NiCd batteries failing. He replaced them, but there are plenty of techniques to rejuvenate old NiCds, both backyard, and refined.
While it’s true that your parts bin might have a few parts harvested from outdated devices of recent vintage, there’s not much to glean anymore aside from wall warts. But the 3×48-character LCD from [Kerry Wong]’s old Uniden cordless landline phone was tempting enough for him to attempt a teardown and reverse engineering, and the results were instructive.
No data sheet? No problem. [Kerry] couldn’t find anything out about the nicely backlit display, so onto the logic analyzer it went. With only eight leads from the main board to the display module, it wasn’t likely to be a parallel protocol, and the video below shows that to be the case. A little fiddling with the parameters showed the protocol was Serial Peripheral Interface, but as with other standards that aren’t exactly standardized, [Kerry] was left with enough ambiguity to make the analysis interesting. Despite a mysterious header of 39 characters, he was able in the end to drive the LCD with an Arduino, and given that these phones were usually sold as a bundle with a base and several handsets, he ought to have a nice collection of displays for the parts bin.
We’ve taken a few microswitches apart, mostly to fix those pesky Logitech mice that develop double-click syndrome, but we’ve never made a video. Luckily, [Julian] did, and it is worth watching if you want to understand the internal mechanism of these components.
[Julian] talks about the way the contacts make and break. He also discusses the mechanical hysteresis inherent in the system because of the metal moving contact having spring-like qualities
“Teardown” isn’t really accurate here, at least by the standard of [electronupdate]’s other component teardowns, like his looks inside LED light bulbs and das blinkenlights. “Rubdown” is more like it here, because what starts out as a rather solid looking SMT component needs to be ground down bit by bit to reveal the inner ferrite and copper goodness. [electronupdate] embedded the R30 SMT inductor in epoxy and hand lapped the whole thing until the windings were visible. Of course, just peeking inside is never enough, so he set upon an analysis of the inductor’s innards. Using a little careful macro photography and some simple image analysis, he verified the component’s data sheet claims; as an aside, is anyone else surprised that a tiny SMT component can handle 30 amps?
[Shahriar] recently posted a review of a 6.8 GHz network analyzer. You can see the full video — over fifty minutes worth — below the break. The device can act as a network analyzer, a spectrum analyzer, a field strength meter, and a signal generator. It can tune in 1 Hz steps down to 9 kHz. Before you rush out to buy one, however, be warned. The cost is just under $2,000.
That sounds like a lot, but test gear in this frequency range isn’t cheap. If you really need it, you’d probably have to pay at least as much for something equivalent.
[Shahriar] had a few issues to report, but overall he seemed to like the device. For example, setting the step size too broad can cause the spectrum analyzer to miss narrow signals.
If your needs are more modest, we’ve covered a much simpler (and less expensive) unit that goes to 6 GHz. If you need even less, an Arduino can do the job with a good bit of help. The Analog Discovery 2 also has a network analyzer feature, along with other tools at a more affordable cost, too. Of course, that’s only good to 10 MHz.
Poke around enough on AliExpress, Alibaba, and especially Taobao—the Chinese facing site that’s increasingly being used by Westerners to find hard to source parts—and you’ll come across some interesting things. The Long-CZ J8 is one of those, it’s 2.67 inch long and weighs just 0.63 ounces, and it’s built in the form factor of a Bluetooth headset.
A couple of months ago Cory Doctorow highlighted this tiny phone, he’d picked up on it because of the marketing. The lozenge-shaped phone was being explicitly marketed that it could “beat the boss”. The boss in question here being the B.O.S.S chair—a scanning technology that has been widely deployed across prisons in the U.K. in an attempt to put a halt to smuggling of mobile phones to inmates.
I wasn’t particularly interested in whether it could make it through a body scanner, or the built-in voice changer which was another clue as to the target market for the phone. However just the size of the thing was intriguing enough that I thought I’d pick one up and take a look inside. So I ordered one from Amazon.