Anatomy Of A Fake CO2 Sensor

February 18, 2023 by Jenny List 41 Comments

The pandemic brought with it a need to maintain adequate ventilation in enclosed spaces, and thus, there’s been considerable interest in inexpensive C02 monitors. Unfortunately, there are unscrupulous actors out there that have seen this as a chance to make a quick profit.

Recently [bigclivedotcom] got one such low-cost CO2 sensor on his bench for a teardown, and confirms that it’s a fake. But in doing so he reveals a fascinating story of design decisions good and bad, from something which could almost have been a useful product.

Behind the slick color display is a PCB with an unidentified microcontroller, power supply circuitry, a DHT11 environmental sensor, and a further small module which purports to be the CO2 sensor. He quickly demonstrates with a SodaStream that it doesn’t respond to CO2 at all, and through further tests is able to identify it as an alcohol sensor.

Beyond the alcohol sensor he analyses the PSU circuitry. It has a place for a battery protection chip but it’s not fitted, and an error in the regulator circuitry leads to a slow drain of the unprotected cell. Most oddly there’s an entire 5 volt switching regulator circuit that’s fitted but unused, being in place to support a missing infra-red module. Finally the screen is an application-specific LCD part.

It’s clear some effort went in to the design of this unit, and we can’t help wondering whether it could have started life as a design for a higher-spec genuine unit. But as [Clive] says, it’s a party detector, and of little more use than as a project case and battery.

Need more dubious instrumentation? How about a magnetic field tester?

Continue reading “Anatomy Of A Fake CO2 Sensor” →

Perhaps It’s Time To Talk About All Those Fakes And Clones

December 5, 2022 by Jenny List 84 Comments

A while back, I bought a cheap spectrum analyser via AliExpress. I come from the age when a spectrum analyser was an extremely expensive item with a built-in CRT display, so there’s still a minor thrill to buying one for a few tens of dollars even if it’s obvious to all and sundry that the march of technology has brought within reach the previously unattainable. My AliExpress spectrum analyser is a clone of a design that first appeared in a German amateur radio magazine, and in my review at the time I found it to be worth the small outlay but a bit deaf and wide compared to its more expensive brethren. Continue reading “Perhaps It’s Time To Talk About All Those Fakes And Clones” →

Junk I Bought: My PSU Just Won’t Do

May 31, 2022 by Jenny List 98 Comments

I have an Acer monitor that I’ve owned for around 15 years, and thanks to my having paid extra at the time for the model sporting a DVI socket for HDMI compatibility it still finds a place as one of my desktop monitors. It has a power brick that supplies it with 1 2V at 4.5 A, and over the years this has developed an annoying whine. Something’s loose in the magnetics, and I really should replace it. So off to AliExpress I went, and dropped in an order for a 12 V, 5 A power brick.

It’s No Heavyweight

A PSU brick, marked as 12V 5A — So far so good…

These units are pretty standard, a box about 130 mm by 60 mm with an IEC socket at one end and a trailing cable at the other for the low voltage. I’ve had enough of them pass through my hands over the years to know what to expect, so I was dismayed to find when I received my PSU that it was suspiciously light. 86 g compared to the around 250 g I’d expect, so I began to smell a rat. Time for a teardown, and a descent into the world of small switch-mode mains power supplies.

Normally it should be easier to break into Fort Knox than to crack open a mains power supply, because for safety they are ultrasonic welded together. The few times I’ve done it have required some Dremel time and a bit of swearing, so when this case turned out to open fairly easily by levering with a screwdriver it was evident this wasn’t a high-quality item. Sure enough my suspicions were confirmed, for there inside was a much smaller board. It’s clear this isn’t a 5 A power supply, so just what have I received? Continue reading “Junk I Bought: My PSU Just Won’t Do” →

X-Ray Sleuthing Unveils The Fake In Your Adaptors

July 15, 2020 by Adil Malik 35 Comments

Lets face it, the knock-off variety of our favourite adaptors, cables and accessories are becoming increasingly challenging to spot. We would be the first to admit, to have at some point, been stooped by a carefully crafted counterfeit by failing to spot the tell-tale yet elusive indicators such as the misplaced font face, the strategically misspelled logo or perhaps the less polished than expected plastic moulding and packaging. When you finally come around to using it, if you are lucky the item is still more or less functionally adequate, otherwise by now the inferior performance (if not the initial cost!) would have made it pretty obvious that what you have is infact a counterfeit.

[Oliver] recently found himself in a similar situation, after acquiring a seemingly original Lightning to Headphone Adaptor. Rather than dismay, [Oliver] decided to channel this energy into an excellent forensic investigation to uncover just what exactly made this imitation so deceptive. He began by comparing the packaging, printed typeface and the plastic moulding, all of which gave very little away. [Oliver] concluded that atleast superficially, the clone was rather good and the only way to settle this was to bring out the X-ray, of course!

The resulting images of the innards make it blatantly obvious as to why the adaptor is indeed very fake. For a start, compared to the original adaptor, the clone hosts a far more thin BOM count! If you are really serious in getting some training to better spot counterfeits, check out a post we featured earlier on the subject!

Hackaday Links: November 17, 2019

November 17, 2019 by Dan Maloney 8 Comments

Friday, November 15, 2019 – PASADENA. The 2019 Hackaday Superconference is getting into high gear as I write this. Sitting in the Supplyframe HQ outside the registration desk is endlessly entertaining, as attendees pour in and get their swag bags and badges. It’s like watching a parade of luminaries from the hardware hacking world, and everyone looks like they came ready to work. The workshops are starting, the SMD soldering challenge is underway, and every nook and cranny seems to have someone hunched over the amazing Hackaday Superconference badge, trying to turn it into something even more amazing. The talks start on Saturday, and if you’re not one of the lucky hundreds here this weekend, make sure you tune into the livestream so you don’t miss any of the action.

The day when the average person is able to shoot something out of the sky with a laser is apparently here. Pablo, who lives in Argentina, has beeing keeping tabs on the mass protests going on in neighboring Chile. Huge crowds have been gathering regularly over the last few weeks to protest inequality. The crowd gathered in the capital city of Santiago on Wednesday night took issue with the sudden appearance of a police UAV overhead. In an impressive feat of cooperation, they trained 40 to 50 green laser pointers on the offending drone. The videos showing the green beams lancing through the air are quite amazing, and even more amazing is the fact that the drone was apparently downed by the lasers. Whether it was blinding the operator through the FPV camera or if the accumulated heat of dozens of lasers caused some kind of damage to the drone is hard to say, and we’d guess that the drone was not treated too kindly by the protestors when it landed in the midsts, so there’s likely not much left of the craft to do a forensic analysis, which is a pity. We will note that the protestors also trained their lasers on a police helicopter, an act that’s extremely dangerous to the human pilots which we can’t condone.

In news that should shock literally nobody, Chris Petrich reports that there’s a pretty good chance the DS18B20 temperature sensor chips you have in your parts bin are counterfeits. Almost all of the 500 sensors he purchased from two dozen vendors on eBay tested as fakes. His Github readme has an extensive list that lumps the counterfeits into four categories of fake-ness, with issues ranging from inaccurate temperature offsets to sensors without EEPROM that don’t work with parasitic power. What’s worse, a lot of the fakes test almost-sorta like authentic chips, meaning that they may work in your design, but that you’re clearly not getting what you paid for. The short story to telling real chips from the fakes is that Maxim chips have laser-etched markings, while the imposters sport printed numbers. If you need the real deal, Chris suggests sticking with reputable suppliers with validated supply chains. Caveat emptor.

A few weeks back we posted a link to the NXP Homebrew RF Design Challenge, which tasked participants to build something cool with NXP’s new LDMOS RF power transistors. The three winners of the challenge were just announced, and we’re proud to see that Razvan’s wonderfully engineered broadband RF power amp, which we recently featured, won second place. First place went to Jim Veatch for another broadband amp that can be built for $80 using an off-the-shelf CPU heatsink for thermal management. Third prize was awarded to a team lead by Weston Braun, which came up with a switch-mode RF amp for the plasma cavity for micro-thrusters for CubeSats, adorably named the Pocket Rocket. We’ve featured similar thrusters recently, and we’ll be doing a Hack Chat on the topic in December. Congratulations to the winners for their excellent designs.

Turning A Sony Into A Leica Through Extreme Camera Modding

August 16, 2019 by Jenny List 12 Comments

The quality of a photograph is a subjective measure depending upon a multitude of factors of which the calibre of the camera is only one. Yet a high quality camera remains an object of desire for many photographers as it says something about you and not just about the photos you take. [Neutral Gray] didn’t have a Leica handheld camera, but did have a Sony. What’s a hacker to do, save up to buy the more expensive brand? Instead he chose to remodel the Sony into a very passable imitation.

This is a Chinese language page but well worth reading. We can’t get a Google Translate link to work, but in Chrome browser, right clicking and selecting “translate” works. If you have a workaround for mobile and other browsers please leave a comment below.

The Sony A7R is hardly a cheap camera in the first place, well into the four-figure range, so it’s a brave person who embarks on its conversion to match the Leica’s flat-top aesthetic. The Sony was first completely dismantled and it was found that the electronic viewfinder could be removed without compromising the camera. In a bold move, its alloy housing was ground away, and replaced with a polished plate bearing a fake Leica branding.

Extensive remodelling of the hand grip with a custom carbon fibre part followed, with significantly intricate work to achieve an exceptionally high quality result. Careful choice of paint finish results in a camera that a non-expert would have difficulty knowing was anything but a genuine Leica, given that it is fitted with a retro-styled lens system.

We’re not so sure we’d like to brace Leica’s lawyers on this side of the world, but we can’t help admiring this camera. If you’re after a digital Leica though, you can of course have a go at the real thing.

Thanks [fvollmer] for the tip.

How Much Apple Does A Hamburger Get You?

March 29, 2019 by Jenny List 28 Comments

A while ago, [Skippy] bought a cheap knock-off of the Apple USB mains charger from an AliExpress seller, for the British low, low price of 89p. Normally we’d give you a dollar conversion, but since that’s coincidentally the price of the basic McDonalds hambuger in the UK we’ll go with the hamburger as a unit of conversion. And as any self-respecting hacker would, he subjected it to a teardown and gave it a few tests.

Surprisingly though its pins were a little long it was just within the BS1363 pin spacing specification, probably due to its external dimensions copying the Apple original. The emissions test he performed might surprise readers, as it gave the little device its first pass. Radiated RF emissions were well below the test threshold, a welcome sight for anyone who has had to test a device. Sadly the same could not be said for conducted emissions, and it was happily spraying RF to all and sundry from its connections.

Taking a look inside revealed the usual litany of frightening safety fails. There was no insulation between the mains pins and the circuit board, and a secondary capacitor was even touching one of the pins. Meanwhile another capacitor connecting both sides of the circuit was not of the required Y rating. These and a raft of others make the device illegal for sale in Europe without further tests, but to give some numbers to it all he subjected it to a screen test applying 600 VAC common mode to its pins and checking for leakage current through the device. This it failed, and indeed it did not recover from the test.

So in this case, the price of a hamburger definitely does not get you an Apple, nor even does it get you an equivalent. But of course, you knew that, because we’ve talked about fake Apple chargers and power supplies many times before.