If you’re lucky, reverse engineering can be a messy business. Sure, there’s something to be said for attacking and characterizing an unknown system and leaving no trace of having been there, but there’s something viscerally satisfying about destroying something to understand it. Especially when homemade fuming nitric acid is involved.
The recipient of such physical and chemical rough love in the video below is a residential electric smart meter, a topic that seems to be endlessly fascinating to [Hash]; this is far from the first time we’ve seen him take a deep dive into these devices. His efforts are usually a little less destructive, though, and his write-ups tend to concentrate more on snooping into the radio signals these meters are using to talk back to the utility company.
This time around, [Hash] has decided to share some of his methods for getting at these secrets, including decapping the ICs inside. His method for making fuming nitric acid from stump remover and battery acid is pretty interesting; although the laboratory glassware needed to condense the FNA approaches the cost of just buying the stuff outright, it’s always nice to have the knowledge and the tools to make your own. Just make sure to be careful about it — the fumes are incredibly toxic. Also detailed is a 3D-printable micropositioner, used for examining and photographing acid-decapped ICs under the microscope, which we’d bet would be handy for plenty of other microscopy jobs.
In addition to the decapping stuff, and a little gratuitous destruction with nitric acid, [Hash] takes a look at the comparative anatomy of smart meters. The tamper-proofing features are particularly interesting; who knew these meters have what amounts to the same thing as a pinball machine’s tilt switch onboard?
We have come a long way since you could pull the meter and just stick it back in upside down and it would go backwards. How easy.
Should not work today, is the only reason I mention that this existed in the past.
A very long time ago someone, who I am not naming – it was Electrical Engineering lecturer at an unnamed university, showed a device (they never opened it or explained the circuit) that would drive an ancient power meter backwards (before the power companies added a mechanical means of blocking an analogue meter from spinning backwards). Apparently someone guessed that it sent a higher current, at a lower voltage, in the opposite direction through the generator. Super illegal (fraud), super inefficient (deliberately slowing down the power companies generators with a reverse EMF).
The easy way was an electromagnet inside the house, on the wall opposite the meter.
Add turns to the magnet until the meter stops. Run magnet on timer.
Beware breaking the meter outright.
I bet the box you describe messed with the power factor.
Or so I’m told…not knowing…as I’m completely honest.
Also fuming nitric acid! I’m still irritated that they wouldn’t sell me glycerin and fuming nitric and sulphuric acids when I was in middle school. For the best, led to the reloading section at the toy store. Good times!
Fascinating
Great video for watching with breakfast on a lazy Sunday morning. Looks like the chip was some kind of propriety thing – but what were it’s functions?
Just a Patreon ad. No interest here.
Last I tried, they wouldn’t sell me even non-fuming nitric acid…there are….implications….and merely trying to buy it probably put me on a watch list! Didn’t help that I also tried at a different time to get a small quantity of diazonium salt (attempting to nickel plate some acrylic – that paper should be safe to google :D)
Why was I looking for nitric acid? To decap an ic of course! Still need to finish that project…too many projects need finishing!
Buy some fuming nitric acid, have fun for a day.
Teach yourself to make fuming nitric acid- Hacker4Lyfe
Great, now let’s not tell people what happens if you combine that nitric acid with cellulose… Or glycerin… Or toluene…
Go on…
It’s nitrocellulose (film stock), nitroglycerine (heart or headache inducing medication), and TNT (blasting agent)
Filmstock…that’s the ticket.
I’m going to make old school filmstock out of smokeless powder. Not making fireworks or anything like that.
If a fed reads this, is it a felony?
Quote my dad: ‘Nitrocellulose is much safer. Don’t be an idiot, get it readymade at the gun store.’
Dad’s never fail to provide “Don’t be an idiot” advice 😂