Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Your DS18B20 temperature sensor is likely a fake, counterfeit, clone

github.com

Post reply on HN
Print view View original

51–60 of 239 posts

Re: Your DS18B20 temperature sensor is likely a fake, counterfeit, clone

#51

Post by fermienrico »

IgorPartola wrote: post #32
myself248 wrote: post #12

Earlier quoted context omitted.

I'd never expect to find these in official products from trusted brands, but off-brand crap? Oh yeah. DIY kits? Absolutely. The parts drawer at the makerspace? One hundred percent. So much stuff on eBay is free shipping, that's huge when you only need a few dollars worth of stuff. If I could convince Digi-Key to lick a 55-cent stamp when I need ten of something, instead of charging me $7 for shipping, I'd have a lot…

This. I buy a decent amount of hobby electronics from eBay and AliExpress because yes it is cheaper. When I need quality, Mouser, DigiKey, and McMaster-Carr are there for me. But the minimum $7-9 shipping is the main reason is forego them. I’d gladly pay 2x for small electronic components (vs directly from China options) if shipping wasn’t a problem.

For any serious person trying to develop a little bit beyond hobby projects: Think about an hourly rate of $80/hour for yourself. If you have to spend an hour trying to fiddle with subpar shady parts, you've already paid for the shipping 8 times over.

Also, it is painful to wait for these packages from China. Digikey ships same day and its at your door step in the morning (I overnight it) and if you use $7, it is usually 2-3 days.

Plus, you're supporting legit businesses and not the shenzhen market.

I can understand total hobbyist who cannot afford $7 shipping often. But even then, you can bundle all your parts and order once.

Any engineer who earns a salary can afford $7 shipping. If you're a business, there is absolutely no excuse to penny pinch here. You're losing money by using unreliable parts, if not now, at some point in the future.

Re: Your DS18B20 temperature sensor is likely a fake, counterfeit, clone

#52

Post by pmiller2 »

sfgweilr4f wrote: post #45
fennecfoxen wrote: post #26

Earlier quoted context omitted.

There will be no licking of 55 cent stamps. US stamps have been 100% self-adhesive since 2016ish. The envelope is of course another matter.

Not to mention the obvious, but that glue isn't necessarily that great* for you either. * allegedly of course.

Is this a Seinfeld reference, or something else I’m not understanding correctly? :)

Re: Your DS18B20 temperature sensor is likely a fake, counterfeit, clone

#53

Post by fermienrico »

godelski wrote: post #14
as-j wrote: post #6

This affects temperature sensors/parts bought from un-official distributors like ebay or AliExpress, not digikey, farnel, etc. Perhaps I've been too lucky in my career and practiced EE for work, but who would you ever go to ebay instead of digikey?? Digikey certainly has a premium, but their speciality is small numbers/cut tape/etc and they have a small order size which makes them ok for hobby work, and I've used the…

Lots of hobbiests will buy things off ebay, Amazon, or Alibaba. It is extremely common and if you go into forums it is even encouraged. I'm not saying you should go to those places, but that lots of people do.

We've spoiled ourselves with CCP subsidy. It wasn't like that about 20 years ago.

You'd pay a pretty penny for things and support local/national businesses. Now, you're funneling fuel into the dragon's mouth. For what? A hobby project? Just spend the $7 shipping and get it from Digikey.

Re: Your DS18B20 temperature sensor is likely a fake, counterfeit, clone

#54

Post by 0x402DF854 »

kregasaurusrex wrote: post #41
ChrisMarshallNY wrote: post #30

Earlier quoted context omitted.

Especially if they are to be used for something like monitoring for excessive heat in some kit that could catch fire.

If this was used in a BMS with a lithium battery, a counterfeit sensor's behavior could result in the total loss of a device. Let's say the device's PCB is designed such that the sensor is connected to a rail that requires parasitic power, and you were unexpectedly shipped the D1 variant that outputs garbage data back to the onboard firmwre instead the proper temperature. Your company would have to recall every devic…

This particular sensor isn't used in mass produced devices AFAIK. NTC thermistors are cheaper and easier to design for using cheap analog components. Reading DS18B20 is quite an exercise when it comes to $0.05 microcontrollers used in e.g. household appliances.

Re: Your DS18B20 temperature sensor is likely a fake, counterfeit, clone

#56

Post by Gracana »

myself248 wrote: post #12
as-j wrote: post #6

This affects temperature sensors/parts bought from un-official distributors like ebay or AliExpress, not digikey, farnel, etc. Perhaps I've been too lucky in my career and practiced EE for work, but who would you ever go to ebay instead of digikey?? Digikey certainly has a premium, but their speciality is small numbers/cut tape/etc and they have a small order size which makes them ok for hobby work, and I've used the…

I'd never expect to find these in official products from trusted brands, but off-brand crap? Oh yeah. DIY kits? Absolutely. The parts drawer at the makerspace? One hundred percent. So much stuff on eBay is free shipping, that's huge when you only need a few dollars worth of stuff. If I could convince Digi-Key to lick a 55-cent stamp when I need ten of something, instead of charging me $7 for shipping, I'd have a lot…

Hmm, I was going to say that digikey has 3 or 4 dollar shipping, but I checked and it's $5 for a first class mail. Maybe they've changed it, or maybe it's COVID-related. I recall that they had a low price for shipping of a small maximum weight, which was good for little orders of just a few components. I generally just suck it up and place the order regardless of the shipping cost, it's not great to spend as much on shipping as you did on parts, but it's still cheaper than buying parts locally. Remember buying the assorted resistor packs at Radio Shack? Ugh.

Re: Your DS18B20 temperature sensor is likely a fake, counterfeit, clone

#57

Post by p1mrx »

myself248 wrote: post #12
as-j wrote: post #6

This affects temperature sensors/parts bought from un-official distributors like ebay or AliExpress, not digikey, farnel, etc. Perhaps I've been too lucky in my career and practiced EE for work, but who would you ever go to ebay instead of digikey?? Digikey certainly has a premium, but their speciality is small numbers/cut tape/etc and they have a small order size which makes them ok for hobby work, and I've used the…

I'd never expect to find these in official products from trusted brands, but off-brand crap? Oh yeah. DIY kits? Absolutely. The parts drawer at the makerspace? One hundred percent. So much stuff on eBay is free shipping, that's huge when you only need a few dollars worth of stuff. If I could convince Digi-Key to lick a 55-cent stamp when I need ten of something, instead of charging me $7 for shipping, I'd have a lot…

When I bought stuff from DigiKey this year, the shipping was $5.

Re: Your DS18B20 temperature sensor is likely a fake, counterfeit, clone

#58

Post by robomartin »

kregasaurusrex wrote: post #36

Trust in hardware supply chains when manufactring a PCB for a product can be quite fragile: when one component operates outside of spec, the entire device could be rendered useless. In the case of the DS18B20, the author states in the 'Warning' section that the primary way of determining counterfeit sensors is to check the ROM output compared to a known format. When counterfeit parts like this are added, it creates v…

> This anti-consumer behavior on behalf of companies

I strongly disagree with this. I see no way to rationalize that a company should be responsible for ensuring that counterfeit devices work correctly by releasing drivers that are tolerant of them or do not stop them from functioning. FTDI's products are the combination of their hardware with their drivers. Both are required in order to delivery functionality and reliability to meet their specifications.

Imagine your drivers are used in some sort of a critical application and a counterfeit device causes a failure that, in turn, causes harm to someone. An example might be a wired remote control for an industrial machine. It seems to met that bricking that device as soon as possible before harm is done is what we would want from a company that delivers a quality product.

Another way to put it is: Let the counterfeiters engineer a real product and be responsible for their own drivers, quality and safety.

The way to see clearly through some of these problems is to extend the definition towards extremes. Let's forget FTDI for a moment and generalize the problem to a microprocessor and a vendor-provided RTOS used to run the flight system of an airliner. This is a contrived hypothetical, forgive me for taking artistic license.

Imagine counterfeit processor make it into the supply chain. Should the avionics OS do its best to work with every possible fake or should it brick it on power-up before that potentially dangerous aircraft gets off the ground?

Another hypothetical could be one where we eliminate hardware completely. Imagine someone creates a fake Amazon, Facebook, NY Times or online brokerage site. Imagine proposing that the real companies would be anti-consumer if they created software that revealed the impostors. I could not imagine anyone who would propose they allow the fakes to continue to deceive consumers.

From my perspective this isn't anti-consumer at all. It's as pro-consumer as you can get: You work hard to ensure quality, consistency, performance and reliability.

The real anti-consumers are the counterfeit manufacturers. They, quite literally, could not care less. All they care about is tricking engineers and consumers into thinking they are designing and buying a quality product when, in reality, they might be dealing with dangerous junk.

Re: Your DS18B20 temperature sensor is likely a fake, counterfeit, clone

#59

Post by panitaxx »

I buy from AliExpress and eBay not because of the shipping fee but because most of the time digikey/mouser doesn't sell hobbyist friendly form factors (like breakout boards) and some of this ic come in really tiny package (like tssop) which for an amateur are difficult to solder. Sometimes they need a resistor or a capacitor or a transistor easier to buy a board with everything on it that you stick to another board and that's it.

Re: Your DS18B20 temperature sensor is likely a fake, counterfeit, clone

#60

Post by teruakohatu »

robomartin wrote: post #58
kregasaurusrex wrote: post #36

Trust in hardware supply chains when manufactring a PCB for a product can be quite fragile: when one component operates outside of spec, the entire device could be rendered useless. In the case of the DS18B20, the author states in the 'Warning' section that the primary way of determining counterfeit sensors is to check the ROM output compared to a known format. When counterfeit parts like this are added, it creates v…

> This anti-consumer behavior on behalf of companies I strongly disagree with this. I see no way to rationalize that a company should be responsible for ensuring that counterfeit devices work correctly by releasing drivers that are tolerant of them or do not stop them from functioning. FTDI's products are the combination of their hardware with their drivers. Both are required in order to delivery functionality and re…

> I strongly disagree with this. I see no way to rationalize that a company should be responsible for ensuring that counterfeit devices work correctly

They destroyed devices that worked perfectly well, but maybe (or maybe not) had a fake FTDI branding on a chip inside the device.

Even the manufacturer may have been a victim of commingled inventory. For this reason I stopped buying anything with FTDI in it, because I didn't want to take the chance it would be bricked because the smalltime seller on Tindie.com bought from a bad supplier.

I would hate to think what you would have Apple do to Hackintosh hardware.

Post reply on HN