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

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

#191

Post by foldr »

sokoloff wrote: post #188
foldr wrote: post #171

Earlier quoted context omitted.

No, I think his point is that fake chips win by default if nothing can be done to disincentivize their manufacture and use. Law enforcement isn't cracking down on fake chips. So what else is FTDI to do if they're to survive as a business? You are fixated on what's best for the consumer in the short term, but the long term consequence of that could be that FTDI goes out of business and can't support any chips, fake or…

I have no problem with FTDI making their Windows driver not work with clone devices, but leaving that device undamaged and working once removed and plugged into a different machine. That is a reasonable action and would be enough to cause at least one more round of cat and mouse with the clone makers, putting a massive dent into their economics. If they’d done that, it might have given FTDI a positive reputation (lik…

You don't have to like it. Just because you don't like it doesn't mean that it isn't ok for FTDI to do it, or that it's a bad business decision for them.

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

#192

Post by alibarber »

amelius wrote: post #183
fermienrico wrote: post #51

Earlier quoted context omitted.

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 usu…

But why can't digikey just charge for what it costs them to send the items? Now it feels like I'm paying some kind of tax.

Because the cost of someone picking up a reel of 10000 resistors, from a warehouse that has to be rented heated/cooled etc etc doesn't scale down to that 1 resistor, even if the shipping cost might... I know, it sucks! - I have seen many suppliers that cater for hobbyists around the world and will mail you a resistor in an envelope. But I'm sure that they don't make enough money to send you a certification and guarantee of authenticity with it, which is why real industrial users won't mind paying $50 for a handful of components because those guarantees are worth far more...

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

#193

Post by amelius »

alibarber wrote: post #192
amelius wrote: post #183

Earlier quoted context omitted.

But why can't digikey just charge for what it costs them to send the items? Now it feels like I'm paying some kind of tax.

Because the cost of someone picking up a reel of 10000 resistors, from a warehouse that has to be rented heated/cooled etc etc doesn't scale down to that 1 resistor, even if the shipping cost might... I know, it sucks! - I have seen many suppliers that cater for hobbyists around the world and will mail you a resistor in an envelope. But I'm sure that they don't make enough money to send you a certification and guaran…

> Because the cost of someone picking up a reel of 10000 resistors, from a warehouse that has to be rented heated/cooled etc etc doesn't scale down to that 1 resistor

I understand that. But please charge me for what it costs. Don't let people with small orders pay the price for people with large orders. They already get discount for their order size!

Or if this is not possible at least call it an order-picking fee, don't lump it in the shipping costs.

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

#194

Post by joshvm »

janekm wrote: post #187
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…

The DS18B20 clones are very popularly assembled into a waterproofed probe with a cable and metal cap. It's a very useful item which as far as I know is difficult to obtain from one of the official distributors (and would cost significantly more than the eBay specials).

You can buy those metal sensor sheaths separately. Search for something like "rtd sheath metal" e.g. ebay #162885663706. $2-3 for a set of 5.

Then you pot the sensor with something thermally conductive and waterproof - waterproof potting compound is cheap (e.g. "RS PRO White Epoxy Potting Compound"). Finally heatshrink the outside.

You will never beat China prices, but this is one of those parts that's relatively easy to make yourself and shouldn't cost a fortune. The most expensive stuff is the epoxy, but it will last for a while.

Purely on performance, does it matter? If it doesn't matter if you're off by a degree or two, then the cheap versions will be OK. If you need the guarantee of a genuine sensor, or a different cable length, or whatever, it'll cost about $20 for five.

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

#195

Post by sokoloff »

foldr wrote: post #191
sokoloff wrote: post #188

Earlier quoted context omitted.

I have no problem with FTDI making their Windows driver not work with clone devices, but leaving that device undamaged and working once removed and plugged into a different machine. That is a reasonable action and would be enough to cause at least one more round of cat and mouse with the clone makers, putting a massive dent into their economics. If they’d done that, it might have given FTDI a positive reputation (lik…

You don't have to like it. Just because you don't like it doesn't mean that it isn't ok for FTDI to do it, or that it's a bad business decision for them.

It seems that FTDI might agree it was a bad business decision, given they reversed their bricking driver in favor of one which returned “NON GENUINE DEVICE FOUND!” as output (which is totally fair play, IMO.)

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

#196

Post by joshvm »

whatusername wrote: post #152
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…

So I ordered a ds18b20 sensor last year from ebay. paid AUD $1.88 for it (including shipping). Digikey looks to be $7 plus $20 shipping (and I'm not certain if those are USD or AUD) As someone who doesn't do this for work - I've never seen/heard of digikey or farnel before. Maybe if I was ordering enough to hit the $60 free shipping limit - but I don't think I've spent that on electrical bits in the last year.

In Oz, you could try Element14 (which is Farnell rebranded). $50 for free shipping, or $15 under. The DS18B20's are about $7 on there too, so that's the correct AUD price.

Also check out RS Components Australia. They often offer free shipping with no minimums. https://au.rs-online.com/web/p/temperature-sensors-humidity-...

RS is also a good place to buy decent mechanical bits and pieces (bearings, drill bits, etc) if you don't want to play the lottery on Amazon. They even do their own 3D printing filament which I've had some good results with.

If you need small quantities (like one-of), you should look at sample requests. This is still alive and well - almost all the big manufacturers still honour them. I've gotten some $40 RTD digitising chips from Analog, micro-coax cables from Samtec and lots of random bits over the years. You may need a non-generic email address, but that's easy to sort.

For example you can sample the DS18B20 straight from Maxim: https://www.maximintegrated.com/en/products/sensors/DS18B20....

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

#197

Post by allo37 »

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…

Hah, first company I worked for involved the development of embedded systems and the boss wasn't shy about buying parts from AliExpress (thankfully most of it was still DigiKey). Some stuff had a significant cost difference: Official Omron rotary encoders vs copies, for example.

Of course they usually worked about 70% as well as the real thing.

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

#198

Post by MaxBarraclough »

nullc wrote: post #11
jerkstate wrote: post #3

Wow, I am pretty sure I had some of these, parasitic power would NOT work, I had it on a scope and everything. What a pain in the butt that was! Why not just give these mostly cloned parts their own honest name and part number?

> Why not just give these mostly cloned parts their own honest name and part number? Would you have bought it, at the same price, if they had?

To put that another way: the reason they go the fraud route is to easily profit from the good reputation of an established brand.

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

#199

Post by kd5bjo »

feteru wrote: post #172
marcan_42 wrote: post #154

Earlier quoted context omitted.

The really sad thing is that the FTDI clones worked better than the original ones. The original FT232R chips have a clocking bug that makes bitbang mode unusable for many applications, with no workaround (their errata sheet suggests a bullshit workaround of setting the clock speed to max, that is unusable in practice because USB can't keep up). It's supposedly fixed in a revision that I've never seen, and I believe t…

Wait so the bricker wouldn't even work on the clones? Or it only works on the clone because they don't have the FTDI checksum algorithm bug?

If I’m reading marcan_42’s comment correctly, the FTDI chip defers any EEPROM write request to an even address until it receives the next write request to the subsequent, odd, location. If the next write is somewhere else, it discards the original data.

The 3rd-party chips, on the other hand, perform each write immedately per the official documentation. The malicious driver uses this difference to overwrite the firmware of the 3rd-party chips with carefully-crafted nonsense that has the same checksum as the legitimate firmware.

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

#200

Post by xxs »

toast0 wrote: post #105
tgsovlerkhgsel wrote: post #91

Earlier quoted context omitted.

I live outside the US. Both Digikey and Mouser will charge me $20+ to ship anything (tried with a small capacitor). Farnell will let me put stuff in the shopping cart, then when I select "individual" as the customer type, tells me that they only ship to companies and redirects me to a "partner site" for individuals, which promptly fails to load (things like this have conditioned me to avoid official distributors). RS…

> tells me that they only ship to companies You often just need to fill that form entry, and not have any sort of official company. Things like Self, or your name again will work just fine. I have a fake company name that one day I'll need to actually register, but in the mean time is used whenever someone is willing to take my money, but not provide service without a company name.

Pretty much not applicable, as "company" requires a valid registration number for the invoice. Selling to individuals in the EU, outside the member state the company has been registered, is somewhat problematic. Currently it does require VAT to be charged at the recipient's country - unless the total yearly revenue from the said member state is low enough (say 35k euro). I have heard there are some 'discussions' (some EU commission) to ease the process but for now that's just rumors.

Flip note: US companies selling to customers in the EU do require EU VAT number as well.

Overall living in the US and applying the same rules/advice to people not living there tends to be wrong.

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