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

Thankfully, 1-2 companies came up with their own competing solutions which you now can buy for cents. If you are still using FTDI chips (fake or original) you might want to update your designs.

But... while I fully understand the ethical issues, there is also an interesting engineering challenge here were you can sometimes get your design to work even with crappy fake components.

Btw, if you think this is bad, try ordering some jfets from China...

Probably he is right though, but to me it reads like the conclusion is the premise. (Might be due to the writeup though)

Edit: here is my bone: it says: how do I know? If the ROM does not follow the pattern 28-xx-xx-xx-xx-00-00-xx then the DS18B20 sensor is a clone [5]. And here I would have expected [5] to be the datasheet or something, but not 'own research'. The idea of citations is also to make your claims more verifiable.

Now, if we look at the Datasheet: https://datasheets.maximintegrated.com/en/ds/DS18B20.pdf it actually says:"The least significant 8 bits of the ROM code contain the DS18B20’s 1-Wire family code: 28h. The next 48 bits contain a unique serial number. The most significant 8 bits contain a cyclic redundancy check (CRC) byte that is calculated from the first 56 bits of the ROM code. A detailed explanation of the CRC bits is provided in the CRC Generation section." So the 28 is required. The '00-00' part is ust the higher bits of the unique serial number.

I wouldnt be surprised if different factories get different higher bits.

One is the issue of intellectual property theft and what a company has a right to do in order to protect itself.

FTDI invested massive amounts of money to produce excellent solutions for a number of problems. I have personally been using their chips in my designs for over twenty years. I don't even remember when I started, it's possible it was at the very start of their history.

The fake chip makers --mostly in China-- steal intellectual property with impunity, hurting companies, ecosystems and costing job. In some cases they have completely imploded companies in the West.

We can either accept this at our peril or take a stand against it. The only people who are OK with intellectual property theft are those who don't understand the subject or haven't lived it.

My experience? I've had the experience of mortgaging my home to fund a business and then watch a company out of China clone my product and bring it into the US and European markets at half my price. I can't even begin to describe what this did do my business, the people who worked for me, my family and my health. I didn't lose it all because I am a resilient SOB, but it put me in the hospital twice in four years due to the stress.

It's really easy to voice opinions from behind a keyboard when the consequences of said opinions carry no personal consequences.

A company like FTDI and their products did not materialize from nothing. There are people, families, investment and hard work behind such offerings. Clones are not a victimless crime.

The other issue, of the two that I said were separable, is the damage to consumers due to fake chips being bricked by FTDI.

That, in my mind, is a separate matter and a very complex one at that.

There are at least two angles to this one. The first is that the hardware they were using was intentionally made with fake FTDI chips. This is likely the case for most cheap hardware coming out of China. If that garbage doesn't work it is 100% the responsibility of the designers of the hardware. They are thieves. Plain and simple.

If, on the other hand, the designers of the hardware had no idea and fake chips got into the supply chain, the problem is far more complex. At that point it is a question of tracing the supply chain in order to understand, if possible, how it happened. I won't go into the many permutations this could put on the table. Suffice it to say that anyone dealing with China knows full-well what they could be in for. Caveat emptor applies in the case of the OEM.

This is where the problem becomes far more complex and it becomes political. It is our politicians (US/Europe) who allowed us to come to a moment in time where an entire country is openly stealing intellectual property at almost every layer in industry as well as freely distributing it across the world with impunity. This is a far larger problem than a bunch of USB devices getting bricked because a company in Europe decides to defend themselves from what must be a massive loss of revenue of unimaginable scale. I can only imagine what FTDI could be, the people they could employ and the technologies they could develop if fakes could not exist in the market.

Counterfeit products have real and non-trivial consequences to entire societies and their existence should not be taken lightly.

I don't have the solution to this problem. Sadly, it's political. What I do know is that I'll be damned if I am going to blame the victim.

I'll bet that's an exaggeration. If you are going to say something like that you have to back it up with data.

I could just as easily make the claim that people have died due to fakes. We can do that and go round and round a silly pointless circle.

The problem of fakes is real. And it is likely very much political (addressed in another comment). What is is NOT is the legitimate manufacturer's fault, even if they defend their existence by refusing to allow fakes to function with their drivers.

Fake chip manufacturers are perfectly free to do the required R&D, issue and support their own drivers. However, they are thieves, and prefer to steal rather than do the hard work and take the risks their victims undertake.