why is this on github? has this guy not heard of literally any blogging platform ever?
Literally any blogging platform is worse than GitHub tho?
Your DS18B20 temperature sensor is likely a fake, counterfeit, clone
81–90 of 239 posts
Re: Your DS18B20 temperature sensor is likely a fake, counterfeit, clone
#82I've bought ~100 of these sensors from ali and ebay and 9/10 had troubles reporting temperatures in passive mode reliably. However simply repeating requests until sensor reports a valid value (!=+85C and !=-127C) works fine. Rarely I've seen sensors not working in passive mode at all. Still, I always recommend running an extra +VDC wire (3 wires vs 2 wires isn't a big inconvenience). When running large 1-wire buses (…
> However simply repeating requests until sensor reports a valid value (!=+85C and !=-127C) works fine.
You know you're dealing with counterfeits and you know they're unreliable, but you've somehow convinced yourself that despite all the uncovered variance sitting on the table, if you keep poking long enough until the component returns some non-edge-case value, then it "works fine".
I must have hopped on the sanity train quicker than I should have because it seems like I'm missing something critical in the narrative here.
Re: Your DS18B20 temperature sensor is likely a fake, counterfeit, clone
#83Earlier 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…
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…
I've made a few orders over the past few months. The $5 is for less than 14 ounces (which is surprisingly heavy, I just had a big heatsink and a bunch of other components shipped in that weight); after that it's $9 for any of UPS/FedEx/USPS. I guess it's just USPS price inflation? I remember when stamps used to be 42 cents.
Re: Your DS18B20 temperature sensor is likely a fake, counterfeit, clone
#84Earlier 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…
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…
I've got this soft spot in my heart for digikey, they've always shipped so quickly and called on the smallest issue and offered to help. When ever they call I always do that "why is someone from Minnesota calling me?" It's interesting how some vendors can build trust easily.
But $5 doesn't feel bad for shipping to get good parts quickly from a company I trust. But your point is taken. Sucks to put a $0.30 temp sesnor and pay $5 to ship it. =)
Re: Your DS18B20 temperature sensor is likely a fake, counterfeit, clone
#85Earlier quoted context omitted.
> 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 by releasing drivers that are tolerant of them or do not stop them from functioning. There's a difference between not taking steps to ensure counterfeit devices function, and purposefully causing hardware to fail on a remote system. For example, I'm pretty sure purpose…
>Refusing to function is acceptable. Bricking the hardware is not.
In some/most cases there is no difference.
Re: Your DS18B20 temperature sensor is likely a fake, counterfeit, clone
#86I am a bit disappointed about that a lot of his claims how to identify clones are referenced with [5] own research. I mean doesnt one need confirmation from the IP holder?
I mean, the entire article is basically documentation of that research.
This isn't a peer-reviewed piece of work, it's a writeup of someone's fairly exhaustive research into a problem they encountered.
I don't see why you'd need confirmation from another person that something you bought doesn't do what it's part number claims it should.
Re: Your DS18B20 temperature sensor is likely a fake, counterfeit, clone
#87I've bought ~100 of these sensors from ali and ebay and 9/10 had troubles reporting temperatures in passive mode reliably. However simply repeating requests until sensor reports a valid value (!=+85C and !=-127C) works fine. Rarely I've seen sensors not working in passive mode at all. Still, I always recommend running an extra +VDC wire (3 wires vs 2 wires isn't a big inconvenience). When running large 1-wire buses (…
> However simply repeating requests until sensor reports a valid value (!=+85C and !=-127C) works fine. You know you're dealing with counterfeits and you know they're unreliable, but you've somehow convinced yourself that despite all the uncovered variance sitting on the table, if you keep poking long enough until the component returns some non-edge-case value, then it "works fine". I must have hopped on the sanity t…
"If a straight line fit is required, only sample two points."
Re: Your DS18B20 temperature sensor is likely a fake, counterfeit, clone
#88>If the ROM does not follow the pattern 28-xx-xx-xx-xx-00-00-xx then the DS18B20 sensor is a clone
Darn, my sensor from usbtemp.com has 28 FF EC C5 21 17 04 99
Re: Your DS18B20 temperature sensor is likely a fake, counterfeit, clone
#89This 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…
I’ve read there’s some financial scheme that you get >100% kickbacks for untracked packets from China through Singapore to destinations. Certain mail containers are going at regular intervals carrying much as possible by volume, paid by governments as investments to build nations might, or something like that.
So sellers pay for shipping, which is cheap, then gets subsidy, then there’s delay between Buy Now and actual transfers and financing to compensate it, those supposedly all add up and turn profits.
Digi-Key on the other hand probably has employee pension plans and that would be as far they go in terms of global financial investment techniques, so...
Re: Your DS18B20 temperature sensor is likely a fake, counterfeit, clone
#90Earlier quoted context omitted.
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.
Same. I read through this thinking "What, my team sensor on the data logger for my coffee grinder might be more than half a degree out? You know what? I totally don't care, and wouldn't have spent an extra 50 cents to get that much accuracy..." I do have ethical qualms about supporting/funding "stolen IP", but then I've kinda got ethical qualms about the whole concept of IP anyway, and if you wanted to go hardline on…
If you don't need that accuracy, why would you use a DS18B20 in the first place. You can use a dirt cheap NTC.