Hello guys,
I am using the DS18B20 normally until the temperature reaches 75 celsius then returns error -127.
Has anyone seen this? Could the component be false?
After searching some time I found many sites that claim that most DS18B20 from Ebay and AliExpress are counterfeit.
I have measured 0°C and 100°C with multiple DS18B20 without problem.
Where did you buy them ?
Do you use three wires ? That is more reliable than two wire parasitic mode.
Do you use 5V or 3.3V ? Running them with 5V seems more reliable.
How long are the wires ? Do you use for example a cable of tens of meters ?
What value has your pullup resistor ? You do have a pullup resistor I assume ?
Koepel:
After searching some time I found many sites that claim that most DS18B20 from Ebay and AliExpress are counterfeit.
I have measured 0°C and 100°C with multiple DS18B20 without problem.Where did you buy them ?
Do you use three wires ? That is more reliable than two wire parasitic mode.
Do you use 5V or 3.3V ? Running them with 5V seems more reliable.
How long are the wires ? Do you use for example a cable of tens of meters ?
What value has your pullup resistor ? You do have a pullup resistor I assume ?
Yes, unfortunately I bought it on aliexpress. I've had others that worked well +100º.
Im using 3 wires and 5v. At this time testing on protoboard, so really short cables.
The resistor are 4,7K pullup.
Probably my problem is a fake DS18B20.
Thank you!
I'm afraid they are indeed fake 
The large distributers (Mouser, Farnell, DigiKey) sell genuine parts, and they often also accept small orders from private persons.
The medium-large distributer Reichelt sells the DS18B20 at a lower price than the three big ones 
I think you can trust Adafruit for selling the genuine DS18B20: DS18B20 Digital temperature sensor + extras : ID 374 : $3.95 : Adafruit Industries, Unique & fun DIY electronics and kits.
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