Thanks for checking @psoro.
28.5ºC here at almost 1am.
Did you take power from 5V or 3V3?
We had some success with 5V but very little with the 3V3.
My pleasure 
!
In this case (with the WeMos) I power the sensor from 3V3.
When I use the Pro Micro or Nano I power from 5V.
In both situations, it works fine.
Regards!!
With a DS18B20 chip the circuit from 3V3 gives 28.25 ºC, with the probe the not connected -127.00 reading.
One last favour.
I and others have picked up almost zero voltage between the data pin and GND when the probe is connected, for me it is just 0.02V.
What does your meter show?
I suspect there is a bad batch of probes doing the rounds. With your working probe can you take the resistance readings across the following leads with the red probe (+ve) of your meter on the first colour shown on each row:
Red and Yellow (140.3K)
Red and Black (90.5K)
Black and Yellow (15.6K)
I don’t think a regular DS18B20 chip shows these resistance figures, other than between GND and data (black and yellow for the probes).
Sorry @Costas, I don’t understand… Signal from data pin is digital, I haven’t got a oscilloscope, I have only a multimeter.
The 3V3 output is 3.29V, the Data Pin shows 3.29V till I request reading values and goes to 3.24V then to 2.92V and come back again to 3.29V…
I’m a bit lost here…
Time to go to sleep mate…
Yes multimeter is fine. With the suspect probes connected the voltage of around 3.3V drops to around 0.02V. See resistance readings in my last post.
Night.
Hello Costas,
I was wondering did you mange to figure out what is causing this issue with DS18B20 probe and ESP?
I have the same problem, data line goes low and reading is always -127.
Yes, faulty components from 2 different suppliers. @psoro did me a few favours and gave me his suppliers details. The batch we bought from his supplier were all fine.
There are 2 possibilities AFAIK.
There are some that only work at 5V and not down to the 3.3V the first 2 suppliers stated or they were just faulty probes.
Do you want the supplier details?
Thank you, also tried 2 probes from two different suppliers,no luck.
You can write me the supplier info, don’t know if I will be able to get it in my county.
Sent you the details.
I know others that have bought faulty ones too.