I am using a DS18B20 to measure water temperature for about a year now, but changed the sensor about two weeks ago (for the exact same model). and that was running perfectly fine. Just yersterday it stopped working. Now the sensor is not properly recognized in /sys/bus/w1/devices. There was always the 28-xx.

All I can see now is 00-2000000000, 00-c0000000000 and the w1_bus_master folder. The sensor is connected like this:

enter image description here

The sensor cable is connected to an extension cable. The only things I can think off is that the sensor is broken (hopefully not after two weeks), the soldering between the cables broke or got wet (it is not under water and it wasn't even raining the last week) or one of the GPIO connections slipped off the pin.

Or could it be a software issue?

My /boot/config.txt has these: dtoverlay=w1-gpio,gpiopin=4,pullup=on

  • I'm not sure what you want. If it was working then what has changed since it was last working? Only you can pin-point where the fault lies. – joan Sep 14 '16 at 10:49
  • Nothing changed as far as I know. The sensor and the Pi are not in reach for a quick look on them. The setup monitors the data and sends it off to a server. I can login on the Pi remotely, but can not check the hardware. So I thought maybe someone had the same problem and can at least point me in the correct direction. I read a few posts here and in forums, but all end up having no solution for the problem or it was that dtoverlay=w1-gpio,gpiopin=4,pullup=on was missing. – BallerNacken Sep 14 '16 at 11:00
  • You could try and see if it works with 5V (especially with long cables). Not sure what happened, but these descriptors (00-2000...) seem to me like data corruption. I also just have 'dtoverlay=w1-gpio', but none of the other stuff in config.txt – Gotschi Sep 14 '16 at 12:07
  • I can't remember exactly, but I had similar problems in the past, which I think were solved by having w1-therm strong_pullup=1 in /etc/modules – calcinai Sep 14 '16 at 12:34
  • Doesn't work either. Will visit the Pi and sensor on Friday and hope I can find the problem. – BallerNacken Sep 14 '16 at 12:52

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