2

I wired 10 DS18B20 to the raspberry pi, in the normal powered mode. I am using the Raspbian's built in w1-gpio and w1-therm. I am able to read all the 10 sensor values.

Problem is, after (seemingly random) few hours of continuous pooling, I observe that all my sensors drop precision to 9 bit and only show temperatures with 0.5 Celsius precision. I can revert the sensors back to the default precision by interrupting their power for a short while.

Anyone knows what might cause this? I started to introduce little changes, to detect the cause, but the long time required for this to happen makes the process tedious.

enter image description here

1
  • i know its been a while, but just in case this is still an issue (with the newest kernel), can you post the exact values for each slaves "w1_slave" file, e.g. via "cat /sys/bus/w1/devices/28-*/w1_slave"
    – x29a
    Apr 11, 2016 at 18:13

1 Answer 1

1

Maybe it's a short? Seems like a similar problem...

1
  • Thanks! Checked, it's not a short. Also there is no mechanical movement during the transition between precisions. I am thinking maybe this guy had similar problem and was actually solved by resetting the DS18B20 during the wire debbugging.
    – sanyi
    Oct 27, 2014 at 15:03

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.