I'm having an issue with my ds18b20.

Raspberry pi 2 model b v1.1 Raspbian Jessie 4.1.13-v7+

I've added w1-gpio and also w1-therm to /etc/modules as well as dtoverlay=w1-gpio to /boot/config.txt

I've done sudo apt-update and sudo apt-upgrade.

My sensor is hooked up to pin 1 to power, pin 7 (gpio 4) to data and pin 6 to ground with a 4.7k resistor between pin 1 and pin 7 (gpio 4)

Also have a second ds18b20 that I bought from a local store that is from df robot (with a 4.7k resistor built into the board.), same issue.

When I cd to /sys/bus/w1/devices/ and see what's in there, I only get the master bus 1 and no sensor (either version that I own)

Am I missing something here?

Edit: pictures of the setup

board bread board adding another picture after sudo modprobe w1-therm after sudo modprobe w1-therm

  • Just tried getting rid of w1-gpio and w1-therm from /etc/modules/. No change. Dec 20, 2015 at 20:28
  • The dtoverlay line in /boot/config.txt and no w1-* entries in /etc/modules is correct. Does lsmod show the modules as loaded after boot? Could you post an image of your setup?
    – joan
    Dec 20, 2015 at 20:50
  • lsmod shows the modules w1_gpio, wire and cn all loaded. I had posted a pic but it was quickly deleted Dec 20, 2015 at 22:01
  • Sorry about that. The first post seems somewhat off. I edited your question to include the other pics though. If in need of the third picture we can have it unburried by a mod. Added: ok, I see that you posted the link yourself.
    – Ghanima
    Dec 20, 2015 at 22:04
  • @MikeCarleton Your lsmod is missing w1-therm. Have you got it blacklisted somewhere? Can you modprobe it manually and does it then appear in lsmod?
    – joan
    Dec 20, 2015 at 22:40

1 Answer 1


There is a very good App Note on the adafruit website for configuring this temperature sensor. It lists a couple of steps that you haven't so it is a good place to start.

(I know it's an old question but hopefully it helps somebody)

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