Things I've tried:

  • Replacing the DS18B20 twice (First one was a different brand than the other 2)
  • Using:
modprobe -r -a w1 w1-therm
modprobe w1 pullup=1
modprobe w1-therm strong_pullup=1
  • Checking dmesg (nothing pertaining to w1 or w1-therm)
  • Using the multimeter to ensure everything is connected
  • Using the multimeter to ensure 3.3v is actually being produced
  • Trying a 3.9k ohm resistor instead of 4.7k (per suggestion from blog article)

My /boot/config.txt had the following currently: dtoverlay=i2c-rtc,pcf2127,w1-gpio,gpiopin=4

I added the gpiopin=4 because it solved it for some people.

/sys/bus/w1/devices is still empty. Not even ghost/bug entries. Completely empty.

Wiring overview wiring overview

Breadboard wiring breadboard wiring

Pi wiring pi wiring

  • I take it you added dtoverlay=w1–gpio in config.txt? – Jaromanda X Feb 6 '19 at 23:47
  • I see there are some tutorials regarding DS18B20 on a pi that either miss this important step, or seem to think editing config.txt doesn't require a reboot - fortunately the majority of tutorials are not written by cowboys, and do mention the dtoverlay step – Jaromanda X Feb 6 '19 at 23:55
  • Yes I did, and I rebooted several times since I added it. – Timberwolf Feb 7 '19 at 0:19
  • cool - didn't see any mention of that step, so wanted to check – Jaromanda X Feb 7 '19 at 0:20
  • Yeah, I completely forgot to add that. I'll go ahead and my dtoverlay line to the original post. – Timberwolf Feb 7 '19 at 0:34

Your merged dtoverlay line is incorrect. Change it to


reboot and it will work.

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