Temperature probe DS18B20 connection

[kurby-reef]

I have a Robo-Tank Deluxe v2 that I am trying to set up with the DS18B20 temperature probe. 

When I go to add the probe in reef-pi, there are no options in the Sensor drop down menu.

   

I have followed all the installation and configuration instructions and used the install script. I have confirmed that /boot/config.txt contained the following lines:

dtoverlay=w1-gpio,gpiopin=4
dtoverlay=w1-gpio,gpiopin=22

In the second line I have tried pins 22 and 23 with no luck. I have also done a full re-install of Robo-Tank with no luck. As far as I can tell, the proper Connectors have been added. 

I have setup and calibrated a pH probe that is functioning as expected. 

What am I missing here?

[Rob F]

Hi kurby-reef, sorry to hear about the trouble, did you get the DS18B20 from me or another source? Reason I ask is the wire colors are not always as expected such as red = 5v and black = ground. I think it's probably a configuration related error as there is no circuit for this, just a pullup resistor so the hardware side is very simple. I'm wondering if by chance the 1-wire bus didn't get enabled on the Pi although it should have with the install script.

Can you run the following command in the Raspberry Pi SSH terminal window.

sudo raspi-config

On the page that loads go down to "Interface Options" and press enter.

Then go down to "1-wire" and press enter and verify it's set to Yes.

If that doesn't work I think it could be a faulty sensor or bad connection. I have seen if a wire is pushed in the connector to far the insulation around the wire can cause a poor connection if it's getting clamped as well. Maybe try losing each wire, pull it out a bit and try to clamp only the exposed wire.

[Rob F]

Here's another command to run in the SSH terminal window, it should list the addresses of each sensor attached.

ls /sys/bus/w1/devices/

[kurby-reef]

Hi Rob- thanks for the reply. I did get the probe from you. But I redid the connection with more exposed wire and it popped up. So I am up and running and lessoned learned. Thanks again!

[Rob F]

Good to hear, the other possible issue you can have with those connectors, if the wire is moved lots it can get cut where it's clamped but other wires will hold it in place so it looks connected but actually just being held in place. This is rare but can happen.