OWFS with I2C support on Raspberry Pi
Using the 1 Wire File System with the 1 Wire Pi Plus and 1 Wire Pi Zero
Created: 02/10/2015 | Last Updated: 25/04/2020
This page details how to set up the 1 Wire File System to use with the 1 Wire Pi Plus and 1 Wire Pi Zero on Raspbian "Stretch" from http://www.raspberrypi.org/downloads
Step 1: Download the latest Raspbian linux image and burn to your SD Card following the instructions on http://elinux.org/RPi_Easy_SD_Card_Setup
Step 2: Follow our I2C, SMBus and Raspbian Linux tutorial to set up I2C on the Raspberry Pi.
Step 3: Go into the raspberry pi config utility and enable 1-Wire.
sudo raspi-config
Select 5 Interface Options and then P7 1-Wire. A prompt will appear asking Would you like the one-wire interface to be enabled?, select Yes, exit the utility and reboot your raspberry pi.
sudo reboot
Step 4: Install OWFS and Python-OW
sudo apt-get update
sudo apt-get install owfs python-ow ow-shell
Step 5: Edit owfs.conf to enable the I2C 1 Wire interface
sudo nano /etc/owfs.conf
Comment out the following line
# server: FAKE = DS18S20,DS2405
Find the following section
# USB device: DS9490
#server: usb = all
Insert the line below to enable i2c support.
server: device = /dev/i2c-1
Find the section titled
######################### OWFS ##########################
Remove the hashes from the lines
mountpoint = /mnt/1wire
allow_other
Save your changes and exit the nano editor.
Step 6: Create a folder where the 1 Wire devices will be mounted.
sudo mkdir /mnt/1wire
Step 7: Reboot your Raspberry Pi
sudo reboot
Step 8: Enable the owserver service
sudo systemctl enable owserver.service
Step 9: Your Raspberry Pi should now work with OWFS. To test this we will create a python script which lists all 1 Wire devices connected to the 1 Wire Pi.
Create a new python script called 1wiretest.py
nano 1wiretest.py
Insert the following python code:
import ow
ow.init('localhost:4304')
sensorlist = ow.Sensor('/').sensorList()
for sensor in sensorlist:
print('Device Found')
print('Address: ' + sensor.address)
print('Family: ' + sensor.family)
print('ID: ' + sensor.id)
print('Type: ' + sensor.type)
print(' ')
Step 10: Save and run the file.
python 1wiretest.py
If everything works correctly the script should list every 1 Wire devices connected to the Raspberry Pi.
Using OWFS you can mount your 1 Wire devices to appear within the linux file system. To mount the available devices run the following command.
sudo owfs -C -uall -m /mnt/1wire --allow_other
Your 1 Wire devices can be found in the directory /mnt/1wire
Note:
On certain versions of owfs available on Raspbian Linux a bug causes devices in the /mnt/1wire directory to be duplicated, showing two folder for each device.
If you encounter this problem it can be resolved by editing the configuration file for the owfs service.
Step 1: Open /lib/systemd/system/owfs.service in an editor.
sudo nano /lib/systemd/system/owfs.service
Step 2: Find the following line.
ExecStart=/usr/bin/owfs -c /etc/owfs.conf --allow_other %t/owfs
Remove "-c /etc/owfs.conf" so the line now looks like this.
ExecStart=/usr/bin/owfs --allow_other %t/owfs
Step 3: Save the file and reboot your Raspberry Pi.
You should now only see one instance of each device in the /mnt/1wire directory.