# Setting up the 1-wire interface for the RPi


Setting up the 1-wire interface using the DS18B20 Temperature Sensor.

First enable the 1-wire interface on the RPi.

The following link demonstrates three methods for enabling 1-Wire Interface on the Raspberry Pi.

https://www.raspberrypi-spy.co.uk/2018/02/enable-1-wire-interface-raspberry-pi/

Methods, 1 and 2 use ‘sudo raspi-config’ or the GUI to enable 1-Wire.

Using ‘sudo raspi-config’ or the GUI will setup the default Pin 7 (GPIO4) port.

Method 3 shows how to enable 1-Wire Interface by editing the /boot/config.txt.

Understanding the manual editing of the /boot/config.txt file is essential for connecting two 1-Wire devices.

In the following example two gpiopins are initialized for 1-Wire interface, gpiopin=4 and gpiopin=5.

pi@aquaponics$tail -6 /boot/config.txt [all] #dtoverlay=vc4-fkms-v3d dtoverlay=w1-gpio,gpiopin=4 dtoverlay=w1-gpio,gpiopin=5  If only one 1-Wire Interface is needed the following methods can be used; Activate the 1-wire interface as shown here; Enabling the 1-wire interface can also be accomplished remotely using ssh on the terminal. sudo raspi-config  Activate the 1-wire interface as shown here; After enabling the 1-Wire Interface by any method a reboot is required. Attached the DS18B20 to the breadboard as shown in the following link; https://learn.adafruit.com/adafruits-raspberry-pi-lesson-11-ds18b20-temperature-sensing?view=all A 4.7K resistor is required, see wiring in the link above. Attached 1-Wire devices can be listed with the following command; ls /sys/bus/w1/devices/  For this example two DS18B20 sensors are shown. pi@aquaponics$ ls /sys/bus/w1/devices/
28-3c01b5569d9e  28-3c01b556bce8  w1_bus_master1  w1_bus_master2


The IDs for the two are 28-3c01b5569d9e  and 28-3c01b556bce8.

These IDs are required for collecting data from the sensors.

The python script used in this example was found here;

https://www.raspberrypi-spy.co.uk/2013/03/raspberry-pi-1-wire-digital-thermometer-sensor/

wget https://bitbucket.org/MattHawkinsUK/rpispy-misc/raw/master/python/ds18b20.py


Note: in the python script ds18b20.py replace the device ID 28-00000482b243 with the ID for the device you are using.

The following link demonstrates how to setup one gpio port for several 1-wire devices.

https://raspberryautomation.com/connect-multiple-ds18b20-temperature-sensors-to-a-raspberry-pi/

The following fritzing diagram was found in the above link.

Note: when one of the two DS18B20 sensors failed the solution was to shut-down the RPi and reseat the pins into the breadboard.  Both sensors were again showing up in the system.

Setting up the 1-wire interface for the RPi is shared under a not declared license and was authored, remixed, and/or curated by LibreTexts.