In this project, we will use Raspberry Pi 2 and DS18B20 temperature sensor to get environment temperature and display it into Linux Shell Window.

Step 1: Connect Raspberry pi 2 and DS18B20 sensor as per following graph:
* the pull up resistor in the graph can be 5Kohm to 10Kohm
**The DS18S20 S pin should connected with Raspberry Pi 2 GPIO 4 pin. For detail of the GPIO connection, please read the Raspberry Pi 2 GPIO Pin Diagram

Step 2: Install One-Wire communication libary
In Rasbian Shell Terminal, run following two commands:
sudo modprobe w1-gpio
sudo modprobe w1_therm

Step 3: use following command to edit config file:
sudo nano /boot/config.txt
Above command will use nano to edit config.txt file, add following line after the last line of config.txt
Then press Ctrl-X and save the file.

Step 4: enter terminal command sudo reboot to restart Raspberry Pi.

Step 5: Type following command and get sensor address in the format 28-00000xxxxxx.
ls -l /sys/bus/w1/devices/
Above command will show some result as following example graph:

In above example, the circled text “28-0000050496de” is the address of our sensor.

Step 6: Test the sensor by running following command:
cat /sys/bus/w1/devices/28-0000050496de/w1_slave
* Don’t forget to substitute 28-0000050496de with your address getting from step 5
The result will shows as following:

In above example “t=22812” means the current temperature is 22.812 Celsius degree

Step 7: You can also use python to read temperature sensor data.
First, Download sample code and rename the file, use winscp or other sftp tool to send it to raspberry pi.
*Again Don’t forget to replace 28-0000050496de in python code with your address from step 5

Next, run following shell command: sudo python
Your will see temperature result in terminal window same as following example: