R1 is 4.7k ohm resistance for pulling up the voltage level
Vcc should be connected to any of the 5v or 3.3v pins of Raspberry pi (PIN : 01, 02, 04, 17).
Gnd should be connected to any of the Gnd pins of Raspberry pi (PIN : 06, 09, 14, 20, 25).
DATA should be connected to (PIN : 07)
Enabling the one-wire interface from the RPi side
Login to Raspberry pi using putty or any other linux/unix terminal.
After login, open the /boot/config.txt file in your favourite browser.
nano /boot/config.txt
Now add the this line `dtoverlay=w1–gpio` to the end of the file.
Now reboot the Raspberry pi `sudo reboot`.
Log in to Raspberry pi, and run `sudo modprobe g1-gpio`
Then run `sudo modprobe w1-therm`
Now go to the directory /sys/bus/w1/devices `cd /sys/bus/w1/devices`
Now you will found out a virtual directory created of your temperature sensor starting from 28-********.
Go to this directory `cd 28-********`
Now there is a file name **w1-slave**, This file contains the temperature and other information like CRC. `cat w1-slave`.
Now write a module in python to read the temperature
import glob
import time
RATE =30
sensor_dirs = glob.glob("/sys/bus/w1/devices/28*")iflen(sensor_dirs)!=0:whileTrue:
time.sleep(RATE)for directories in sensor_dirs:
temperature_file =open(directories +"/w1_slave")# Reading the files
text = temperature_file.read()
temperature_file.close()# Split the text with new lines (\n) and select the second line.
second_line = text.split("\n")[1]# Split the line into words, and select the 10th word
temperature_data = second_line.split(" ")[9]# We will read after ignoring first two character.
temperature =float(temperature_data[2:])# Now normalise the temperature by dividing 1000.
temperature = temperature /1000print'Address : '+str(directories.split('/')[-1])+', Temperature : '+str(temperature)
Above python module will print the temperature vs address for infinite time. RATE parameter is defined to change or adjust the frequency of temperature query from the sensor.
