DS18b20 python example

This is follow on from the DS18b20 terminal example at http://www.pibits.net/learning/120.php , this time a python example

Code

[codesyntax lang=”python”]

import os                                               
import glob                                            
import time                                              

os.system('modprobe w1-gpio')                              #load one wire communication device kernel modules
os.system('modprobe w1-therm')                                                 
base_dir = '/sys/bus/w1/devices/'                          #point to the address
device_folder = glob.glob(base_dir + '28*')[0]             
device_file = device_folder + '/w1_slave'                  

def read_temp_raw():
   f = open(device_file, 'r')
   lines = f.readlines()                                   
   f.close()
   return lines

def read_temp():
   lines = read_temp_raw()
   while lines[0].strip()[-3:] != 'YES':                  
      time.sleep(0.2)
      lines = read_temp_raw()
   equals_pos = lines[1].find('t=')                        #find temperature
   if equals_pos != -1:
      temp_string = lines[1][equals_pos+2:]
      temp_c = float(temp_string) / 1000.0              
      return temp_c

while True:
   print(read_temp())                                      #Print temperature    
   time.sleep(1)

[/codesyntax]

You should see something like

ds18b20 output