CRC Probleme DS18S20 an Raspberry

  sensor_device = '/sys/bus/w1/devices/' + str(sensor_slave) + '/w1_slave'

  try:

        file = open(sensor_device)

        filecontent = file.read()                              # Read content from 1-wire slave file

        file.close()                                           # Close 1-wire slave file

        stringvalue = filecontent.split("\n")[1].split(" ")[9] # Extract temperature string

#       print filecontent

        if filecontent.find("NO") > 0:

                temperature = error_temp

                print "CRC failure" + sensor_slave

        else:

                temperature = float(stringvalue[2:]) / 1000            # Convert temperature value

  file = open(sensor_slaves)

  w1_slaves = file.readlines()            # Read 1-wire slaves list

  file.close()                            # Close 1-wire slaves list

  # Print header for results table

  if verbose_level>0: print('Sensor ID       | Temperature')

  if verbose_level>0: print('-----------------------------')

  # Repeat following steps with each 1-wire slave

  for line in w1_slaves:

     w1_slave = line.split("\n")[0]        # Extract 1-wire slave

     for i in range(20):  # try 20 reads on CRC failure

        temperature = read_sensor( w1_slave)  # call read function 

        if (temperature != error_temp): break  # success

        temperature=10

        time.sleep(0.3)

     sensor_count = sensor_count + 1

     if temperature!=error_temp:

       if read_level:sensordata.append((w1_slave, temperature)) # store temperature in database

  return(sensor_count)