exec/temperature/DS18B20..temp_poll.py

   1 #!/usr/bin/env python3
   2
   3 import os
   4 import glob
   5 import time
   6 from time import strftime
   7
   8 os.system('modprobe w1-gpio')
   9 os.system('modprobe w1-therm')
  10
  11 base_dir = '/sys/bus/w1/devices/'
  12 device_folder = glob.glob(base_dir + '28*')[0]
  13 device_file = device_folder + '/w1_slave'
  14
  15 def read_temp_raw():
  16     f = open(device_file, 'r')
  17     lines = f.readlines()
  18     f.close()
  19     return lines
  20
  21 def read_temp():
  22     lines = read_temp_raw()
  23     while lines[0].strip()[-3:] != 'YES':
  24         time.sleep(0.2)
  25         lines = read_temp_raw()
  26     equals_pos = lines[1].find('t=')
  27     if equals_pos != -1:
  28         temp_string = lines[1][equals_pos+2:]
  29         temp_c = float(temp_string) / 1000.0
  30         temp_f = temp_c * 9.0 / 5.0 + 32.0
  31         temp_c_2dec = f"{temp_c:.5f}" # https://stackoverflow.com/a/15263885/10850071
  32         #return temp_c, temp_f
  33         return temp_c_2dec
  34
  35 while True:
  36     nowTimeIso8601 = strftime("%Y%m%dT%H%M%S%z")
  37     nowTimeUE = strftime("%s")
  38     nowTemp = read_temp()
  39     print(str(nowTimeIso8601) + ',' + str(nowTimeUE) + ',' + str(nowTemp))
  40     time.sleep(1)