read_temp_sensors.py

import os
import time
import datetime
import sqlite3
import re

def get_sensors():
   sensors = []
   for filename in os.listdir("/sys/bus/w1/devices"):
           if re.match( r'\w{2}-\w{12}', filename ):
               sensors.append( filename )
   return sensors

def read_temp_raw(device_file):
   with open(device_file) as dev_fh:
      return dev_fh.readlines()

def read_temp(sensor):
   device_file = '/sys/bus/w1/devices/' + sensor + '/w1_slave'
   lines = read_temp_raw(device_file)
   while lines[0].strip()[-3:] != 'YES':
       time.sleep(0.2)
       lines = read_temp_raw(device_file)
   equals_pos = lines[1].find('t=')
   if equals_pos != -1:
       temp_string = lines[1][equals_pos+2:]
       temp_c = float(temp_string) / 1000.0
       temp_f = temp_c * 9.0 / 5.0 + 32.0
       return temp_f

current_time = datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")

conn = sqlite3.connect('hometemp.db')
cur = conn.cursor()

sensors = get_sensors()

for sensor in sensors:
   temp_f = read_temp(sensor)
   reading = ( sensor, current_time, temp_f )
   cur.execute( 'INSERT INTO readings( sensor, datetime, temperature) VALUES(?, ?, ?)', reading )
   conn.commit()