- add ds18S20 1-Wire sensor support

- gitignore emacs backup files

.gitignore

@@ -63,3 +63,6 @@ nosetests.xml
 .mr.developer.cfg
 .project
 .pydevproject
+
+# Hide emacs backups
+*~

homeassistant/components/sensor/onewire.py

@@ -0,0 +1,93 @@
+""" Support for DS18B20 One Wire Sensors"""
+from homeassistant.helpers.entity import Entity
+from homeassistant.const import TEMP_CELCIUS, TEMP_FAHRENHEIT
+from glob import glob
+import os
+import time
+import logging
+
+
+BASE_DIR = '/sys/bus/w1/devices/'
+DEVICE_FOLDERS = glob(os.path.join(BASE_DIR, '28*'))
+SENSOR_IDS = [os.path.split(device_folder)[1] for device_folder in DEVICE_FOLDERS]
+DEVICE_FILES = [os.path.join(device_folder, 'w1_slave') for device_folder in DEVICE_FOLDERS]
+
+_LOGGER = logging.getLogger(__name__)
+
+# pylint: disable=unused-argument
+def setup_platform(hass, config, add_devices, discovery_info=None):
+    """ Sets up the one wire Sensors"""
+    # TODO check if kernel modules are loaded
+
+    # TODO implment config fore the name, but also default solution
+    if DEVICE_FILES == []:
+        _LOGGER.error('No onewire sensor found')
+        return
+
+    devs = []
+    names = []
+    try:
+        ## only one name given
+        if type(config['names']) == str:
+            names = [names]
+        
+        ## map names and sensors in given order
+        elif type(config['names']) == list:
+            names = config['names']
+
+        ## map names with ids
+        elif type(config['names']) == dict:
+            for sensor_id in SENSOR_IDS:
+                names.append(config['names'][sensor_id])
+                
+    except KeyError:
+        ## use id as name
+        if not config['names']:
+            for sensor_id in SENSOR_IDS:
+                names.append(sensor_id)
+        
+    for device_file, name in zip(DEVICE_FILES, names):
+        devs.append(OneWire(name, device_file, TEMP_CELCIUS))
+    add_devices(devs)
+
+class OneWire(Entity):
+    """ A Dallas 1 Wire Sensor"""
+
+    def __init__(self, name, device_file, unit_of_measurement):
+        self._name = name
+        self._device_file = device_file
+        self._unit_of_measurement = unit_of_measurement
+
+    def _read_temp_raw(self):
+        f = open(self._device_file, 'r')
+        lines = f.readlines()
+        f.close()
+        return lines
+
+    @property
+    def should_poll(self):
+        return True
+
+    @property
+    def name(self):
+        return self._name
+
+    @property
+    def state(self):
+        """ return temperature in unit_of_measurement"""
+        lines = self._read_temp_raw()
+        while lines[0].strip()[-3:] != 'YES':
+            time.sleep(0.2)
+            lines = self._read_temp_raw()
+        equals_pos = lines[1].find('t=')
+        if equals_pos != -1:
+            temp_string = lines[1][equals_pos+2:]
+            temp = float(temp_string) / 1000.0
+            if self._unit_of_measurement ==  TEMP_FAHRENHEIT:
+                temp = temp * 9.0 / 5.0 + 32.0
+            return temp
+
+    @property
+    def unit_of_measurement(self):
+        return self._unit_of_measurement
+