--- a/py/sensor_ds18b20.py	Tue Nov 20 22:03:10 2012 +0800
+++ b/py/sensor_ds18b20.py	Mon Nov 26 23:21:03 2012 +0800
@@ -1,21 +1,59 @@
 #!/usr/bin/env python2.7
 
-class DS18B20s(object):
+import gevent
+import config
+import re
+from utils import L,W,E,EX
+
+class DS18B20s(gevent.Greenlet):
+
+    THERM_RE = re.compile('.* YES\n.*t=(.*)\n', re.MULTILINE)
 
-    def __init__(self):
-        # query the bus 
-        pass
+    def __init__(self, server):
+        gevent.Greenlet.__init__(self)
+        self.server = server
+        # XXX set up paths
+        # XXX set up drain etc
+
+    def _run(self):
+        while True:
+            self.do()
+            gevent.sleep(config.SENSOR_SLEEP)
+
+    def sensor_path(self, s):
+        return os.path.join(self.master_dir, s)
 
-    def get_sensors(self):
-        """ Returns a sequence of sensorname """
-        pass
+    def do_sensor_name(self, s, contents = None):
+        try:
+            if contents is None:
+                fn = os.path.join(self.sensor_path(s), 'w1_slave')
+                f = open(fn, 'r')
+                contents = f.read()
+            match = self.THERM_RE.match(contents)
+            if match is None:
+                return None
+            temp = int(match.groups(1)[0])
+            return temp / 1000.0
+        except Exception, e:
+            EX("Problem reading sensor '%s': %s" % (s, str(e)))
+            return None
 
-    def read(self):
-        """ Returns a map of sensorname->temperature """
-        pass
+    def do(self):
+        vals = {}
+        for n in self.sensor_names():
+                value = do_sensor(n)
+                if value is not None:
+                    vals[n] = value
+
+        self.server.add_reading(vals)
+
+    def sensor_names(self):
+        """ Returns a sequence of sensorname """
+        return [d for d in os.listdir(self.master_dir) if
+            os.stat(sensor_path(d)).st_mode & stat.S_ISDIR]
 
     def wort_name(self):
-        pass
+        return config.WORT_NAME
 
     def fridge_name(self):
-        pass
+        return config.FRIDGE_NAME