--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/service/arduinoNode/devices.py	Mon Apr 06 02:13:39 2015 -0700
@@ -0,0 +1,70 @@
+from rdflib import Namespace, RDF, URIRef
+
+ROOM = Namespace('http://projects.bigasterisk.com/room/')
+
+class BoardInput(object):
+    """
+    one device that gives us input. this includes processing to make
+    statements, but this object doesn't store state
+    """
+    def __init__(self, graph, uri):
+        self.graph, self.uri = graph, uri
+        
+    def readFromPoll(self, read):
+        """
+        read an update message returned as part of a poll bundle. This may
+        consume a varying number of bytes depending on the type of
+        input (e.g. IR receiver).
+        Returns rdf statements.
+        """
+        raise NotImplementedError
+
+    def generateSetupCode(self):
+        return ''
+        
+    def generatePollCode(self):
+        return ''
+
+    def pinNumber(self, pred=ROOM['pin']):
+        pinUri = self.graph.value(self.uri, pred)
+        return int(self.graph.value(pinUri, ROOM['pinNumber']))
+
+_inputForType = {}
+def registerInput(deviceType):
+    def newcls(cls):
+        _inputForType[deviceType] = cls
+        return cls
+    return newcls
+        
+class PingInput(BoardInput):
+    def generatePollCode(self):
+        return "Serial.write('k');"
+    def readFromPoll(self, read):
+        if read(1) != 'k':
+            raise ValueError('invalid ping response')
+        return [(self.uri, ROOM['ping'], ROOM['ok'])]
+
+@registerInput(deviceType=ROOM['MotionSensor'])
+class MotionSensorInput(BoardInput):
+    def generateSetupCode(self):
+        return 'pinMode(%(pin)d, INPUT); digitalWrite(%(pin)d, LOW);' % {
+            'pin': self.pinNumber(),
+        }
+        
+    def generatePollCode(self):
+        return "Serial.write(digitalRead(%(pin)d) ? 'y' : 'n');" % {
+            'pin': self.pinNumber()
+        }
+        
+    def readFromPoll(self, read):
+        b = read(1)
+        if b not in 'yn':
+            raise ValueError('unexpected response %r' % b)
+        motion = b == 'y'
+        return [(self.uri, ROOM['sees'],
+                 ROOM['motion'] if motion else ROOM['noMotion'])]
+
+def makeBoardInput(graph, uri):
+    deviceType = graph.value(uri, RDF.type)
+    return _inputForType[deviceType](graph, uri)
+