--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Control.py	Sat Sep 29 14:39:59 2007 +0000
@@ -0,0 +1,121 @@
+#!/usr/bin/env python
+
+############################################################################
+# Control class for beermon
+#
+# $Id: Control.py,v 1.1 2007/09/29 14:39:59 darius Exp $
+#
+# Depends on: Python 2.3 (I think)
+#
+############################################################################
+#
+# Copyright (C) 2007 Daniel O'Connor. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+############################################################################
+
+import threading, ConfigParser, time
+
+class OWReadError(Exception):
+    """Raised when we failed to read from a 1-wire device, could be a timeout
+or the device is non-existent, etc"""
+    pass
+
+class ThreadDied(Exception):
+    """Raised when the monitor thread has died for some reason"""
+    pass
+
+class Control():
+    """This class is responsible for controlling the temperature of
+the fermenter by switching the heater & cooler."""
+    staleDataTime = 30
+    
+    def __init__(self, _log, m, conf):
+        """m is a MonitorDev object, conf is a ConfigParser object"""
+        global log
+        log = _log
+
+        self.m = m
+
+        self.targetTemp = conf.getfloat('control', 'targetTemp')
+        self.hysteresis = conf.getfloat('control', 'hysteresis')
+        self.pollInterval = conf.getfloat('control', 'pollInterval')
+
+        log.debug("target temperature - %3.2f" % (self.targetTemp))
+        log.debug("hysteresis - %3.2f" % (self.hysteresis))
+        log.debug("pollInterval - %d" % (self.pollInterval))
+
+        self.cv = threading.Condition()
+        self.cv.acquire()
+        
+    def doit(self):
+        """Runs forever controlling the temperature until something breaks or interrupted"""
+        log.debug("=== Starting ===")
+        log.debug("Fermenter	Fridge	Ambient	State	New State")
+        while True:
+            # Check if our monitor thread has died
+            if (not self.m.isAlive()):
+                raise ThreadDied, "Monitor thread has died"
+
+            # Check for stale data
+            if (self.m.lastUpdate[self.m.fermenterId] + self.staleDataTime < time.time()):
+                log.debug("Stale data")
+                self.cv.wait(self.pollInterval)
+                self.m.setState('idle')
+                continue
+
+            # Work out what state we should go into
+            nextState = "-"
+            # Temperature diff, -ve => too cold, +ve => too warm
+            diff = self.m.temps[self.m.fermenterId] - self.targetTemp
+            if (self.m.currState == 'idle'):
+                # If we're idle then only heat or cool if the temperate difference is out of the
+                # hysteresis band
+                if (abs(diff) > self.hysteresis):
+                    if (diff < 0 and self.m.minHeatOffTime + self.m.lastHeatOff < time.time()):
+                        nextState = 'heat'
+                    elif (diff > 0 and self.m.minHeatOffTime + self.m.lastHeatOff < time.time()):
+                        nextState = 'cool'
+            elif (self.m.currState == 'cool'):
+                # Work out if we should go idle (based on min on time & overshoot)
+                if (diff + self.m.minCoolOvershoot < 0 and self.m.minCoolOnTime + self.m.lastCoolOn < time.time()):
+                    nextState = 'idle'
+            elif (self.m.currState == 'heat'):
+                # Ditto
+                if (diff - self.m.minHeatOvershoot > 0 and self.m.minHeatOnTime + self.m.lastHeatOn < time.time()):
+                    nextState = 'idle'
+            else:
+                # Not possible..
+                raise KeyError
+
+            log.debug("%3.2f   	%3.2f	%3.2f	%s	%s" %
+                      (self.m.temps[self.m.fermenterId],
+                       self.m.temps[self.m.fridgeId], self.m.temps[self.m.ambientId],
+                       self.m.currState, nextState))
+
+            if (nextState != "-"):
+                self.m.setState(nextState)
+
+            self.cv.wait(self.pollInterval)
+            
+