Mercurial > ~darius > hgwebdir.cgi > beermon

comparison Control.py @ 6:45d9895a5020

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Split into seperate files.
author darius
date Sat, 29 Sep 2007 14:39:59 +0000
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children 24c7e85c3efd
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5:8d471840b153 6:45d9895a5020
1 #!/usr/bin/env python
2
3 ############################################################################
4 # Control class for beermon
5 #
6 # $Id: Control.py,v 1.1 2007/09/29 14:39:59 darius Exp $
7 #
8 # Depends on: Python 2.3 (I think)
9 #
10 ############################################################################
11 #
12 # Copyright (C) 2007 Daniel O'Connor. All rights reserved.
13 #
14 # Redistribution and use in source and binary forms, with or without
15 # modification, are permitted provided that the following conditions
16 # are met:
17 # 1. Redistributions of source code must retain the above copyright
18 # notice, this list of conditions and the following disclaimer.
19 # 2. Redistributions in binary form must reproduce the above copyright
20 # notice, this list of conditions and the following disclaimer in the
21 # documentation and/or other materials provided with the distribution.
22 #
23 # THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 # ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
27 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 # SUCH DAMAGE.
34 #
35 ############################################################################
36
37 import threading, ConfigParser, time
38
39 class OWReadError(Exception):
40 """Raised when we failed to read from a 1-wire device, could be a timeout
41 or the device is non-existent, etc"""
42 pass
43
44 class ThreadDied(Exception):
45 """Raised when the monitor thread has died for some reason"""
46 pass
47
48 class Control():
49 """This class is responsible for controlling the temperature of
50 the fermenter by switching the heater & cooler."""
51 staleDataTime = 30
52
53 def __init__(self, _log, m, conf):
54 """m is a MonitorDev object, conf is a ConfigParser object"""
55 global log
56 log = _log
57
58 self.m = m
59
60 self.targetTemp = conf.getfloat('control', 'targetTemp')
61 self.hysteresis = conf.getfloat('control', 'hysteresis')
62 self.pollInterval = conf.getfloat('control', 'pollInterval')
63
64 log.debug("target temperature - %3.2f" % (self.targetTemp))
65 log.debug("hysteresis - %3.2f" % (self.hysteresis))
66 log.debug("pollInterval - %d" % (self.pollInterval))
67
68 self.cv = threading.Condition()
69 self.cv.acquire()
70
71 def doit(self):
72 """Runs forever controlling the temperature until something breaks or interrupted"""
73 log.debug("=== Starting ===")
74 log.debug("Fermenter Fridge Ambient State New State")
75 while True:
76 # Check if our monitor thread has died
77 if (not self.m.isAlive()):
78 raise ThreadDied, "Monitor thread has died"
79
80 # Check for stale data
81 if (self.m.lastUpdate[self.m.fermenterId] + self.staleDataTime < time.time()):
82 log.debug("Stale data")
83 self.cv.wait(self.pollInterval)
84 self.m.setState('idle')
85 continue
86
87 # Work out what state we should go into
88 nextState = "-"
89 # Temperature diff, -ve => too cold, +ve => too warm
90 diff = self.m.temps[self.m.fermenterId] - self.targetTemp
91 if (self.m.currState == 'idle'):
92 # If we're idle then only heat or cool if the temperate difference is out of the
93 # hysteresis band
94 if (abs(diff) > self.hysteresis):
95 if (diff < 0 and self.m.minHeatOffTime + self.m.lastHeatOff < time.time()):
96 nextState = 'heat'
97 elif (diff > 0 and self.m.minHeatOffTime + self.m.lastHeatOff < time.time()):
98 nextState = 'cool'
99 elif (self.m.currState == 'cool'):
100 # Work out if we should go idle (based on min on time & overshoot)
101 if (diff + self.m.minCoolOvershoot < 0 and self.m.minCoolOnTime + self.m.lastCoolOn < time.time()):
102 nextState = 'idle'
103 elif (self.m.currState == 'heat'):
104 # Ditto
105 if (diff - self.m.minHeatOvershoot > 0 and self.m.minHeatOnTime + self.m.lastHeatOn < time.time()):
106 nextState = 'idle'
107 else:
108 # Not possible..
109 raise KeyError
110
111 log.debug("%3.2f %3.2f %3.2f %s %s" %
112 (self.m.temps[self.m.fermenterId],
113 self.m.temps[self.m.fridgeId], self.m.temps[self.m.ambientId],
114 self.m.currState, nextState))
115
116 if (nextState != "-"):
117 self.m.setState(nextState)
118
119 self.cv.wait(self.pollInterval)
120
121