/[anoncvs]/projects/dispense2/sql-edition/servers/VendingMachine.py


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Contents of /projects/dispense2/sql-edition/servers/VendingMachine.py

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Revision 1.20 - (show annotations) (download) (as text)
Sun Jan 6 06:11:33 2008 UTC (13 years, 5 months ago) by root
Branch: MAIN
Changes since 1.19: +5 -0 lines
File MIME type: text/x-python
note vis pyserial

change of timeout

1 # vim:ts=4
2 import re
3 from CRC import do_crc
4 from select import select
5 import socket, logging
6 from time import time, sleep
7
8 asynchronous_responses = [ '400', '401', # door open/closed
9 '610', # switches changed
10 '200', '201', '202', '203', '204', '205', '206',
11 '207', '208', '209', '211', # key presses
12 ]
13 DOOR = 1
14 SWITCH = 2
15 KEY = 3
16 TICK = 4
17
18 class VendingException(Exception): pass
19
20 class VendingMachine:
21 def __init__(self, rfh, wfh):
22 self.events = []
23 # Secret
24 self.secret = 'SN4CKZ0RZZZZZZZZ'
25 self.rfh = rfh
26 self.wfh = wfh
27 self.challenge = None
28 # Initialise ourselves into a known state
29 self.wfh.write('\n')
30 self.await_prompt()
31 self.wfh.write('echo off\n')
32 self.await_prompt()
33 self.wfh.write('PING\n')
34 code = ''
35 while code != '000':
36 code = self.get_response()[0]
37 self.get_switches()
38
39 def await_prompt(self):
40 self.wfh.flush()
41 state = 1
42 timeout = 0.5
43 prefix = ''
44 s = ''
45 # mtearle - vending machine was dying wait for a response from
46 # the hardware, suspect it was missing characters
47 #
48 # fixed by migration to pyserial - but future good place to start
49 while True:
50 try:
51 s = self.rfh.read(1)
52 except socket.error:
53 raise VendingException('failed to read input from vending machine')
54 if s == '': raise VendingException('nothing read!')
55 if (s != '#' and s != '%') and state == 1: prefix += s
56 if s == '\n' or s == '\r':
57 state = 1
58 prefix = ''
59 if (s == '#' or s == '%') and state == 1: state = 2
60 if s == ' ' and state == 2:
61 if prefix == '':
62 self.challenge = None
63 return
64 if re.search('^[0-9a-fA-F]{4}$', prefix):
65 self.challenge = int(prefix, 16)
66 return
67
68 def get_response(self, async = False):
69 self.wfh.flush()
70 while True:
71 s = ''
72 while s == '':
73 s = self.rfh.readline()
74 if s == '':
75 raise VendingException('Input socket has closed!')
76 s = s.strip('\r\n')
77 code = s[0:3]
78 text = s[4:]
79 if code in asynchronous_responses:
80 self.handle_event(code, text)
81 if async: return None
82 else:
83 self.await_prompt()
84 return (code, text)
85
86 def get_switches(self):
87 self.wfh.write('S\n')
88 (code, text) = self.get_response()
89 if code != '600':
90 return (False, code, text)
91 self.interpret_switches(text)
92 return (True, code, text)
93
94 def interpret_switches(self, text):
95 self.switches = (int(text[0:2], 16) << 8) | int(text[3:5], 16)
96
97 def handle_event(self, code, text):
98 if code == '400':
99 self.events.append((DOOR, 1))
100 elif code == '401':
101 self.events.append((DOOR, 0))
102 elif code == '610':
103 # NOP this. Nothing handles this yet.
104 #self.events.append((SWITCH, None))
105 self.interpret_switches(text)
106 elif code[0] == '2':
107 self.events.append((KEY, int(code[1:3])))
108 else:
109 logging.warning('Unhandled event! (%s %s)\n'%(code,text))
110
111 def authed_message(self, message):
112 if self.challenge == None:
113 return message
114 crc = do_crc('%c%c'%(self.challenge >> 8, self.challenge & 0xff))
115 crc = do_crc(self.secret, crc)
116 crc = do_crc(message, crc)
117 return message+'|'+('%04x'%crc)
118
119 def ping(self):
120 self.wfh.write('PING\n')
121 (code, string) = self.get_response()
122 return (code == '000', code, string)
123
124 def vend(self, item):
125 if not re.search('^[0-9][0-9]$', item):
126 return (False, 'Invalid item requested (%s)'%item)
127 self.wfh.write(self.authed_message(('V%s'%item))+'\n')
128 (code, string) = self.get_response()
129 return (code == '100', code, string)
130
131 def beep(self, duration = None, synchronous = True):
132 msg = 'B'
133 if synchronous: msg += 'S'
134 if duration != None:
135 if duration > 255: duration = 255
136 if duration < 1: duration = 1
137 msg += '%02x'%duration
138 self.wfh.write(msg+'\n')
139 (code, string) = self.get_response()
140 return (code == '500', code, string)
141
142 def silence(self, duration = None, synchronous = True):
143 msg = 'C'
144 if synchronous: msg += 'S'
145 if duration != None:
146 if duration > 255: duration = 255
147 if duration < 1: duration = 1
148 msg += '%02x'%duration
149 self.wfh.write(msg+'\n')
150 (code, string) = self.get_response()
151 return (code == '501', code, string)
152
153 def display(self, string):
154 if len(string) > 10:
155 string = string[0:10]
156 string = re.sub('(.)\.', lambda match: '.'+match.group(1), string)
157 self.wfh.write('D'+string+'\n')
158 (code, string) = self.get_response()
159 return (code == '300', code, string)
160
161 def next_event(self, timeout = None):
162 # we don't want to buffer in the serial port, so we get all the events
163 # we can ASAP.
164 if timeout < 0: timeout = 0
165 if len(self.events) > 0: timeout = 0
166 while True:
167 (r, _, _) = select([self.rfh], [], [], timeout)
168 if r:
169 self.get_response(async = True)
170 timeout = 0
171 else:
172 break
173 if len(self.events) == 0: return (TICK, time())
174 ret = self.events[0]
175 del self.events[0]
176 return ret

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