/[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 1.6 - (show annotations) (download) (as text)
Sun Jun 27 11:11:00 2004 UTC (17 years, 2 months ago) by dagobah
Branch: MAIN
Changes since 1.5: +1 -2 lines
File MIME type: text/x-python
Silence bug in ROM fixed.

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

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