4 from select import select
7 asynchronous_responses = [ '400', '401', # door open/closed
8 '610', # switches changed
9 '200', '201', '202', '203', '204', '205', '206',
10 '207', '208', '209', '211', # key presses
16 class VendingException(Exception): pass
19 def __init__(self, rfh, wfh):
21 self.secret = 'AAAAAAAAAAAAAAAA'
25 # Initialise ourselves into a known state
28 self.wfh.write('echo off\n')
30 self.wfh.write('PING\n')
33 code = self.get_response()[0]
36 def await_prompt(self):
45 raise VendingException('failed to read input from vending machine')
46 if s == '': raise VendingException('nothing read!')
47 if (s != '#' and s != '%') and state == 1: prefix += s
48 if s == '\n' or s == '\r':
51 if (s == '#' or s == '%') and state == 1: state = 2
52 if s == ' ' and state == 2:
56 if re.search('^[0-9a-fA-F]{4}$', prefix):
57 self.challenge = int(prefix, 16)
60 def get_response(self, async = False):
65 s = self.rfh.readline()
67 raise VendingException('Input socket has closed!')
71 if code in asynchronous_responses:
72 self.handle_event(code, text)
78 def get_switches(self):
80 (code, text) = self.get_response()
82 return (False, code, text)
83 self.interpret_switches(text)
84 return (True, code, text)
86 def interpret_switches(self, text):
87 self.switches = (int(text[0:2], 16) << 8) | int(text[3:5], 16)
89 def handle_event(self, code, text):
91 self.events.append((DOOR, 1))
93 self.events.append((DOOR, 0))
95 self.events.append((SWITCH, None))
96 self.interpret_switches(text)
98 self.events.append((KEY, int(code[1:3])))
100 logging.warning('Unhandled event! (%s %s)\n'%(code,text))
102 def authed_message(self, message):
103 if self.challenge == None:
105 crc = do_crc('%c%c'%(self.challenge >> 8, self.challenge & 0xff))
106 crc = do_crc(self.secret, crc)
107 crc = do_crc(message, crc)
108 return message+'|'+('%04x'%crc)
111 self.wfh.write('PING\n')
112 (code, string) = self.get_response()
113 return (code == '000', code, string)
115 def vend(self, item):
116 if not re.search('^[0-9][0-9]$', item):
117 return (False, 'Invalid item requested (%s)'%item)
118 self.wfh.write(self.authed_message(('V%s'%item))+'\n')
119 (code, string) = self.get_response()
120 return (code == '100', code, string)
122 def beep(self, duration = None, synchronous = True):
124 if synchronous: msg += 'S'
126 if duration > 255: duration = 255
127 if duration < 1: duration = 1
128 msg += '%02x'%duration
129 self.wfh.write(msg+'\n')
130 (code, string) = self.get_response()
131 return (code == '500', code, string)
133 def silence(self, duration = None, synchronous = True):
135 if synchronous: msg += 'S'
137 if duration > 255: duration = 255
138 if duration < 1: duration = 1
139 msg += '%02x'%duration
140 self.wfh.write(msg+'\n')
141 (code, string) = self.get_response()
142 return (code == '501', code, string)
144 def display(self, string):
146 string = string[0:10]
147 self.wfh.write('D'+string+'\n')
148 (code, string) = self.get_response()
149 return (code == '300', code, string)
151 def next_event(self, timeout = None):
152 # we don't want to buffer in the serial port, so we get all the events
154 if len(self.events) > 0: timeout = 0
156 (r, _, _) = select([self.rfh], [], [], timeout)
158 self.get_response(async = True)
162 if len(self.events) == 0: return None