-from CRC import do_crc
-from binascii import unhexlify
-
-asynchronous_responses = [ '400', '401', # door open/closed
- '610', # switches changed
- ]
-
-class VendingMachine:
- def __init__(self, rfh, wfh):
- self.secret = 'AAAAAAAAAAAAAAAA'
- self.rfh = rfh
- self.wfh = wfh
- self.challenge = None
- # Initialise ourselves into a known state
- self.wfh.write('\n')
- self.await_prompt()
- self.wfh.write('echo off\n')
- self.await_prompt()
- self.wfh.write('PING\n')
- code = ''
- while code != '000':
- (code, _) = self.get_response()
-
- def await_prompt(self):
- self.wfh.flush()
- state = 1
- prefix = ''
- s = ''
- while True:
- s = self.rfh.read(1)
- if s == '': raise Exception
- if s == '\n' or s == '\r':
- state = 1
- prefix = ''
- if (s == '#' or s == '%') and state == 1: state = 2
- if s == ' ' and state == 2:
- if prefix == '':
- self.challenge = None
- return
- if re.search('^[0-9a-fA-F]{4}$', prefix):
- self.challenge = unhexlify(prefix)
- return
-
- def get_response(self):
- self.wfh.flush()
- while True:
- s = ''
- while s == '':
- s = self.rfh.readline()
- if s == '': return None
- s = s.strip('\r\n')
- code = s[0:3]
- text = s[4:]
- if code in asynchronous_responses:
- self.handle_event(code, text)
- else:
- self.await_prompt()
- return (code, text)
-
- def handle_event(self, code, text):
- pass
-
- def authed_message(self, message):
- if self.challenge == None:
- return message
- crc = do_crc('%c%c'%(self.challenge >> 8, self.challenge & 0xff))
- crc = do_crc(self.secret, crc)
- crc = do_crc(message, crc)
- return message+'|'+('%04x'%crc)
-
- def ping(self):
- self.wfh.write('PING\n')
- (code, string) = self.get_response()
- return (code == '000', code, string)
-
- def vend(self, item):
- if not re.search('^[0-9][0-9]$', item):
- return (False, 'Invalid item requested (%s)'%item)
- self.wfh.write(self.authed_message(('V%s\n'%item)+'\n'))
- (code, string) = self.get_response()
- return (code, string)
-
- def beep(self, duration = None, synchronous = True):
- msg = 'B'
- if synchronous: msg += 'S'
- if duration != None:
- if duration > 255: duration = 255
- if duration < 1: duration = 1
- msg += '%02x'%duration
- self.wfh.write(msg+'\n')
- (code, string) = self.get_response()
- return (code == '500', code, string)
-
- def silence(self, duration = None, synchronous = True):
- msg = 'C'
- if synchronous: msg += 'S'
- if duration != None:
- if duration > 255: duration = 255
- if duration < 1: duration = 1
- msg += '%02x'%duration
- self.wfh.write(msg+'\n')
- (code, string) = self.get_response()
- # FIXME: workaround a bug in rom W. should be just: return (code == '500', code, string)
- return (code == '500' or code == '501', code, string)
-
- def display(self, string):
- if len(string) > 10:
- string = string[0:10]
- self.wfh.write('D'+string+'\n')
- (code, string) = self.get_response()
- return (code == '300', code, string)