Source Code for Module nxt.usbsock

 1  # nxt.usbsock module -- USB socket communication with LEGO Minstorms NXT 
 2  # Copyright (C) 2006-2007  Douglas P Lau 
 3  # Copyright (C) 2009  Marcus Wanner 
 4  # 
 5  # This program is free software: you can redistribute it and/or modify 
 6  # it under the terms of the GNU General Public License as published by 
 7  # the Free Software Foundation, either version 3 of the License, or 
 8  # (at your option) any later version. 
 9  # 
10  # This program is distributed in the hope that it will be useful, 
11  # but WITHOUT ANY WARRANTY; without even the implied warranty of 
12  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
13  # GNU General Public License for more details. 
14   
15  import usb 
16  from nxt.brick import Brick 
17   
18  ID_VENDOR_LEGO = 0x0694 
19  ID_PRODUCT_NXT = 0x0002 
20   
21 -class USBSock(object): 
22          'Object for USB connection to NXT' 
23   
24          bsize = 60      # USB socket block size 
25   
26 -        def __init__(self, device): 
27                  self.device = device 
28                  self.handle = None 
29                  self.debug = False 
30   
31 -        def __str__(self): 
32                  return 'USB (%s)' % (self.device.filename) 
33   
34 -        def connect(self): 
35                  'Use to connect to NXT.' 
36                  if self.debug: 
37                          print 'Connecting via USB...' 
38                  config = self.device.configurations[0] 
39                  iface = config.interfaces[0][0] 
40                  self.blk_out, self.blk_in = iface.endpoints 
41                  self.handle = self.device.open() 
42                  self.handle.setConfiguration(1) 
43                  self.handle.claimInterface(0) 
44                  self.handle.reset() 
45                  if self.debug: 
46                          print 'Connected.' 
47                  return Brick(self) 
48   
49 -        def close(self): 
50                  'Use to close the connection.' 
51                  if self.debug: 
52                          print 'Closing USB connection...' 
53                  self.device = None 
54                  self.handle = None 
55                  self.blk_out = None 
56                  self.blk_in = None 
57                  if self.debug: 
58                          print 'USB connection closed.' 
59   
60 -        def send(self, data): 
61                  'Use to send raw data over USB connection ***ADVANCED USERS ONLY***' 
62                  if self.debug: 
63                          print 'Send:', 
64                          print ':'.join('%02x' % ord(c) for c in data) 
65                  self.handle.bulkWrite(self.blk_out.address, data) 
66   
67 -        def recv(self): 
68                  'Use to recieve raw data over USB connection ***ADVANCED USERS ONLY***' 
69                  data = self.handle.bulkRead(self.blk_in.address, 64) 
70                  if self.debug: 
71                          print 'Recv:', 
72                          print ':'.join('%02x' % (c & 0xFF) for c in data) 
73                  # NOTE: bulkRead returns a tuple of ints ... make it sane 
74                  return ''.join(chr(d & 0xFF) for d in data) 
75   
76 -def find_bricks(host=None, name=None): 
77          'Use to look for NXTs connected by USB only. ***ADVANCED USERS ONLY***' 
78          # FIXME: probably should check host and name 
79          for bus in usb.busses(): 
80                  for device in bus.devices: 
81                          if device.idVendor == ID_VENDOR_LEGO and \ 
82                             device.idProduct == ID_PRODUCT_NXT: 
83                                  yield USBSock(device) 
84