/scripts/galaxy_messaging/client/scanner_interface.py

 1import sys, os
 2import serial
 3import array
 4import time
 5import optparse
 6import ConfigParser
 7import logging
 8
 9logging.basicConfig(level=logging.INFO)
10log = logging.getLogger( 'ScannerInterface' )
11
12class ScannerInterface( object ):
13    cmdprefix = [22, 77, 13]
14    response = { 6: 'ACK', 5: 'ENQ', 21: 'NAK' }
15    
16    def __init__( self, port ):
17        if os.name in ['posix', 'mac']:
18            self.port = port
19        elif os.name == 'nt':
20            self.port = int(port)
21        if self.port:
22            self.open()
23            
24    def open(self):
25        try:
26            self.serial_conn = serial.Serial(self.port)
27        except serial.SerialException:
28            log.exception('Unable to open port: %s' % str(self.port))
29            sys.exit(1)
30        log.debug('Port %s is open: %s' %( str(self.port), self.serial_conn.isOpen() ) )
31        
32    def is_open(self):
33        return self.serial_conn.isOpen()
34        
35    def close(self):
36        self.serial_conn.close()
37        log.debug('Port %s is open: %s' %( str(self.port), self.serial_conn.isOpen() ) )
38        
39    def send(self, msg):
40        message = self.cmdprefix + map(ord, msg)
41        byte_array = array.array('B', message)
42        log.debug('Sending message to %s: %s' % ( str(self.port), message) )
43        bytes = self.serial_conn.write( byte_array.tostring() )
44        log.debug('%i bytes out of %i bytes sent to the scanner' % ( bytes, len(message) ) )
45        
46    def recv(self):
47        time.sleep(1)
48        self.serial_conn.flush()
49        nbytes = self.serial_conn.inWaiting()
50        log.debug('%i bytes received' % nbytes)
51        if nbytes:
52            msg = self.serial_conn.read(nbytes)
53            byte_array = map(ord, msg)
54            log.debug('Message received [%s]: %s' % (self.response.get(byte_array[len(byte_array)-2], byte_array[len(byte_array)-2]),
55                                                     msg))
56            return msg
57        else:
58            log.error('Error!')
59            return None
60            
61    def setup_recv(self, callback):
62        self.recv_callback = callback
63        
64    def wait(self):
65        nbytes = self.serial_conn.inWaiting()
66        if nbytes:
67            msg = self.serial_conn.read(nbytes)
68            byte_array = map(ord, msg)
69            log.debug('Message received [%s]: %s' % (self.response.get(byte_array[len(byte_array)-2], byte_array[len(byte_array)-2],
70                                                     msg)))
71            if self.recv_callback:
72                self.recv_callback(msg)
73            return
74    
75    
76