def connect(self, port_name):
if self.connection_open():
raise IOError('Connection still open.')
if self.parser:
# Ask old parser to stop before we create another one for the new connection.
self.parser.stop_request.set()
self.connection = SerialConnection(port=port_name, timeout=0.3, writeTimeout=0.5, baudrate=115200)
connection_thread = threading.Thread(target=self.connection.run)
connection_thread.setDaemon(True)
connection_thread.start()
self.parser = ParserThread(self.connection, self.message_start_byte, self.new_message)
self.parser.setDaemon(True)
self.parser.start()
class GlobLink(QObject):
new_message = pyqtSignal(int, int, bytearray)
def __init__(self):
super(GlobLink, self).__init__()
# Port to receive and transmit bytes over.
self.connection = None
# Special byte that begins each new message.
self.message_start_byte = 0xFE
self.parser = None
# Transfer fields
self.num_bytes_sent = 0
self.num_messages_sent = 0
#self.transfer_buffer = array.array('c', '\0' * 300)
self.transfer_buffer = bytearray(300)
self.next_packet_num = 0 # used to detect dropped packets
def connect(self, port_name):
if self.connection_open():
raise IOError('Connection still open.')
if self.parser:
# Ask old parser to stop before we create another one for the new connection.
self.parser.stop_request.set()
self.connection = SerialConnection(port=port_name, timeout=0.3, writeTimeout=0.5, baudrate=115200)
connection_thread = threading.Thread(target=self.connection.run)
connection_thread.setDaemon(True)
connection_thread.start()
self.parser = ParserThread(self.connection, self.message_start_byte, self.new_message)
self.parser.setDaemon(True)
self.parser.start()
def disconnect(self):
# reset stats
self.num_bytes_sent = 0
self.num_messages_sent = 0
if self.parser:
self.parser.stop_request.set()
self.parser = None
if self.connection_open():
self.connection.close()
self.connection = None
return True
return False # connection already closed
def connection_open(self):
return self.connection and self.connection.connection_is_open()
def send(self, glob):
if not self.connection_open():
return
body_bytes = glob.pack()
body_size = len(body_bytes)
# Send a 1 at start of header to show that CRC and packet number should be valid.
header_fmt = '<BBBHBB'
header = (self.message_start_byte, 1, glob.id, glob.instance, self.next_packet_num, body_size)
header_size = 7
struct.pack_into(header_fmt, self.transfer_buffer, 0, *header)
self.transfer_buffer[header_size : header_size + body_size] = body_bytes # array.array('c', body_bytes)
crc = calculate_crc(self.transfer_buffer, header_size + body_size, 0xFFFF)
struct.pack_into('<H', self.transfer_buffer, header_size + body_size, crc)
footer_size = 2
message_size = header_size + body_size + footer_size
self.connection.write(self.transfer_buffer[:message_size])
self.num_bytes_sent += message_size
self.num_messages_sent += 1
self.next_packet_num += 1
if self.next_packet_num > 255:
self.next_packet_num = 0
@property
def num_messages_received(self):
if self.parser:
return self.parser.num_messages_received
return 0
@property
def num_bytes_received(self):
if self.parser:
return self.parser.num_bytes_received
return 0
@property
def num_bad_crc_messages(self):
if self.parser:
return self.parser.num_bad_crc_messages
return 0
@property
def num_dropped_messages(self):
if self.parser:
return self.parser.num_dropped_messages
return 0
