Beispiel #1
0
def openSerial( port = 0, rate = 19200, tout = 60 ):
	"""Open serial port for SNAP RepRap communications"""
	global serialPort
	try:
		serialPort = serial.Serial( port, rate, timeout = tout )
	except:
		raise _RepRapError("You do not have permissions to use the serial port, try running as root")
Beispiel #2
0
def getPacket(ser):
	bytes = []
	# Read in 5 bytes
	while len(bytes) <= 4:
		byte = ser.read()
		if len(byte) > 0:
			# If this is the sync then clear the byte buffer.
			if byte == SYNC_BYTE:
				bytes = []
			bytes.append( ord(byte) )
		else:
			raise _SNAPError("Serial timeout")
	
	# Read the expected packet length from Header Byte 1
	packetLength = _breakHDB1( bytes[HDB1_OFFSET] ) + PAYLOAD_OFFSET + 1
	
	while len(bytes) < packetLength:
		byte = ser.read()
		if len(byte) > 0:
			bytes.append( ord(byte) )
		else:
			raise _SNAPError("Serial timeout")
	
	# We have enough bytes, create packet object
	p = Packet()
	p._setBytes(bytes)
	p._decode()
	p._check()
	
	if printIncoming:
		p.printPacket("Incoming")
	if p.DAB == localAddress:
		return p
	else:
		raise _RepRapError( "Received packet bound for " + str(p.DAB) )