PyS60: Bluetooth GPS polling class

ejot (Magnus Persson) — Fri, 16 Nov 2007 14:09:19 GMT

Threaded approach for reading NMEA data from a bluetooth GPS.



import thread, socket



class BTGPSPoller(object):

	def __init__(self, address):

		address, services = socket.bt_discover(address)

		self.target = (address, services.values()[0])

		self.active = True

		self.connected = False

		self.lock = thread.allocate_lock()

		self.sentances = list()

		

	def connect(self):

		if not self.connected:

			thread.start_new_thread(self.run, ())



	def run(self):

		print "BTGPSPoller thread activated"

		try:

			conn = socket.socket(socket.AF_BT, socket.SOCK_STREAM)

			conn.connect(self.target)

			self.connected = True

		except:

			print "Unable to connect"

		

		if self.connected:

			try:

				to_gps = conn.makefile("r", 0)

			except:

				print "Failure calling conn.makefile()"

			while self.active:

				#e32.ao_sleep(1)

				msg = None

				try:

					msg = to_gps.readline()

					if not msg == None and msg.startswith("$GPGGA"):

						gps_data = msg.split(",")

						if not gps_data[2] == "":

							self.lock.acquire()

							self.sentances.append(msg)

							if len(self.sentances) > 10:

								self.sentances.pop(0)

							self.lock.release()

				except:

					self.active = False



			try:

				to_gps.close()

				conn.close()

				self.connected = False

				print "Closed and disconnected"

			except:

				self.connected = False

				print "Unable to close"



	def disconnect(self):

		self.active = False

		print "Disconnecting from GPS"



	def getSentances(self):

		self.lock.acquire()

		l = self.sentances[:]

		self.lock.release()

		return l

DZone Snippets: bluetooth code

PyS60: Bluetooth GPS polling class