dgps_server.py

在linux系统下开发的GPS接收程序,具有良好的图形操作界面.

#!/usr/env python
#------------------------------------------------------------------------------
# dgps_server.py : DGPS server that send RTCM correction data
#
#	- programmed by Boyoon Jung ([e-mail])
#------------------------------------------------------------------------------
import uspp.uspp
from SocketServer import *
import socket
import time
import sys
import thread
import os


# constants
DGPSServerPort = 7777


# global variables
rtcm_msg = ''
counter = 0
terminated = 0


# DGPS server class
class DGPSServer (BaseRequestHandler):
    """
    DGPSServer: a TCP server that send RTCM correction data."
    """

    def handle(self):
	"""
	process a request from clients.
	"""
	# global variables
	global rtcm_msg
	global counter

	# local variable
	cntr = counter
	dir(self)
	conn = self.request

	try:
	    peer = conn.getpeername()
	    print '[Info] accepted a request from ', peer, '.'

	    # send RTCM messages
	    while not terminated:
		if cntr != counter:
		    conn.send(rtcm_msg)
		    cntr = counter
		time.sleep(0.1)
	except:
	    print '[Info] unexpected socket close by a client (', peer, ').'


# main function
if __name__ == '__main__':

    # default settings
    device = '/dev/ttyS0'
    baudrate = 9600

    # process the command-line arguments
    if len(sys.argv) > 1: device = sys.argv[1]
    if len(sys.argv) > 2: baudrate = int(sys.argv[2])

    # open a seiral port
    serial = uspp.SerialPort(device, 100, baudrate)

    # start a DGPS server
    dgps_server = ThreadingTCPServer(('', DGPSServerPort), DGPSServer)
    thread.start_new_thread(dgps_server.serve_forever, ())

    # start to send RTCM messages
    try:
	print 'Started to send RTCM messages.'

	while 1:
	    # retrieve a RTCM message
	    try:
		message = ''
		while 1:
		    message = message + serial.read()

	    # send the RTCM message if it is valid
	    except uspp.SerialPort_linux.SerialPortException:
		if message:
		    rtcm_msg = message
		    counter += 1
		    print message

    except:
	terminated = 1
	print 'Terminated.'