Skip to content
Snippets Groups Projects
Select Git revision
  • master default protected
  • new_code
2 results
Blame Permalink
GPS_receiver.py 2.34 KiB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71 






import socket
import socketserver
import logging
import threading
import pynmea2 #nmea message parser
import sys
from datetime import datetime

from global_vars import *

#if we have not had a GPS signal yet the coordates are set to 0,0.
#once we have a signal and lose it again we keep sending the same coordinates.
#(lozing the signal means GPS_FIX == 0)

TCPServerInstance = None #link to the TCPserver thread so we can stop it

#RUTX11 NMEA string receiver
class TCPReceiver(socketserver.StreamRequestHandler):    
    #receive the NMEA messages
    def handle(self):
        global GPS_lock, GPS_ringbuf
        msg = self.request.recv(1024).strip().decode('ascii')
        msgList = msg.split("\x00")
        #on startup we get a lot of qued messages, we only look at the latest compleet request:
        if len(msgList) > 1:
            nmea_msg = pynmea2.parse(msgList[-2])
        else:
            nmea_msg = pynmea2.parse(msgList[0])
        #print(repr(nmea_msg)) #prints everything compactly.
        if type(nmea_msg).__name__ != "GGA":
            raise Exception("wrong data type received!")
        with GPS_lock:
            if nmea_msg.gps_qual != 0:
                GPS_ringbuf.put(nmea_msg, datetime.utcnow())


#start TCP server which receives the messages from the RUTX11
def start_GPSthread(CONFIG):
    global TCPServerInstance, GPS_Ringbuffer
    GPS_ringbuf.set_min_frame_movement(CONFIG['min-movement-frame'])
    GPS_poort = 8500    #port to which the TCP nmea string is send
    for _ in range(0,5):
        ip_address = get_ip_address()
        if ip_address != None: break
    if ip_address == None:
        raise Exception("Router not connected, shutting down!")
    ServerAddress = (ip_address, GPS_poort)
    TCPServerInstance = socketserver.ThreadingTCPServer(ServerAddress, TCPReceiver)
    threading.Thread(target=TCPServerInstance.serve_forever).start()


def stop_GPSthread():
    global TCPServerInstance
    if TCPServerInstance != None:
        TCPServerInstance.server_close()


#get own ip_address
def get_ip_address():
    try:
        test_IP = "8.8.8.8"
        s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        s.connect((test_IP, 0))
        ipaddres = s.getsockname()[0]
    except Exception as e:
        print("tried to connect before the networkdriver and router are online: %s" %e)
        return None
    return str(ipaddres)