NMEA0183 (GPS) and Python

1_pyserial.py

import serial 
import pynmea2
import collections
def signal_handle( sig, frame ):
    # Save JSON 
    import json 
    with open( '/home/mpkuse/try/gps_nmea/data.json', 'w' ) as outfile:
            json.dump( ARY, outfile )
    exit(0)

ser = serial.Serial( '/dev/ttyUSB0', 4800 )
ARY =  collections.OrderedDict() # To save the data for reference
import signal
signal.signal( signal.SIGINT, signal_handle )
while True:
    print '\n---' 

    # Get data from the device 
    line = ser.readline()
    print "raw data:", line

    # Parse the data
    try:
        msg = pynmea2.parse( line )
        #print 'status=', msg.status,
        print 'lat=', msg.lat,
        print 'lon=', msg.lon,
        #print '#sats=', msg.num_sats,
        print 'datetime=', msg.datetime
        #ARY.append( (msg.datetime,msg.latitude, msg.latitude_minutes, msg.latitude_seconds, msg.longitude, msg.longitude_minutes, msg.longitude_seconds) )
        Q = {} 
        Q[ 'latitude' ] = msg.latitude
        Q[ 'latitude_minutes' ] = msg.latitude_minutes
        Q[ 'latitude_seconds' ] = msg.latitude_seconds
        Q[ 'longitude' ] = msg.longitude
        Q[ 'longitude_minutes' ] = msg.longitude_minutes
        Q[ 'longitude_seconds' ] = msg.longitude_seconds
        ARY[ msg.datetime.__str__() ] = Q
    except:
        continue

README.md

A demo of how to read nmea devices and some related utils for data manipulation.

json_to_geojson.py

# Geojson is a common format used on the internet for plotting geo-cordinates
import json

with open( 'data.json') as f:
    data = json.load( f )


cords = []
for k in data.keys():
    #print data[k]
    lat = float(data[k]["latitude"]) +\
          float( data[k]["latitude_minutes"] )/60. +\
          float( data[k]["latitude_seconds"] )/3600.
    long = float(data[k]["longitude"]) +\
        float( data[k]["longitude_minutes"] )/60. +\
        float( data[k]["longitude_seconds"] )/3600.
    print lat,',', long
    cords.append( [long, lat] )

out = {}
out["type"] = "MultiPoint"
out["coordinates"] = cords

usb_devices.sh

#!/bin/bash

for sysdevpath in $(find /sys/bus/usb/devices/usb*/ -name dev); do
    (
        syspath="${sysdevpath%/dev}"
        devname="$(udevadm info -q name -p $syspath)"
        [[ "$devname" == "bus/"* ]] && continue
        eval "$(udevadm info -q property --export -p $syspath)"
        [[ -z "$ID_SERIAL" ]] && continue
        echo "/dev/$devname - $ID_SERIAL"
    )
done

# Sample Output
# /dev/bsg/6:0:0:0 - VT_SSD_USB_3.0_000000000002-0:0
# /dev/sda - VT_SSD_USB_3.0_000000000002-0:0
# /dev/sda1 - VT_SSD_USB_3.0_000000000002-0:0
# /dev/sg0 - VT_SSD_USB_3.0_000000000002-0:0
# /dev/input/event2 - LiteON_HP_Basic_USB_Keyboard
# /dev/hidraw0 - LiteON_HP_Basic_USB_Keyboard
# /dev/input/event3 - PixArt_USB_Optical_Mouse
# /dev/input/mouse0 - PixArt_USB_Optical_Mouse
# /dev/hidraw1 - PixArt_USB_Optical_Mouse