gpvtg.py

#!/usr/bin/env python2
# -*- coding: utf-8 -*-
#
# This file is part of Camino.
# Copyright (C) 2017 Manuel Luitz <manuel.luitz@gmail.com>
#
# Camino is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Camino is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Camino. If not, see <http://www.gnu.org/licenses/>.
#
# $GPVTG,054.7,T,034.4,M,005.5,N,010.2,K*48

class GPVTGMessage(object):
    def __init__(self):
        # hhmmss.ss = UTC of position
        self.track_made_good = "0.0"
        self.degrees_true = "T"
        self.track_magnetic = "0.0"
        self.degrees_magnetic = "M"
        self.speed_over_ground_knots = "0.0"
        self.speed_over_ground_knots_unit = "N"
        # Fixed text "K" (knots)
        self.speed_over_ground_kmh = "0.0"
        # Fixed text "K" (km/h)
        self.speed_over_ground_kmh_unit = "K"

    def parseGPVTGMessage(self, msg):
        msg = msg.split('*')[0].split(',')
        self.track_made_good = msg[1]
        self.degrees_true = msg[2]
        self.track_magnetic = msg[3]
        self.degrees_magnetic = msg[4]
        self.speed_over_ground_knots = msg[5]
        self.speed_over_ground_knots_unit = msg[6]
        self.speed_over_ground_kmh = msg[7]
        self.speed_over_ground_kmh_unit = msg[8]

    def formatSpeedOverGroundKmh(self):
        try:
            return u"{sog:} km/h".format(sog=float(self.speed_over_ground_kmh))
        except:
            return u"0.0 km/h"


    def formatSpeedOverGroundKnots(self):
        return u"{sog:} knots".format(sog=float(self.speed_over_ground_knots))

    def getSpeedOverGroundStringMetric(self):
        return self.formatSpeedOverGroundKmh()

    def getSpeedOverGroundStringImperial(self):
        return self.formatSpeedOverGroundKnots()