Class: NMEAParser

Inherits:
Object
  • Object
show all
Defined in:
lib/nmea_parser.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(s = nil) ⇒ NMEAParser

Returns a new instance of NMEAParser.



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# File 'lib/nmea_parser.rb', line 14

def initialize(s=nil)
  parse(s) if s
end

Instance Attribute Details

#latitude ⇒ Object (readonly)

Returns the value of attribute latitude.



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# File 'lib/nmea_parser.rb', line 12

def latitude
  @latitude
end

#longitude ⇒ Object (readonly)

Returns the value of attribute longitude.



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# File 'lib/nmea_parser.rb', line 12

def longitude
  @longitude
end

#time ⇒ Object (readonly)

Returns the value of attribute time.



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# File 'lib/nmea_parser.rb', line 12

def time
  @time
end

Instance Method Details

#parse(raw_line) ⇒ Object 



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# File 'lib/nmea_parser.rb', line 18

def parse(raw_line)

  msgcode = raw_line[/^\$GP(\w+)/]
  return unless msgcode

  a = raw_line.split(',')

  case msgcode

    when /GGA/

      _, raw_time, raw_lat, ns, raw_lon, ew = a
      @time, @latitude, @longitude = Time.parse(raw_time), 
                             decimalize(raw_lat, ns), decimalize(raw_lon, ew)

      # additional data captured 
      #
      # Fix quality, Number of satellites being tracked, Horizontal dilution
      # of position, Altitude (Meters, above mean sea level), Height of 
      # geoid, time in seconds since last DGPS update, DGPS station ID number

      @quality, @num_sat, @hdop, @altitude, @alt_unit, @height_geoid,
      @height_geoid_unit, @last_dgps, @dgps = a[6..-2] << a[-1][/^[^\*]+/]

    when /RMC/

      _, raw_time, _, raw_lat, ns, raw_lon, ew = a
      @time, @latitude, @longitude = Time.parse(raw_time), 
                             decimalize(raw_lat, ns), decimalize(raw_lon, ew)

      # additional data captured 
      #
      # Speed over the ground in knots, Track angle in degrees True, 
      # Date, Magnetic Variation, 

      @speed, @course = a[7..8]
      @date, @variation = Date.parse(a[9]), a[10]
      @var_direction =  a[-1][/^[^\*]+/]

    when /VTG/

      # data captured      
    
      # True track made good (degrees), Magnetic track made good, 
      # Ground speed (knots), Ground speed (Kilometers per hour)

      @track, @mag_track, @speed, @speed_kph = a.values_at(1,3,5,7)

  end

end

#to_h ⇒ Object 



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# File 'lib/nmea_parser.rb', line 70

def to_h()  
  {
    time: @time, latitude: @latitude, longitude: @longitude, 
    quality: @quality, num_sat: @num_sat, hdop: @hdop, altitude: @altitude,
    alt_unit: @alt_unit, height_geoid: @height_geoid, 
    height_geoid_unit: @height_geoid_unit, last_dgps: @last_dgps, 
    dgps: @dgps, speed: @speed, course: @course, date: @date, 
    variation: @variation, var_direction: @var_direction, track: @track, 
    mag_track: @mag_track, speed: @speed, speed_kph: @speed_kph
  }
end

#to_struct ⇒ Object 



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# File 'lib/nmea_parser.rb', line 82

def to_struct()
  h = self.to_h
  Struct.new(*h.keys.map(&:to_sym)).new(*h.values).freeze    
end