rosaic_driver::GpggaParser Class Reference

Derived class for parsing GGA messages. More...

#include <gpgga.hpp>

Inheritance diagram for rosaic_driver::GpggaParser:

Collaboration diagram for rosaic_driver::GpggaParser:

Public Member Functions
	GpggaParser ()
	Constructor of the class GpggaParser. More...
const std::string	GetMessageID () const override
	Returns the ASCII message ID, here "$GPGGA". More...
rosaic::GpggaPtr	ParseASCII (const NMEASentence &sentence) noexcept(false) override
	Parses one GGA message. More...
bool	WasLastGPGGAValid () const
	Tells us whether the last GGA message was valid or not. More...
Public Member Functions inherited from rosaic_driver::BaseParser< rosaic::GpggaPtr >
	BaseParser ()=default
	Default constructor of the class BaseParser. More...
virtual	~BaseParser ()=default
	Default destructor of the class BaseParser. More...
rosaic::GpggaPtr	ParseBinary (const SBFStructT &bin_msg) noexcept(false)
	Converts bin_msg into a ROS message pointer (e.g. nmea_msgs::GpggaPtr) and returns it. More...

Static Public Attributes
static const std::string	MESSAGE_ID = "$GPGGA"
	Declares the string MESSAGE_ID. More...

Private Attributes
bool	was_last_gpgga_valid_
	Declares a boolean representing whether or not the last GPGGA message was valid. More...

Detailed Description

Derived class for parsing GGA messages.

Date

13/08/20

Definition at line 86 of file gpgga.hpp.

Constructor & Destructor Documentation

GpggaParser()

rosaic_driver::GpggaParser::GpggaParser ( )

inline

Constructor of the class GpggaParser.

Definition at line 93 of file gpgga.hpp.

References GetMessageID(), ParseASCII(), and WasLastGPGGAValid().

: BaseParser<rosaic::GpggaPtr>(), was_last_gpgga_valid_(false) {}

Here is the call graph for this function:

Member Function Documentation

GetMessageID()

const std::string rosaic_driver::GpggaParser::GetMessageID ( ) const

overridevirtual

Returns the ASCII message ID, here "$GPGGA".

Returns

The message ID

Implements rosaic_driver::BaseParser< rosaic::GpggaPtr >.

Definition at line 41 of file gpgga.cpp.

References MESSAGE_ID.

Referenced by GpggaParser().

{
    return rosaic_driver::GpggaParser::MESSAGE_ID;
}

Here is the caller graph for this function:

ParseASCII()

rosaic::GpggaPtr rosaic_driver::GpggaParser::ParseASCII ( const NMEASentence &  sentence )

overridevirtualnoexcept

Parses one GGA message.

Parameters

[in]

sentence

The GGA message to be parsed

Returns

A ROS message pointer of ROS type rosaic::GpggaPtr

Caution: Due to the occurrence of the throw keyword, this method ParseASCII should be called within a try / catch framework... Note: This method is called from within the read() method of the mosaicMessage class by including the checksum part in the argument "sentence" here, though the checksum is never parsed: It would be sentence.get_body()[15] if anybody ever needs it.

Reimplemented from rosaic_driver::BaseParser< rosaic::GpggaPtr >.

Definition at line 51 of file gpgga.cpp.

References rosaic_driver::ConvertDMSToDegrees(), frame_id, rosaic_driver::ParseDouble(), rosaic_driver::ParseFloat(), rosaic_driver::ParseUInt32(), string_utilities::ToDouble(), rosaic_driver::UTCDoubleToSeconds(), rosaic_driver::UTCtoUnix(), and was_last_gpgga_valid_.

Referenced by GpggaParser(), and io_comm_mosaic::mosaicMessage::Read().

{
    //ROS_DEBUG("Just testing that first entry is indeed what we expect it to: %s", sentence.get_body()[0].c_str());
    // Check the length first, which should be 16 elements.
    const size_t LEN = 16;
    if (sentence.get_body().size() > LEN || sentence.get_body().size() < LEN)
    {
        std::stringstream error;
        error << "GGA parsing failed: Expected GPGGA length is " << LEN << ", but actual length is " << sentence.get_body().size();
        throw ParseException(error.str());
    }

    rosaic::GpggaPtr msg = boost::make_shared<rosaic::Gpgga>();
    msg->header.frame_id = frame_id;

    msg->message_id = sentence.get_body()[0];

    if (sentence.get_body()[1].empty() || sentence.get_body()[1] == "0")
    {
        msg->utc_seconds = 0;
    }
    else
    {
        double utc_double;
        if (string_utilities::ToDouble(sentence.get_body()[1], utc_double))
        {
            //ROS_DEBUG("utc_double is %f", (float) utc_double);
            msg->utc_seconds = UTCDoubleToSeconds(utc_double);
            
            // The Header's Unix Epoch time stamp
            time_t unix_time_seconds = UTCtoUnix(utc_double);
            // The following assumes that there are two digits after the decimal point in utc_double, i.e. in the NMEA UTC time.
            uint32_t unix_time_nanoseconds = (static_cast<uint32_t>(utc_double*100)%100)*10000; 
            msg->header.stamp.sec = unix_time_seconds;
            msg->header.stamp.nsec = unix_time_nanoseconds;
        }
        else
        {
            throw rosaic_driver::ParseException("Error parsing UTC seconds in GPGGA"); // E.g. if one of the fields of the NMEA UTC string is empty
        }
    }

    bool valid = true;

    double latitude = 0.0;
    valid = valid && rosaic_driver::ParseDouble(sentence.get_body()[2], latitude);
    msg->lat = ConvertDMSToDegrees(latitude);

    double longitude = 0.0;
    valid = valid && rosaic_driver::ParseDouble(sentence.get_body()[4], longitude);
    msg->lon = ConvertDMSToDegrees(longitude);

    msg->lat_dir = sentence.get_body()[3];
    msg->lon_dir = sentence.get_body()[5];
    valid = valid && rosaic_driver::ParseUInt32(sentence.get_body()[6], msg->gps_qual);
    valid = valid && rosaic_driver::ParseUInt32(sentence.get_body()[7], msg->num_sats);
    //ROS_INFO("Valid is %s so far with number of satellites in use being %s", valid ? "true" : "false", sentence.get_body()[7].c_str());

    valid = valid && rosaic_driver::ParseFloat(sentence.get_body()[8], msg->hdop);
    valid = valid && rosaic_driver::ParseFloat(sentence.get_body()[9], msg->alt);
    msg->altitude_units = sentence.get_body()[10];
    valid = valid && rosaic_driver::ParseFloat(sentence.get_body()[11], msg->undulation);
    msg->undulation_units = sentence.get_body()[12];
    double diff_age_temp;
    valid = valid && rosaic_driver::ParseDouble(sentence.get_body()[13], diff_age_temp);
    msg->diff_age = static_cast<uint32_t>(round(diff_age_temp));
    msg->station_id = sentence.get_body()[14];

    if (!valid)
    {
        was_last_gpgga_valid_ = false;
        throw ParseException("GPGGA message was invalid.");
    }

    // If we made it this far, we successfully parsed the message and will consider it to be valid.
    was_last_gpgga_valid_ = true;

    return msg;
}

Here is the call graph for this function:

Here is the caller graph for this function:

WasLastGPGGAValid()

bool rosaic_driver::GpggaParser::WasLastGPGGAValid

(

)

const

Tells us whether the last GGA message was valid or not.

Returns

True if last GGA message was valid, false if not

Definition at line 131 of file gpgga.cpp.

References was_last_gpgga_valid_.

Referenced by GpggaParser().

{
    return was_last_gpgga_valid_;
}

Here is the caller graph for this function:

Field Documentation

MESSAGE_ID

const std::string rosaic_driver::GpggaParser::MESSAGE_ID = "$GPGGA"

static

Declares the string MESSAGE_ID.

Definition at line 117 of file gpgga.hpp.

Referenced by GetMessageID().

was_last_gpgga_valid_

bool rosaic_driver::GpggaParser::was_last_gpgga_valid_

private

Declares a boolean representing whether or not the last GPGGA message was valid.

Definition at line 123 of file gpgga.hpp.

Referenced by ParseASCII(), and WasLastGPGGAValid().

---

The documentation for this class was generated from the following files:

• include/rosaic/parsers/nmea_parsers/gpgga.hpp
• src/rosaic/parsers/nmea_parsers/gpgga.cpp