EasyNmea¶

class eduponz::easynmea::EasyNmea¶

This class provides an interface with NMEA modules using NMEA 0183 protocol over serial connections.

It can be used to:

Open and close serial connection with the modules.
Wait for specific NMEA sentences to be received.
Read incoming NMEA data in a parsed and understandable manner.

Public Functions

EasyNmea() noexcept¶: Default constructor. Constructs a EasyNmea.

~EasyNmea() noexcept¶: Virtual default destructor.

ReturnCode open(const char *serial_port, long baudrate) noexcept¶

Open a serial connection.

It opens a serial connection on a given port with a given baudrate; given that the connection was not previously opened.

Pre

The EasyNmea does not have any serial port opened. That is, either it is the first call to open(), or close() has been called before open().

Return

open() can return:

ReturnCode::RETURN_CODE_OK if the port is opened correctly.
ReturnCode::RETURN_CODE_ERROR is the port could not be opened.
ReturnCode::RETURN_CODE_ILLEGAL_OPERATION if a previous call to open was performed in the same EasyNmea instance, regardless of the port.

Parameters

[in] serial_port: A string containing the serial port name.
[in] baudrate: The communication baudrate.

bool is_open() noexcept¶

Check whether a serial connection is opened

Return: true if there is an opened serial connection; false otherwise.

ReturnCode close() noexcept¶

Close a serial connection

Pre

A successful call to open() has been performed.

Return

close() can return:

ReturnCode::RETURN_CODE_OK if the connection was successfully closed.
ReturnCode::RETURN_CODE_ERROR if the connection could not be closed.
ReturnCode::RETURN_CODE_ILLEGAL_OPERATION if there was not open connection.

ReturnCode take_next(GPGGAData &gpgga) noexcept¶

Take the next untaken GPGGA data sample available.

EasyNmea stores up to the last 10 reported GPGGA data samples. take_next() is used to retrieve the oldest untaken GPGGA sample.

Return

take_next() can return:

ReturnCode::RETURN_CODE_OK if the operation succeeded.
ReturnCode::RETURN_CODE_NO_DATA if there are not any untaken GPGGAData samples.

Parameters

[out] gpgga: A GPGGAData instance which will be populated with the sample.

ReturnCode wait_for_data(NMEA0183DataKindMask data_mask = NMEA0183DataKindMask::all(), std::chrono::milliseconds timeout = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::hours(8760))) noexcept¶

Block the calling thread until there is data available.

Block the calling thread until data of the specified kind or kinds is available for the taking, or the timeout expires.

Return

wait_for_data() can return:

ReturnCode::RETURN_CODE_OK if a sample of any of the kinds specified in the mask has been received.
ReturnCode::RETURN_CODE_TIMEOUT if the timeout was reached without receiving any data sample of the kinds specified in the data_mask.
ReturnCode::RETURN_CODE_ILLEGAL_OPERATION if there was not open connection.
ReturnCode::RETURN_CODE_ERROR if some other thread called close() on the EasyNmea instance, which unblocks any wait_for_data() calls.

Parameters

[in] data_mask: A NMEA0183DataKindMask used to specify on which data kinds should the call return, thus unblocking the calling thread. When wait_for_data returns data_mask holds the types of data that have been received. Defaults to NMEA0183DataKindMask::all().
[in] timeout: The time in millisecond after which the function must return even when no data was received. Defaults to 8760 hours (1 year).