nmea(3tcl) 0.1 nmea "NMEA protocol implementation"

NAME

nmea - Process NMEA data

    TABLE OF CONTENTS
    SYNOPSIS
    DESCRIPTION
    COMMANDS
    VARIABLES
    BUGS, IDEAS, FEEDBACK
    KEYWORDS
    COPYRIGHT

SYNOPSIS

package require Tcl 8.2
package require nmea ?0.1.1?

::nmea::open_port port ?speed?

::nmea::open_file file rate

::nmea::configure_port settings

::nmea::close_port

::nmea::close_file

::nmea::do_line

::nmea::log file

::nmea::checksum data

::nmea::write sentence data

This package provides commands to read NMEA standard data from COM ports or files. The sentences are optionally checksummed and then passed on to user defined procs for handling. To use a handler, create a proc with the NMEA sentence name in the ::nmea namespace. For example to process GPS fix data use "proc ::nmea::GPGSA". The proc must take one argument, which is a list of the data values.

COMMANDS

::nmea::open_port port ?speed?: Open the specified COM port and read NMEA sentences when available. Port speed is set to 4800bps by default or to speed.
::nmea::open_file file rate: Open file file and read NMEA sentences, one per line, at the rate by rate in milliseconds. The file format may omit the leading $ and/or the checksum. If rate is <= 0 then lines will only be processed when a call to do_line is made. The rate may be adjusted by setting ::nmea::nmea(rate).
::nmea::configure_port settings: Changes the current port settings. settings has the same format as fconfigure -mode.
::nmea::close_port: Close the open port
::nmea::close_file: Close the open file
::nmea::do_line: If there is a currently open file, this command will read and process a single line from it.
::nmea::log file: Starts or stops file logging. If a file name is specified then all NMEA output will be logged to the file in append mode. If file is an empty string then any logging will be stopped.
::nmea::checksum data: Returns the checksum of the supplied data
::nmea::write sentence data: If there is a currently open port, this command will write the specified sentence and data in proper NMEA checksummed format.

VARIABLES

::nmea::checksum: A boolean value which determines whether incoming sentences are validated or not.
::nmea::rate: When reading from a file this sets the rate that lines are processed in milliseconds.

BUGS, IDEAS, FEEDBACK

This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category nmea of the Tcllib SF Trackers. Please also report any ideas for enhancements you may have for either package and/or documentation.

KEYWORDS

gps, nmea