nmea.3tcl

Langue: en

Autres versions - même langue

Version: 0.1 (debian - 07/07/09)

Section: 3 (Bibliothèques de fonctions)

Sommaire

NAME

nmea - Process NMEA data

SYNOPSIS

package require Tcl 8.2

package require nmea ?0.1.1?

::nmea::open_port port ?speed?

::nmea::open_file file rate

::nmea::input sentence

::nmea::configure_port settings

::nmea::close_port

::nmea::close_file

::nmea::do_line

::nmea::log file

::nmea::checksum data

::nmea::write sentence data

DESCRIPTION

This package provides a standard interface for writing software which recieves NMEA standard input data. It allows for reading data from COM ports, files, or programmatic input. It also supports the checksumming and logging of incoming data. After parsing, input is dispatched to user defined handler commands for processing. To define 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::input sentence
Processes and dispatches the supplied sentence. If sentence contains no commas it is treated as a Tcl list, otherwise it must be standard comma delimited NMEA data, with an optional checksum and leading $.
::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. Returns the number of lines read.
::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 [http://sourceforge.net/tracker/?group_id=12883]. Please also report any ideas for enhancements you may have for either package and/or documentation.

KEYWORDS

gps, nmea 
 Copyright (c) 2006-2007, Aaron Faupell <afaupell@users.sourceforge.net>