GPSCSV

NAME

gpscsv - dump the JSON output from gpsd as CSV

SYNOPSIS

gpscsv [-?] [--class MCLASS] [--count COUNT] [--cvt-isotime] [--debug LVL] [--device DEVICE] [--fields FIELDS] [--file FILE] [--header HEADER] [--help] [--host HOST] [--port PORT] [--seconds FIELDS] [--separator SEPARATOR] [--version] [-c MCLASS] [-D  LVL] [-f  FIELDS] [-h] [-n COUNT] [-V] [-x FIELDS] [host[:port[:device]]]

DESCRIPTION

gpscsv is a simple Python program for reading a gpsd JSON data streams and outputting them in Comma Separated Values (CSV) format. It takes input from a specified gpsd and reports to standard output. The program runs until the gpsd dies, "-n COUNT" messages are processed, "-x SECONDS" have passed, or it is interrupted by ˆC or other means.

One good use of gpscsv is to create CSV files for use with the gnuplot program.

OPTIONS

The program accepts the following options:

-?, -h, --help

Show help information and exit.

-c MCLASS, --class MCLASS

Select the JSON class messages of type MCLASS. Default is TPV. .

--cvt-isotime

Convert fields named "time" from ISO time to UNIX time.

-D LVL, --debug LVL

Set debug level to LVL. Default 0. Higher arguments than 0 produce more debug output.

--device DEVICE

The DEVICE on the gpsd to connect to. Defaults to all.

-f FIELDS, -fields FIELDS

The FIELDS from the JSON message to dump to the output. Set FIELD to empty ('') for all fields Default varies by CLASS.

--file FILE

Read JSON from FILE instead of from gpsd..

--header HEADER

Set header style to HEADER. 0 for no header, 1 output fields as header, 2 send fields as a comment ('#'). Defaults to 1.

--host HOST

Connect to the gpsd on HOST. Defaults to localhost.

-n COUNT, --count COUNT

Exit after outputting COUNT records. Set COUNT to 0 to disable. Default is 0

--port PORT

Use PORT to connect to gpsd. Defaults to 2947.

--separator SEPARATOR

Use SEPARATOR as the field separator. Default separator is a comma (',').

-V, --version

Show gpscsv version, and exit.

-x SECONDS, --seconds SECONDS

Exit after SECONDS number of seconds have passed. Set SECONDS to 0 to disable. Default is 0

EXAMPLES

Some basic examples, do them in exact order shown:

Grab 100 samples of time,lat,lon,altHAE:

$ gpscsv -n 100 --cvt-isotime > tpv.dat

Grab 100 samples of time,epx,epy,epv,eph,sep

$ gpscsv -n 100 --cvt-isotime -f time,epx,epy,epv,eph,sep > ep.dat

Grab 100 samples of time,xdop,ydop,vdop,tdop,hdop,gdop,pdop

$ gpscsv -n 100 --cvt-isotime -c SKY > sky.dat

Grab 100 samples of time,nSat,uSat

$ gpscsv -n 100 --cvt-isotime -c SKY -f time,nSat,uSat > sat.dat

start gnuplot in interactive mode:

$ gnuplot

Some gnuplot housekeeping:

# this are csv files
gnuplot> set datafile separator ','
# use the first line as title
gnuplot> set key autotitle columnhead
# X axis is UNIT time in seconds.
gnuplot> set xdata time
gnuplot> set timefmt "%s"

Now to plot time vs latitude:

gnuplot> plot 'tpv.dat' using 1:2

Then to plot longitude and altHAE, in separate plots:

gnuplot> plot 'tpv.dat' using 1:3
gnuplot> plot 'tpv.dat' using 1:4

Put both latitude and longitude on one plot:

gnuplot> set y2tics
gnuplot> plot 'tpv.dat' using 1:2, '' using 1:3 axes x1y2

Plot epx, epy, epv, eph, and sep in one plot:

gnuplot> plot 'ep.dat' using 1:2, '' using 1:3, \
'' using 1:4, '' using 1:5, '' using 1:6

Plot all the DOPs on one plot:

gnuplot> plot 'sky.dat' using 1:2, '' using 1:3, '' using 1:4, \
'' using 1:5, '' using 1:6, '' using 1:7, '' using 1:8

Plot nSat and uSat together:

gnuplot> plot 'sat.dat' using 1:2, '' using 1:3

Lat/lon scatter plot:

# x is no longer time
gnuplot> set xdata
gnuplot> plot 'tpv.dat' using 3:2 title 'fix'

SEE ALSO

gpsd(8),

AUTHOR

Gary E. Miller <gem@rellim.com>.