91 lines
2.9 KiB
Io
91 lines
2.9 KiB
Io
|
This document describes how to invoke FlightGear's generic IO subsystem.
|
||
|
|
|
||
|
|
FlightGear has a fairly flexible generic IO subsystem that allows you
|
||
|
|
to speak any supported protocol over any supported medium. The IO
|
||
|
|
options are configured at runtime via command line options. You can
|
||
|
|
specify multiple entries, one per option.
|
||
|
|
|
||
|
|
The general form of the command line option is as follows:
|
||
|
|
|
||
|
|
--protocol=medium,direction,hz,medium_options,...
|
||
|
|
|
||
|
|
protocol = { native, nmea, garmin, fgfs, rul, pve, ray, etc. }
|
||
|
|
medium = { serial, socket, file, etc. }
|
||
|
|
direction = { in, out, bi }
|
||
|
|
hz = number of times to process channel per second (floating
|
||
|
|
point values are ok.
|
||
|
|
|
||
|
|
Serial Port Communication:
|
||
|
|
|
||
|
|
--nmea=serial,dir,hz,device,baud
|
||
|
|
|
||
|
|
device = OS device name of serial line to be open()'ed
|
||
|
|
baud = {300, 1200, 2400, ..., 230400}
|
||
|
|
|
||
|
|
example to pretend we are a real gps and output to a moving map application:
|
||
|
|
|
||
|
|
--nmea=serial,out,0.5,COM1,4800
|
||
|
|
|
||
|
|
Note that for unix varient you might use a device name like "/dev/ttyS0"
|
||
|
|
|
||
|
|
Socket Communication:
|
||
|
|
|
||
|
|
--native=socket,dir,hz,machine,port,style
|
||
|
|
|
||
|
|
machine = machine name or ip address if client (leave empty if server)
|
||
|
|
port = port, leave empty to let system choose
|
||
|
|
style = tcp or udp
|
||
|
|
|
||
|
|
example to slave one copy of fgfs to another
|
||
|
|
|
||
|
|
fgfs1: --native=socket,out,30,fgfs2,5500,udp
|
||
|
|
fgfs2: --native=socket,in,30,,5500,udp --fdm=external
|
||
|
|
|
||
|
|
This instructs the first copy of fgfs to send UDP packets in the
|
||
|
|
native format to a machine called fgfs2 on port 5500.
|
||
|
|
|
||
|
|
The second copy of fgfs will accept UDP packets (from anywhere) on
|
||
|
|
port 5500. Note the additional --fdm=external option. This tells
|
||
|
|
the second copy of fgfs to not run the normal flight model, but
|
||
|
|
instead set the FDM values based on an external source (the
|
||
|
|
network in this case.)
|
||
|
|
|
||
|
|
|
||
|
|
File I/O:
|
||
|
|
|
||
|
|
--garmin=file,dir,hz,filename
|
||
|
|
|
||
|
|
filename = file system file name
|
||
|
|
|
||
|
|
example to record a flight path at 10 hz:
|
||
|
|
|
||
|
|
--native=file,out,10,flight1.fgfs
|
||
|
|
|
||
|
|
example to replay your flight
|
||
|
|
|
||
|
|
--native=file,in,10,flight1.fgfs
|
||
|
|
|
||
|
|
|
||
|
|
Moving Map Example:
|
||
|
|
|
||
|
|
Per Liedman has developed a moving map program called Atlas
|
||
|
|
(atlas.sourceforge.net) The initial inspiration and much code came
|
||
|
|
from Alexei Novikov.
|
||
|
|
|
||
|
|
The moving map supports NMEA format input either via network or
|
||
|
|
via serial port. Either way will work, but this example
|
||
|
|
demonstrates the use of a socket connection.
|
||
|
|
|
||
|
|
Start up fgfs with:
|
||
|
|
|
||
|
|
fgfs --nmea=socket,out,0.5,atas-host-name,5500,udp
|
||
|
|
|
||
|
|
Start up the Atlas program with:
|
||
|
|
|
||
|
|
Atlas --udp=5500 --fgroot=path-to-fg-root --glutfonts
|
||
|
|
|
||
|
|
Once both programs are running, the Atlas program should display
|
||
|
|
your current location. Atlas is a really nifty program with many
|
||
|
|
neat optoins such as the ability to generate and use background
|
||
|
|
bitmaps that show the terrain, cities, lakes, oceans, rivers, etc.
|