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'''For a more general overview of our GPS modules, please see our [wiki:gps Main GPS Page] for more information.'''

= Hardware Mappings =
Please see [wiki:gps this] page for which serial port the GPS is on


= OpenWrt GPS configuration and GPSD =
OpenWrt supports the popular opensource {{{gpsd}}} application: http://gpsd.berlios.de/

The configuration for gpsd is stored in {{{/etc/config/gpsd}}} and accessible via {{{uci}}}:
{{{#!bash
uci show gpsd
}}}

One must configure the following.
 1. The port is typically 2947 but can be changed if desired
 2. device is where the GPS chip is mapped on the board, please see the [wiki:OpenWrt/GPS#HardwareMappings Hardware Mappings] above
 3. To test {{{gpsd}}} from an external computer, you will need to set the {{{listen_globally}}} variable to {{{true}}}. Modify it using a editor like {{{vi}}} or {{{uci}}} commands.

Example output:
{{{#!bash
root@OpenWrt:/# uci show gpsd
gpsd.core=gpsd
gpsd.core.device=/dev/ttyUSB0
gpsd.core.port=2947
gpsd.core.listen_globally=false
gpsd.core.enabled=true
}}}

{{{gpsd}}} is a '''service''' and therefore can be started and stopped with the standard commands.
{{{#!bash
/etc/init.d/gpsd start
}}}

To verify the GPS data output, you can {{{cat}}} the serial port that the GPS is mapped on. For example, on the GW2388, the GPS is mapped to COM2 port (ttyS2): '''Please view product manual for correct port or [wiki:OpenWrt/GPS#HardwareMappings Hardware Mappings] above'''

'''Note''': ''Ventana may spit out binary OSP mode''

{{{#!bash
root@OpenWrt:/# stty -F /dev/ttyS2 4800 ;# set baudrate to 4800bps, also possibly 9600
root@OpenWrt:/# cat /dev/ttyS2

$GPGGA,000113.037,,,,,0,0,,,M,,M,,*4F
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,1,1,00*79
$GPRMC,000113.037,V,,,,,0.00,0.00,060180,19.9,W,N*0D
$GPGGA,000113.037,,,,,0,0,,,M,,M,,*4F
}}}

You can also install a {{{gpsd}}} client such as {{{xgps}}} and test it via an external PC.

Example shown below has a Gateworks board at 192.168.1.78 on the network.  A Linux Desktop PC is running at 192.168.1.22 and has {{{xgps}}} installed:
{{{#!bash
xgps 192.168.1.78
}}}
[[Image(xgps.png,300px)]]

For a '''Windows''' client, please search on Google and refer to the gpsd page where it lists:
{{{#!bash
Applications that presently use gpsd include pyGPS, gpsdrive, Kismet, GPSdrive, gpeGPS, position, roadmap, roadnav, navit, viking, tangogps, foxtrot, opencpn, obdgpslogger, geohist, LiveGPS, geoclue, qlandkartegt, gpredict, OpenCPN, gpsd-navigator, gpsd-ais-viewer, and firefox/mozilla.
}}}


= Hardware-specific init scripts =
Some hardware may require configuration each time you boot that you likely want place in an init-script.  For example:
 * specific AT commands to enable/configure NMEA mode
 * software controlled USB steering (for boards that route USB to front-panel by default but need to have USB routed to PCIe slot for a PCIe USB modem with GPS support)


== Option Globetrotter GTM671WFS ==
The Option Globetrotter modules combine multiple features into a single device.  The GPS module on supported devices has a serial port to control/configure the GPS and another serial port to obtain data from the GPS.  By default the data port does not display NMEA messages and must be enabled with the following AT commands:
{{{#!bash
AT_OGPSMODE=1
AT_OGPS=2
}}}

An OpenWrt init script can be created for performing this on bootup.  Here we add a UCI configuration {{{ctrl_device}}} to the gpsd configuration to describe the configuration serial port:
 * create and enable a gps init script
{{{#!bash
cat << EOF > /etc/init.d/option_gps_init
#!/bin/sh /etc/rc.common
# Copyright (C) 2009 OpenWrt.org
START=85

boot() {
    config_load gpsd
    config_get ctrl_device core ctrl_device
    [ "\$ctrl_device" ] || exit
    logger -t "gps" "Initializing GPS on \$ctrl_device"
    echo -e -n "AT_OGPSMODE=1\015" > \$ctrl_device
    echo -e -n "AT_OGPS=2\015" > \$ctrl_device
}
EOF
chmod +x /etc/init.d/option_gps_init
/etc/init.d/option_gps_init enable
}}}
 * specify UCI config used by the init script above:
{{{#!bash
uci set gpsd.core.device=/dev/ttyHS1
uci set gpsd.core.ctrl_device=/dev/ttyHS2
uci set gpsd.core.enabled=true
uci commit
}}}
 * and make sure gpsd is enabled on boot:
{{{#!bash
/etc/init.d/gpsd enable
}}}