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APRS

app_rpt can post position reports to the APRS™ network. APRS is an acronym for Automatic Packet Reporting System. APRS is the registered trademark of Bob Bruninga, WB4APR (SK). app_gps supports standard position reports and APRStt (touchtone).

For fixed position nodes, like repeaters, reporting your node's position allows visiting operators to easily see the nodes/repeaters in the area. Some radios allow operators to use the position reports to automatically tune their radios to the node's frequency.

You can see a map of APRS unit locations at https://aprs.to or https://aprs.fi.

An external GPS device can be configured to receive GPS position information. This is needed for mobile nodes to post their live position. Fixed stations do not require a GPS device. app_gps can be configured with a default latitude, longitude, and elevation.

app_gps posts position report to the global APRS-IS servers. An Internet connection is required.

Configuration

Enable app_gps

To enable app_gps, edit /etc/asterisk/modules.conf and change noload => app_gps.so to load => app_gps.so

Edit gps.conf

The gps.conf file now uses Asterisk templates. See Templates for more information.

Edit /etc/asterisk/gps.conf with your favorite editor. The configuration file is filled with comments to assist you with the configuration.

If you will be using a GPS device, set the comport and baudrate for your connected device. If you don't have a GPS device, comport should not have a value.

Update call with the node's callsign and SSID. For example: WB6NIL-1. Additional information on the callsign/SSID format can be found at https://www.aprs-is.net/Connecting.aspx.

Update password with your APRS-IS password. This password is a computed number based on the callsign. You can generate the password on-line at https://n5dux.com/ham/aprs-passcode.

Note: This password must be correct for app_gps to log into the APRS-IS server.

The gps.conf contains a number of settings that configure how your node is displayed on APRS maps. The comments in the configuration file will help you configure your node.

The comment field can be used to describe your node and/or provide information about your local radio club. See the configuration file for more information.

You can configure the map symbol used for your node by changing the icontable and icon values. To display an "R" inside a diamond, set icontable = R and icon = &. See http://www.aprs.org/symbols.html for more information.

Note: app_gps supports multiple nodes. To add additional nodes, add another section to the configuration file. For example [1998](general).

Restart Asterisk

After making these initial changes to modules.conf and gps.conf, restart Asterisk at the command line type:

systemctl restart asterisk

Changes made to gps.conf in the future do not require restarting Asterisk. After making changes to the configuration file, you can enter these commands in the Asterisk CLI. 

module unload app_gps  
module load app_gps

Monitoring the GPS device

You can get the status of the connected GPS device by typing the following command in the Asterisk CLI.

gps show status

This command will tell you if the GPS device is locked on the satellite signal and the current position. If you are not using a GPS device, it will show the default latitude, longitude, and elevation.

APRStt (touchtone)

APRStt allows operators with analog radios to report to the APRS system. Specially crafted DTMF sequences can be sent to app_rpt to generate APRS position reports.

To enable this feature, edit /etc/asterisk/rpt.conf and add or enable aprstt = general for your node. The value after 'aprstt' is the section in gps.conf to use for APRStt. This value can be different for each node. It does require a matching section in gps.conf.

Callsigns received by APRStt are reported as objects to APRS using the '-12' SSID.

To send WB4APR using APRStt, you would send the DTMF sequence, A9A2B42A7A7C91#. app_rpt will translate the DTMF sequence and send it to app_gps for processing.

For more information on the APRStt DTMF format and how to construct DTMF sequences, see http://www.aprs.org/aprstt/aprstt-user.txt.

Note: Some radios natively support APRStt.

Note: At the time of this writing, app_rpt only supports the APRStt A format.