Configuring APRS on Linux

Running APRS on Linux can be done in a few ways.

The short version can be found here: Rpi-aprs-what-do-i-need

If we assume a setup that can:

• receive packets that come in from over the the air

• receive packets that come in from over a network adapter (e.g. connected to the Internet)

• transmit packets over the air (i.e. to 'rf', radio frequency)

• transmit packets to a network adapter (e.g. to the Internet)

..then the following components are identified

A device to receive the packets

• a ham radio (e.g. base station or handheld transceiver)

• SDR (software defined radio)

• a Network Adapter (e.g. from the APRS-IS network on the Internet)

A device to convert analogue (audible) signals to some form of digital signals

(not required for packets originating from a network adapter)

• TNC (Terminal Node Controller)

• some fancier ham radios have a built in converter that just spits out RS-232

• a computer sound card (either in a laptop, or a dedicated PCI or USB device)

• SDR (software defined radio)

Protocol Software that converts the digital signals to APRS packets

• TNC (e.g. reads from an AX.25 interface or directly from a serial or USB port)

• soundmodem (converts soundcard signals to the AX.25 protocol)

Application Software that processes the packets based on their information

Most of these programs can be configured to listen to serial devices or network adapters, including the AX.25 interfaces.

• TNC (Terminal Node Controller)

• APRS client (aprx, xastir, direwolf, UI-View, etc..)

One of my first experiences with APRS was to configure a receive and transmit station (a digipeater) using:

• a basic USB sound card

• a 2-metre handheld transceiver (Icom IC-P2AT, maximum 5 Watts output power)

• a Raspberry Pi 'single-board-computer'

I have created a dedicated page for this project: aprs-on-rpi

Below is a collection of configuration files that have been known to work:

rpi-aprs-asound.conf

rpi-aprs-cmdline.txt

rpi-aprs-axports

rpi-aprs-soundmodem.conf

rpi-aprs-aprx.conf

rpi-aprs-CM106-sound-settings