In the early days of Amateur Packet Radio, it was necessary to use an expensive “Terminal Node Controller” (TNC) with specialized hardware. Those days are gone. You can now get better results at lower cost by connecting your radio to the “soundcard” interface of a computer and using software to decode the signals.
Dire Wolf now includes FX.25 which adds Forward Error Correction (FEC) in a way that is completely compatible with existing systems. If both ends are capable of FX.25, your information will continue to get through under conditions where regular AX.25 is completely useless.
Dire Wolf is a modern software replacement for the old 1980’s style TNC built with special hardware.
Without any additional software, it can perform as:
- APRS GPS Tracker
- Internet Gateway (IGate)
- APRStt gateway
There are two APRS Digipeaters in the Newcastle area, but none so north as Ashington, so I considered building my own device, having a spare Raspberry Pi 3B and plenty of ex-commercial radios about the house. I noticed that from my recent experiments that no additional interface would be required as the new CM-108 sound card could be modified to include a PTT operation.
The source of the software for Direwolf is https://github.com/wb2osz/direwolf, where it can be downloaded onto a Raspberry Pi running Raspberry OS lite (Bullseye). On starting the software and updating it, ‘sudo apt install git’ will be essential prior to downloading the Direwolf package. Full instructions are included and are very easy.
The modifications for the sound card can be found here – but you will need a small soldering iron and a steady hand.
As for most software of this type they are for ‘headless’ operation, having no graphical interface, so I set out to provide this, using apache2 and PHP. You may take advantage of what I have made so far, by checking out this. It will require particular attention to the compilation of Direwolf, so that its configuration file will be /etc/direwolf/direwolf.conf, and the logfile can be found at /var/log/direwolf.log.
This is an early build, as I shall be expanding the dashboard to include modification of parameters when I find the time.
Thanks go to WB2OSZ for the Direwolf package, YD0NXX for the CM-108 soundcard modification, and KC1AWV for the rudiments of the PHP code to construct the Dashboard.