APRS on Linux – Direwolf and Xastir

I recently built a usb soundcard with push-to-talk functionality, which is perfect for interfacing the Baofeng UV-5R to the PC and sending APRS over it. It is quite simple to set-up and works well.

First clone my fork of direwolf with support of the CM108 soundcard:

git clone https://github.com/donothingloop/direwolf_cm108.git
cd direwolf_cm108
make

Open the direwolf.conf file and set the following options:

MYCALL <YOUR CALLSIGN>
AGWPORT 8000
KISSPORT 8001
PTT CM108

Then install xastir.
For Ubuntu, Raspbian, Debian enter:

apt-get update
apt-get install xastir

After the installation has completed, start xastir. You should get a window looking like this:

xastir
xastir (no, i’m not in Africa)

Click on Interface and then on Interface Control.
In the following dialog click Add.
Select Networked AGWPE and click on Add.

xastir1

Check if the port is 8000 and change your Digipeater paths according to your country’s requirements. Then click on OK.

You can now try to transmit. Set your radio to your local APRS frequency, click on Interface and then on Transmit Now!.
The red led of your soundcard should turn on and your radio should start transmitting.

New design of my PTT Soundcard

I already mentioned in another post that I hacked together a CM108 based sound card with a PTT output. Unfortunately there are no pictures of the build-process which involved a lot of hot-glue. But as it worked really well and some friends already wanted to have one I decided to build a more professional version of it. It is based on the reference design of the CM108. The USB connector is a micro-USB one, which has the advantage that everyone has already got the required cables for their smartphones.

Top view of the soundcard
schematic
board

Continue reading New design of my PTT Soundcard