Today I found some time for playing around with my newly build APRS modem. During breakfast I read an interesting article in CQ DL 9-2012 from Markus DL8RDS. He described a homebrew IGate for APRS the he called AirGate. It is using an Arduino and the RadioShield from ArgentData. The RadioShield acts as a modem and decodes incoming AX.25 data frames whereas the Arduino forwards the received data frames to an APRS server over a network connection. The Arduino program was very simple.
But my harware setup is a little bit different. Instead of the RadioShield I have the a MicroAPRS based modem that sends the decoded APRS data over a serial port using the SimpleSerial protocol format. So I decided to write a small .NET program that would take the data from the serial port, transforms it to the TNC2 data format and send the transformed data over TCP/IP to an APRS server sitting in the internet.
For now my focus was to understand howto talk to an APRS server and check with a small prototype if I understood correctly. Just in time for my evening walk with our dog I ended up with something working. You can find the track of our walk on APRS. Since the data will not be stored for too long on aprs.fi, I have taken a screenshots. For my handy I had used the call sign HB9TWS-7:
The IGate program that took the APRS data and send it to the APRS server was running on my laptop and used the call HB9TWS-10. Here are some raw data:
Now that I have got a basic understanding of howto communicate with an APRS Server, I want to go a little bit further and write a small APRS client running Windows.