ArgentData Radio Shield

Recently I purchased a ArgentData RadioShield. This is an addon board for Arduino microcontrollers. It has the wonderful capability of receiving and transliterating audio APRS messages, but it can also generate APRS messages into audio. For this reason it is perfectly suited to operate as a RX IGate with minimum power consumption.

1 Movie

I created a Youtube movie that demonstrates the shield's capabilities:

• http://www.youtube.com/watch?v=SuR8mAFtHw8

2 Project Decription

This project tries to build a RX only gateway for DB0MHB. I am about to redesign the relay main control mincrocontroller and so I decided to use the RadioShield as a new part of it since it has all the necessary components onboard, except a HF receiver.

3 Progress

• 2011-07-30
  • I found out that the controller program can just take the packet lines as they come from the RadioShield buffer and send them off to the aprs servers tight after the tcp connection has been established.
  • The dest port is TCP/14580
  • Since the MTU in packet is 256 bytes, the TCP connection can be closed right afterwards. The Ethernet MTU is almost always 1500 bytes, so there is practically no risk at all.
  • The dest hostname is igates.aprs.fi but a dns lookup should be made from time to time because the IP may change. There is also a rotation to distribute traffic to different machines.
• 2011-07-31 Rebuilt the controller into a neat 19" format. The wiring is still not complete, but it already looks nice and clean.

4 Links

• http://wiki.argentdata.com/index.php/Radio_Shield
• http://www.dallasmakerspace.org/wiki/APRS
• http://wiki.ham.fi/APRS_iGate_properties data format description
• http://wiki.ham.fi/Aprs.fi_Network_tools additional data description
• http://ham.zmailer.org/oh2mqk/aprx/PROTOCOLS Protocols
• http://gkaindl.com/software/arduino-ethernet/dns Arduino library to support DNS