Communicating with a modem - where to start?

Good morning,

Feels like I'm just missing some key information to something many people think of as easy. So this is more a request to point me in the right direction rather than asking a specific technical question.

I have a Kenwood radio with a built in modem (terminal node controller or TNC) which accepts an 8N1 serial input. I want to have my Arduino (I have both an Uno and a Mega) connect serially and transmit data. I know where the serial pins are on the Arduino, I have some libraries (APRS.h and ax25.h, along with the .cpp files) and feel comfortable massaging square pegs into round holes. But while I have 25+ years of tinkering with stuff like this, I have a hard time coding from scratch.

Any homework assignment you'd care to point me toward would be appreciated. I am a teacher and it would be nice to tinker with this stuff in the classroom in a couple months.

-- Markus

Welcome to the Arduino forum. The best beginning will be to go to this tutorial and follow it: Come back to the forum when you have questions.


You might find useful information at the MicroModem site.

You could probably even use Micromodem as is with your radio, bypassing the built in modem.