Ham Radio project - Arduino and MFJ TNC

Just wondering about the software serial library and using that to communicate with my old MFJ TNC.
Does it simulate the RS-232 serial interface?

I would like to have the Arduino send APRS packets.

Perhaps digipeating thru the ISS, mobile?
Or part of a weather station project, sending WX data.

The serial output on an Arduino doesn't match the RS-232 voltage levels. To do the conversion, you can get a MAX232 module through eBay for a few dollars.

JD3:
Thanks - I guess I need a 12 volt module?

Not just a 12V module but one that converts the TTL to +/- 12V, with +5V converting to -12V and 0V converting to +12V.

Thanks again - I looked up the specs on Digikey.

Exactly what I need :slight_smile: