This is a hardware and software project to control multiple radios in a SO2R environment using the Open Two Radio Switching Protocol (OTRSP).

The software runs on the popular Arduino. It also includes a shield to make connecting everything to the Arduino much cleaner. I have designed the shield to be compatible with the Arduino Mega.

Allows an operator to listen and transmit on two (or four) radios, transmitting on one and listening on another, or listening on two radios at the same time. It has switching for headphones and microphone. I plan to add keyer support too.

Idea inspired by Paul Young, K1XM who created the OTRSP protocol.

• Blog posts can be found at http://www.m1dst.co.uk/category/projects/so2r/
• Article by Paul Young - http://www.ncjweb.com/julaug10feat.pdf
• What is OTRSP - http://www.k1xm.org/OTRSP/index.html