This is an iambic keyer based upon the Arduino UNO platform. It provides a means to generate audio sidetone for the purpose of implementing modulated FM that can be used on 2M repeaters.
The initial ideas came from an article "Iambic Keyer" in "Arduino For Ham Radio - A Radio Amateur's Guide to Open Source Electronics and Microcontroller Projects," Chapter 17, by Glen Popiel, KW5GP.
Refer to PROJECT - Iambic Electronic Keyer Utilizing The Arduino Duo.odt for project specifications and links to materials list.
REVISION HISTORY 03/30/2017 JRH Initial creation of this history. Severl earlier updates have been made. The code appears to be stable and functional in most regards. More work is needed in documentation and in testing. There are several additional features that could be added.