I found that the range was from 800-3300 Hz which I find to large. The program worked fine but the Tone tune was very small. I tested it with an Arduino program called ‘cw_foxhunt’ which you can find here.
I liked the project and built it in a home made enclosure made from PCB. In the VERON magazine of November 2015 there was a description of a CW Morse decoder built around an Arduino Nano.
