ArKeyer
A beacon keyer built on a DigiSpark arduino module
This is a simple, very low cost, CW beacon keyer for amateur radio beacon transmitters. The code is written for a DigiSpark (ATtiny) from http://digistump.com/ which can be powered from a 5V supply or from a 7V to 35V source. The DigiSpark provides both a positive and a negative keying output for the transmitter.