This project enables ham radio operators to use their android phones as memory keyers to send CW or Hellschreiber signals using any radio transmitter capable of putting out a carrier wave. The application presents a list of editable phrases, then plays the selected phrase as morse code (or Hellschriber) through the sound output. The audible tones produced may be used directly if a modulated signal is desired, but the sound can also be routed through an easy-to-build interface which converts this sound into on/off keying for the transmitter. You can build your own circuit to do this:

This keyer's morse code repertoire includes extended (non-English) latin alphabet characters, as well as Russian morse code and Japanese wabun code variants. Phrases may include common prosigns and special characters that expand into text substitutions. The keyer also has a beacon mode that can be used to trigger messages at intervals.