Raspberry PI 4 complete CW KEYER(iambics, st key & keyboard) using free software from LSP & Recri

[Chuck aa0hw]

https://lsp-plug.in/?page=manuals&section=trigger_midi_mono

https://github.com/recri/keyer

CW KEYER SETUP overview: 4 different 555 timer chip oscillators that have been set to different individual frequencies - are "keyed" directly - by iambic paddles( dit side & dah side) and also by a straight key and also by a CW KEYBOARD using its RIG KEYING Output jack that connects to the 555 TIMER chip's typical CPO circuit keying pin the four 555 timer oscillator frequencies used for this demo were: 2Khz(dit), 7Khz(dah), 11Khz(st key), and 19Khz(cw keyboard)

The Recri CW Keyer APP takes the CW KEYING DATA(midi) at its input and converts it to CW AUDIO OUTPUT(what you hear on this video demo)

Each TMM has a different purpose, 1 for dits, 1 for dahs, 1 for straight key and the last one for CW KEYBOARD

TMM has its own set of AUDIO BANDPASS FILTERs that only allow the desired frequency at TMM's input, to trigger its MIDI CW NOTE OUTPUT