this video is a follow up to the first video here: https://youtu.be/RQh_4JW6adw
this video adds a CW KEYBOARD, and straight key to the Raspberry PI 4 iambic CW keyer shown in the first video... by using a 2nd keyed CPO at a different PITCH than the 1st keyed CPO in the first video
TRIGGER MIDI MONO is the CW audio to CW midi app CW to MIDI app keys a software CPO called RECRI KEYER 'KEY' that has adjustable settings for any iambic CW keying parameter desired.. it also allows a straight key & CW keyboard using midi note ZERO at RECRI KEYER's 'KEY's 2nd midi input port...
iambic setup uses midi note zero for dits and midi note ONE for dahs... dit tone from the 555 goes into the line input LEFT CHANNEL dah tone from the same 555 goes into the line input RIGHT CHANNEL the output of the 555(1500 hertz) goes to the PADDLE'S GROUND, the the dit paddle sends the 555 tone to the LEFT channel when closing, and dah paddle sends the 555 tone to the RIGHT channel when closing and inside the Pi, each Trigger Midi MONO(TMM) responds in kind, and produces an exact midi note keying message to key RECRI KEYER's 'KEY' dit or dah or dah/di/dah/di/dah etc....
TRIGGER MIDI MONO for imabics, is setup on its BANDPASS FILTER to only allow the 1st pitch from the 555 to get through to its internals... that pitch was around 1500 hertz.... the 2nd cpo is about 700 hertz and does not get through the iambic trigger midi mono's bandpass filter to volume past the threshold setting... so that only the iambic 1500 hertz from the 555 triggers the dits & dahs
the 3rd trigger midi mono is setup to recive a CPO TONE of 700 hertz, and then send out midi note ZERO accordingly ... its CW MIDI NOTE output connects to the 2nd CW midi NOTE input stage of RECRI KEYER's 'KEY' midi input... the 1st midi input of 'KEY' performs the iambic conversion....to capture incoming midi notes ZERO and ONE and convert them to DITs and Dahs and basically keys the 2nd midi input of 'KEY' like a straight key... so a straight key can do the same with its 2nd CPO set to about 700 hertz( it is a twin-t cpo...any pitch can be used as long as it is far enough away from the 1st CPO pitch of the iambic setup)
https://lsp-plug.in/?page=manuals§ion=trigger_midi_mono one of the differences between this video's setup of TMM is that this video shows the use of the 'JACK' audio engine command; direct loading by terminal commands, of all 3 TMM apps instead of using CARLA and LV2 plugins in the 1st video demo
here is a copy past from terminal of one of them....
qrq@pi4b:~ $ lsp-plugins-trigger-midi-mono Trying to connect to JACK Successfully connected to JACK