KXstudio's CARLA as a standalone APP to conduct QRQ CW over SONOBUS operations - using ALSA on a Pi4

[Chuck aa0hw]

- a Pi4 has a usb sound card with LINE INPUT/line output/headphone output

- fldigi is keying a 555 square wave oscillator(by connecting pin 4 of the 555 to its POS RAIL through an H11F1 OPTOisolator chip) using FLdigi's KEY BY SERIAL PORT RTS PIN feature and sends its audio output to the pi's usb sound card's line input

- CARLA is using the ALSA SOUND CARD(not JACK)

- CARLA allows a JACK APP to operate even when JACK is not really running (this allows bringing in 2 jack apps a sine wave MIDI KEY'd CPO, and a CW audio bandpass filter, both which are highly adjustable to create a desired QRQ CW NOTE)

- the keyed '555' is converted to a CW MIDI NOTE OUTPUT that is used to 'KEY' the midi input of THE SINE WAVE CPO/bp filter combo by a plugin called TRIGGER MIDI MONO

- Sonobus as a plugin is brought into the CARLA CONNECTION BAY https://sonobus.net/ jack apps

- for the software adjustable CPO and BP FILTER https://github.com/recri/keyer

NOTE: CARLA has an experimental feature, "ADD JACK APPLICATION" and you just punch in the usual command line scripts to bring up the RECRI KEYER CW modules

TRIGGER MIDI MONO audio to midi plugin https://lsp-plug.in/?page=manuals&section=trigger_midi_mono