So I must use reversed connection to keyboard with a two keys pressing trick. When I look at serial monitor (firmware enable switching between serial and USB-midi) I get this:
Which seems right.
But when I switch to USB-midi output I get this in MIDI-OX software:
When I debug over serial midi driver I get this:
As if serial driver and USB-midi driver are expecting long midi command and getting short 3 byte one?
Any thoughts?