If anyone wants to join in finalizing the code for our community - I have opened a new discussion : Hagiwo 6ch drum sequencer + 4x4 matrix keypad.
Hagiwo code: https://note.com/solder_state/n/n17c69afd484d
MY sourse code: GitHub - Kozak-derezak00/drum_trig_seq_6ch: in this project is a module 6 channel trig sequencer from Hagiwo, but with the addition of me matrix keyboard 4x4 to control the steps of the sequences, the code is very raw and not attractive but WORKABLE, sketch uses 97% of the resource arduino nano.