?: Optional parameter. The default are song_name = 'test',speed = 210, duration = 8, octave = 5. Parameter-numbers can be string or int. In case it does not match critera, they will be set to default.

; (at your option) any later version. ; BLHeli is distributed in the hope that it will be useful, ; but WITHOUT ANY WARRANTY; without even the implied warranty of ; MERCHANTABILITY or FITNESS FOR A ...