code: func (m *MotorDriver) On() (err error) {
  	if m.isDigital() {
  		err = m.changeState(1)
  	} else {
  		if m.CurrentSpeed == 0 {
  			m.CurrentSpeed = 255
  		}
  		err = m.Speed(m.CurrentSpeed)
  	}
  	return
  }
docs: // On turns the motor on or sets the motor to a maximum speed