docs: def write(self,buf):
          """
          Write command to blink(1), low-level internal use
          Send USB Feature Report 0x01 to blink(1) with 8-byte payload
          Note: arg 'buf' must be 8 bytes or bad things happen
          """
          log.debug("blink1write:" + ",".join('0x%02x' % v for v in buf))
          self.dev.send_feature_report(buf)