atu_send_command
err = atu_send_command(sc, (uint8_t *)&radio,
err = atu_send_command(sc, (uint8_t *)&cmd, sizeof (cmd));
err = atu_send_command(sc, (uint8_t *)&scan, sizeof (scan));
err = atu_send_command(sc, (uint8_t *)&join, sizeof (join));