def _build_robovac_command(mode, command):
    """ Compile the given mode and command into the bytes data sent to the RoboVac. """
    mcu_ota_header_0xa5 = 165
    cmd_data = mode.value + command.value
    return bytes([mcu_ota_header_0xa5, mode.value, command.value, cmd_data,
        250])
