def _build_robovac_command(mode, command):
    """ Compile the given mode and command into the bytes data sent to the RoboVac. """
    mcu_ota_header_0xa5 = 0xA5
    cmd_data = (mode.value + command.value)

    return bytes([mcu_ota_header_0xa5, mode.value, command.value, cmd_data, 0xFA])