老是 a frame error
搜索了一下论坛的帖子，
看到有人说The framing error is detected by the UART (universal asynchronous receiver/transmitter) when the last bit received is not a stop bit. It�s a general term, not reserved by National Instruments.
The reason for receiving this error is most likely due to improper initialization of your serial port.
但是我初始化没啥问题啊 请大家帮忙看看
