Solution: Baud rate deviation can receive data, but may be unstable, the international standard is 1% range can be that is, 250K Set 250 + 1% * 250K can be. However, other baud rates around 250K can also be received. Therefore, the detected baud rate is a range. To obtain the most accurate baud rate, it is recommended to choose the middle of the detected range. In this case, the detected range is 200K-296.296K, so the most accurate baud rate is 250K.