单片机unsigned char定义的buzz on数据长度是多少

正文摘要:

如代码所示，我通过串口发送buzz on,7蜂鸣器不响，试过buzz on,6buzz on,12buzz on,14buzz on,24buzz on,28buzz on,48buzz on,56都返回bad command.代码老师说没有问题，请问buzz on数据长度是多少？我应该发送buzz ...