看似简单的串口问题，竟出了问题！
用C编了一个串口的接收程序，外部设备一直在往串口写数据，所以串口只需要打开和读就可以了
这个看似简单的串口问题，竟出了问题！
接收的数据在超级终端上打印，打印出来的结果如下，大家帮我分析一下啊，谢谢
/—————————————结果————————————————————/
# ./recv
fd = 4
ready for sending command——-
<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0’
<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0’
<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0’
<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0’
<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0’
<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0’
<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0′<‘0’nread = 128
<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘~'<‘?
<‘?<‘?<‘?<‘?<‘?<‘?<‘~'<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?
<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?'<‘?<‘?
<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?
<‘?<‘?<‘ ‘<‘?<‘'<‘D'<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?<‘?
/———————————————————————————————————/
程序代码如下：
另外一个问题是：sleep(1)的问题，怎么串口打开后需要延迟一段时间才能读到足够多的数据（比如256个）？
应该不是波特率的原因.
在你打开串口并设置好后,串口开始接收数据,根据你的波特率,串口最快一秒钟也就接收3600个字节.即1ms接收3.6个字节左右,从你设置好串口到开始读取数据,由于没有其它操作也就1ms左右,即到你开始读取数据时,串口的缓冲区中有4个字节左右,即你能读取4-5个字节.你加入了sleep(1)后,到你读取数据时缓冲区中最多可能有3600个字节了,故你能读取够128个字节.
计算一下,你usleep(50)左右差不多就可以了.
printf(" < ‘%c ‘",qq[i]) ;
改
printf(" < 0x%x",qq[i]) ;
打印16进制，去掉‘’
%c字符型的只能显示128内的
