请问USB字符串描述符

sgch

请问USB字符串描述符 [复制链接]

请问在USB设备向主机发送字符串描述符时，怎么定义一个从指定FLASH空间地址中读取的变量数据呢？如何将读取的内容以字符串的形式发送到主机？一般定义字符串都是常量定义的，谢谢！

lylnk

楼主有没有看过ST官方库的USB例程代码
在每个例子的hw_config.c文件里面有这样一段
/*******************************************************************************
* Function Name  : Get_SerialNum.
* Description : Create the serial number string descriptor.
* Input       : None.
* Output       : None.
* Return       : None.
*******************************************************************************/
void Get_SerialNum(void)
{
  u32 Device_Serial0, Device_Serial1, Device_Serial2;

  Device_Serial0 = *(u32*)(0x1FFFF7E8);
  Device_Serial1 = *(u32*)(0x1FFFF7EC);
  Device_Serial2 = *(u32*)(0x1FFFF7F0);

  if (Device_Serial0 != 0)
  {
Speaker_StringSerial[2] = (u8)(Device_Serial0 & 0x000000FF);
Speaker_StringSerial[4] = (u8)((Device_Serial0 & 0x0000FF00) >> 8);
Speaker_StringSerial[6] = (u8)((Device_Serial0 & 0x00FF0000) >> 16);
Speaker_StringSerial[8] = (u8)((Device_Serial0 & 0xFF000000) >> 24);

Speaker_StringSerial[10] = (u8)(Device_Serial1 & 0x000000FF);
Speaker_StringSerial[12] = (u8)((Device_Serial1 & 0x0000FF00) >> 8);
Speaker_StringSerial[14] = (u8)((Device_Serial1 & 0x00FF0000) >> 16);
Speaker_StringSerial[16] = (u8)((Device_Serial1 & 0xFF000000) >> 24);

Speaker_StringSerial[18] = (u8)(Device_Serial2 & 0x000000FF);
Speaker_StringSerial[20] = (u8)((Device_Serial2 & 0x0000FF00) >> 8);
Speaker_StringSerial[22] = (u8)((Device_Serial2 & 0x00FF0000) >> 16);
Speaker_StringSerial[24] = (u8)((Device_Serial2 & 0xFF000000) >> 24);
  }
}
这段代码的意思是把序列号字符串用芯片的唯一ID来替换
你只需要把芯片ID换成你想要的字符就行了