换晶振导致stm32串口数据飞码的解决办法(补充)

客官°小女子只卖身不卖艺 2022-08-27 00:28 147阅读 0赞

今天（2014.4.21）把stm32f107的程序下载到stm32f103的板子上，发现串口收不到数据，突然想起晶振频率没有修改，\#define HSE\_VALUE    ((uint32\_t)13560000) /\*!< Value of the External oscillator in Hz \*/ 这个要改回去，因为外接晶振是8M  
之后试验，发现有数据，但是乱码。百思不得其解，无意中发现，PC的波特率设置为9600，板子的波特率设置为19200就不会乱码。刚好是2倍的关系。顺藤摸瓜问度娘！一个帖子也是这种情况，一个回答是“问题解决了，把target options里\#define里的STM32F10X\_HD\_VL改成STM32F10X\_MD就正常了（我用的是中密度器件）”，楼下有人说：  
看库里面的stm32f10x.h文件，里面很多内容与系统时钟的配置有关。该文件会根据选择的芯片类型来进行时钟配置，要在此位置将选用的芯片类型去掉注释符。当然不想每次修改此文件，比较方便的方法就是你所说是在编译器的target options选项框中define。。。效果一样。  
  
  
我翻开那个头文件  
\#if !defined (STM32F10X\_LD) && !defined (STM32F10X\_LD\_VL) && !defined (STM32F10X\_MD) && !defined (STM32F10X\_MD\_VL) && !defined (STM32F10X\_HD) && !defined (STM32F10X\_HD\_VL) && !defined (STM32F10X\_XL) && !defined (STM32F10X\_CL)   
  /\* \#define STM32F10X\_LD \*/     /\*!< STM32F10X\_LD: STM32 Low density devices \*/  
  /\* \#define STM32F10X\_LD\_VL \*/  /\*!< STM32F10X\_LD\_VL: STM32 Low density Value Line devices \*/    
   /\*\#define STM32F10X\_MD \*/    /\*!< STM32F10X\_MD: STM32 Medium density devices \*/  
  /\* \#define STM32F10X\_MD\_VL \*/  /\*!< STM32F10X\_MD\_VL: STM32 Medium density Value Line devices \*/    
  /\* \#define STM32F10X\_HD \*/     /\*!< STM32F10X\_HD: STM32 High density devices \*/  
  /\* \#define STM32F10X\_HD\_VL \*/  /\*!< STM32F10X\_HD\_VL: STM32 High density value line devices \*/    
  /\* \#define STM32F10X\_XL \*/     /\*!< STM32F10X\_XL: STM32 XL-density devices \*/  
  /\* \#define STM32F10X\_CL \*/     /\*!< STM32F10X\_CL: STM32 Connectivity line devices \*/  
\#endif  
/\*  Tip: To avoid modifying this file each time you need to switch between these  
        devices, you can define the device in your toolchain compiler preprocessor.  
 - Low-density devices are STM32F101xx, STM32F102xx and STM32F103xx microcontrollers  
   where the Flash memory density ranges between 16 and 32 Kbytes.  
 - Low-density value line devices are STM32F100xx microcontrollers where the Flash  
   memory density ranges between 16 and 32 Kbytes.  
 - Medium-density devices are STM32F101xx, STM32F102xx and STM32F103xx microcontrollers  
   where the Flash memory density ranges between 64 and 128 Kbytes.  
 - Medium-density value line devices are STM32F100xx microcontrollers where the   
   Flash memory density ranges between 64 and 128 Kbytes.     
 - High-density devices are STM32F101xx and STM32F103xx microcontrollers where  
   the Flash memory density ranges between 256 and 512 Kbytes.  
 - High-density value line devices are STM32F100xx microcontrollers where the   
   Flash memory density ranges between 256 and 512 Kbytes.   - XL-density devices are STM32F101xx and STM32F103xx microcontrollers where  
   the Flash memory density ranges between 512 and 1024 Kbytes.  
 - Connectivity line devices are STM32F105xx and STM32F107xx microcontrollers.  
  \*/  
  
  
似乎有了思路。查找工程代码，定义了\#define STM32F10X\_MD\_VL，（好像上一位工程师写错了），我修改为\#define STM32F10X\_MD，问题解决。