USART1 通讯设置问题

最新推荐文章于 2024-11-30 16:44:54 发布

原创最新推荐文章于 2024-11-30 16:44:54 发布 · 2.7k 阅读

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#通讯 #struct #编译器 #工作

在使用USART1进行初始化时遇到了编译错误，错误涉及结构体字段。对比英文库函数例子发现，示例代码存在混淆。修复后，通讯仍然无法正常工作，原因是忘了使能USART1的时钟。启用时钟后，通讯成功。

1 问题
在利用USART 结构体进行初始化操作时，

根据函数库提供的例子进行初始化时候
compiling main.c...

../User/main.c(73): error: #134: expected a field name

../User/main.c(78): error: #136: struct "<unnamed>" has no field "USART_Clock"

../User/main.c(79): error: #136: struct "<unnamed>" has no field "USART_CPOL"

../User/main.c(80): error: #136: struct "<unnamed>" has no field "USART_CPHA"

../User/main.c(81): error: #136: struct "<unnamed>" has no field "USART_LastBit"

../User/main.c - 5 Error(s), 0 Warning(s).

通过查看相关头文件时候发现

typedef struct
{
uint32_t USART_BaudRate;
uint16_t USART_WordLength;
uint16_t USART_StopBits;
uint16_t USART_Parity;
uint16_t USART_Mode;
uint16_t USART_HardwareFlowControl;
} USART_InitTypeDef;

typedef struct
{
uint16_t USART_Clock;
uint16_t USART_CPOL;
uint16_t USART_CPHA;
uint16_t USART_LastBit;
} USART_ClockInitTypeDef;

中文提供的初始化例子如下
{
    USART_InitStructure.USART_BaudRate = 9600;
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;
    USART_InitStructure.USART_Parity_Odd;
    USART_InitStructure.USART_HardwareFlowControl =
    USART_HardwareFlowControl_RTS_CTS;
    USART_InitStructure.USART_Mode = USART_Mode_Tx|USART_Mode_Rx;

    USART_InitStructure.USART_Clock = USART_Clock_Disable;
    USART_InitStructure.USART_CPOL = USART_CPOL_High;
    USART_InitStructure.USART_CPHA = USART_CPHA_1Edge;
    USART_InitStructure.USART_LastBit = USART_LastBit_Enable;

    USART_Init(USART1,&USART_InitStructure);
}

根据ST英文库函数提供的例子
Example:
/* The following example illustrates how to configure the USART1 */

USART_InitTypeDef USART_InitStructure;
USART_InitStructure.USART_BaudRate = 9600;
USART_InitStructure.USART_WordLength = USART_WordLength_8b;
USART_InitStructure.USART_StopBits = USART_StopBits_1;
USART_InitStructure.USART_Parity = USART_Parity_Odd;
USART_InitStructure.USART_HardwareFlowControl =
USART_HardwareFlowControl_RTS_CTS;
USART_InitStructure.USART_Mode = USART_Mode_Tx I USART_Mode_Rx;
USART_Init(USART1, &USART_InitStructure);

通过比较可以发现第一个提供的例子的确是存在问题！
就是分明是两个函数体的参数在该例子中统一赋值处理！早上编译器出现问题

得出结论！学习以英文为参考！！

当我在将串口进行设置完毕后，用软件进行仿真，始终不能得到我想要发送字符0xaa~~

仔细检查设置情况没问题，通过外设端口设置发现在USART1 的通讯设置如下

Clock Disabled, 9603 baud,
1 Start Bit,
8 Data Bits,
1.0 Stop Bits,
No Parity

发现USART1的时钟为 Disable状态~！

O ！ my god！！！

又是忘记了将外设始终进行使能了~~！~！

//注意此处要打开用到USART1的时钟否则引脚不工作
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);

编译后用软件仿真后成功~~~！！