蓝桥杯嵌入式组开发——USART

初始化时钟，
中断
对RX(A3),TX(A2)口进行配置
USART配置
中断使能
打开总开关

1.初始化代码

void USART_INIT(void)
{
	USART_InitTypeDef USART_InitStructure;
	GPIO_InitTypeDef GPIO_InitStructure;

	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);

	NVIC_Configuration_USART();

	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
	GPIO_Init(GPIOA, &GPIO_InitStructure);	

	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
	GPIO_Init(GPIOA, &GPIO_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_No;
	USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
	USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;

	USART_Init(USART2, &USART_InitStructure);


	USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);

	USART_Cmd(USART2,ENABLE);

}

2.发送数据函数

void Usart_SendString(char *str)
{
	char index = 0;
	do{
		USART_SendData(USART2, str[index]);
		while(USART_GetFlagStatus(USART2, USART_FLAG_TXE) == 0);
		index++;
	
	}
	while(str[index] != 0 );
	USART_SendData(USART2, '\n');	
}

3.中断接收函数

void USART2_IRQHandler(void)
{
	uint8_t temp;
	
	if(USART_GetITStatus(USART2,USART_IT_RXNE) != RESET){
		USART_ClearITPendingBit(USART2,USART_IT_RXNE);		
		temp = USART_ReceiveData(USART2);
		if((temp == 'x') || (RXCUNT == 20))
		{
			RXCUNT = 0;
			RXOVER = 1;  //接收完成标志位置位
			USART_ITConfig(USART2,USART_IT_RXNE,DISABLE);
		}
		else{
			USART_RXBUF[RXCUNT] = temp;
			++RXCUNT;			
		}
	}
}

4.参考库函数

STM32_MCU\stm32f10x_stdperiph_lib\STM32F10x_StdPeriph_Lib_V3.5.0\Project\STM32F10x_StdPeriph_Examples\USART\Interrupt

初始化参考：

中断接收数据函数参考如下：

GPIO口配置参考：
STM32_MCU\stm32f10x_stdperiph_lib\STM32F10x_StdPeriph_Lib_V3.5.0\Project\STM32F10x_StdPeriph_Examples\USART\HyperTerminal_HwFlowControl文件下的IO口配置