STM32F103C8 串口2

NBNOWORDS · 发表于 2018-10-19 16:53:18

用STM32F103C8，没有使用外部晶振，将SystemInit()改成64M __IO uint32_t StartUpCounter = 0, HSEStatus = 0;
RCC_DeInit();

  /* SYSCLK, HCLK, PCLK2 and PCLK1 configuration ---------------------------*/
  /* Enable HSI */
RCC->CR |= ((uint32_t)RCC_CR_HSION);

/* Wait till HSI is ready and if Time out is reached exit */
  do
  { HSEStatus = RCC->CR & RCC_CR_HSIRDY;
StartUpCounter++;
  } while((HSEStatus == 0) && (StartUpCounter != HSE_STARTUP_TIMEOUT));
if ((RCC->CR & RCC_CR_HSIRDY) != RESET)
  {
   HSEStatus = (uint32_t)0x01;
  }
  else
  {
HSEStatus = (uint32_t)0x00;
  }
  if (HSEStatus == (uint32_t)0x01)
  {
/* Enable Prefetch Buffer */
FLASH->ACR |= FLASH_ACR_PRFTBE;
/* Flash 2 wait state */
FLASH->ACR &= (uint32_t)((uint32_t)~FLASH_ACR_LATENCY);
FLASH->ACR |= (uint32_t)FLASH_ACR_LATENCY_2;
/* HCLK = SYSCLK */
RCC->CFGR |= (uint32_t)RCC_CFGR_HPRE_DIV1;

/* PCLK2 = HCLK */
RCC->CFGR |= (uint32_t)RCC_CFGR_PPRE2_DIV1;

/* PCLK1 = HCLK */
RCC->CFGR |= (uint32_t)RCC_CFGR_PPRE1_DIV2;

/*? PLL configuration: PLLCLK = HSI/2 *?16 =?64 MHz */
RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_PLLSRC | RCC_CFGR_PLLXTPRE | RCC_CFGR_PLLMULL));
RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLSRC_HSI_Div2| RCC_CFGR_PLLMULL16);

/* Enable PLL */
RCC->CR |= RCC_CR_PLLON;
/* Wait till PLL is ready */
while((RCC->CR & RCC_CR_PLLRDY) == 0)
{
}

/* Select PLL as system clock source */
RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_SW));
RCC->CFGR |= (uint32_t)RCC_CFGR_SW_PLL;
/* Wait till PLL is used as system clock source */
while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS) != (uint32_t)0x08)
  {
}
  }
  else
  {
  }

}

然后用例程的串口通信，改成PA2,PA3，使用USART2，串口发送都是乱码，求解
#include "stm32f10x.h"
void My_USART2_Init(void)
{
GPIO_InitTypeDef GPIO_InitStrue;
USART_InitTypeDef USART_InitStrue;
NVIC_InitTypeDef NVIC_InitStrue;
   RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO,ENABLE);//①
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2,ENABLE);

GPIO_InitStrue.GPIO_Mode=GPIO_Mode_AF_PP;
GPIO_InitStrue.GPIO_Pin=GPIO_Pin_2;
GPIO_InitStrue.GPIO_Speed=GPIO_Speed_50MHz;
  GPIO_Init(GPIOA,&GPIO_InitStrue);//②

GPIO_InitStrue.GPIO_Mode=GPIO_Mode_IN_FLOATING;
GPIO_InitStrue.GPIO_Pin=GPIO_Pin_3;
GPIO_InitStrue.GPIO_Speed=GPIO_Speed_50MHz;
  GPIO_Init(GPIOA,&GPIO_InitStrue);//②

USART_InitStrue.USART_BaudRate=115200;
USART_InitStrue.USART_HardwareFlowControl=USART_HardwareFlowControl_None;
USART_InitStrue.USART_Mode=USART_Mode_Tx|USART_Mode_Rx;
USART_InitStrue.USART_Parity=USART_Parity_No;
USART_InitStrue.USART_StopBits=USART_StopBits_1;
USART_InitStrue.USART_WordLength=USART_WordLength_8b;

USART_Init(USART2,&USART_InitStrue);//③

USART_Cmd(USART2,ENABLE);//使能串口2

USART_ITConfig(USART2,USART_IT_RXNE,ENABLE);//开启接收中断

NVIC_InitStrue.NVIC_IRQChannel=USART2_IRQn;
NVIC_InitStrue.NVIC_IRQChannelCmd=ENABLE;
NVIC_InitStrue.NVIC_IRQChannelPreemptionPriority=1;
NVIC_InitStrue.NVIC_IRQChannelSubPriority=1;
NVIC_Init(&NVIC_InitStrue);

}

void USART2_IRQHandler(void)
{
u8 res;
   if(USART_GetITStatus(USART2,USART_IT_RXNE))
{
   res= USART_ReceiveData(USART2);
   USART_SendData(USART2,res);
  }
}

int main(void)
{
  NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
My_USART2_Init();
   while(1);

}