stm32 3.5库函数串口问题

suse110 · 发表于 2012-9-15 20:50:03

我用stm32自带串口例程(Examples\ST\STM32F10xFWLib\Examples\USART\Printf)做串口实验总是乱码，
觉得可能是波特率有问题，然后我就用原子例程里面的uart_init()函数修改了下波特率，这下接收数据正确了。

问题是，stm32自带库函数应该不会有问题吧，是不是哪里还需要设置下什么？？

#include "stm32f10x_lib.h"
#include "stdio.h"
#include "platform_config.h"

USART_InitTypeDef USART_InitStructure;
ErrorStatus HSEStartUpStatus;

void RCC_Configuration(void);
void GPIO_Configuration(void);
void NVIC_Configuration(void);
void uart_init(u32 pclk2,u32 bound);

#ifdef __GNUC__
/* With GCC/RAISONANCE, small printf (option LD Linker->Libraries->Small printf
set to 'Yes') calls __io_putchar() */
#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#else
#define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
#endif /* __GNUC__ */

int main(void)
{

RCC_Configuration();
NVIC_Configuration();

GPIO_Configuration();

USART_InitStructure.USART_BaudRate = 115200;
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;

/* Configure the USARTx */
USART_Init(USARTx, &USART_InitStructure);
// uart_init(72,115200); //加上这句串口数据接收才正常,uart_init()函数只修改了波特率，函数体见下面
/* Enable the USARTx */
USART_Cmd(USARTx, ENABLE);

USART_SendData(USART1, 0xdd);
while (1)
{
  }
}

void uart_init(u32 pclk2,u32 bound)
{
float temp;
u16 mantissa;
u16 fraction;
temp=(float)(pclk2*1000000)/(bound*16);//得到USARTDIV
mantissa=temp;     //得到整数部分
fraction=(temp-mantissa)*16; //得到小数部分
mantissa<<=4;
mantissa+=fraction;
// RCC->APB2ENR|=1<<2;   //使能PORTA口时钟
// RCC->APB2ENR|=1<<14; //使能串口时钟
// GPIOA->CRH&=0XFFFFF00F;
// GPIOA->CRH|=0X000008B0;//IO状态设置
// RCC->APB2RSTR|=1<<14;   //复位串口1
// RCC->APB2RSTR&=~(1<<14);//停止复位
//波特率设置
  USART1->BRR=mantissa; // 波特率设置
// USART1->CR1|=0X200C; //1位停止,无校验位.
//#ifdef EN_USART1_RX    //如果使能了接收
// //使能接收中断
// USART1->CR1|=1<<8;    //PE中断使能
// USART1->CR1|=1<<5;    //接收缓冲区非空中断使能
// MY_NVIC_Init(3,3,USART1_IRQChannel,2);//组2，最低优先级
//#endif
}

/*******************************************************************************
* Function Name : RCC_Configuration
* Description    : Configures the different system clocks.
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
void RCC_Configuration(void)
{
/* RCC system reset(for debug purpose) */
RCC_DeInit();

/* Enable HSE */
RCC_HSEConfig(RCC_HSE_ON);

/* Wait till HSE is ready */
HSEStartUpStatus = RCC_WaitForHSEStartUp();

if(HSEStartUpStatus == SUCCESS)
{
/* Enable Prefetch Buffer */
FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);

    /* Flash 2 wait state */
    FLASH_SetLatency(FLASH_Latency_2);

    /* HCLK = SYSCLK */
    RCC_HCLKConfig(RCC_SYSCLK_Div1);

    /* PCLK2 = HCLK */
    RCC_PCLK2Config(RCC_HCLK_Div1);

/* PCLK1 = HCLK/2 */
RCC_PCLK1Config(RCC_HCLK_Div2);

/* PLLCLK = 8MHz * 9 = 72 MHz */
RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_9);

/* Enable PLL */
RCC_PLLCmd(ENABLE);

    /* Wait till PLL is ready */
    while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET)
    {
    }

/* Select PLL as system clock source */
RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);

    /* Wait till PLL is used as system clock source */
    while(RCC_GetSYSCLKSource() != 0x08)
    {
    }
}

/* Enable GPIOx clock */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOx, ENABLE);

/* Enable USARTx clocks */
#ifdef USE_USART1
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
#else
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USARTx, ENABLE);
#endif
}

void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;

#if defined USE_USART2 && defined USE_STM3210B_EVAL
/* Enable AFIO clock */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);

/* Enable the USART2 Pins Software Remapping */
GPIO_PinRemapConfig(GPIO_Remap_USART2, ENABLE);
#endif

/* Configure USARTx_Tx as alternate function push-pull */
GPIO_InitStructure.GPIO_Pin = GPIO_TxPin;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(GPIOx, &GPIO_InitStructure);

/* Configure USARTx_Rx as input floating */
GPIO_InitStructure.GPIO_Pin = GPIO_RxPin;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(GPIOx, &GPIO_InitStructure);

}

void NVIC_Configuration(void)
{
#ifdef VECT_TAB_RAM
/* Set the Vector Table base location at 0x20000000 */
NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0);
#else /* VECT_TAB_FLASH */
/* Set the Vector Table base location at 0x08000000 */
NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0);
#endif
}