TIM5定时器点亮LED

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在路上11111111 发布时间：2017-3-9 21:06

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#include "stm32f10x.h"
#include "stdio.h"
uint8_t flag = 0;
void STM32_LED_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD,ENABLE);
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2|GPIO_Pin_3|GPIO_Pin_4|GPIO_Pin_7;
GPIO_Init(GPIOD,&GPIO_InitStructure);
GPIOD->BSRR = GPIO_Pin_2|GPIO_Pin_3|GPIO_Pin_4|GPIO_Pin_7;
}
void NVIC_TIM5Configuration(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);
NVIC_InitStructure.NVIC_IRQChannel = TIM5_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
void TIM5_Init(void)
{
TIM_TimeBaseInitTypeDef TIM_Time_BaseInitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM5,ENABLE);//打开TIM5的时钟;
TIM_Time_BaseInitStructure.TIM_Prescaler = (100 - 1);//预分频器寄存器1ms
//这个是你要设置的预分频器的数值;
//就是将你的频率分成多少比如说你要将其分频成36000HZ的话就是预分频的数值设置成72000000/36000;
//这个值就是用来和计数值相互合作的,可以减少一个数值的使用大小的范围;
//16位可编程(可以实时修改)预分频器，计数器时钟频率的分频系数为1～65536之间的任意
TIM_Time_BaseInitStructure.TIM_Period = (720 - 1);//自动装载寄存器
//这个是你要自动重装载的值;
//只要这两个数是72M的整数倍即可(72M是APB1没有进行分频的情况下的数值,如果分频的话
//需要的就是*2,
TIM_Time_BaseInitStructure.TIM_ClockDivision = 0;//这个就是一个时钟分割;现阶段没怎么用的到
TIM_Time_BaseInitStructure.TIM_CounterMode = TIM_CounterMode_Down;
//计数的方式;
//向下计数;
TIM_TimeBaseInit(TIM5,&TIM_Time_BaseInitStructure);
//初始化TIM5
TIM_ClearITPendingBit(TIM5,TIM_IT_Update);
TIM_ITConfig(TIM5,TIM_IT_Update,ENABLE);
//这个是使能中断;
TIM_Cmd(TIM5,ENABLE);
//使能TIM5
}
void TIM5_IRQHandler(void)
{
if(TIM_GetITStatus(TIM5,TIM_IT_Update) != RESET)
{
TIM_ClearITPendingBit(TIM5,TIM_IT_Update);
flag = 1;
GPIOD->ODR ^= GPIO_Pin_7;
}
}
void STM32_USART_Config()
{
USART_InitTypeDef USART_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD|RCC_APB2Periph_AFIO,ENABLE);
GPIO_PinRemapConfig(GPIO_Remap_USART2,ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2,ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOD,&GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOD,&GPIO_InitStructure);
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_Mode = USART_Mode_Rx|USART_Mode_Tx;
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
USART_Init(USART2,&USART_InitStructure);
USART_Cmd(USART2,ENABLE);
}
#ifndef MicroLIB
//#pragma import(__use_no_semihosting) //没有实现fgetc时需要声明该参数
/* 标准库需要的支持函数使用printf()调试打印不需要实现该函数 */
struct __FILE
{
int handle;
/* Whatever you require here. If the only file you are using is */
/* standard output using printf() for debugging, no file handling */
/* is required. */
};
FILE __stdout;
//定义_sys_exit()以避免使用半主机模式
_sys_exit(int x)
{
x = x;
}
/* 重定义fputc函数如果使用MicroLIB只需要重定义fputc函数即可 */
int fputc(int ch, FILE *f)
{
/* Place your implementation of fputc here */
/* e.g. write a character to the USART */
USART_SendData(USART2, (uint8_t) ch);
/* Loop until the end of transmission */
while (USART_GetFlagStatus(USART2, USART_FLAG_TC) == RESET)
{}
return ch;
}
/*
可以直接使用putchar
不需要再定义 int putchar(int ch)，因为stdio.h中有如下定义
#define putchar(c) putc(c, stdout)
*/
int ferror(FILE *f) {
/* Your implementation of ferror */
return EOF;
}
#endif
FILE __stdin;
int fgetc(FILE *fp)
{
int ch = 0;
while(USART_GetFlagStatus(USART2, USART_FLAG_RXNE) == RESET)
{
}
ch = (int)USART2->DR & 0xFF;
putchar(ch); //回显
return ch;
}
int main()
{
uint8_t Count =0;
uint32_t PwmValue = 0;
uint32_t DirValue = 0;
STM32_LED_Configuration();
NVIC_TIM5Configuration();
TIM5_Init();
STM32_USART_Config();
while(1)
{
if(flag == 1)
{
flag = 0;
printf("\r\n TIMI的实验,第%d个周期发送数据 \r\n",Count++);
}
}
}
<img src="https://www.stmcu.org.cn/module/forum/forum.php?mod=image&aid=390661&size=300x300&key=254b7fc2b1c5f5b3&nocache=yes&type=fixnone" aid="attachimg_390661" alt="" border="0">
在下有个两个问题想问一下:
1:为什么我设置的是1ms去点亮一下，为什么测试的是500HZ；
2：我在改定时器的数值大小的时候,为什么我改到频率的数值好几M以后，还是显示300KHz；
希望大家帮我解决一下