使用定时计数器4,实现每500ms让灯闪烁一次
时间: 2024-02-26 13:58:43 浏览: 31
下面是使用定时计数器4实现每500ms让LED灯闪烁一次的代码:
```c
#include "stm32f4xx.h"
void TIM4_Init(void);
void TIM4_IRQHandler(void);
int main(void)
{
GPIO_InitTypeDef GPIO_InitStruct;
/* Enable clock for GPIOB */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
/* Configure PB0 as output */
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_0;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_Init(GPIOB, &GPIO_InitStruct);
/* Initialize TIM4 */
TIM4_Init();
while(1)
{
/* Do something else */
// ...
}
}
void TIM4_Init(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct;
NVIC_InitTypeDef NVIC_InitStruct;
/* Enable clock for TIM4 */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);
/* TIM4 configuration */
TIM_TimeBaseInitStruct.TIM_Prescaler = 42000 - 1; // 84MHz / 42000 = 2kHz
TIM_TimeBaseInitStruct.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInitStruct.TIM_Period = 1000 - 1; // 2kHz / 1000 = 2Hz
TIM_TimeBaseInitStruct.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseInitStruct.TIM_RepetitionCounter = 0;
TIM_TimeBaseInit(TIM4, &TIM_TimeBaseInitStruct);
/* Enable interrupt */
TIM_ITConfig(TIM4, TIM_IT_Update, ENABLE);
/* Enable TIM4 */
TIM_Cmd(TIM4, ENABLE);
/* Configure NVIC */
NVIC_InitStruct.NVIC_IRQChannel = TIM4_IRQn;
NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStruct.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStruct);
}
void TIM4_IRQHandler(void)
{
if (TIM_GetITStatus(TIM4, TIM_IT_Update) != RESET)
{
/* Clear interrupt flag */
TIM_ClearITPendingBit(TIM4, TIM_IT_Update);
/* Toggle LED */
GPIO_ToggleBits(GPIOB, GPIO_Pin_0);
}
}
```
在该代码中,我们使用 TIM4_Init() 函数初始化定时计数器4,并在 TIM4_IRQHandler() 函数中实现每500ms改变一次LED灯的状态。具体地,我们将定时器的计数频率设置为2kHz,计数器的周期设置为1000,即每500ms触发一次中断,然后在中断处理函数中通过 GPIO_ToggleBits() 函数改变LED灯的状态。