蓝桥杯嵌入式组开发——TIM3实现定时器功能

1.定时器初始化

时钟初始化 中断配置 TIM初始化50000 // 50ms一次中断 TIM_PrescalerConfig 72分频 //和TIM_PWM_OUT一样 中断使能 打开总开关

void NVIC_Configuration(void) { NVIC_InitTypeDef NVIC_InitStructure; /* Enable the TIM2 global Interrupt */ NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); } void TIM_Init(void) { TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); NVIC_Configuration(); /* Time base configuration */ TIM_TimeBaseStructure.TIM_Period = 50000; TIM_TimeBaseStructure.TIM_Prescaler = 0; TIM_TimeBaseStructure.TIM_ClockDivision = 0; TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); /* Prescaler configuration */ TIM_PrescalerConfig(TIM3, 71, TIM_PSCReloadMode_Immediate); TIM_ITConfig(TIM3, TIM_IT_Update, ENABLE); TIM_Cmd(TIM3, ENABLE); }

2.定时器中断处理函数

void TIM3_IRQHandler(void) { if (TIM_GetFlagStatus(TIM3, TIM_FLAG_Update) == 1) { TIM_ClearFlag(TIM3, TIM_FLAG_Update); t_50ms++; if( t_50ms >=20 ) { t_50ms = 0; num++; } } }

3.参考官方库函数

STM32_MCU\stm32f10x_stdperiph_lib\STM32F10x_StdPeriph_Lib_V3.5.0\Project\STM32F10x_StdPeriph_Examples\TIM\TimeBase