本例程通过将PB0、PB1两个GPIO分别配置为TIM1_CH2N、TIM1_CH2,实现两个LED的交替闪烁。
1 GPIO初始化
void initGPIO_Timer1(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource0, GPIO_AF_2);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource1, GPIO_AF_6);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0; //TIM1_CH2N
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1; //TIM1_CH2
GPIO_Init(GPIOB, &GPIO_InitStructure);
}
2 TIM1初始化
void initTIM1(u16 prescaler, u16 period, u16 dutyCycle)
{
TIM_TimeBaseInitTypeDef TIM_StructInit;
TIM_OCInitTypeDef TIM_OCInitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);
TIM_TimeBaseStructInit(&TIM_StructInit);
TIM_StructInit.TIM_Period = period;
TIM_StructInit.TIM_Prescaler = prescaler;
TIM_StructInit.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_StructInit.TIM_CounterMode = TIM_CounterMode_Up;
TIM_StructInit.TIM_RepetitionCounter = 0;
TIM_TimeBaseInit(TIM1, &TIM_StructInit);
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
TIM_OCInitStructure.TIM_Pulse = dutyCycle;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Reset;
TIM_OC2Init(TIM1, &TIM_OCInitStructure);
TIM_OC2PreloadConfig(TIM1, TIM_OCPreload_Enable);
TIM_ARRPreloadConfig(TIM1, ENABLE);
TIM_ITConfig(TIM1, TIM_IT_CC2, ENABLE);
TIM_CtrlPWMOutputs(TIM1, ENABLE);
}
3 中断初始化
void initNVIC_TIM1(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
NVIC_InitStructure.NVIC_IRQChannel = TIM1_CC_IRQn; // Config TIM1_CC_IRQn NVIC config
NVIC_InitStructure.NVIC_IRQChannelPriority = 0; // PreemptionPriority : 1
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; // Enable IRQn
NVIC_Init(&NVIC_InitStructure);
}
4 中断服务程序
void TIM1_CC_IRQHandler()
{
if (TIM_GetITStatus(TIM1, TIM_IT_CC2) != RESET) {
TIM_ClearITPendingBit(TIM1, TIM_IT_CC2); // Clear the CC2 flag
}
}
5 main函数
int main(void)
{
initGPIO_Timer1();
initTIM1(479, 29999, 15000); //config TIM to PWM output
initNVIC_TIM1();
OnTIM1(); //enable TIM;
while(1) {
}
}
官方例程的修正已基本完成,需要程序的同学可以到百度网盘下载。
提取码:0o5i