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发表于 2018-11-25 22:11:18
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用407做过定时器级联输出精确脉冲个数的应用，可以参考下面代码。
void TIM8_PWM_Init(INT32U arr, INT32U psc)
{
//此部分需手动修改IO口设置
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
PWM_CH1_Init();
PWM_CH2_Init();
PWM_CH3_Init();
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM8, ENABLE); //TIM8时钟使能
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE); //TIM2时钟使能
//RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOI, ENABLE); //使能PORTI时钟
//GPIO_PinAFConfig(GPIOI, GPIO_PinSource5, GPIO_AF_TIM8); //GPIOI5复用为定时器8
//GPIO_PinAFConfig(GPIOI, GPIO_PinSource6, GPIO_AF_TIM8); //GPIOI6复用为定时器8
//GPIO_PinAFConfig(GPIOI, GPIO_PinSource7, GPIO_AF_TIM8); //GPIOI7复用为定时器8
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE); //使能PORTC时钟
GPIO_PinAFConfig(GPIOC, GPIO_PinSource6, GPIO_AF_TIM8); //GPIOC6复用为定时器8
//GPIO_PinAFConfig(GPIOC, GPIO_PinSource7, GPIO_AF_TIM8); //GPIOC7复用为定时器8
//GPIO_PinAFConfig(GPIOC, GPIO_PinSource8, GPIO_AF_TIM8); //GPIOC8复用为定时器8
//GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_6 | GPIO_Pin_7; //GPIOI5
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 ; //GPIOI6
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; //复用功能
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz; //速度100MHz
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //推挽复用输出
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; //上拉
//GPIO_Init(GPIOI, &GPIO_InitStructure); //初始化PI5/6/7
GPIO_Init(GPIOC, &GPIO_InitStructure); //初始化PI5/6/7
TIM_TimeBaseStructure.TIM_Prescaler = psc; //定时器分频
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //向上计数模式
TIM_TimeBaseStructure.TIM_Period = arr; //自动重装载值
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseInit(TIM8, &TIM_TimeBaseStructure); //初始化定时器8
//初始化TIM8 Channel1 PWM模式
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //选择定时器模式:TIM脉冲宽度调制模式2
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; //输出极性:TIM输出比较极性低
TIM_OC1Init(TIM8, &TIM_OCInitStructure); //根据T指定的参数初始化外设TIM1 4OC1
TIM_SelectMasterSlaveMode(TIM8, TIM_MasterSlaveMode_Enable);
TIM_UpdateRequestConfig(TIM8, TIM_UpdateSource_Global);
TIM_SelectOutputTrigger(TIM8, TIM_TRGOSource_Update);
TIM_OC1PreloadConfig(TIM8, TIM_OCPreload_Enable); //使能TIM8在CCR1上的预装载寄存器
//TIM_OC2PreloadConfig(TIM8, TIM_OCPreload_Enable); //使能TIM8在CCR1上的预装载寄存器
//TIM_OC3PreloadConfig(TIM8, TIM_OCPreload_Enable); //使能TIM8在CCR1上的预装载寄存器
TIM_ARRPreloadConfig(TIM8, ENABLE); //ARPE使能
//定时器2用来做脉冲计数
TIM_TimeBaseStructure.TIM_Prescaler = 0; //定时器分频
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Down; //向下计数模式
TIM_TimeBaseStructure.TIM_Period = 100; //自动重装载值
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure); //初始化定时器2
TIM_SelectSlaveMode(TIM2, TIM_SlaveMode_Gated);
TIM_SelectMasterSlaveMode(TIM2, TIM_MasterSlaveMode_Enable);
TIM_SelectInputTrigger(TIM2,TIM_TS_ITR1);
//TIM_SelectOnePulseMode(TIM2,TIM_OPMode_Single);
TIM_SelectOutputTrigger(TIM2,TIM_TRGOSource_Update);
TIM_ITConfig(TIM2,TIM_IT_Update,ENABLE); //允许定时器2更新中断
NVIC_InitStructure.NVIC_IRQChannel=TIM2_IRQn; //定时器2中断
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0x01; //抢占优先级1
NVIC_InitStructure.NVIC_IRQChannelSubPriority=0x03; //子优先级3
NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
NVIC_Init(&NVIC_InitStructure);
//TIM_Cmd(TIM2, ENABLE); //使能TIM2
//TIM_Cmd(TIM8, ENABLE); //使能TIM8
//TIM_CtrlPWMOutputs(TIM8, ENABLE);
}
void PWM_OutCnt(INT32U Value)
{
TIM2->PSC=(Value>>16);
TIM2->ARR=Value/(TIM2->PSC+1);
TIM2->CNT=Value/(TIM2->PSC+1);
TIM2->EGR |= 0x01;
TIM_Cmd(TIM8, ENABLE); //使能TIM8
TIM_Cmd(TIM2, ENABLE); //使能TIM2
TIM_CtrlPWMOutputs(TIM8, ENABLE);
}
void TIM2_IRQHandler(void)
{
if(TIM_GetITStatus(TIM2,TIM_IT_Update)==SET) //溢出中断
{
TIM_Cmd(TIM8, DISABLE); //使能TIM8
TIM_CtrlPWMOutputs(TIM8, DISABLE);
}
TIM_ClearITPendingBit(TIM2,TIM_IT_Update); //清除中断标志位
}
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发表于 2018-9-5 10:50:37
楼主
