我想从stm32f103c8t6TIM3的通道2输出两个频率一样，占空比不同的PWM波，字符0代表的是1/4的波形，1代表3/4的波形，问题出现了这么几个：1、这个频率应该是800khz吧，我把占空比调到1/5的时候，他的频率变成80khz 2.从通道2里本来应该输出的波形是01010101这样的，就是一个1/4一个3/4，但是实际出来的是乱的，麻烦各位大神帮忙看下，是不是代码哪里错了，还是我的理解错了，刚开始搞单片机可能很多理解错误，急急急急急急
//函数声明
void TIM3_Config(u16 arr,u16 psc,u16 ccr2);
void TIM4_Interrupt_Init(u16 arr,u16 psc);
//=============================================================================
//文件名称：main
//功能概要：主函数
//参数说明：无
//函数返回：int
//=============================================================================
int main(void)
{
// char buf[30] = {"01010101"};
// u32 i = 0;
//u32 num = 0;
SystemInit();
TIM3_Config(89,0,18);
TIM4_Interrupt_Init(89,0);
// TIM3_Config(89,0,18);
// NVIC_Configuration();
while (1);
}
void TIM3_Config(u16 arr,u16 psc,u16 ccr2)
{
//u16 ccr2 = 18;
//结构体定义
GPIO_InitTypeDef GPIO_InitStructure;//定义GPIO结构体
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;//定义时钟初始化结构体
TIM_OCInitTypeDef TIM_OCInitStructure;//定义结构体
//使能相关的东西
//GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable , ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); //使能定时器3时钟
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);
//GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable , ENABLE);
//GPIO_PinRemapConfig(GPIO_FullRemap_TIM2, ENABLE); //全映射
//GPIO_PinRemapConfig(GPIO_PartialRemap_TIM3, ENABLE); //选择Timer3部分重映像
GPIO_InitStructure.GPIO_Pin = /*GPIO_Pin_6 |*/ GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; // 复用推挽输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
//初始化TIM3
TIM_TimeBaseStructure.TIM_Period = arr; //自动重装载寄存器的值，溢出大小，每1000个数产生一个更新事件
TIM_TimeBaseStructure.TIM_Prescaler = psc; //TIMX预分频时钟的值 72 / (psc + 1) = 72M
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //时钟分割 时钟分频因子 0表示滤波器的频率和定时器的频率是一样的
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //向上计数模式
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); //根据以上功能对定时器进行初始化
/*新加的中断的两句话*/
TIM_ClearFlag(TIM3,TIM_FLAG_Update); //中断标志位清零
TIM_ITConfig(TIM3,TIM_IT_Update,ENABLE); //允许更新中断
//TIM_ClearITPendingBit(TIM3,TIM_IT_Update); //清除中断标志函数
//TIM1_OC2(设置2通道占空比)
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;//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_Pulse = ccr2; //设置跳变值，当计数器计数到这个值时，电平发生跳变
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;//输出比较极性高
TIM_OC2Init(TIM3, &TIM_OCInitStructure);//根据结构体信息进行初始化,使能通道2
TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable); //使能定时器TIM1在CCR2上的预装载值
//OC1(设置通道1占空比)
/*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_Pulse = CCR1; //设置跳变值，当计数器计数到这个值时，电平发生跳变
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;//输出比较极性高
TIM_OC1Init(TIM3, &TIM_OCInitStructure);//根据结构体信息进行初始化,使能通道2
TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable); //使能定时器TIM1在CCR2上的预装载值
//TIM_CtrlPWMOutputs(TIM3,ENABLE);*/
TIM_ARRPreloadConfig(TIM3, ENABLE); //这两句是可频率不变，改变占空比
TIM_Cmd(TIM3, ENABLE); //使能定时器TIM3
}
void TIM4_Interrupt_Init(u16 arr,u16 psc)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);
TIM_TimeBaseStructure.TIM_Period = arr;
TIM_TimeBaseStructure.TIM_Prescaler = psc;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);
TIM_ITConfig(TIM4,TIM_IT_Update | TIM_IT_Trigger,ENABLE);
//TIM_ITConfig(TIM4,TIM_IT_Update ,ENABLE);
/* Enable the TIM3 gloabal Interrupt*/
NVIC_InitStructure.NVIC_IRQChannel = TIM4_IRQn; //更新事件
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;//抢占优先级0级
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; //相应优先级1级
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道被使能
NVIC_Init(&NVIC_InitStructure); //初始化NVIC寄存器
TIM_Cmd(TIM4,ENABLE);
}
void TIM4_IRQHandler(void)
{
u32 i = 0;
//u32 count = 0;
u32 num = 0;
char buf[30] = {"0101010101"};
//u32 pwmval;
if (TIM_GetITStatus(TIM4,TIM_IT_Update | TIM_IT_Trigger) != RESET)
{
//TIM_ClearITPendingBit(TIM3, TIM_IT_CC2|TIM_IT_Update);
//capture = TIM_GetCapture2(TIM3);
for(i = 0;buf[i] != '\0';i++)
{
num = (int)(buf[i] - '0');
switch(num)
{
case 0:
TIM3_Config(89,0,18);
//TIM_SetAutoreload(TIM3,89);//设置频率的函数
// TIM_SetCompare2(TIM3,18);
break;
case 1:
TIM3_Config(89,0,23);
// TIM_SetAutoreload(TIM3,89);//设置频率的函数
// TIM_SetCompare2(TIM3,68);
break;
default:
break;
}
//count ++;
}
TIM_ClearITPendingBit(TIM4,TIM_IT_Update);
//TIM_SetCompare2(TIM3,68);
}
} |
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