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注册时间 2017-9-2
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请问,怎么设置才能使TIM1里的CH1 CH1N CH2N CH3N这四个通道产生的PWM波是独立的呢
下面这个代码是我根据正点原子PWM实验里面改出来的,
void TIM1_Int_Init(u16 arr,u16 psc)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1 , ENABLE); //时钟使能
TIM_TimeBaseStructure.TIM_Period = arr; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值 计数到5000为500ms
TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置用来作为TIMx时钟频率除数的预分频值 10Khz的计数频率
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分割:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上计数模式
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位
TIM_ITConfig(TIM1,TIM_IT_Update,ENABLE ); //使能指定的TIM3中断,允许更新中断
TIM_Cmd(TIM1, ENABLE); //使能TIMx外设
}
void PWM_Init(u16 arr,u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure2;
TIM_OCInitTypeDef TIM_OCInitStructure1;
TIM_OCInitTypeDef TIM_OCInitStructure3;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1|RCC_APB2Periph_GPIOB|RCC_APB2Periph_GPIOA, ENABLE); //使能定时器3时钟
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8; //TIM_CH1
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GPIO
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13|GPIO_Pin_14|GPIO_Pin_15; //TIM_CH1N TIM_CH2N TIM CH3N
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //复用推挽输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);//初始化GPIO
//初始化TIM3
TIM_TimeBaseStructure.TIM_Period = arr; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值
TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置用来作为TIMx时钟频率除数的预分频值
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分割:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上计数模式
TIM_TimeBaseStructure.TIM_RepetitionCounter=0;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位
TIM_ARRPreloadConfig(TIM1, ENABLE);
//初始化TIM3 Channel2 PWM模式
TIM_OCInitStructure2.TIM_OCMode = TIM_OCMode_PWM1; //选择定时器模式:TIM脉冲宽度调制模式2
TIM_OCInitStructure2.TIM_OutputNState = TIM_OutputNState_Enable; //比较输出使能
TIM_OCInitStructure2.TIM_OCNPolarity = TIM_OCNPolarity_High; //输出极性:TIM输出比较极性高
TIM_OC2Init(TIM1, &TIM_OCInitStructure2); //根据T指定的参数初始化外设TIM3 OC2
TIM_OCInitStructure1.TIM_OCMode = TIM_OCMode_PWM1; //选择定时器模式:TIM脉冲宽度调制模式2
TIM_OCInitStructure1.TIM_OutputNState = TIM_OutputNState_Enable; //比较输出使能
TIM_OCInitStructure1.TIM_OCNPolarity = TIM_OCNPolarity_High; //输出极性:TIM输出比较极性高
TIM_OCInitStructure1.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能
TIM_OCInitStructure1.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC1Init(TIM1, &TIM_OCInitStructure1); //根据T指定的参数初始化外设TIM3 OC2
TIM_OCInitStructure3.TIM_OCMode = TIM_OCMode_PWM1; //选择定时器模式:TIM脉冲宽度调制模式2
TIM_OCInitStructure3.TIM_OutputNState = TIM_OutputNState_Enable; //比较输出使能
TIM_OCInitStructure3.TIM_OCNPolarity = TIM_OCNPolarity_High; //输出极性:TIM输出比较极性高
TIM_OC3Init(TIM1, &TIM_OCInitStructure3); //根据T指定的参数初始化外设TIM3 OC2
TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable); //使能TIM3在CCR2上的预装载寄存器
TIM_OC2PreloadConfig(TIM1, TIM_OCPreload_Enable);
TIM_OC3PreloadConfig(TIM1, TIM_OCPreload_Enable);
TIM_Cmd(TIM1, ENABLE); //使能TIM3
TIM_CtrlPWMOutputs(TIM1,ENABLE);
}
int main(void)
{
u8 a=1;
u8 b=0;
delay_init();
PWM_Init(1439,0);
while(1)
{
delay_ms(50);
// TIM_SetCompare1(TIM1,720);
if(b) a--;
else a++;
if (a==3)b=1;
if (a==1)b=0;
if (a==1) TIM_SetCompare1(TIM1,720);
else TIM_SetCompare1(TIM1,0);
if (a==2) TIM_SetCompare2(TIM1,720);
else TIM_SetCompare2(TIM1,0);
if (a==3) TIM_SetCompare3(TIM1,720);
else TIM_SetCompare3(TIM1,0);
}
}
这个主函数最后软件模拟出来的结果是下面这个
CH1N CH1通道互补输出,但是满足主函数里的条件,CH2N CH3N则一直是高电平。
我应该是设置的不对,请问CH1 CH1N CH2N CH3N独立作为PWM输出的库函数是怎么写的,CH2 CH3通道可以不设置吗,还是说一定要设置呢。
萌新初学,求助
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