在main()中

ch1_open();

delay_ms(1000);

ch2_open();

delay_ms(1000);

ch3_open();

delay_ms(1000);

ch4_open();

delay_ms(1000);

在timer.c中添加了

//開(kāi)啟通道一，同時(shí)關(guān)閉通道二三四

void ch1_open(void)

{

TIM3->CCER|=(1<<1);

TIM3->CCER&=~(1<<4);

TIM3->CCER&=~(1<<8);

TIM3->CCER&=~(1<<12);

}

//開(kāi)啟通道二，同時(shí)關(guān)閉通道一三四

void ch2_open(void)

{

TIM3->CCER&=~(1<<1);

TIM3->CCER|=(1<<4);

TIM3->CCER&=~(1<<8);

TIM3->CCER&=~(1<<12);

}

//開(kāi)啟通道三，同時(shí)關(guān)閉通道一二四

void ch3_open(void)

{

TIM3->CCER&=~(1<<1);

TIM3->CCER&=~(1<<4);

TIM3->CCER|=(1<<8);

TIM3->CCER&=~(1<<12);

}

//開(kāi)啟通道四，同時(shí)關(guān)閉通道一二三

void ch4_open(void)

{

TIM3->CCER&=~(1<<1);

TIM3->CCER&=~(1<<4);

TIM3->CCER&=~(1<<8);

TIM3->CCER|=(1<<12);

}