pwm输入模式测量占空比实践-凯发app官方网站

捕获代码：
void tim4_cap_init(u16 arr, u16 psc)
{
    //1. 使能时钟
    rcc_apb2periphclockcmd(rcc_apb2periph_gpiod|rcc_apb2periph_afio, enable);

    //配置gpio口
    gpio_inittypedef gpio_initstructure;
    gpio_initstructure.gpio_pin = gpio_pin_12;
    gpio_initstructure.gpio_mode = gpio_mode_in_floating; //浮空输入模式
    gpio_initstructure.gpio_speed = gpio_speed_50mhz;
    gpio_init(gpiod, &gpio_initstructure);
    //gpio_resetbits(gpiod, gpio_pin_12); //1214pm2：先删除

    //2.tim4配置
    //gpio_afiodeinit(); //刚开始没有这个语句，所以一直没有重映射成功
    gpio_pinremapconfig(gpio_remap_tim4, enable); //这个就是重映射功能函数
    rcc_apb1periphclockcmd(rcc_apb1periph_tim4, enable);

    //配置tim4
    tim_timebaseinittypedef tim_timebasestructure;
    tim_timebasestructure.tim_clockdivision = tim_ckd_div1;
    tim_timebasestructure.tim_countermode = tim_countermode_up;
    tim_timebasestructure.tim_period = arr;
    tim_timebasestructure.tim_prescaler= psc;
    tim_timebaseinit(tim4, &tim_timebasestructure);

    //3. 配置tim4 channel输入捕获
    tim_icinittypedef tim_icinitstructure;
    tim_icinitstructure.tim_channel = tim_channel_1;
    tim_icinitstructure.tim_icpolarity = tim_icpolarity_rising; //上升沿捕获
    tim_icinitstructure.tim_icprescaler = tim_icpsc_div1;   //对输入的pwm信号不分频
    tim_icinitstructure.tim_icselection = tim_icselection_directti; // ic1直接连接ti1fp1
    tim_icinitstructure.tim_icfilter = 0x00;
    //tim_icinit(tim4, &tim_icinitstructure);
    tim_pwmiconfig(tim4, &tim_icinitstructure);

#if 0   //实测不需要这个
    //配置ch2
    tim_icinitstructure.tim_channel = tim_channel_2;
    tim_icinitstructure.tim_icpolarity = tim_icpolarity_falling;      //下降沿触发；
    tim_icinitstructure.tim_icselection = tim_icselection_indirectti; //ic2间接连接ti1fp2
    tim_icinitstructure.tim_icprescaler = tim_icpsc_div1;             //对输入的pwm信号不分频
    tim_icinitstructure.tim_icfilter = 0x0;
    tim_pwmiconfig(tim4, &tim_icinitstructure);
#endif

    //选择输入捕获的触发信号；
    tim_selectinputtrigger(tim4, tim_ts_ti1fp1);

    // 选择从模式
    // pwm输入模式时，从模式必须工作在复位模式，当捕获开始时，计数器cnt被复位清零；
    tim_selectslavemode(tim4, tim_slavemode_reset);
    tim_selectmasterslavemode(tim4, tim_masterslavemode_enable); 

    //配置中断分组
    //https://blog.csdn.net/qq_42475191/article/details/120535222
    //这个函数的作用是对中断的优先级进行分组，这个函数在系统中只能被调用一次，一旦分组确定就{banned}最佳好不要更改。
   nvic_prioritygroupconfig(nvic_prioritygroup_2); //设置nvic中断分组2:2位抢占优先级，2位响应优先级

    nvic_inittypedef nvic_initstructure;
    nvic_initstructure.nvic_irqchannel = tim4_irqn;
    nvic_initstructure.nvic_irqchannelcmd = enable;
    nvic_initstructure.nvic_irqchannelpreemptionpriority = 1; //3; //抢占优先级3
    nvic_initstructure.nvic_irqchannelsubpriority = 3;        //0; //子优先级2
    nvic_init(&nvic_initstructure);

    // 使能捕获中断，这个中断主要针对的是主捕获通道（ti1fp1）
    tim_itconfig(tim4, tim_it_cc1, enable);
    // 清除中断标志位
    tim_clearitpendingbit(tim4, tim_it_cc1);

    //计数器开始计数
    tim_cmd(tim4, enable); //使能tim4

    #if 0
    tim_itconfig(tim4,tim_it_update,enable); //允许溢出中断
    tim_itconfig(tim4,tim_it_cc1,enable);    //允许捕获中断
    tim_itconfig(tim4,tim_it_cc2,enable);
    tim_itconfig(tim4,tim_it_cc3,enable);
    tim_itconfig(tim4,tim_it_cc4,enable);
    #endif
}

void tim4_irqhandler(void)
{
    int ret;

    ret = tim_getflagstatus(tim4, tim_flag_cc1);
    if (ret)
    {
        tim_clearitpendingbit(tim4, tim_it_cc1);
  
        uint32_t ic1_ccr1, ic2_ccr2;
        ic1_ccr1 = tim_getcapture1(tim4); //获取周期值ccr1
        ic2_ccr2 = tim_getcapture2(tim4); //获取高电平时间ccr2

        if (ic1_ccr1 > 0) {
            tim4_pwm.pwm_0 = ((float)ic2_ccr2 / ic1_ccr1) * 100;  /* 这里 * 100, 便于计算和显示 */
        }
    }
}