【英飞凌CYW20829测评】-4-PWM呼吸灯

最新推荐文章于 2025-05-03 23:54:14 发布

21ic电子工程师

最新推荐文章于 2025-05-03 23:54:14 发布

阅读量89

点赞数

分类专栏：嵌入式基础知识文章标签：嵌入式硬件单片机

原文链接：https://bbs.21ic.com/icview-3390628-1-1.html

版权

嵌入式基础知识专栏收录该内容

2545 篇文章

订阅专栏

开发板上有两个用户LED，丝印分别是USER LED1和USER LED2，电路原理图如下：

本次实验计划使用PWM内部连接到USER LED2，实现呼吸灯效果；在定时器内通过GPIO正常驱动USER LED1，周期2s。

接着通过BSP Configurators -> Device Configurator 4.20进行外设配置和引脚等配置界面。

配置USER LED2内部连接到TCPWM信号：

时钟分配：

PWM参数配置：

点击SAVE后，自动检测配置是否有错误，如果没有错误，自动生成代码。

复制

const cy_stc_tcpwm_pwm_config_t tcpwm_0_group_1_cnt_5_config =

{

    .pwmMode = CY_TCPWM_PWM_MODE_PWM,

    .clockPrescaler = CY_TCPWM_PWM_PRESCALER_DIVBY_1,

    .pwmAlignment = CY_TCPWM_PWM_LEFT_ALIGN,

    .deadTimeClocks = 0,

    .runMode = CY_TCPWM_PWM_CONTINUOUS,

    .period0 = 32768,

    .period1 = 32768,

    .enablePeriodSwap = false,

    .compare0 = 16384,

    .compare1 = 16384,

    .enableCompareSwap = false,

    .interruptSources = (CY_TCPWM_INT_ON_TC & 0U) | (CY_TCPWM_INT_ON_CC0 & 0U) | (CY_TCPWM_INT_ON_CC1 & 0U),

    .invertPWMOut = CY_TCPWM_PWM_INVERT_DISABLE,

    .invertPWMOutN = CY_TCPWM_PWM_INVERT_DISABLE,

    .killMode = CY_TCPWM_PWM_STOP_ON_KILL,

    .swapInputMode = tcpwm_0_group_1_cnt_5_INPUT_DISABLED & 0x3U,

    .swapInput = CY_TCPWM_INPUT_0,

    .reloadInputMode = tcpwm_0_group_1_cnt_5_INPUT_DISABLED & 0x3U,

    .reloadInput = CY_TCPWM_INPUT_0,

    .startInputMode = tcpwm_0_group_1_cnt_5_INPUT_DISABLED & 0x3U,

    .startInput = CY_TCPWM_INPUT_0,

    .killInputMode = tcpwm_0_group_1_cnt_5_INPUT_DISABLED & 0x3U,

    .killInput = CY_TCPWM_INPUT_0,

    .countInputMode = tcpwm_0_group_1_cnt_5_INPUT_DISABLED & 0x3U,

    .countInput = CY_TCPWM_INPUT_1,

    .swapOverflowUnderflow = false,

    .immediateKill = false,

    .tapsEnabled = 45,

    .compare2 = 16384,

    .compare3 = 16384,

    .enableCompare1Swap = false,

    .compare0MatchUp = true,

    .compare0MatchDown = false,

    .compare1MatchUp = true,

    .compare1MatchDown = false,

    .kill1InputMode = tcpwm_0_group_1_cnt_5_INPUT_DISABLED & 0x3U,

    .kill1Input = CY_TCPWM_INPUT_0,

    .pwmOnDisable = CY_TCPWM_PWM_OUTPUT_HIGHZ,

    .trigger0Event = CY_TCPWM_CNT_TRIGGER_ON_DISABLED,

    .trigger1Event = CY_TCPWM_CNT_TRIGGER_ON_DISABLED,

    .reloadLineSelect = false,

    .line_out_sel = CY_TCPWM_OUTPUT_PWM_SIGNAL,

    .linecompl_out_sel = CY_TCPWM_OUTPUT_INVERTED_PWM_SIGNAL,

    .line_out_sel_buff = CY_TCPWM_OUTPUT_PWM_SIGNAL,

    .linecompl_out_sel_buff = CY_TCPWM_OUTPUT_INVERTED_PWM_SIGNAL,

    .deadTimeClocks_linecompl_out = 0,

#if defined (CY_IP_MXS40TCPWM)

    .hrpwm_enable = false,

    .hrpwm_input_freq = CY_TCPWM_HRPWM_FREQ_80MHZ_OR_100MHZ,

    .kill_line_polarity = CY_TCPWM_LINEOUT_AND_LINECMPOUT_IS_LOW,

    .deadTimeClocksBuff = 0,

    .deadTimeClocksBuff_linecompl_out = 0,

    .buffer_swap_enable = false,

    .glitch_filter_enable = false,

    .gf_depth = CY_GLITCH_FILTER_DEPTH_SUPPORT_VALUE_0,

    .dithering_mode = CY_TCPWM_DITHERING_DISABLE,

    .period_dithering_value = 128,

    .duty_dithering_value = 128,

    .limiter = CY_TCPWM_DITHERING_LIMITER_7,

#endif /* defined (CY_IP_MXS40TCPWM) */

};

接下来在主函数中进行相关初始化与应用程序编写：
首先是定时器设定为1ms一次中断

复制

void timer_init(void)

 {

    cy_rslt_t result;



    const cyhal_timer_cfg_t led_blink_timer_cfg =

    {

        .compare_value = 0,                 /* Timer compare value, not used */

        .period = LED_BLINK_TIMER_PERIOD,   /* Defines the timer period */

        .direction = CYHAL_TIMER_DIR_UP,    /* Timer counts up */

        .is_compare = false,                /* Don't use compare mode */

        .is_continuous = true,              /* Run timer indefinitely */

        .value = 0                          /* Initial value of counter */

    };



    /* Initialize the timer object. Does not use input pin ('pin' is NC) and

     * does not use a pre-configured clock source ('clk' is NULL). */

    result = cyhal_timer_init(&led_blink_timer, NC, NULL);



    /* timer init failed. Stop program execution */

    if (result != CY_RSLT_SUCCESS)

    {

        CY_ASSERT(0);

    }



    /* Configure timer period and operation mode such as count direction,

       duration */

    cyhal_timer_configure(&led_blink_timer, &led_blink_timer_cfg);



    /* Set the frequency of timer's clock source */

    cyhal_timer_set_frequency(&led_blink_timer, LED_BLINK_TIMER_CLOCK_HZ);



    /* Assign the ISR to execute on timer interrupt */

    cyhal_timer_register_callback(&led_blink_timer, isr_timer, NULL);



    /* Set the event on which timer interrupt occurs and enable it */

    cyhal_timer_enable_event(&led_blink_timer, CYHAL_TIMER_IRQ_TERMINAL_COUNT,

                              7, true);



    /* Start the timer with the configured settings */

    cyhal_timer_start(&led_blink_timer);

 }

接下来进行pwm初始化：

复制

static void isr_timer(void* callback_arg, cyhal_timer_event_t event)

{

    (void)callback_arg;

    (void)event;



    if(timer_count > 0)

        timer_count -= 1;

    if(timer_count == 0)

    {

        timer_count = 2000;

        cyhal_gpio_toggle(CYBSP_USER_LED1);

    }

    if(timer_count < 1000)

    {

            cyhal_pwm_set_duty_cycle(&pwm_led2_control,timer_count/10.0,10000);

    }

    else {

            cyhal_pwm_set_duty_cycle(&pwm_led2_control, (2000-timer_count)/10.0,10000);

    }

}

最终效果如下：