基于GD32F303RCT6芯片 通过PWM与DMA结合硬件控制呼吸灯，用C语言写一份代码

A：

#include "gd32f3x0.h"

#define LED_PIN         GPIO_PIN_13
#define LED_PORT        GPIOC
#define PWM_CHANNEL     TIMER_CH_0
#define PWM_PERIOD      1000

void pwm_init(void);
void dma_init(void);

int main(void)
{
    /* 初始化PWM和DMA */
    pwm_init();
    dma_init();
    
    /* 循环呼吸灯效果 */
    uint16_t duty = 0;
    uint8_t direction = 0;
    while (1)
    {
        /* 根据呼吸灯方向调整占空比 */
        if (direction == 0)
        {
            duty++;
            if (duty == PWM_PERIOD)
            {
                direction = 1;
            }
        }
        else
        {
            duty--;
            if (duty == 0)
            {
                direction = 0;
            }
        }
        
        /* 设置PWM占空比 */
        timer_channel_output_pulse_value_config(TIMER0, PWM_CHANNEL, duty);
        
        /* 等待一段时间 */
        delay_1ms(10);
    }
}

void pwm_init(void)
{
    /* GPIO初始化 */
    rcu_periph_clock_enable(RCU_GPIOC);
    gpio_mode_set(LED_PORT, GPIO_MODE_AF, GPIO_PUPD_NONE, LED_PIN);
    gpio_output_options_set(LED_PORT, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, LED_PIN);
    gpio_af_set(LED_PORT, GPIO_AF_2, LED_PIN);
    
    /* 定时器初始化 */
    rcu_periph_clock_enable(RCU_TIMER0);
    timer_prescaler_config(TIMER0, 71);
    timer_auto_reload_value_config(TIMER0, PWM_PERIOD - 1);
    timer_enable(TIMER0);
    
    /* PWM输出配置 */
    timer_channel_output_mode_config(TIMER0, PWM_CHANNEL, TIM_OC_MODE_PWM0);
    timer_channel_output_pulse_value_config(TIMER0, PWM_CHANNEL, 0);
    timer_channel_output_state_config(TIMER0, PWM_CHANNEL, TIM_OUTPUT_STATE_ENABLE);
    timer_primary_output_config(TIMER0, ENABLE);
}

void dma_init(void)
{
    /* DMA初始化 */
    rcu_periph_clock_enable(RCU_DMA0);
    dma_deinit(DMA0, DMA_CH1);
    dma_init_struct.direction = DMA_MEMORY_TO_PERIPH;
    dma_init_struct.memory_addr = (uint32_t)&PWM_DUTY_VAL;
    dma_init_struct.memory_inc = DMA_MEMORY_INC_NONE;
    dma_init_struct.memory_width = DMA_MEMORY_WIDTH_16BIT;
    dma_init_struct.periph_addr = (uint32_t)&TIMER0->CCR0;
    dma_init_struct.periph_inc = DMA_PERIPH_INC_NONE;
    dma_init_struct.periph_width = DMA_PERIPHERAL_WIDTH_16BIT;
    dma_init_struct.number = PWM_PERIOD;
    dma_init_struct.priority = DMA_PRIORITY_MEDIUM;
    dma_init(DMA0, DMA_CH1, &dma_init_struct);
    
    /* 启动DMA */
    dma_channel_enable(DMA0, DMA_CH1);
}