【GD32L233C-START】3、pwm实现呼吸灯

1、硬件连接

2、PWM通道

可以看出，PC6对应的是TIMER2的CH0通道。

3、实现方法

通过调整占空比，使其递增，LED逐渐变亮，从而在视觉上实现呼吸灯的效果。

4、核心代码

（1）PWM初始化

void PwmInit(void){    rcu_periph_clock_enable(RCU_GPIOC);    /* TIMER1 GPIO */    gpio_mode_set(GPIOC, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO_PIN_6 );    gpio_output_options_set(GPIOC, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_6);    gpio_af_set(GPIOC, GPIO_AF_1, GPIO_PIN_6);    //64000000/6400=10k    //TIMER2CLK = SystemCoreClock/6400 = 0.01MHz, the period is 1s(100/10000).=0.01s=10ms=100hz    timer_oc_parameter_struct timer_ocinitpara;    timer_parameter_struct timer_initpara;    /* enable the peripherals clock */    rcu_periph_clock_enable(RCU_TIMER2);    /* deinit a TIMER */    timer_deinit(TIMER2);    /* initialize TIMER init parameter struct */    timer_struct_para_init(&timer_initpara);    /* TIMER2 configuration */    timer_initpara.prescaler        = 6399;    timer_initpara.alignedmode      = TIMER_COUNTER_EDGE;    timer_initpara.counterdirection = TIMER_COUNTER_UP;    timer_initpara.period           = 99;    timer_initpara.clockdivision    = TIMER_CKDIV_DIV1;    timer_init(TIMER2, &timer_initpara);    /* initialize TIMER channel output parameter struct */    timer_channel_output_struct_para_init(&timer_ocinitpara);    /* configure TIMER channel output function */    timer_ocinitpara.outputstate    = TIMER_CCX_ENABLE;    timer_ocinitpara.ocpolarity     = TIMER_OC_POLARITY_HIGH;    timer_channel_output_config(TIMER2, TIMER_CH_0, &timer_ocinitpara);    timer_channel_output_pulse_value_config(TIMER2, TIMER_CH_0, 99);    /* CH0 configuration in OC timing mode */    timer_channel_output_mode_config(TIMER2, TIMER_CH_0, TIMER_OC_MODE_PWM0);    /* enable a TIMER */    timer_enable(TIMER2);}