stm32pwm控制多个呼吸灯

要控制多个呼吸灯，可以使用多个PWM输出通道，并在每个通道上设置不同的呼吸灯参数。

以下是一个简单的示例代码，控制两个呼吸灯，分别连接到两个PWM输出通道PA0和PA1上：

#include "stm32f4xx.h"

#define LED1_PIN GPIO_Pin_0
#define LED1_GPIO GPIOA
#define LED1_GPIO_CLK RCC_AHB1Periph_GPIOA
#define LED1_TIM TIM2
#define LED1_TIM_CLK RCC_APB1Periph_TIM2
#define LED1_CHANNEL TIM_OCMode_PWM1
#define LED1_PRESCALER 84
#define LED1_PERIOD 999

#define LED2_PIN GPIO_Pin_1
#define LED2_GPIO GPIOA
#define LED2_GPIO_CLK RCC_AHB1Periph_GPIOA
#define LED2_TIM TIM3
#define LED2_TIM_CLK RCC_APB1Periph_TIM3
#define LED2_CHANNEL TIM_OCMode_PWM1
#define LED2_PRESCALER 84
#define LED2_PERIOD 999

void LED_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_OCInitTypeDef TIM_OCInitStructure;

    RCC_AHB1PeriphClockCmd(LED1_GPIO_CLK | LED2_GPIO_CLK, ENABLE);
    RCC_APB1PeriphClockCmd(LED1_TIM_CLK | LED2_TIM_CLK, ENABLE);

    GPIO_InitStructure.GPIO_Pin = LED1_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
    GPIO_Init(LED1_GPIO, &GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin = LED2_PIN;
    GPIO_Init(LED2_GPIO, &GPIO_InitStructure);

    GPIO_PinAFConfig(LED1_GPIO, GPIO_PinSource0, GPIO_AF_TIM2);
    GPIO_PinAFConfig(LED2_GPIO, GPIO_PinSource1, GPIO_AF_TIM3);

    TIM_TimeBaseStructure.TIM_Period = LED1_PERIOD;
    TIM_TimeBaseStructure.TIM_Prescaler = LED1_PRESCALER;
    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(LED1_TIM, &TIM_TimeBaseStructure);

    TIM_OCInitStructure.TIM_OCMode = LED1_CHANNEL;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
    TIM_OCInitStructure.TIM_Pulse = 0;
    TIM_OC1Init(LED1_TIM, &TIM_OCInitStructure);

    TIM_TimeBaseStructure.TIM_Period = LED2_PERIOD;
    TIM_TimeBaseStructure.TIM_Prescaler = LED2_PRESCALER;
    TIM_TimeBaseInit(LED2_TIM, &TIM_TimeBaseStructure);

    TIM_OCInitStructure.TIM_OCMode = LED2_CHANNEL;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
    TIM_OCInitStructure.TIM_Pulse = 0;
    TIM_OC1Init(LED2_TIM, &TIM_OCInitStructure);

    TIM_Cmd(LED1_TIM, ENABLE);
    TIM_Cmd(LED2_TIM, ENABLE);
}

void LED_Breath(uint16_t duty1, uint16_t duty2)
{
    uint16_t i;

    for (i = 0; i <= LED1_PERIOD; i++)
    {
        TIM_SetCompare1(LED1_TIM, i * duty1 / LED1_PERIOD);
        TIM_SetCompare1(LED2_TIM, i * duty2 / LED2_PERIOD);
        delay_ms(10);
    }

    for (i = LED1_PERIOD; i >= 0; i--)
    {
        TIM_SetCompare1(LED1_TIM, i * duty1 / LED1_PERIOD);
        TIM_SetCompare1(LED2_TIM, i * duty2 / LED2_PERIOD);
        delay_ms(10);
    }
}

int main(void)
{
    LED_Init();

    while (1)
    {
        LED_Breath(500, 800);
    }
}

在上面的代码中，LED_Init函数用于初始化两个PWM输出通道，LED_Breath函数用于控制呼吸灯的亮度。在LED_Breath函数中，使用for循环逐步增加和减少PWM输出的占空比，从而实现呼吸灯的效果。循环中的delay_ms函数用于延迟一段时间，以便呼吸灯的亮度变化更加平滑。