用stm32写一个ws2812流水灯的代码，仅使用pwm

好的，下面是使用STM32单片机控制WS2812流水灯的代码，仅使用PWM输出模块：

#include "stm32f10x.h"

#define LED_NUM 60 // 定义LED灯的数量
#define TIM_PERIOD 90 // 定义PWM输出模块的周期

// 定义颜色结构体，包括红、绿、蓝三个分量
typedef struct {
    uint8_t r;
    uint8_t g;
    uint8_t b;
} Color;

// 定义全局变量，存储每个LED的颜色
Color led_colors[LED_NUM];

// 定义函数，将RGB颜色转换为WS2812协议下的数据格式
void RGB2WS2812(Color color, uint8_t *data) {
    uint8_t i;
    uint32_t R = color.r, G = color.g, B = color.b;
    for (i = 0; i < 8; i++) {
        if (G & (0x80 >> i)) {
            data[i] = TIM_PERIOD;
        } else {
            data[i] = TIM_PERIOD / 3;
        }
    }
    for (i = 0; i < 8; i++) {
        if (R & (0x80 >> i)) {
            data[8 + i] = TIM_PERIOD;
        } else {
            data[8 + i] = TIM_PERIOD / 3;
        }
    }
    for (i = 0; i < 8; i++) {
        if (B & (0x80 >> i)) {
            data[16 + i] = TIM_PERIOD;
        } else {
            data[16 + i] = TIM_PERIOD / 3;
        }
    }
}

// 定义函数，将所有LED的颜色数据转换为WS2812协议下的数据格式
void LED2WS2812(uint8_t *data) {
    uint8_t i, j;
    for (i = 0; i < LED_NUM; i++) {
        Color color = led_colors[i];
        RGB2WS2812(color, data + i * 24);
    }
}

int main(void) {
    // 定义GPIO端口和引脚
    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    // 定义定时器TIM2
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_OCInitTypeDef TIM_OCInitStructure;
    TIM_TimeBaseStructure.TIM_Period = TIM_PERIOD - 1;
    TIM_TimeBaseStructure.TIM_Prescaler = 0;
    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

    // 定义PWM输出模块
    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_Pulse = 0;
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OC1Init(TIM2, &TIM_OCInitStructure);
    TIM_OC1PreloadConfig(TIM2, TIM_OCPreload_Enable);

    // 启动定时器TIM2
    TIM_Cmd(TIM2, ENABLE);

    // 设置TIM2的DMA传输模式
    DMA_InitTypeDef DMA_InitStructure;
    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t) & (TIM2->CCR1);
    DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t) & led_data;
    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
    DMA_InitStructure.DMA_BufferSize = 24 * LED_NUM;
    DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
    DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
    DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
    DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
    DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
    DMA_InitStructure.DMA_Priority = DMA_Priority_High;
    DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
    DMA_Init(DMA1_Channel7, &DMA_InitStructure);

    // 启动DMA传输
    DMA_Cmd(DMA1_Channel7, ENABLE);

    while (1) {
        // 将某个LED的颜色设置为红色
        led_colors[0].r = 255;
        led_colors[0].g = 0;
        led_colors[0].b = 0;

        // 将所有LED的颜色数据转换为WS2812协议下的数据格式
        LED2WS2812(led_data);

        // 等待一段时间
        for (uint32_t i = 0; i < 1000000; i++);
    }
}

此代码中使用了一个DMA传输模块，用于将颜色数据传输到PWM输出模块中。在代码中，并没有直接使用PWM输出模块的占空比来控制LED灯的颜色，而是将RGB颜色转换为WS2812协议下的数据格式，然后通过PWM输出模块输出到LED灯中。