写一个STM32F103C8T6 的pwm程序，占空比为0.2%，频率1HZ

好的，以下是使用STM32F103C8T6的PWM程序，占空比为0.2％，频率为1HZ的代码：

#include "stm32f10x.h"

void delay_ms(uint32_t ms)
{
    for(uint32_t i=0; i<ms; i++)
    {
        for(uint32_t j=0; j<7200; j++);
    }
}

void GPIO_Configuration(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
}

void TIM_Configuration(void)
{
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_OCInitTypeDef TIM_OCInitStructure;

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);

    TIM_TimeBaseStructure.TIM_Prescaler = 7199;
    TIM_TimeBaseStructure.TIM_Period = 9999;
    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_Pulse = 20; // 0.2% duty cycle
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OC1Init(TIM3, &TIM_OCInitStructure);

    TIM_Cmd(TIM3, ENABLE);
}

int main(void)
{
    GPIO_Configuration();
    TIM_Configuration();

    while(1)
    {
        // do nothing
    }
}

这个程序通过TIM3通道1产生PWM信号，占空比为0.2％，频率为1HZ。在GPIOA1引脚上输出PWM信号。在main函数中，使用两个函数分别进行GPIO和TIM的配置。之后进入一个无限循环，程序会一直输出PWM信号。为了让程序保持运行，我们在循环中添加了一个什么也不做的代码。