写一个用stm32f103c8t6使用按键输出不同的pwm的代码

以下是使用STM32F103C8T6控制外部设备（如LED）亮度的示例代码，它使用按键控制PWM占空比：

#include "stm32f10x.h"

void delay(int time)
{
    for (int i = 0; i < time; i++);
}

void GPIO_Config(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    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 PWM_Config(void)
{
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_OCInitTypeDef TIM_OCInitStructure;

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

    TIM_TimeBaseStructure.TIM_Period = 999;
    TIM_TimeBaseStructure.TIM_Prescaler = 71;
    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

    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);

    TIM_Cmd(TIM2, ENABLE);
}

int main(void)
{
    int pulse = 0;
    int direction = 1;

    GPIO_Config();
    PWM_Config();

    while (1)
    {
        if (GPIO_ReadInputDataBit(GPIOA, GPIO_Pin_0) == 0)
        {
            delay(100000);
            direction = -direction;
        }

        pulse += direction;

        if (pulse >= 1000)
        {
            pulse = 999;
            direction = -1;
        }