stm32按键控制灯的亮度代码

以下是一个基于STM32的按键控制LED灯亮度的代码示例：

#include "stm32f10x.h"

#define LED_PIN     GPIO_Pin_13
#define LED_PORT    GPIOC

#define KEY_PIN     GPIO_Pin_0
#define KEY_PORT    GPIOA

#define MAX_BRIGHTNESS  1000    // 最大亮度值
#define MIN_BRIGHTNESS  0       // 最小亮度值

volatile uint16_t brightness = MAX_BRIGHTNESS;  // 初始亮度为最大亮度值

void GPIO_Configuration(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOC, ENABLE);

    // LED灯
    GPIO_InitStructure.GPIO_Pin = LED_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(LED_PORT, &GPIO_InitStructure);

    // 按键
    GPIO_InitStructure.GPIO_Pin = KEY_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(KEY_PORT, &GPIO_InitStructure);
}

void TIM2_Configuration(void)
{
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

    TIM_TimeBaseStructure.TIM_Period = 1000 - 1;   // 定时器周期为1ms
    TIM_TimeBaseStructure.TIM_Prescaler = 71;      // 定时器分频系数为72
    TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

    TIM_Cmd(TIM2, ENABLE);
}

int main(void)
{
    GPIO_Configuration();
    TIM2_Configuration();

    while (1)
    {
        if (GPIO_ReadInputDataBit(KEY_PORT, KEY_PIN) == 0)   // 按键按下
        {
            if (brightness > MIN_BRIGHTNESS)    // 亮度值减小
            {
                brightness--;
            }
        }
        else    // 按键释放
        {
            if (brightness < MAX_BRIGHTNESS)    // 亮度值增加
            {
                brightness++;
            }
        }

        TIM_SetCompare2(TIM2, brightness);  // 设置PWM占空比
    }
}

这个代码使用了STM32的定时器和PWM输出，当按键按下时，亮度值会逐渐减小，当按键释放时，亮度值会逐渐增加。通过修改PWM输出的占空比，来实现LED灯的亮度控制。