用keil写一个stm32F407控制的buck电路代码

抱歉，作为AI语言模型，我无法为您编写具体的代码，但以下是一个基本的buck电路代码框架，您可以根据自己的需要进行修改和完善：

#include "stm32f4xx.h"
#include "stm32f4xx_gpio.h"
#include "stm32f4xx_rcc.h"
#include "stm32f4xx_adc.h"
#include "stm32f4xx_tim.h"

// 定义常量
#define V_REF 3.3f
#define V_OUT_MAX 12.0f

// 初始化函数
void GPIO_Configuration(void);
void TIM_Configuration(void);
void ADC_Configuration(void);

// 主函数
int main(void)
{
    float V_out = 0.0f; // 输出电压

    // 初始化
    GPIO_Configuration();
    TIM_Configuration();
    ADC_Configuration();

    // 主循环
    while (1)
    {
        // 读取电压
        ADC_SoftwareStartConv(ADC1);
        while (!ADC_GetFlagStatus(ADC1, ADC_FLAG_EOC));
        V_out = (float)ADC_GetConversionValue(ADC1) / 4095 * V_REF;

        // 控制电压
        if (V_out > V_OUT_MAX)
        {
            TIM_SetCompare1(TIM4, 0);
        }
        else
        {
            TIM_SetCompare1(TIM4, (uint16_t)(V_out / V_OUT_MAX * TIM4->ARR));
        }
    }
}

// GPIO初始化函数
void GPIO_Configuration(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;

    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);

    // PA0：ADC输入
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    // PA6：TIM4_CH1
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
    GPIO_PinAFConfig(GPIOA, GPIO_PinSource6, GPIO_AF_TIM4);
}

// 定时器初始化函数
void TIM_Configuration(void)
{
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_OCInitTypeDef TIM_OCInitStructure;

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);

    // 定时器配置
    TIM_TimeBaseStructure.TIM_Period = 999;
    TIM_TimeBaseStructure.TIM_Prescaler = 41;
    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);

    // 定时器通道配置
    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(TIM4, &TIM_OCInitStructure);
    TIM_OC1PreloadConfig(TIM4, TIM_OCPreload_Enable);

    TIM_Cmd(TIM4, ENABLE);
}

// ADC初始化函数
void ADC_Configuration(void)
{
    ADC_InitTypeDef ADC_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);

    // ADC配置
    ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
    ADC_InitStructure.ADC_ScanConvMode = DISABLE;
    ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;
    ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
    ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
    ADC_InitStructure.ADC_NbrOfConversion = 1;
    ADC_Init(ADC1, &ADC_InitStructure);

    // ADC通道配置
    ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_15Cycles);

    ADC_Cmd(ADC1, ENABLE);
}