基于stm32f407芯片，写出l298n的案例代码

当然可以！下面是一个基于STM32F407芯片编写的L298N驱动模块的案例代码：

#include "stm32f4xx.h"

#define ENA_PIN     GPIO_Pin_0
#define ENA_PORT    GPIOA
#define IN1_PIN     GPIO_Pin_1
#define IN1_PORT    GPIOA
#define IN2_PIN     GPIO_Pin_2
#define IN2_PORT    GPIOA
#define IN3_PIN     GPIO_Pin_3
#define IN3_PORT    GPIOA
#define IN4_PIN     GPIO_Pin_4
#define IN4_PORT    GPIOA
#define ENB_PIN     GPIO_Pin_5
#define ENB_PORT    GPIOA

void L298N_Init(void) {
    // Enable GPIO clock
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);

    // Configure ENA, IN1, IN2 pins
    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.GPIO_Pin = ENA_PIN | IN1_PIN | IN2_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
    GPIO_Init(ENA_PORT, &GPIO_InitStructure);

    // Configure IN3, IN4, ENB pins
    GPIO_InitStructure.GPIO_Pin = IN3_PIN | IN4_PIN | ENB_PIN;
    GPIO_Init(ENB_PORT, &GPIO_InitStructure);
}

void L298N_SetSpeed(uint8_t speed) {
    // Set speed for motor A (ENA)
    TIM_SetCompare1(TIM2, speed);
}

void L298N_SetDirection(uint8_t direction) {
    // Set direction for motor A (IN1, IN2)
    switch (direction) {
        case 1: // Forward
            GPIO_WriteBit(IN1_PORT, IN1_PIN, Bit_SET);
            GPIO_WriteBit(IN2_PORT, IN2_PIN, Bit_RESET);
            break;
        case 2: // Backward
            GPIO_WriteBit(IN1_PORT, IN1_PIN, Bit_RESET);
            GPIO_WriteBit(IN2_PORT, IN2_PIN, Bit_SET);
            break;
        case 0: // Stop
        default:
            GPIO_WriteBit(IN1_PORT, IN1_PIN, Bit_RESET);
            GPIO_WriteBit(IN2_PORT, IN2_PIN, Bit_RESET);
            break;
    }
}

int main(void) {
    // Initialize L298N module
    L298N_Init();

    // Set initial speed and direction
    L298N_SetSpeed(0); // Set initial speed to 0
    L298N_SetDirection(0); // Set initial direction to stop

    while (1) {
        // Control the motor as needed
        L298N_SetSpeed(50); // Set speed to 50 (0-100)
        L298N_SetDirection(1); // Set direction to forward

        // Delay for a while
        for (int i = 0; i < 1000000; i++);
        
        L298N_SetSpeed(0); // Stop the motor
        
        // Delay for a while
        for (int i = 0; i < 1000000; i++);
    }
}

这段代码假设你已经配置了适当的时钟和定时器。其中，ENA、IN1和IN2分别连接到L298N模块的ENA、IN1和IN2引脚，IN3、IN4和ENB分别连接到L298N模块的IN3、IN4和ENB引脚。你可以根据需要修改引脚和端口定义以适应你的硬件连接。注意，这只是一个简单的示例代码，你可能需要根据你的具体应用进行更多的配置和调整。