stm32怎样设置lcd_command函数用于向LCD控制器发送命令，参考代码

下面是一个使用STM32的GPIO控制LCD的例子，其中包含了设置LCD命令的函数：

#include "stm32f10x.h"

#define LCD_RS_Pin      GPIO_Pin_0
#define LCD_RS_Port     GPIOB
#define LCD_RW_Pin      GPIO_Pin_1
#define LCD_RW_Port     GPIOB
#define LCD_E_Pin       GPIO_Pin_2
#define LCD_E_Port      GPIOB
#define LCD_D4_Pin      GPIO_Pin_4
#define LCD_D4_Port     GPIOB
#define LCD_D5_Pin      GPIO_Pin_5
#define LCD_D5_Port     GPIOB
#define LCD_D6_Pin      GPIO_Pin_6
#define LCD_D6_Port     GPIOB
#define LCD_D7_Pin      GPIO_Pin_7
#define LCD_D7_Port     GPIOB

void LCD_Init(void);
void LCD_Command(unsigned char command);
void LCD_Data(unsigned char data);

int main(void)
{
    LCD_Init();

    // 发送清屏命令
    LCD_Command(0x01);

    while(1)
    {
        // 循环发送数据
    }
}

void LCD_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;

    // 使能GPIOB时钟
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

    // 配置GPIO为推挽输出
    GPIO_InitStructure.GPIO_Pin = LCD_RS_Pin | LCD_RW_Pin | LCD_E_Pin | LCD_D4_Pin | LCD_D5_Pin | LCD_D6_Pin | LCD_D7_Pin;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOB, &GPIO_InitStructure);

    // 初始化LCD
    LCD_Command(0x28);  // 4位总线，2行显示，5x8点阵
    LCD_Command(0x0C);  // 开启显示，不显示光标，不闪烁
    LCD_Command(0x06);  // 光标右移，字符不移动
    LCD_Command(0x01);  // 清屏
}

void LCD_Command(unsigned char command)
{
    GPIO_ResetBits(LCD_RS_Port, LCD_RS_Pin);   // RS=0，选择命令
    GPIO_ResetBits(LCD_RW_Port, LCD_RW_Pin);   // RW=0，写入数据
    GPIO_SetBits(LCD_E_Port, LCD_E_Pin);       // E=1，使能LCD
    GPIO_WriteBit(LCD_D4_Port, LCD_D4_Pin, (command & 0x10) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(LCD_D5_Port, LCD_D5_Pin, (command & 0x20) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(LCD_D6_Port, LCD_D6_Pin, (command & 0x40) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(LCD_D7_Port, LCD_D7_Pin, (command & 0x80) ? Bit_SET : Bit_RESET);
    GPIO_ResetBits(LCD_E_Port, LCD_E_Pin);     // E=0，禁用LCD
    GPIO_SetBits(LCD_E_Port, LCD_E_Pin);       // E=1，使能LCD
    GPIO_WriteBit(LCD_D4_Port, LCD_D4_Pin, (command & 0x01) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(LCD_D5_Port, LCD_D5_Pin, (command & 0x02) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(LCD_D6_Port, LCD_D6_Pin, (command & 0x04) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(LCD_D7_Port, LCD_D7_Pin, (command & 0x08) ? Bit_SET : Bit_RESET);
    GPIO_ResetBits(LCD_E_Port, LCD_E_Pin);     // E=0，禁用LCD
}

void LCD_Data(unsigned char data)
{
    GPIO_SetBits(LCD_RS_Port, LCD_RS_Pin);     // RS=1，选择数据
    GPIO_ResetBits(LCD_RW_Port, LCD_RW_Pin);   // RW=0，写入数据
    GPIO_SetBits(LCD_E_Port, LCD_E_Pin);       // E=1，使能LCD
    GPIO_WriteBit(LCD_D4_Port, LCD_D4_Pin, (data & 0x10) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(LCD_D5_Port, LCD_D5_Pin, (data & 0x20) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(LCD_D6_Port, LCD_D6_Pin, (data & 0x40) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(LCD_D7_Port, LCD_D7_Pin, (data & 0x80) ? Bit_SET : Bit_RESET);
    GPIO_ResetBits(LCD_E_Port, LCD_E_Pin);     // E=0，禁用LCD
    GPIO_SetBits(LCD_E_Port, LCD_E_Pin);       // E=1，使能LCD
    GPIO_WriteBit(LCD_D4_Port, LCD_D4_Pin, (data & 0x01) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(LCD_D5_Port, LCD_D5_Pin, (data & 0x02) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(LCD_D6_Port, LCD_D6_Pin, (data & 0x04) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(LCD_D7_Port, LCD_D7_Pin, (data & 0x08) ? Bit_SET : Bit_RESET);
    GPIO_ResetBits(LCD_E_Port, LCD_E_Pin);     // E=0，禁用LCD
}

在上面的代码中，`LCD_Command`函数用于向LCD控制器发送命令，`LCD_Data`函数用于向LCD控制器发送数据。其中，`LCD_RS_Pin`、`LCD_RW_Pin`和`LCD_E_Pin`分别是LCD的RS、RW和E引脚，而`LCD_D4_Pin`~`LCD_D7_Pin`则是LCD的数据引脚。在函数中，我们通过设置GPIO的输出电平来模拟LCD的通讯协议，从而向LCD控制器发送命令或数据。