如何使用串口通信在LCD上显示时间

首先，需要连接一个实时时钟（RTC）模块到单片机上。然后，使用单片机的串口模块与RTC模块进行通信，获取当前时间。最后，将获取到的时间数据通过串口发送到LCD模块上进行显示。

以下是一个简单的示例代码，以STM32为例：

#include "stm32f10x.h"
#include "stdio.h"

#define LCD_RS_PIN  GPIO_Pin_0
#define LCD_E_PIN   GPIO_Pin_1
#define LCD_D4_PIN  GPIO_Pin_2
#define LCD_D5_PIN  GPIO_Pin_3
#define LCD_D6_PIN  GPIO_Pin_4
#define LCD_D7_PIN  GPIO_Pin_5

void LCD_Init(void);
void LCD_WriteCommand(uint8_t command);
void LCD_WriteData(uint8_t data);
void LCD_WriteString(char* str);
void LCD_SetCursor(uint8_t row, uint8_t col);

int main(void)
{
    // 初始化串口和LCD
    USART_Init(USART1, &USART_InitStructure);
    USART_Cmd(USART1, ENABLE);
    LCD_Init();
    
    while (1)
    {
        // 从RTC模块获取当前时间
        // 假设时间数据存储在变量time中
        
        // 将时间数据转换为字符串格式
        char time_str[12];
        sprintf(time_str, "%02d:%02d:%02d", time.hour, time.minute, time.second);
        
        // 在LCD上显示时间
        LCD_SetCursor(0, 0);  // 第一行第一列
        LCD_WriteString(time_str);
        
        // 延时一段时间（如1秒）
        delay_ms(1000);
    }
}

void LCD_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    
    // 初始化LCD的引脚
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
    
    GPIO_InitStructure.GPIO_Pin = LCD_RS_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(GPIOA, &GPIO_InitStructure);

    // 初始化LCD
    LCD_WriteCommand(0x33);
    LCD_WriteCommand(0x32);
    LCD_WriteCommand(0x28);
    LCD_WriteCommand(0x0C);
    LCD_WriteCommand(0x01);
    LCD_WriteCommand(0x06);
}

void LCD_WriteCommand(uint8_t command)
{
    GPIO_ResetBits(GPIOA, LCD_RS_PIN);  // RS = 0
    GPIO_ResetBits(GPIOA, LCD_E_PIN);   // E = 0
    
    GPIO_WriteBit(GPIOA, LCD_D4_PIN, (BitAction)((command >> 4) & 0x01));
    GPIO_WriteBit(GPIOA, LCD_D5_PIN, (BitAction)((command >> 5) & 0x01));
    GPIO_WriteBit(GPIOA, LCD_D6_PIN, (BitAction)((command >> 6) & 0x01));
    GPIO_WriteBit(GPIOA, LCD_D7_PIN, (BitAction)((command >> 7) & 0x01));
    
    GPIO_SetBits(GPIOA, LCD_E_PIN);     // E = 1
    delay_us(1);
    GPIO_ResetBits(GPIOA, LCD_E_PIN);   // E = 0
    delay_us(100);
    
    GPIO_WriteBit(GPIOA, LCD_D4_PIN, (BitAction)(command & 0x01));
    GPIO_WriteBit(GPIOA, LCD_D5_PIN, (BitAction)((command >> 1) & 0x01));
    GPIO_WriteBit(GPIOA, LCD_D6_PIN, (BitAction)((command >> 2) & 0x01));
    GPIO_WriteBit(GPIOA, LCD_D7_PIN, (BitAction)((command >> 3) & 0x01));
    
    GPIO_SetBits(GPIOA, LCD_E_PIN);     // E = 1
    delay_us(1);
    GPIO_ResetBits(GPIOA, LCD_E_PIN);   // E = 0
    delay_us(100);
}

void LCD_WriteData(uint8_t data)
{
    GPIO_SetBits(GPIOA, LCD_RS_PIN);    // RS = 1
    GPIO_ResetBits(GPIOA, LCD_E_PIN);   // E = 0
    
    GPIO_WriteBit(GPIOA, LCD_D4_PIN, (BitAction)((data >> 4) & 0x01));
    GPIO_WriteBit(GPIOA, LCD_D5_PIN, (BitAction)((data >> 5) & 0x01));
    GPIO_WriteBit(GPIOA, LCD_D6_PIN, (BitAction)((data >> 6) & 0x01));
    GPIO_WriteBit(GPIOA, LCD_D7_PIN, (BitAction)((data >> 7) & 0x01));
    
    GPIO_SetBits(GPIOA, LCD_E_PIN);     // E = 1
    delay_us(1);
    GPIO_ResetBits(GPIOA, LCD_E_PIN);   // E = 0
    delay_us(100);
    
    GPIO_WriteBit(GPIOA, LCD_D4_PIN, (BitAction)(data & 0x01));
    GPIO_WriteBit(GPIOA, LCD_D5_PIN, (BitAction)((data >> 1) & 0x01));
    GPIO_WriteBit(GPIOA, LCD_D6_PIN, (BitAction)((data >> 2) & 0x01));
    GPIO_WriteBit(GPIOA, LCD_D7_PIN, (BitAction)((data >> 3) & 0x01));
    
    GPIO_SetBits(GPIOA, LCD_E_PIN);     // E = 1
    delay_us(1);
    GPIO_ResetBits(GPIOA, LCD_E_PIN);   // E = 0
    delay_us(100);
}

void LCD_WriteString(char* str)
{
    while (*str != '\0')
    {
        LCD_WriteData(*str);
        str++;
    }
}

void LCD_SetCursor(uint8_t row, uint8_t col)
{
    uint8_t address = 0;
    
    if (row == 0)
    {
        address = 0x00;
    }
    else if (row == 1)
    {
        address = 0x40;
    }
    else if (row == 2)
    {
        address = 0x14;
    }
    else if (row == 3)
    {
        address = 0x54;
    }
    
    address += col;
    
    LCD_WriteCommand(0x80 | address);
}

注意：以上代码仅供参考，具体实现方式需要根据实际硬件和软件环境进行调整。