将北斗模块连接到单片机系统板，将经纬度和海拔数据解析出来，并在液晶显示出来。请给出代码

以下是将北斗模块连接到单片机系统板，解析经纬度和海拔数据并在液晶显示出来的示例代码。我们假设使用的是STM32系列单片机，液晶屏幕为16x2字符型液晶。

#include <stdio.h>
#include "stm32f10x.h"
#include "lcd.h"

#define BAUDRATE 9600

void USART1_Init(void)
{
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1 | RCC_APB2Periph_GPIOA, ENABLE);

    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    USART_InitTypeDef USART_InitStructure;
    USART_InitStructure.USART_BaudRate = BAUDRATE;
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;
    USART_InitStructure.USART_StopBits = USART_StopBits_1;
    USART_InitStructure.USART_Parity = USART_Parity_No;
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
    USART_Init(USART1, &USART_InitStructure);

    USART_Cmd(USART1, ENABLE);
}

void USART1_SendByte(uint8_t byte)
{
    while (USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET);
    USART_SendData(USART1, byte);
}

uint8_t USART1_ReceiveByte(void)
{
    while (USART_GetFlagStatus(USART1, USART_FLAG_RXNE) == RESET);
    return USART_ReceiveData(USART1);
}

void USART1_SendString(const char* str)
{
    while (*str)
        USART1_SendByte(*str++);
}

void USART1_SendNumber(uint32_t num)
{
    char buffer[10];
    sprintf(buffer, "%d", num);
    USART1_SendString(buffer);
}

void USART1_SendFloat(float num)
{
    char buffer[16];
    sprintf(buffer, "%.2f", num);
    USART1_SendString(buffer);
}

void NMEA_Parse(char* sentence)
{
    // Check if it is a GGA sentence
    if (sentence[3] == 'G' && sentence[4] == 'G' && sentence[5] == 'A')
    {
        // Parse latitude and longitude
        char* token = strtok(sentence, ",");
        for (int i = 0; i < 2; i++)
            token = strtok(NULL, ",");
        float latitude = atof(token) / 100;
        token = strtok(NULL, ",");
        if (token[0] == 'S')
            latitude = -latitude;
        token = strtok(NULL, ",");
        float longitude = atof(token) / 100;
        token = strtok(NULL, ",");
        if (token[0] == 'W')
            longitude = -longitude;

        // Parse altitude
        token = strtok(NULL, ",");
        float altitude = atof(token);

        // Display data on LCD
        LCD_Clear();
        LCD_SetCursor(0, 0);
        LCD_Print("Latitude:");
        LCD_SetCursor(10, 0);
        USART1_SendFloat(latitude);
        LCD_SetCursor(0, 1);
        LCD_Print("Longitude:");
        LCD_SetCursor(11, 1);
        USART1_SendFloat(longitude);
        LCD_SetCursor(0, 2);
        LCD_Print("Altitude:");
        LCD_SetCursor(9, 2);
        USART1_SendFloat(altitude);
    }
}

int main(void)
{
    LCD_Init();
    USART1_Init();

    char buffer[128];
    int buffer_index = 0;

    while (1)
    {
        char byte = USART1_ReceiveByte();
        if (byte == '$')
        {
            buffer_index = 0;
            buffer[buffer_index++] = byte;
        }
        else if (byte == '\r')
        {
            buffer[buffer_index++] = '\0';
            NMEA_Parse(buffer);
        }
        else
        {
            buffer[buffer_index++] = byte;
        }
    }
}

上述代码中，我们使用了USART1串口与北斗模块通讯，并使用了液晶屏幕进行显示。在接收到北斗模块传来的数据后，我们使用了NMEA协议解析经纬度和海拔数据，并通过串口和液晶屏幕进行显示。

需要注意的是，上述代码中的解析方式仅适用于GGA类型的NMEA语句，如果北斗模块传来的语句类型不是GGA，则需要根据具体情况进行修改。另外，上述代码中的串口波特率为9600，如果北斗模块的波特率不同，则需要调整串口波特率。