功能

（1）通過LCD12864顯示GPS模塊的經緯度數據；

（2）可設定當前的定位位置，自動計算與設定位置的距離，當檢測到位置超過設定位置200M時，通過GPRS模塊發送報警信息；

（3）報警時通過通過蜂鳴器發出警報；

（4）根據位置自動計算定位的距離，當找到兒童時，成人可主動關閉警報器；

（5）可實現“一一鍵報警”功能，當按下按鍵時，主動發送當前的位置給設定的手機號；

（6）當找到兒童時，可手動取消報警。

系統框圖

原理圖

程序源代碼

#include  "project.h"
unsigned char ucMode = 0;
unsigned char xdata Longitude[13] = "E:";  //保存經度數據
unsigned char xdata Latitude[13] = "N:";//保存緯度數據
bit PosSuc = 0;  //定位成功的標志，為1時表示定位成功，為0表示定位不成功
double fLongitude = 0.0;   //保存浮點型數據，經度
double fLatitude = 0.0;    //保存浮點型數據， 緯度


double fLongitudeLoa = 0.0; //當前所在地的經度
double fLatitudeLoa = 0.0;    //當前所在地的緯度


    double Dis = 0.0;  
#define PI                      3.1415926
#define EARTH_RADIUS            6378.004        //地球近似半徑
 
// 求弧度
double radian(double d)
{
    return d * PI / 180.0;   //角度1? = π / 180
}
 
//計算距離
double get_distance(double lat1, double lng1, double lat2, double lng2)
{
    xdata double radLat1 = radian(lat1);
    xdata double radLat2 = radian(lat2);
    xdata double a = radLat1 - radLat2;
    xdata double b = radian(lng1) - radian(lng2);
     
    xdata double dst = 2 * asin((sqrt(pow(sin(a / 2), 2) + cos(radLat1) * cos(radLat2) * pow(sin(b / 2), 2) )));
     
    dst = dst * EARTH_RADIUS;
    //dst= round(dst * 10000) / 10000;
    return dst;
}






/*********************************************************************************************************
** 函數名稱:      ProcRxBuf
** 函數描述:      處理GPS接收的數據
** 輸入參數:      NONE
** 輸出參數:      NONE
** 返回值:        NONE
*********************************************************************************************************/
void ProcRxBuf(void)
{
    if(RxFlag == 1)  //數據接收完畢
    {
        
        EA = 0;
        RxFlag = 0;
        
        if(RxBuf[17] == 'A')
        {      
            ucMode = 1;
            if(PosSuc == 0)   //初次定位成功
            {
                
                fLongitudeLoa = fLongitude; //當前所在地的經度
                fLatitudeLoa = fLatitude;    //當前所在地的緯度
                fLongitudeLoa = fLongitude; //當前所在地的經度
                fLatitudeLoa = fLatitude;    //當前所在地的緯度   
                PosSuc = 1;
            }
            LCD_Location(1,0);
            LCD_Display("  GPS 定位成功  ");
            PosSuc = 1;  //定位成功標志置1
            Latitude[0] = 'N';
            Latitude[1] = ':';
            fLatitude = (double)atof(&RxBuf[21]) / (double)60.0 + (RxBuf[19] - 0x30)*10 + (RxBuf[20]- 0x30);
            Latitude[12] = 0;
            Latitude[2] =  (unsigned long)fLatitude %100 / 10 + 0x30;
            Latitude[3] =  (unsigned long)fLatitude % 10+ 0x30;
            Latitude[4] =  '.';
            Latitude[5] =  (unsigned long)(fLatitude * 10) % 10+ 0x30;
            Latitude[6] =  (unsigned long)(fLatitude * 100) % 10+ 0x30;
            Latitude[7] =  (unsigned long)(fLatitude * 1000) % 10+ 0x30;
            Latitude[8] =  (unsigned long)(fLatitude * 10000) % 10+ 0x30;
            Latitude[9] =  (unsigned long)(fLatitude * 100000) % 10+ 0x30;
            Latitude[10] =  (unsigned long)(fLatitude * 1000000) % 10+ 0x30;
            Latitude[11] =  (unsigned long)(fLatitude * 10000000) % 10+ 0x30;
            Latitude[12] = 0;          


            Longitude[0] = 'E';
            Longitude[1] = ':';   
            fLongitude = (double)atof(&RxBuf[34]) / (double)60.0 + (RxBuf[31] - 0x30)*100 + (RxBuf[32]- 0x30) * 10 + (RxBuf[33]- 0x30);
            Longitude[2] =  (unsigned long)fLongitude / 100 + 0x30;
            Longitude[3] =  (unsigned long)fLongitude %100 / 10 + 0x30;
            Longitude[4] =  (unsigned long)fLongitude % 10+ 0x30;
            Longitude[5] =  '.';
            Longitude[6] =  (unsigned long)(fLongitude * 10) % 10+ 0x30;
            Longitude[7] =  (unsigned long)(fLongitude * 100) % 10+ 0x30;
            Longitude[8] =  (unsigned long)(fLongitude * 1000) % 10+ 0x30;
            Longitude[9] =  (unsigned long)(fLongitude * 10000) % 10+ 0x30;
            Longitude[10] =  (unsigned long)(fLongitude * 100000) % 10+ 0x30;
            Longitude[11] =  (unsigned long)(fLongitude * 1000000) % 10+ 0x30;
            Longitude[12] = 0;    
        }
        else
        {
            PosSuc = 0;   //定位成功標志清零
        }
        
        memset(RxBuf,0,80);
        RxWP = 0;
        EA = 1;
    }
}


bit Key1Up = 1;  //按鍵松開標志，為1時表示按鍵已經松開，為0時，表示按鍵未松開
sbit KEY1 = P3^4;  //按鍵，按下按鍵時發送定位信息到手機
sbit KEY2 = P3^5;  //按鍵，按下按鍵時存儲正確的定位信息


/*********************************************************************************************************
** 函數名稱:      SendHelp
** 函數描述:      發送求救信息
** 輸入參數:      NONE
** 輸出參數:      NONE
** 返回值:        NONE
*********************************************************************************************************/
void SendHelp(double Dis)
{
    unsigned char i = 0;
    xdata unsigned char ucTemp[45] = {0};


    for(i = 0; i < 13;i++)
    {
        ucTemp[i] = Latitude[i];
    }
    for(i = 0; i < 13; i++)
    {
        ucTemp[i+12] = Longitude[i];
    }
    strcat(ucTemp,"distance=");
    ucTemp[33] = ((unsigned long)Dis % 100 /  10 + 0x30);
    ucTemp[34] = ((unsigned long)Dis %10 + 0x30);
    ucTemp[35] = ('.');
    ucTemp[36] = ((unsigned long)(Dis * 10) %  10 + 0x30);
    ucTemp[37] = ((unsigned long)(Dis * 100) %  10 + 0x30);
    ucTemp[38] = ((unsigned long)(Dis * 1000) %  10 + 0x30);
    ucTemp[39] = 'k';
    ucTemp[40] = 'm';
    SendSMS(ucTemp,41);  //發送手機短信 
    DelayMs(1000);
    UART1_ClearRxBuf();
}


/*********************************************************************************************************
** 函數名稱:      ProcKey
** 函數描述:      處理按鍵函數，按鍵按下時發送定位信息到手機
** 輸入參數:      NONE
** 輸出參數:      NONE
** 返回值:        NONE
*********************************************************************************************************/
void ProcKey1(void)
{    


    if( (Key1Up == 1) && (KEY1 == 0))  //按鍵處于松開狀態時，按鍵按下,定位完成才判斷按鍵
    {
        DelayMs(20);   //防抖動延時
        if(KEY1 == 0)
        {       
            Key1Up = 0;            
            if(PosSuc == 1)
            {            
                SendHelp(Dis);
            }
            else if(PosSuc == 0)
            {
                LCD_Location(3,0);
                LCD_Display("請等定位成功    ");
                DelayMs(2000);
                LCD_Location(3,0);
                LCD_Display("                ");
            }
        }
    }    
    else if(KEY1 == 1)
    {
        Key1Up = 1;
    }
}