安信可A9G-Pudding开发板 GPS功能使用及固件开发

使用

注意：

1.板子上UART2_TX与UART2_RX丝印层位置错误；

2.波特率默认9600，UART2_RX需要悬空

3.天线最好在室外

 

固件开发

1.编译烧录运行

源代码在demo/gps文件夹下

串口1波特率115200，输出print NMEA infomation数据

 

串口2波特率9600，输出gps原始数据

2.源代码分析

1.程序入口

2.gps_MainTask()

3.gps_testTask()

void gps_testTask(void *pData)
{
    GPS_Info_t* gpsInfo = Gps_GetInfo();
    uint8_t buffer[300];

    //wait for gprs register complete
    //The process of GPRS registration network may cause the power supply voltage of GPS to drop,
    //which resulting in GPS restart.
    while(!flag)
    {
        Trace(1,"wait for gprs regiter complete");
        OS_Sleep(2000);
    }

    //open GPS hardware(UART2 open either)
    GPS_Init();
    GPS_Open(NULL);

    //wait for gps start up, or gps will not response command
    while(gpsInfo->rmc.latitude.value == 0)
        OS_Sleep(1000);
    

    // set gps nmea output interval
    for(uint8_t i = 0;i<5;++i)
    {
        bool ret = GPS_SetOutputInterval(10000);
        Trace(1,"set gps ret:%d",ret);
        if(ret)
            break;
        OS_Sleep(1000);
    }

    // if(!GPS_ClearInfoInFlash())
    //     Trace(1,"erase gps fail");
    
    // if(!GPS_SetQzssOutput(false))
    //     Trace(1,"enable qzss nmea output fail");

    // if(!GPS_SetSearchMode(true,false,true,false))
    //     Trace(1,"set search mode fail");

    // if(!GPS_SetSBASEnable(true))
    //     Trace(1,"enable sbas fail");
    
    if(!GPS_GetVersion(buffer,150))
        Trace(1,"get gps firmware version fail");
    else
        Trace(1,"gps firmware version:%s",buffer);

    // if(!GPS_SetFixMode(GPS_FIX_MODE_LOW_SPEED))
        // Trace(1,"set fix mode fail");

    if(!GPS_SetOutputInterval(1000))
        Trace(1,"set nmea output interval fail");
    
    Trace(1,"init ok");

    while(1)
    {
        if(isGpsOn)
        {
            //show fix info
            uint8_t isFixed = gpsInfo->gsa[0].fix_type > gpsInfo->gsa[1].fix_type ?gpsInfo->gsa[0].fix_type:gpsInfo->gsa[1].fix_type;
            char* isFixedStr;            
            if(isFixed == 2)
                isFixedStr = "2D fix";
            else if(isFixed == 3)
            {
                if(gpsInfo->gga.fix_quality == 1)
                    isFixedStr = "3D fix";
                else if(gpsInfo->gga.fix_quality == 2)
                    isFixedStr = "3D/DGPS fix";
            }
            else
                isFixedStr = "no fix";

            //convert unit ddmm.mmmm to degree(°) 
            int temp = (int)(gpsInfo->rmc.latitude.value/gpsInfo->rmc.latitude.scale/100);
            double latitude = temp+(double)(gpsInfo->rmc.latitude.value - temp*gpsInfo->rmc.latitude.scale*100)/gpsInfo->rmc.latitude.scale/60.0;
            temp = (int)(gpsInfo->rmc.longitude.value/gpsInfo->rmc.longitude.scale/100);
            double longitude = temp+(double)(gpsInfo->rmc.longitude.value - temp*gpsInfo->rmc.longitude.scale*100)/gpsInfo->rmc.longitude.scale/60.0;

            
            //you can copy ` latitude,longitude ` to http://www.gpsspg.com/maps.htm check location on map

            snprintf(buffer,sizeof(buffer),"GPS fix mode:%d, BDS fix mode:%d, fix quality:%d, satellites tracked:%d, gps sates total:%d, is fixed:%s, coordinate:WGS84, Latitude:%f, Longitude:%f, unit:degree,altitude:%f",gpsInfo->gsa[0].fix_type, gpsInfo->gsa[1].fix_type,
                                                                gpsInfo->gga.fix_quality,gpsInfo->gga.satellites_tracked, gpsInfo->gsv[0].total_sats, isFixedStr, latitude,longitude,gpsInfo->gga.altitude);
            //show in tracer
            Trace(2,buffer);
            //send to UART1
            UART_Write(UART1,buffer,strlen(buffer));
            UART_Write(UART1,"\r\n\r\n",4);
        }

        OS_Sleep(5000);
    }
}

 

4.主要API

4.1. GPS_Open

bool GPS_Open(UART_Callback_t gpsReceivedCallback);

功能

开启GPS电源，GPS进入工作状态

参数

• gpsReceivedCallback：串口回调函数，如果设置为NULL，则收到串口2收到GPS数据后不会产生回调，而是将GPS的数据以事件的方式发送给主任务；若不为NULL，则不会产生事件，设置的串口回调函数会被调用，不要在处理函数中消耗太多时间。建议使用事件的方式，参考GPS例程

返回值

• 是否成功打开GPS

4.2. GPS_Close

bool GPS_Close();

功能

关闭GPS电源

参数

无

返回值

是否成功关闭GPS