Re: [Gumstix-users] gpsutil and GPSstix

[James C. <ja...@ca...>]

Hey Rodrigo,

Its not really like that. There are a few options: 1) Use just perl - this=
=20
is what i use as perl is good at parsing strings. The script i have grabs=
=20
the data from the gps, converts it into something useful and then logs it.=
=20
2)Run GPSD as a daemon and use some C to access it (via a sort of telnet=20
system) to get commands. This is pretty easy to do, something like this:

int gpsd_connect(void)
{
//int hSocket;                 /* handle to socket */
    struct hostent* pHostInfo;   /* holds info about a machine */
    struct sockaddr_in Address;  /* Internet socket address stuct */
    long nHostAddress;
//    char pBuffer[BUFFER_SIZE];
//=09unsigned nReadAmount;
    char strHostName[HOST_NAME_SIZE];
    int nHostPort;


    printf("\nMaking a socket");
    /* make a socket */
    hSocket=3Dsocket(AF_INET,SOCK_STREAM,IPPROTO_TCP);

    if(hSocket =3D=3D SOCKET_ERROR)
    {
        printf("\nCould not make a socket\n");
        return 0;
    }

    /* get IP address from name */
    pHostInfo=3Dgethostbyname(GPSD_HOSTNAME);
    /* copy address into long */
    memcpy(&nHostAddress,pHostInfo->h_addr,pHostInfo->h_length);

    /* fill address struct */
    Address.sin_addr.s_addr=3DnHostAddress;
    Address.sin_port=3Dhtons(GPSD_PORT);
    Address.sin_family=3DAF_INET;

    printf("\nConnecting to %s on port %d\n",strHostName,nHostPort);

    /* connect to host */
    if(connect(hSocket,(struct sockaddr*)&Address,sizeof(Address))=20
       =3D=3D SOCKET_ERROR)
    {
        printf("\nCould not connect to host\n");
        return 0;
    }
}

int gps_lock(void){
=09write(hSocket,"s",1);
=09nReadAmount=3Dread(hSocket,pBuffer,BUFFER_SIZE);
=09printf("%s",pBuffer);=09
}

Though it isn't complete that will connect to GPSD and then send an "s"=20
command to find out whether the gps has a lock.

3)Or you can look into using libgps directly to access the gps from you=20
code which is probably the best option though i don't actually have any=20
working code available - Ben(phatmonkey) do you?

James


On Aug 31 2006, Rodrigo Sosa wrote:

>Hey James,
>
>That sounds interesting, verry, in particular the part of libgps
>communicating with the gpsd
>Im doing all in C, as is what i "know" most than others ("know"=3Dnoob
>speeching), so the libgps sounds cool.
>So if i understand correctly you use the perl script to setup the GPS to
>your needs and then access it with your code using libgps?
>If you can send me some code as a guideline of all what you have used MUCH
>appreciated :D
>best regards
>
>Rodrigo
>