File content as of revision 0:6256752abece:

#include "GPSUBX.hpp"
#include "mbed.h"

GPSUBX::GPSUBX(PinName sda, PinName scl, char address = GPS_ADDRESS, int timedifference = 9, int hz = 100000)
    :i2c(sda, scl), Address(address), TimeDifference(timedifference)
{
    i2c.frequency(hz);
}

void GPSUBX::Checksum(char payload[], int n, char* ck_a, char* ck_b)
{
    int ca = 0;
    int cb = 0;
    for (int i = 0; i < n+4; i++)
    {
        ca += (unsigned char)payload[i+2];
        cb += ca;
    }
    *ck_a = (char)(ca & 0xff);
    *ck_b = (char)(cb & 0xff);
}

int GPSUBX::GetGPSData(GPSData* pdata)
{
    POSLLH posllh;
    char command[8] = {0xb5, 0x62, 0x01, 0x02, 0x00, 0x00, 0x00, 0x00};
    Checksum(command, 0, &command[6], &command[7]);
    
    i2c.write(Address << 1, command, 8);
    i2c.read(Address << 1 | 1, posllh.byte_data, POSLLH_LEN+8);
    
    for (int i = 0; i < POSLLH_LEN+8; i++)
    {
        pc.printf("%x ", posllh.byte_data[i]);
    }
    pc.printf("\r\n");
    if (posllh.data.sync == UBX_SYNC && posllh.data.m_class == 0x01 && posllh.data.m_id == 0x02 && posllh.data.pay_len == POSLLH_LEN)
    {
        char ca, cb;
        Checksum(posllh.byte_data, POSLLH_LEN, &ca, &cb);
        if (posllh.data.check_a == ca && posllh.data.check_b == cb)
        {
            pdata->Longitude = (float)posllh.data.lon * 1e-7f;
            pdata->Latitude = (float)posllh.data.lat * 1e-7f;
            pdata->Height = (float)posllh.data.height / 1000.0f;
            pc.printf("%f, %f, %f\r\n", pdata->Longitude, pdata->Latitude, pdata->Height);
        }
        else
        {
            pc.printf("#1\r\n");
            return 0;
        }
            pc.printf("#2\r\n");
        return 1;
    }
    else
    {
        pc.printf("#3\r\n");
        return 0;
    }
}

int GPSUBX::GetTimeData(GPSData* pdata)
{
    TIMEUTC timeutc;
    char command[8] = {0xb5, 0x62, 0x01, 0x21, 0x00, 0x00, 0x00, 0x00};
    Checksum(command, 0, &command[6], &command[7]);
    
    i2c.write(Address << 1, command, 8);
    i2c.read(Address << 1 | 1, timeutc.byte_data, TIMEUTC_LEN+8);
    
    for (int i = 0; i < TIMEUTC_LEN+8; i++)
    {
        pc.printf("%x ", timeutc.byte_data[i]);
    }
    pc.printf("\r\n");
    if (timeutc.data.sync == UBX_SYNC && timeutc.data.m_class == 0x01 && timeutc.data.m_id == 0x21 && timeutc.data.pay_len == TIMEUTC_LEN)
    {
        char ca, cb;
        Checksum(timeutc.byte_data, TIMEUTC_LEN, &ca, &cb);
        if (timeutc.data.check_a == ca && timeutc.data.check_b == cb)
        {
            pdata->Year = timeutc.data.year;
            pdata->Month = timeutc.data.month;
            pdata->Day = timeutc.data.day;
            pdata->Hours = timeutc.data.hour;
            pdata->Minutes = timeutc.data.min;
            pdata->Seconds = timeutc.data.sec;
            pc.printf("%4d/%2d/%2d %2d:%2d %2d\r\n", pdata->Year, pdata->Month, pdata->Day, pdata->Hours, pdata->Minutes, pdata->Seconds);
        }
        else
        {
            pc.printf("#4\r\n");
            return 0;
        }
            pc.printf("#5\r\n");
        return 1;
    }
    else
    {
        pc.printf("#6\r\n");
        return 0;
    }
}