tell me if this one works (made on turbo c)
/* Defines required for serial i/o */
#define COM_PORT 1 /* Serial device connected to COM 1 */
#define SPEED 4800 /* baud rate = 4800 */
#define CR 0x0d
#define LF 0x0a
#define ESC 0x1b
#define BEEP 0x07
/* Some helpful defines */
#define SPACE 0x20
#define COMMA 0x2C
#define MAXSIZE 100 /* GPS at most, sends 80 or so chars per message string. So set maximum to 100 */
#include < stdio.h >
#include < ctype.h > /* required for the isalnum function */
#include < stdlib.h >
#include < string.h >
#include < conio.h >
#include < math.h >
#include < dos.h >
#include "ibmcom3.h" /* for serial */
/* Prototypes */
void comm_setting(void); /* Set com port */
void close_com(void); /* Close com port */
int main(void) {
unsigned char charRead; /* char read from COM port */
unsigned char stringRead[MAXSIZE]; /* Buffer collects chars read from GPS */
unsigned char tempString[MAXSIZE];
unsigned char timeString[12];
unsigned char latitudeString[11];
unsigned char latitudeCardinalString[3];
unsigned char longitudeString[12];
unsigned char longitudeCardinalString[3];
unsigned char *pChar;
unsigned char dummyChar;
unsigned long utcTime, estTime; /* Coordinated Universal Time and Eastern Standard Time */
unsigned long utcHour, estHour;
unsigned long utcMinutes, estMinutes;
unsigned long utcSeconds, estSeconds;
unsigned char lastCommaPosition;
float latitude;
int latDegrees;
float latMinutes;
float longitude;
int longDegrees;
float longMinutes;
FILE *gpsFile; /* Text file of GPS strings read */
unsigned int j, k; /* dummy variable */
unsigned int i; /* Number of chars read per GPS message string */
unsigned int numLinesRead; /* Number of GPS strings read */
dummyChar = 'A'; pChar = &dummyChar;
gpsFile = fopen("gpsData.txt", "w");
printf("Initializing port...");
comm_setting();
printf("done/n");
numLinesRead = 0;
printf("Entering while loop.../n");
do {
charRead = com_rx(); /* read char from serial port */
if(charRead == '$') { /* GPS messages start with $ char */
i = 0;
numLinesRead++;
stringRead = charRead;
do {
charRead = com_rx();
if( (charRead != '/0') && (isalnum(charRead) || isspace(charRead) || ispunct(charRead)) ) {
i++;
stringRead = charRead;
}
} while(charRead != CR);
/* By this point, a complete GPS string has been read so save it to file */
/* Append the null terminator to the string read */
stringRead[i+1] = ' ';
/* Analyze string that we collected */
j = 0;
pChar = stringRead;
while(*(pChar+j) != COMMA) {
tempString[j] = *(pChar+j);
j++;
}
tempString[j] = ' ';
/* Check if string we collected is the $GPGGA message */
if(tempString[3] == 'G' && tempString[4] == 'G' && tempString[5] == 'A') {
/*
Found GPGGA string. It has 14 commas total. Its NMEA sentence structure is:
$GPGAA,hhmmss.ss,ddmm.mmmm,n,dddmm.mmmm,e,q,ss,y.y,a.a,z,g.g,z,t.t,iii*CC
| | | | | | | | | | | | | | |
0 1 2 3 4 5 6 7
0123456789012345678901234567890123456789012345678901234567890123456789012
where:
GPGAA : GPS fixed data identifier
hhmmss.ss : Coordinated Universal Time (UTC), also known as GMT
ddmm.mmmm,n : Latitude in degrees, minutes and cardinal sign
dddmm.mmmm,e : Longitude in degrees, minutes and cardinal sign
q : Quality of fix. 1 = there is a fix
ss : Number of satellites being used
y.y : Horizontal dilution of precision
a.a,M : GPS antenna altitude in meters
g.g,M : geoidal separation in meters
t.t : Age of the defferential correction data
iiii : Deferential station's ID
*CC : checksum for the sentence
*/
pChar = stringRead;
/* Get UTC time */
j = 7; /* start of time field */
k = 0;
while(*(pChar+j) != COMMA) {
timeString[k] = *(pChar+j);
j++;
k++;
}
lastCommaPosition = j;
timeString[k] = ' ';
sscanf(timeString, "%ld", &utcTime);
utcHour = (utcTime/10000); /* extract Hours from long */
utcMinutes = (utcTime - (utcHour*10000))/100; /* extract minutes from long */
utcSeconds = utcTime - (utcHour*10000) - (utcMinutes*100); /* extract seconds from long */
if(utcHour >= 4 && utcHour <= 23) estHour = utcHour - 4;
else estHour = utcHour + 20;
estMinutes = utcMinutes;
estSeconds = utcSeconds;
/* NB: %02ld formats long to print 2 chars wide, padding with 0 if necessary */
printf("%02ld:%02ld:%02ld UTC = %02ld:%02ld:%02ld EST", utcHour, utcMinutes, utcSeconds, estHour, estMinutes, estSeconds);
/* Get lattitude: ddmm.mmmm */
pChar = stringRead;
j = lastCommaPosition + 1;
k = 0;
while(*(pChar+j) != COMMA) {
latitudeString[k] = *(pChar+j);
j++;
k++;
}
lastCommaPosition = j;
latitudeString[k] = ' ';
sscanf(latitudeString, "%f", &latitude);
latDegrees = (int)(latitude/100);
latMinutes = (float)(latitude - latDegrees*100);
printf("/t%02d DEG/t%2.4f MIN", latDegrees, latMinutes);
/* Get lattitude Cardinal direction */
pChar = stringRead;
j = lastCommaPosition + 1;
k = 0;
while(*(pChar+j) != COMMA) {
latitudeCardinalString[k] = *(pChar+j);
j++;
k++;
}
lastCommaPosition = j;
latitudeCardinalString[k] = ' ';
printf(" %s", latitudeCardinalString);
/* Get longitude: dddmm.mmmm */
pChar = stringRead;
j = lastCommaPosition + 1;
k = 0;
while(*(pChar+j) != COMMA) {
longitudeString[k] = *(pChar+j);
j++;
k++;
}
lastCommaPosition = j;
longitudeString[k] = ' ';
sscanf(longitudeString, "%f", &longitude);
longDegrees = (int)(longitude/100);
longMinutes = (float)(longitude - longDegrees*100);
printf("/t%03d DEG/t%2.4f MIN", longDegrees, longMinutes);
printf("/n");
} /* else not a GPGGA sentence */
fprintf(gpsFile, "%d: (%d) %s/n", numLinesRead, i, stringRead);
} /* otherwise not a $ character... so loop back until one arrives */
} while(!kbhit());
printf("Exiting...");
close_com(); /* Finished with serial port so close it */
fclose(gpsFile);
printf("done/n");
return (0);
} /* end of main */
void comm_setting(void) {
int dummy;
dummy = com_install(COM_PORT);
if(dummy != 0) {
switch (dummy) {
case 1 : printf("Invaid port number/n");
break;
case 2 : printf("No UART fot specified port/n");
break;
case 3 : printf("Drivers already installed/n");
break;
default : printf("Err #%d/n", dummy);
break;
}
exit(1);
} com_raise_dtr();
com_set_speed(SPEED);
com_set_parity(COM_NONE, STOP_BIT_1);
}
void close_com(void) {
com_lower_dtr();
com_deinstall();
}