Hello,
I want to read GPS data from a GPS acquisition card and parse the data on screen. I use the rs232.h library but i don't know why every time I run the program, it says that the buffer is always empty. I also get the error "I/O operation timed out" as a result with the detection functions errors but after changing the timeout, nothing changes. I know the GPS card functions and can display data with the manufacturer software. Does anybody know what mistakes i did ?
Here is my code, I know it is not fully optimised, sorry about that :
#include <stdio.h>
#include <stdlib.h>
#include <ansi_c.h>
#include <rs232.h>
#include <formatio.h>
#include <string.h>
#define BUFFER_SIZE 1024
#define MAX_DEVICE_ID_LEN 200
int parseportRS232()
{
int portNum = 48; // Com port COM48
//int baudRate = 9600; // Baudrate
int comStat;//pour les stats du port en lecture
char buffer[BUFFER_SIZE]; // reading input data
int bufferRead; // in order to stock the return value of ComRd function
int i = 0; //in order to count the number of attempts to read the buffer
int inqlen; //in order to get the buffer's size in input
int errorNumber;
// open serial port
printf("Trying to open serial port... \n");
if (OpenCom(portNum, "COM48") != 0)
{
printf("Return RS232 Error : %d ", ReturnRS232Err());
printf("Error while opening serial port\n");
}
//errors detection
printf("function OpenCom state: %d, %s \n",
ReturnRS232Err(),GetRS232ErrorString(ReturnRS232Err()) );
printf("function GetComStat state: %d, %s \n", GetComStat(portNum),
GetRS232ErrorString(ReturnRS232Err()));
printf("Serial port opened successfully \n\n");
/*SetComTime :
For read operations, timeout occurs when the COM port input queue is empty
and no byte is read into the queue for the duration of the timeout time.
For write operations, timeout occurs when the COM port output queue is full
and LabWindows/CVI cannot write to the queue for the duration of the timeout
time.
SetComTime returns an error if you have not opened the port or if you pass
an invalid parameter value.*/
SetComTime(portNum, 40);
printf("Trying to read input data...\n");
//main loop
while (i<=10)
{
printf("test reading a buffer, \n");
bufferRead = ComRd(portNum, buffer, BUFFER_SIZE - 1);
printf("function bufferRead state : %d, %s, \n",
ReturnRS232Err(),GetRS232ErrorString(ReturnRS232Err()) );
GetComStat(portNum);
printf("function GetComStat state : %d, %s, \n",
ReturnRS232Err(),GetRS232ErrorString(ReturnRS232Err()) );
if(GetComStat(portNum)>0)
{
if (bufferRead > 0)
{
buffer[bufferRead] = '\0';
printf("Donnees recues : %s\n", buffer);
}
else {
printf("error : %d \n", bufferRead );
}
}
else
{
inqlen = GetInQLen (portNum);
//errors detection
printf("function GetInQLen state : %d, %s \n",
ReturnRS232Err(),GetRS232ErrorString(ReturnRS232Err()) );
printf("input buffer lenght %d, ", inqlen);
printf("No available data, test %d \n\n", i);
i++;
}
//printf("Return RS232 Error : %d \n", ReturnRS232Err());
}
printf("End of serial port reading...\n");
//Close serial port
CloseCom(portNum);
printf("Closing serial port...\n");
return 0;
}