Styjun

I am having problems with changing character size and parity bit in serial communication between 2 serial ports.

Currently, after opening serial ports, I want to change character size, stop bit and parity. If character size is 7bit, 8bit, writing and reading between 2 ports works fine. However, with character size of 5bit, 6bit and enable parity are not.

I'm thinking of tcsetattr() function which might set limit 7bit, 8bit in low layer linux kernel. I tried to debug around but I couldn't observe anything.

Could you guys give me any suggestion?

P/S: HW supports for whole setting.

Thanks so much!

My code as follows:

menu_serialparametersR()

 printf ("Setting:n")
 printf ("[Character size] [Stop bit] [Parity] [Flow control]n");
 printf (" 1.5bit 5.1bit 7.Enable-Odd 10. HW n");
 printf (" 2.6bit 6.2bit 8.Enable-Even 11. SW n");
 printf (" 3.7bit 9.Disable n");
 printf (" 4.8bit n");


setup_serial_port(int uart, unsigned char *uart_name)
 CREAD);
 tty.c_iflag 

process_data(int fd1, int fd2, unsigned char *uart1_n, unsigned char *uart2_n)

 int getatt_tst1, getatt_tst2, successdata;
 struct termios tty1, tty2;

 successdata = 0;

 // Get attribute to print out parameters
 getatt_tst1 = tcgetattr(fd1, &tty1);
 getatt_tst2 = tcgetattr(fd2, &tty2);
 if (getatt_tst1 < 0)
 
 printf("Error [%d] from tcgetattr in %s: %sn", getatt_tst1, uart1_n, strerror(errno));
 return;
 
 if (getatt_tst2 < 0)
 
 printf("Error [%d] from tcgetattr in %s: %sn", getatt_tst2, uart2_n, strerror(errno));
 return;
 

 /*** Writing random data to enable read function in fd2 ***/
 // Fixed position. Don't move it after.

 if ((wr_size = write (fd2, "a",1))<0)
 
 printf ("Error [%d] while writing in %s: %sn",wr_size, uart2_n, strerror(errno));
 return;
 

 ntestdata = 100; // Just random number

 successdata = write_read_byte(ntestdata, fd1, fd2, uart1_n, uart2_n);
 if (successdata == ntestdata)
 
 printf ("Finish Write/Read %d byte successful.n", successdata); 
 
 else
 printf ("Failed. Only finish Write/Read %d byte successful.n", successdata); 
 return;


// Define random array for testing (ensure that length's above 8)
char test_data[]= "ABCDEFGHIJK12345678";

int write_read_byte(int num_testbytes, int fd1, int fd2,
 unsigned char *uart1_name, unsigned char *uart2_name)

 // VARIABLES
 int wr_size, rd_size, array_i, rdcounter, wrcounter;
 char *buf_ptr;
 char buf_read[0x800];
 int testbyte, successbyte;

 // Initializations
 wr_size = 0; // Write size
 rd_size = 0; // Read size
 array_i = 0; // Element index in testing array
 rdcounter = 0; // Read counter
 wrcounter = 0; // Write counter
 successbyte = 0; // amount of byte write/read successful

 memset (buf_read, 0 , 0x800);
 testbyte = num_testbytes;

 /**************** Start testing *************************/
 while (testbyte > 0) // Do loop until num_testbytes
 
 // Reset counter
 rdcounter = 0;
 wrcounter = 0;

 // 1. Start writing 1 byte to fd1

 wr_size = write (fd1, &test_data[array_i], 1);
 printf ("Write: %c", test_data[array_i]);

 if (wr_size < 0)
 
 printf ("Error [%d] while writing in %s: %s. n", wr_size, uart2_name, strerror(errno));
 return successbyte;
 

 // 2. Start reading wr_size byte from fd2
 while (wrcounter < wr_size) // Listening enough written byte
 
 // Reset everything before read 1 byte
 buf_ptr = 0;
 rdcounter = 0;
 rd_size = read(fd2, &buf_ptr, 1);
 if (rd_size > 0)
 
 for (rdcounter = 0; rdcounter < rd_size; rdcounter++)
 
 printf (" - Read: %cn", buf_ptr); // using for testing
 // Copy 1 read byte to read array
 memcpy(&buf_read[(num_testbytes - testbyte)], &buf_ptr, 1);
 // If reading right data
 if (buf_read[(num_testbytes - testbyte)] == test_data[array_i])
 successbyte = (successbyte + 1);
 else // Wrong read byte
 
 printf ("nTesting failed. Reason: Read wrong data in %s.nPlease check for configuration.n", uart2_name);
 return successbyte;
 
 
 
 else if (rd_size < 0)
 
 printf ("nTesting failed. Reason: Error [%d] while reading in %s: %sn",
 rd_size, uart2_name, strerror(errno));
 printf ("Please check for:n1. Connection between 2 portsn2. Configurationn");
 return successbyte;
 
 else
 
 printf ("nTesting failed. Reason: Timeout for reading in %s.n", uart2_name );
 printf ("Please check for:n1. Connection between 2 portsn2. Configurationn");
 return successbyte;
 
 wrcounter = (wrcounter + 1) ;
 

 testbyte = (testbyte-1);

 // Limit test data element index
 if (array_i >= (sizeof(test_data) - 2))
 
 array_i = 0;
 printf ("n");
 
 else
 array_i = (array_i + 1);
 
 return successbyte;


#define TTYO2 "/dev/ttyO2"
#define TTYO3 "/dev/ttyO3"

int main(void)
 O_SYNC);
 if (fd1 < 0)
 
 printf ("Error %d opening %s: %s.n", errno, uart1, strerror(errno));
 return -1;
 

 // 2. Open COM2
 // Open to read once data available (!NONBLOCK)
 fd2 = open (uart2, O_RDWR