Hello I am trying to program my UEIPAC 600-1G cube to receive data from a temperature sensor. In order to activate the sensor I have to send it binary data. I am trying to send chars set as hex values but something is wrong. I have tested by dumping the data into a text file and I get spaces followed by some giberish characters. How do I send Binary data through a serial port?
struct timespec tim, tim2;
unsigned char access_code[] =" ";
int bytes=256; /*num of bytes to read at a time*/
char re[bytes];
int re_len = 0;
int n_access = 0; /* store number of bytes written from access code */
int n_read =0;
int i=0;
int baud=0;
int bytes_written=0;
/* hold the file descriptor */
int fd = 0;
access_code[0]=0x01; /*fill access code with correct hex data */
access_code[1]=0x00;
access_code[2]=0x00;
access_code[3]=0x00;
access_code[4]=0x08;
access_code[5]=0x02;
access_code[6]=0x03;
re_len = bytes;
memset(re, 0, sizeof(char)*bytes);
//nanopause initialization data
tim.tv_sec = 0;
tim.tv_nsec = 95000000;
/* open the device for writing and reading later. */
fd = open( "/tyCo/0", O_RDWR, 0);
//fd = open("TEST.txt", O_RDWR, 0);
//baud = ioctl(fd, FIOBAUDRATE, 19200); /*note test length maybe 576000 b/c terminal*/
for (i=0;i<7;i++){
n_access = n_access+write( fd, &access_code[i], 1); /* write */
}
logfile=fopen ("LOGFILE.txt","a"); /* open log file*/
outputfile=fopen ("SENSORDATA.txt","a"); /* open output file*/
if(fd<0) /* check for open error */
fprintf(logfile,"%s","\nerror opening file\n");
fprintf(logfile,"%s" "%d" "%c","number of access code bytes written: ",n_access,'\n'); /* display bytes written*/
//step 1 call completed now pause with nano pause
if(nanosleep(&tim,&tim2)<0){
fprintf(logfile,"%s","Nano sleep system call failed \n");
}
//step 2 complete now read with read code
n_read = read( fd, re, re_len); /* read */
if(n_read<0)
fprintf(logfile,"%s","error reading serial data from sensor\n");
bytes_written=fprintf(outputfile,"%s",re);
fprintf(logfile,"%s" "%d" "%c","call and response executed number of bytes written: ",bytes_written,'\n');
//baud = ioctl(fd, FIOBAUDRATE, 57600);
close( fd ); /* close */
fclose(logfile);
fclose(outputfile);
It will write out "001 \0 \0 \0 \b 002 003" to /tyCo/0 which is what is expected. Why do you need to write it one byte at a time?
Make sure the TEST.txt file does not have anything in it after the 7 bytes before you write to it since you are only writing 7 bytes. You could also remove the TEST.txt file, touch the file so it exists and then it will only have the 7 bytes that you write to it.