I am reading binary data from a serial port on Phidget sbc using Linux to get a command from an application running on a PC. I wrote a test program in VB to read the data into a byte array and convert it to decimal to use it but can’t figure out how to do it in c. I am unable to come up with anything with the research I have done on the internet. Command sent from PC is 0x0F. To check if I am getting correct data I read the data and send it back. Here is what I get back. Returned data has a carriage return added to it. Hex Display 0F00 0000 0D ‘\’ Display \0F\00\00\00\r Normal display just display a strange character. This tells me that the data is there that I can use, but can’t figure out to extract the value 0F or 15. How can I convert the incoming data to use it? I tried converting the received data using strtol, but it returns 0. I also tried setting the port to raw but it did not make any difference. unsigned char buffer1[1]; int ReadPort1() { int result; result = read(file1, &buffer1,1); if(result > 0) { WritePort1(buffer1); sprintf(tempstr, "Port1 data %s %d", buffer1, result); DisplayText(2,tempstr); } return result; } Port Open/Setup void OpenPort1() { //file1 = open("/dev/ttyUSB1", O_RDWR | O_NOCTTY | O_NONBLOCK); file1 = open("/dev/ttyUSB1", O_RDWR | O_NOCTTY | O_NODELAY); if(file1 < 0) printf("Error opening serial port1.\n"); else { SetPort(file1, 115200, 8, 1, 0, 1); port1open = 1; } } void SetPort(int fd, int Baud_Rate, int Data_Bits, int Stop_Bits, int Parity, int raw) { long BAUD; // derived baud rate from command line long DATABITS; long STOPBITS; long PARITYON; long PARITY; struct termios newtio; switch (Baud_Rate) { case 115200: BAUD = B115200; break; case 38400: BAUD = B38400; break; case 19200: BAUD = B19200; break; case 9600: BAUD = B9600; break; } //end of switch baud_rate switch (Data_Bits) { case 8: default: DATABITS = CS8; break; case 7: DATABITS = CS7; break; case 6: DATABITS = CS6; break; case 5: DATABITS = CS5; break; } //end of switch data_bits switch (Stop_Bits) { case 1: default: STOPBITS = 0; break; case 2: STOPBITS = CSTOPB; break; } //end of switch stop bits switch (Parity) { case 0: default: //none PARITYON = 0; PARITY = 0; break; case 1: //odd PARITYON = PARENB; PARITY = PARODD; break; case 2: //even PARITYON = PARENB; PARITY = 0; break; } //end of switch parity newtio.c_cflag = BAUD | DATABITS | STOPBITS | PARITYON | PARITY | CLOCAL | CREAD; newtio.c_iflag = IGNPAR; if(raw == 1) { newtio.c_oflag &= ~OPOST; newtio.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); } else { newtio.c_lflag = 0; //ICANON; newtio.c_oflag = 0; } newtio.c_cc[VMIN]=1; newtio.c_cc[VTIME]=0; tcflush(fd, TCIFLUSH); tcsetattr(fd,TCSANOW,&newtio); }