SerialPortSettings.c_cflag &= ~PARENB /* Disables the Parity Enable bit(PARENB),So No Parity */
Tcgetattr(fd, &SerialPortSettings) /* Get the current attributes of the Serial port */Ĭfsetispeed(&SerialPortSettings,B19200) /* Set Read Speed as 19200 */Ĭfsetospeed(&SerialPortSettings,B19200) /* Set Write Speed as 19200 */ Struct termios SerialPortSettings /* Create the structure */ *- Setting the Attributes of the serial port using termios structure - */ Printf("\n ttyUSB0 Opened Successfully ") * Open in blocking mode,read will wait */ * O_NOCTTY - No terminal will control the process */ * O_RDWR - Read/Write access to serial port */ fd = open("/dev/ttyUSB0",O_RDWR | O_NOCTTY | O_NDELAY) /* ttyUSB0 is the FT232 based USB2SERIAL Converter */ * Change /dev/ttyUSB0 to the one corresponding to your system */įd = open("/dev/ttyUSB0",O_RDWR | O_NOCTTY) /* ttyUSB0 is the FT232 based USB2SERIAL Converter */ #include /* POSIX Terminal Control Definitions */ * use "man termios" to get more info about termios structure */ * termios structure - /usr/include/asm-generic/termbits.h */ * /dev/ttySx - for PC hardware based Serial ports, where x can be 0,1,2.etc */ * /dev/ttyUSBx - when using USB to Serial Converter, where x can be 0,1,2.etc */ * Sellecting the Serial port Number on Linux */ * "sudo" command to execute the compiled binary as super user. * 2) Linux will not allow you to access the serial port from user space,you have to be root.So use */ * " gcc -o serialport_read serialport_read.c " */ * 1) Compile the serialport_read.c file using gcc on the terminal (without quotes) */ * OS : Linux(x86) (Linux Mint 13 Maya)(Linux Kernel 3.x.x) */ * Commands : gcc -o serialport_read serialport_read.c */ * Program reads a string from the serial port at 9600 bps 8N1 format */ * Serial Port Programming in C (Serial Port Read) */
To be able to output the value I use the following code using termios libraries: /*=*/ Then if cat /dev/ttyUSB0 has been listening, I get the following output: -2.250416E-14A,+8.320175E+03,+0.000000E+00,of which the first number is the desired value. I am trying to write a simple application to read out a current value from a Keithley 6485 picoammeter, connected via serial communication (RS232USB) on linux.Ĭurrently, such a value can be retrieved by doing all the needed initialization of the device and sending "READ?" to it: echo "READ?" > /dev/ttyUSB0.