serial_communication.cpp

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#include "serial_communication.h"


SerialCommunication::SerialCommunication() :
    _file_descriptor(-1)
{
}


SerialCommunication::~SerialCommunication()
{
}


void SerialCommunication::set_serial_device(std::string serial_device)
{
    _serial_device = serial_device;
}


int SerialCommunication::open_port(struct termios *oldtio)
{
    struct termios newtio;
    int error = 0;

    // open the serial port
    _file_descriptor = open(_serial_device.c_str(), O_RDWR | O_NOCTTY);

    if (_file_descriptor < 0) {
        ROS_ERROR("[EYELIDS] Error: opening serial device %s", _serial_device.c_str());
        exit(-1);
    }

    // save current port settings
    if (tcgetattr(_file_descriptor, oldtio) != 0) {
        error = -1;
    }

    bzero(&newtio, sizeof(newtio));
    newtio.c_cflag = B9600 | CS8 | CLOCAL | CREAD;
    newtio.c_cflag &= ~PARENB;
    newtio.c_cflag &= ~CSTOPB;
    newtio.c_cflag &= ~CSIZE;
    newtio.c_cflag |= CS8;
    newtio.c_oflag = 0;

    // set input mode (non-canonical, no echo,...)
    newtio.c_lflag = 0;

    newtio.c_cc[VTIME] = 0; // inter-character timer unused
    newtio.c_cc[VMIN] = 1;  // blocking read until 1 chars received

    if (tcflush(_file_descriptor, TCIFLUSH) != 0) {
        error = -1;
    }
    if (tcsetattr(_file_descriptor, TCSANOW, &newtio) != 0) {
        error = -1;
    }

    return error;
}


int SerialCommunication::close_port(struct termios *oldtio)
{
    int error = 0;

    if (tcsetattr(_file_descriptor, TCSANOW, oldtio) != 0) {
        error = -1;
    }
    if (close(_file_descriptor) != 0) {
        error = -1;
    }

    return error;
}


int SerialCommunication::send_character(unsigned char *str)
{
    int error = 0;

    if (write(_file_descriptor, str, 1) == -1) {
        ROS_ERROR("[EYELIDS] Error: sending character by the serial port");
        error = -1;
    }
    ROS_DEBUG("[EYELIDS] Character sent: %u", *str);

    return error;
}