Serial.cpp

#include "Serial.h"

Serial::Serial() {

}

Serial::Serial(char *portName, int speed, int parity, int shouldBlock) {
    fd = open (portName, O_RDONLY | O_NOCTTY | O_SYNC);

    if (fd < 0) {
        cout << "Error opening " << portName << " error code: " << strerror(errno) << endl;
    } else {
        setInterfaceAttribs(speed, parity);
        setBlocking(shouldBlock);
    }
    startRead();
}

Serial::~Serial() {
    delete readPortThread;
}

int Serial::setInterfaceAttribs(int speed, int parity)
{
    struct termios tty;
    memset (&tty, 0, sizeof tty);

    if (tcgetattr (fd, &tty) != 0)
    {
        cout << "Error from tcgetattr: " << strerror(errno);
        return -1;
    }

    cfsetospeed (&tty, speed);
    cfsetispeed (&tty, speed);

    tty.c_cflag = (tty.c_cflag & ~CSIZE) | CS8;     // 8-bit chars
    // disable IGNBRK for mismatched speed tests; otherwise receive break
    // as \000 chars
    tty.c_iflag &= ~IGNBRK;         // disable break processing
    tty.c_lflag = 0;                // no signaling chars, no echo,
    // no canonical processing

    tty.c_oflag &= ~OPOST;                // no remapping, no delays
    tty.c_cc[VMIN]  = 0;            // read doesn't block
    tty.c_cc[VTIME] = 100;            // 0.5 seconds read timeout

    tty.c_iflag &= ~(IXON | IXOFF | IXANY); // shut off xon/xoff ctrl

    tty.c_cflag |= (CLOCAL | CREAD);// ignore modem controls,
    // enable reading
    tty.c_cflag &= ~(PARENB | PARODD);      // shut off parity
    tty.c_cflag |= parity;
    tty.c_cflag &= ~CSTOPB;
    tty.c_cflag &= ~CRTSCTS;

    if (tcsetattr (fd, TCSANOW, &tty) != 0)
    {
        cout << "Error from tcgetattr" << strerror(errno);
        return -1;
    }
    return 0;
}

void Serial::setBlocking (int should_block)
{
    struct termios tty;
    memset (&tty, 0, sizeof tty);

    if (tcgetattr (fd, &tty) != 0) {
        cout << "Error from tcgetattr: " << strerror(errno);
        return;
    }

    tty.c_cc[VMIN]  = should_block ? 1 : 0;
    tty.c_cc[VTIME] = 5;            // 0.5 seconds read timeout

    if (tcsetattr (fd, TCSANOW, &tty) != 0) {
        cout << "Error at setting term attributes" << strerror(errno);
    }
}

void Serial::startRead() {
    readPortThread = new thread(&Serial::readPort, this);
    cout << "starting sensor read thread" << endl;
}

void Serial::readPort() {
    size_t nrBytesRead = 0;
    uint8_t buffer[50];

    while (!readPortThreadStop) {
        nrBytesRead = read(fd, buffer, 50);
        //cout << nrBytesRead << " bytes read" << endl;

        if (nrBytesRead > 0) {
            for (unsigned int i = 0; i < nrBytesRead; i++) {
                data.push(buffer[i]);
                //cout << "buffer value on i=" << i << "/" << nrBytesRead << ": " << to_string(buffer[i]) << endl;
            }
            //cout << "stopping read" << endl;
        } else if (nrBytesRead == -1) {
            //cout << "erronous read, error: " << strerror(errno) << endl;
        } else {
            //cout << "no bytes read"<< endl;
        }

        usleep(7000);
    }
}

unsigned short Serial::bytesAvailable() {
    return data.size();
}

uint8_t Serial::readQueue() {
    uint8_t returnData = data.front();
    data.pop();

    return returnData;
}

vector <uint8_t> Serial::readQueue(const uint8_t &nrBytes) {
    vector <uint8_t> returnData;
    for (uint8_t i = 0; i < nrBytes; i++) {
        returnData.push_back(data.front());
        data.pop();
    }

    return returnData;
}