Serial::Serial(const char * device_name, unsigned long baud_rate)
{
struct termios options;
std::cout << ">> starting Serial::Serial(.)" << std::endl;
fd = open(device_name, O_RDWR | O_NOCTTY | O_NDELAY);
if(fd == -1)
throw SerialException("Could not open serial device.\n", errno);
std::cout << " -- serial device is open, fd: " << fd << std::endl;
fcntl(fd, F_SETFL, 0); // blocking
std::cout << " -- blocking" << std::endl;
tcgetattr(fd, &options); // get the current options // TODO: restore on destruction of the object
std::cout << " -- got the current options" << std::endl;
tcgetattr(fd, &options);
options.c_cflag=B57600;
tcsetattr(fd, TCSANOW, &options);
std::cout << " -- set baud rate uart0_filestream" << std::endl;
#ifndef __APPLE__
if(cfsetispeed(&options, B57600) != 0)
throw SerialException("Could not set baud rate for input", errno);
std::cout << " -- set baud rate for input" << std::endl;
if(cfsetospeed(&options, B57600) != 0)
throw SerialException("Could not set baud rate for output", errno);
std::cout << " -- set baud rate for output" << std::endl;
#endif
options.c_cflag |= (CS8 | CLOCAL | CREAD);
options.c_iflag = IGNPAR;
options.c_oflag = 0;
options.c_lflag = 0;
options.c_cc[VMIN] = 0;
options.c_cc[VTIME] = 1; // tenth of seconds allowed between bytes of serial data
// but since VMIN = 0 we will wait at most 1/10 s for data then return
tcflush(fd, TCIOFLUSH);
tcsetattr(fd, TCSANOW, &options); // set the options
#ifdef __APPLE__
cfmakeraw(&options); // necessary for ioctl to function; must come after setattr
const speed_t TGTBAUD = baud_rate;
int ret = ioctl(fd, IOSSIOSPEED, &TGTBAUD); // sets also non-standard baud rates
if (ret)
throw SerialException("Could not set baud rate", errno);
std::cout << " -- set baud rate for output" << std::endl;
#endif
}
size_t Serial::read(char* data, size_t length) {
waitForData();
logger.debug(MODULE, "Reading data");
ssize_t br = ::read(fd, data, length);
logger.debug(MODULE, "Read %u bytes", br);
if (br == -1) {
throw SerialException("Could not read data");
}
return br;
}
void Serial::waitToWrite() {
fd_set writeset;
int result;
logger.debug(MODULE, "Waiting to write");
do {
FD_ZERO(&writeset);
FD_SET(fd, &writeset);
timeval timeout = {0, 100};
result = select(fd + 1, nullptr, &writeset, nullptr, &timeout);
} while (result == 0 && !abortFlag);
if (abortFlag) {
throw SerialException("Aborted by client request");
}
if (result < 0) {
throw SerialException("Lost serial connection during select");
}
}
Serial::Serial(const std::string& device, Logger& logger) : logger(logger), abortFlag(false) {
fd = open(device.c_str(), O_RDWR | O_NOCTTY | O_NONBLOCK);
if (-1 == fd) {
throw SerialException("Could not open device");
}
if (!isatty(fd)) {
close(fd);
throw SerialException("Specified device is not a TTY");
}
termios termAttr;
if (-1 == tcgetattr(fd, &termAttr)) {
close(fd);
throw SerialException("Could not get device attributes");
}
termAttr.c_cc[VTIME] = 0;
termAttr.c_cc[VMIN] = 0;
termAttr.c_iflag = 0;
termAttr.c_oflag = 0;
termAttr.c_cflag = CS8 | CREAD | CLOCAL;
termAttr.c_lflag = 0;
if (0 > cfsetispeed(&termAttr, B115200) ||
0 > cfsetospeed(&termAttr, B115200)) {
close(fd);
throw SerialException("Could not set device baud rate");
}
if (-1 == tcsetattr(fd, TCSAFLUSH, &termAttr)) {
close(fd);
throw SerialException("Could not set device attributes");
}
}
void Serial::write(const char* data, size_t length) {
ssize_t bw = 0;
logger.debug(MODULE, "Writing %u bytes", length);
while (length > 0) {
waitToWrite();
bw = ::write(fd, data, length);
if (-1 == bw) {
throw SerialException("Could not write data");
}
length -= bw;
data += bw;
}
}
void Serial::waitForData() {
fd_set readset;
int result;
logger.debug(MODULE, "Waiting for data");
do {
FD_ZERO(&readset);
FD_SET(fd, &readset);
timeval timeout = {0, 100};
result = select(fd + 1, &readset, nullptr, nullptr, &timeout);
} while (result == 0 && !abortFlag);
logger.debug(MODULE, "Got some data? %d %d %s", result, errno, abortFlag ? "true" : "false");
if (abortFlag) {
throw SerialException("Aborted by client request");
}
if (result < 0) {
throw SerialException("Lost serial connection during select");
}
}