Custom Baudrate OSX

[saynono]

Hi.
It seems that following line:441 in unix Serial::SerialImpl::reconfigurePort resets custom baudrates on OSX.

  // activate settings
  ::tcsetattr (fd_, TCSANOW, &options);

Setting custom baudrates after this line fixes this as far as I can tell.
Also for noobs as myself, might be helpfull mentioning to call this on OSX:

stty ospeed <custom_baudrate>
stty ispeed <custom_baudrate>

and on linux

sudo stty -F <port> <custom_baudrate>

My changes here:
saynono@c997027

[willemkempers]

I had the same issue, but found adding the following block to line 343 a bit more elegant:

#if defined(MAC_OS_X_VERSION_10_4) && (MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_X_VERSION_10_4)
  else {
      speed_t new_baud = static_cast<speed_t> (baudrate_);
      ::cfsetispeed(&options, new_baud);
      ::cfsetospeed(&options, new_baud);
  }
#endif

Tested this super quickly on my macbook running macOS 10.12

[atomiechen]

Setting custom baudrates after this line fixes this as far as I can tell.

@saynono This is correct as far as I can see. I look into source code of PySerial (in serialposix.py):

def _reconfigure_port(self, force_update=False):
    ...
    # activate settings
    if force_update or [iflag, oflag, cflag, lflag, ispeed, ospeed, cc] != orig_attr:
        termios.tcsetattr(
            self.fd,
            termios.TCSANOW,
            [iflag, oflag, cflag, lflag, ispeed, ospeed, cc])

    # apply custom baud rate, if any
    if custom_baud is not None:
        self._set_special_baudrate(custom_baud)

We need to set custom baudrate after calling tcsetattr. Since I can use PySerial to connect my Arduino by 250000 baudrate yet I cannot do this via this c++ serial library, I believe this is at least a big difference I can find. Same issue also showed up in other project and a similar solution here: Custom baud rate in OSX won't work #57, npat-efault/picocom.

In my scenario the problem is solved on macOS Mojave 10.14.4. My commit: 4773265