[squeak-dev] Serial ports on Linux

Jon Hylands jon at huv.com
Wed Sep 1 13:55:43 UTC 2010


On Tue, 31 Aug 2010 23:57:39 -0400, "Schwab,Wilhelm K"
<bschwab at anest.ufl.edu> wrote:

>I have been able to do serial I/O on Windows, but not Linux.  Running in a terminal to capture output yields "Error while saving old state" while trying to open just about any number or name I can think of (including 0 and /dev/ttyS0), but the open method gives no indication that there is a problem; it returns a perfectly valid looking serial port with the #port set to whatever it was given.
>
>Subsequent reads fail, and are probably a bit more honest about what is happening: "Error while reading: serial port is not open."  I am not sure whether that is always the case, but it certainly is on this machine when I try /dev/ttyUSB0, which does not exist here.

If you're trying to use a USB->Serial port, what I normally do is
create a symbolic link to /dev/ttyUSB0 from /dev/ttyS4, and open the
port as port #4.

ln -s /dev/ttyUSB0 /dev/ttyS4

In terms of errors, though, the new SerialPort >> #openPort: in 4.1 is
really borked - it returns no indication that the open succeeded or
failed.

The old one, in 3.8, was much better.

Later,
Jon




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