[Rxtx] RTS control in RXTX
tjarvi at qbang.org
Wed Sep 20 20:37:22 MDT 2006
> It seems that RXTX (and the javax comm API) can't really deal with
> this difference, even if the underlying OS (e.g. Windows) allows
> access to both behaviors. This would seem to partly be a shortcoming
> of the termios interface, which the javax comm API seems to have been
> based on (makes sense given it came from Sun), but I don't know
> termios very well, so I can't say for sure.
> So the next question is: what would people think would be the best way
> to extend the javax.com (aka gnu.io) API to allow an application
> program access to whichever behavior they want? I don't want (and
> literlly can't since they will likely get pulled into the same JVM) to
> have multiple versions of RXTX around.
> My initial thought was to actually modify RXTX to start paying
> attention to the IN/OUT HW flow control values - I think right now, it
> just maps either to enabling both direction of HW flow control. My
> mod would change it so that RTSCTS_OUT by itself would turn on the old
> behavior, whle RTSCTS_OUT|IN would turn on the new behavior.
> Then there's the whole DTR/DSR behavior as well, which RXTX seems to
> require a more or less manual intervention by whatever application
> wants to use it.
> Anyway, I haven't thought much beyond all this. I wanted to get the
> groups feedback so that I don't paint myself into a corner. Has
> anyone else seen any other Java Serial Port implementations that do
> something like this (like one of the commercial ones?). Anyone have
> any other suggestions?
My concern is mainly platform neutrality. We can do some of this but
other parts are very MSFT Windows specific. I suspect that commapi had a
Windows developer involved early on based upon some of the functionality
already in the API.
How much of this is just trying to fit as much of the Windows API in as
possible vs known usage cases? If there are usage cases and Unix just
can't do it, thats one thing vs advertising features which are just really
obscure corner cases at best alongside what everyone uses.
It is possible to work through much of this. There are folks looking at
an API update [under NDA now?].
tjarvi at qbang.org
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