[ECOS] Q: Serial Port Non-Echo?

David Oberbeck dgo@microsynetics.com
Thu Jan 3 07:42:00 GMT 2002


Gary,

   You're right, I was opening /dev/tty0 rather than /dev/ser0 (oops).

   Thank you - that was it!

Regards,
	David

On Thursday 03 January 2002 06:14, Gary Thomas Wrote Thusly:
> On Thu, 2002-01-03 at 01:34, David Oberbeck wrote:
> > Greetings all,
> >
> >    A (hopefully) quick question:
> >
> > 	How do I get a serial port to not echo bytes?
> >
> >    Background: iPAQ target, recent CVS version of eCos, gcc 3.0.3,
> > Insight 5.1. We can receive just great using non-blocking reads, but
> > the driver is echoing the bytes back before we 'see' them; we need to
> > control what gets echoed back.
> >
> >    I looked at the Ref Manual, walked through parts of the code; I did
> > find a no-echo flag in tty mode but not in raw ( e.g. cyg_io_read() )
> > mode. There seems to be no config key (e.g. cyg_io_set_config() which
> > has the right parms to read or set...
> >
> >    Am I missing something obvious? What's the best way around this?
>
> The only place that "echo" happens is in the TTY driver(s) [either ttyXX
> or termiosX].  You can control that behaviour with cyg_io_set_config()
> or using the POSIX termios functions.
>
> The lowest level read functions/driver (/dev/serX) only move data, there
> is no interpretation and thus, no echoing.

-- 

"Entropy Requires No Maintenance"



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