[gentoo-user] Re: serial port identification question

[James]

David Relson <relson <at> osagesoftware.com> writes:


> Having solved/learned the above on the Gentoo box, the next trick is
> getting my code to work on the embedded 486SX linux system (non-Gentoo).


There is a very exceptional collection of talent on the gentoo-embedded
list, that you cannot even image exists.... USE IT.....


> So far I know that programmed setting of baud rate is working (as
> confirmed with stty).  However no data is being seen  from the keypad
> or the two connected preamps.  They should all be continuously sending
> data to com3, com2, and com4 (respectively).


I usally use a baseline system to ensure that the hardware/device is working
before trying on a new hardware platform. That way, you know your device
is working and your just trying to get a serial port on an embedded system
working.....


Also, you did not mention anything about PARITY and STOP BITS. Ensure that these
are set correctly, in addition to baud rate..

Serial ports usely need only 3 pins to work, tx, rx and ground. Google for
loopbacks and null modem configurations as there are lots of tricky versions...

Realize that serial ports can be build on a variety of hardware. 8250, 16550,
etc or 'bit-banged' on general I/O pins on a micro or a dedicated chip
in your hardwared. I do not have the "fogiest" idea what your hardware
actually is. Some PC board manufacturers have done amazingly funky things
over the years, like use a non standard baud rate to run a keyboard
(keypad) over a serial port. Over at emebedded-gentoo, exact state what
your hardware is what works and what you are trying to do. Make sure it's using
embedded gentoo, or that is the goal, or you'll just get 'punted' elsewhere.

CAVEAT EMPTOR.

Last, this is not the place for minutia on serial port devices.So move
over to the gentoo-embedded list for lost of folks, smarter than I?
(yes)......



James



If you are using a 'keypad' realize that they use s