From: James Snow <JS<now@pi...> - 2007-06-30 05:56:08
Hello I'm a new user. I'm currently working on a project involving
I was wondering if anybody has looked into a software solution to
"hanging RxD line" when there isn't anything to drive that line. The
hardware solution by which you add a 10k pull-up resistor on the
board will work, however I would prefer an easily reversible solution.
Is this even feasible? Would it be worth the time?
If this has been done, or, if there are any other solutions to this
problem please post.
Info referring to the problem can be found here. http://
- J. Snow
From: Dave Hylands <dhylands@gm...> - 2007-06-30 06:15:36
> I was wondering if anybody has looked into a software solution to
> "hanging RxD line" when there isn't anything to drive that line. The
> hardware solution by which you add a 10k pull-up resistor on the
> board will work, however I would prefer an easily reversible solution.
Removing the resistor would be the reversible part. It's perfectly
fine to install the resistor and just leave it there forever. When the
robostix finally gets fixed, that's essentially what it will do.
It probably is possible to fix this by modifying u-boot.
I think that the problem happens when u-boot initializes the registers
that LDD14 winds up getting strobed (LDD14 controls the 5v to 3.3v
voltage converter) and this effectively causes noise on the RxD line
which looks like a character was typed.
If u-boot were to clear the UART after initializing the GPIO pins,
then it might prevent the "drop into u-boot".
Vancouver, BC, Canada
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