[Gumstix-users] Overo Sand usb serial corruption

[Paul G. <p.g...@ut...>]

I have an Oveo Sand on a Chestnut43 expansion board.  I am currently
using the omap3-desktop-nand-image-overo-booted root filesystem, the
MLO from the wiki (but not the mlo-updated), u-boot.bin and uImage from
the wiki page on building a bootable SD card.  I am booting the sand
from a 2GB SD card, and connecting with a mini-USB to USB cable to my
linux desktop.  I run kermit, with 115200 8n1 settings for the correct
serial port (ttyUSB0 connects to ttyO2 on the Sand).

The system boots, spews correct boot messages, and gives me a prompt.
However, it will immediately receive/generate garbage at the prompt,
and my keyboard input is not correctly echoed; letters become control
codes, lower case letters echoed uppercase, delete becomes ~, etc.
This problem coincides with connecting a 1.7 V 4800 baud serial signal
to RXD1 of the Overo through the 40-pin header on the Chestnut43.

If I disconnect the serial lines to/from GPIO148 and GPIO151 (TXD1, RXD1),
the problem doesn't happen as often.  Once the corrupted output occurs,
power cycling doesn't help.  Eventually, the problem just spontaneously
fixes itself.  After fixing itself, I can log in to the console and send
data out TXD1 (ttyO0) just fine without affecting the console (TTYO2),
I think.

Any ideas on why feeding a serial signal to RXD1 (RX for TTYO0) would
corrupt ttyO2?  Or is there some other problem that coincedentally
happens at the same time?

--
  It's a great life, if you don't weaken.
  	--Don Percious