Help with working with ttyS1

David Reyes Samblas Martinez david at
Wed Apr 21 11:23:24 EDT 2010

Surelly I'm doing something wrong, and I beg for help for serial gurus here,
I'm trying to read/write from ttyS1 but I no receive/send anything.
What I have done:

flash the u-boot from Xiang Fu that enables ttyS1[1]
connect UART1 of NN Using the ttl-USB cable to PC
installing coreutils-stty form opkg in NN
Executing(extracted from arduino serial comunications):
on NN
#stty -F /dev/ttyS1 cs8 57600 ignbrk -brkint -icrnl -imaxbel
-opost -onlcr -isig -icanon -iexten -echo -echoe -echok -echoctl -echoke noflsh
-ixon -crtscts
on PC
#stty -F /dev/ttyUSB1 cs8 57600 ignbrk -brkint -icrnl -imaxbel
-opost -onlcr -isig -icanon -iexten -echo -echoe -echok -echoctl -echoke noflsh
-ixon -crtscts

to make sure both sides are "talking" same bitrate.
but then when I try to
on NN
#tail -f /dev/ttyS1
on PC
#echo "Hello NanoNote" > /dev/ttyUSB1

on PC
#tail -f /dev/ttyUSB1
on NN
#echo "Hello NanoNote" > /dev/ttyS1

Nothing happens, I have tried diferent serial bitrates, and also
checking cable works,
 by the way Xiang , with u-boot provided if I press S+Power serial
returs this in ttyS0

-----------------------------Serial log message
NAND Secondary Program Loader

[U] not pressed
Starting U-Boot ...
[S] pressed, enable UART0

U-Boot 2009.11-dirty (Apr 18 2010 - 22:05:47)

Board: Qi LB60 (Ingenic XBurst Jz4740 SoC, Speed 336 MHz)
DRAM:  32 MB
NAND:  2048 MiB
*** Warning - bad CRC or NAND, using default environment
-------------------------END LOG------------------------

And I have to hard reset to make NN turn to live
David Reyes Samblas Martinez
Open ultraportable & embedded solutions
Ben NanoNote, Arduino, Openmoko
Hey, watch out!!! There's a linux in your pocket!!!

More information about the discussion mailing list