UART simple test

[Andrey1984]

after adding wire to shortcut pin8-pin10

one terminal

 echo "1" > /dev/ttyTHS0

another terminal

cat /dev/ttyTHS0

shows the output “1”

Next challenge is to show UART output from a second devkit
which results in symbols/huerogliphs as for now as you can see in the related original thread Does JP4.6.1 sdcard oem setup boot break integrity of initrd installed nvme ssd OS? - #53 by _av

sudo gtkterm -p /dev/ttyTHS0 -s 115200 -a none -t 1 -b 8 
���@�����pR�����@���~����������p��V�q��d���@�r���*V���������v������@��4�� ��������������x���`�����z>���������
                                    �����������������@����v��2

[linuxdev]

By default the two should both be 3.3V. However, there is a level shift jumper (I have never used it before) which I think can change it to 1.8V. Is it possible one side has the jumper such that it is 1.8V?

One other question is if the output of “$LANG” is the same at both sides where the serial console program and generated data are run. If for some reason the character set differs, then the data would be 100% correct, but displayed wrong.

[DaneLLL]

Hi,
We don’t test this case on default release. In general we use this kind of cable:
https://www.amazon.com/USB-to-TTL-Serial-Cable/dp/B00N2FPJ0Q
To connect to a host PC and run minicom/cutecom to get log.

The supported mode is to get UART log through a host PC. Would need to check with our teams if we can support getting the log from the other Jetson device in the future.

If you have to run this use-case, please try linuxdev’s suggestion.

@linuxdev thanks for your help.