Need help on accessing Serial Console on Jetson K1

Does anyone knows how to connect to the Debug Console on the Jetson K1 boards?

I don’t see any information on it like baud rate, configuration, voltage level, TTL, etc …

Also, is there a pinout layout of the GPIO block on it as well?

(What Debug Console do you mean? And which baud rate etc.?)

EDIT: Ah, I just re-read the subject I realized what you meant. I believe it’s a standard RS-232 port which will dictate the voltage levels etc. For the baudrate I would guess 115200.

You can find a lot of information, including the schematics of the board, from the support page:

I didn’t think just look into the schematic.
It was easier to use if I used the Searchable in conjunction.

I really never gotten a real lock of the voltages level on the RS232.
I have gotten some boards that are either a 5V,3.3V, 12V, R2R, etc…
Usually using the wrong one will damage it.

So I connect the DB9 port but so far I don’t see any TX/RX responses.
I don’t seem to see any services running that indicate it is connected to a serial port.

I’m looking the getty calls.

I am also having this issue though I haven’t really looked too far into seeing if it was on Windows’ side or the actual configuration. I’m using a work around for prolific compatibility issues on windows 8, not sure if this is the smoking gun.

Here’s a silly question: why use it? You have USB and ethernet will let you get on via SSH. For the straight serial port, if that’s what you want to use, my first guess would be 9600 baud 8-bits No parity and 1 stop-bit.

Also, I seem to recall from the Linux For Tegra 19.2 flash instructions, whether or not the serial port was turned on by default could be set from the config files for the flasher. You may need to re-flash it, you will definitley have to reflash it if you want to get USB 3.0 functionality and you additionally will have to load a firmware from system-space or userspace after the boot.

UPDATED a few minutes later. You may need to use a Nullmodem, if you can still find one of those anywhere but a dinosaur gallery where they sell old SPARC boxes and their spare parts.;)

According to ./kernel/arch/arm/boot/dts/tegra124-pm375.dts baud rate is set to 115200

bootargs = “tegraid= vmalloc=256M video=tegrafb console=ttyS0,115200n8 earlyprintk”;

You can use screen.
This is what I use from my Mac, you will probably need to change the /dev/tty:

screen -U /dev/tty.KeySerial1 115200

Should of posted earlier.

Yes, you need a null modem as posted in the Release Notes.
… And need a working 5V RS232 which was my problem.

Thanks, Nico, I stand corrected.

‘screen’ should work, sometimes distros have ‘minicom’ and that usually works pretty well.

That depends on what you are doing :)

If you work on the application layer, then you can mostly trust that the lower level works and you can use the “normal” means to access it.

But if you want to e.g. try out different kernel options, then the board may not boot far enough for you to have ethernet or USB. In that case the serial access is often the only one printing out debug messages etc.

@kulve: I understand that. ;) I used to work at a certain outfit which was known for their “repurposing” of old SPARC boxes and comparable equipment which had been mostly retired by more cutting-edge and heavily-funded startups. There’s no way to know what is happening on a headless SPARC unless you want to hook up a console to the serial port.

I guess people are recompiling the kernel but not getting a lot of success, hence the need for the console? :-D

I need to ask them a question but should start a new thread for that.

I use 115200 8N1.

FYI, there may be cases where power has to be applied to the unit before starting the serial console…I’m using serial-to-USB, and this is the case for me. USB simplifies life.