Connection via UART1

Im facing a problem with connecting my Jetson Orin Nano Dev Kit via 8, 10 pins (UART1_TXD, UART1_RXD) to my custom board with mcu.
I’ve had no issues with the Jetson Nano Dev Kit and the same board before. I used /dev/ttyTHS1 file to access the uart. But now there is no ttyTHS1.
ls /dev/ | grep THS output:
So I don’t really know which of those files corresponds to UART1 (8, 10 pins).
I tried to use them all, but no avail. I saw something like this fix overlay_usb_35.3.1.tbz2 on Jetson Linux 35.3.1 page but I’m not entirely sure if it’s related to my issue. And I dont understand how I can applay this fix. So I have two questions:

  1. Which of the ttyTHS files is corresponds to UART1 (8, 10 pins)?
  2. And if the fix is related with my problem, then how can I applay it?

JetPack: 5.1.1

Hi farhatyakubov,

You could refer to the following thread for UART usage on Orin NX/Nano.
OrinNX : How to check UART is working? - #3 by KevinFFF

It should be /dev/ttyTHS0 for UART1

The overlay package for Orin series is bout usb firmware to fix packet lost issue.
You could just extract that in your BSP package before flash the board to apply it.

how apply it in a existent installation , I cannot reinstall my system again, just recovered for a total lost of data due to the jetpack upgrade, just I found this bug as my usb serial devices doesn’t work.
can you make a .deb upgrade or something?

Hi! To be honest, my problem was not related to the fix. Perhaps you should look into the uart setup or the physical connection in more detail.
I can confirm that my Orin Nano dev kit with JetPack 5.1.1 works correctly with uart without/with overlay_usb_35.3.1.tbz2 applied

thanks, my issue is with uart over usb, in my case I need the file, because that my question to @kevinff966 , as there is no instructions to install it in a existent and running installation that I cannot wipe.

Hi @fpsychosis,
Do you mean that you want apply the overlay package for Orin issue about uart over usb but you don’t want to re-flash the board?

exactly, I come from a full lost of data from jetpack update, and now I found this issue with the uart via usb that wont read data of my motor controller, gps and ardupilot, I need apply the patch and I cannot reflash. Something like a kernel update via .deb or apt as it is done when update jetpack via apt , just add the update to the apt repository.

Just curious, can both a device tree and device tree overlay both be specified in extlinux.conf?

You could refer this topic about applying overlay dtbo.

Could you help to apply the overlay and generate BUP package to update?

Not sure what is described in that post, my problem is not related with boot order, I use NVME in Orin NX production module on waveshare carrier board (same as Xavier NX Dev kit I think.
The file described in that post is not the same the one I need flash.
I need specific and clear instructions of what I need to do to be sure I don’t lose my data again, that post doesn’t look ideal for me as something I would follow with confidence.

Could you help to apply the overlay and generate BUP package to update?

No idea what is a BUP package.
I would expect if there was a bug and a solution, in this case a patch, I would expect it is documented how to do it.
In my opinion should be documentation how to do it with the SBC affected and how to do it from SD card , Flash and NVME. Also the ideal would be just an apt upgrade.

If I receive clear instructions a can help to make the BUP file, but If it is interest of nVidia, I have not problem to grant remote access to my Jetson Orin NX to nVidia staffto they can make the FIX and the BUP file, I have not confidential info there can grant access to anyone, just I cannot afford lose the data. I will happy to help and make easier others can fix it easier, I understand Orin NX maybe is not in hands of all the nVidia support team, so I have no problem in grant access.

That topic is provided to linuxdev for reference. You could just ignore it.

You could refer to the instruction here for the detail of BUP. It is used to update the bootloader.

If you are afraid of losing the data, you could wait for the next Jetpack release (5.1.2,) and use OTA update for this overlay, it should be included.

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You’ll see a lot of references to “Board Support Package” (BSP) and “Board Update Package” (BUP). Basically the flash software and/or firmware.

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that is fine then , I will wait if the release is not too far away, any idea when could be released 5.1.2?

@linuxdev thanks , I will check it out but I don’t feel confident, last jetpack uprade, just killed my installation and in theory was a easy thing, flash the bootloader looks more delicate, and I’m not confident to be honest.

After check the BUP instructions they are not having in account that boards now can run from NVME, same reason than problably the jetpack upgrade via apt killed my instalation.
If there is a new way to boot, should be incorporated to the technical documents and guides, at the moment if I follow that tutorial won’t work, as it aims to SDcard, I have no one I use NVME. I could imagine will be fine just changing the device name, but how to be sure, is what the last time I though and everything went wrong.
I’m in Karen mode, sorry.

Please try the steps and see if you can trigger the update:

  1. Overwrite the files in:
    Serial device hangs after closing, unable to re-open without first unplugging it - #9 by DaneLLL
  2. Boot target device in recovery mode and connect to host
  3. Run the command:
Linux_for_Tegra$ sudo ./ jetson-orin-nano-devkit mmcblk0p1
Linux_for_Tegra$ ./generate_capsule/ -i bootloader/payloads_t23x/bl_only_payload -o ./TEGRA_BL.Cap t234
  1. Copy TEGRA_BL.Cap to target device


  1. Run the command on target:
$ ll /dev/disk/by-partlabel/esp
$ sudo mount /dev/nvme0n1p11 /mnt/
$ cd /mnt/EFI
# mkdir UpdateCapsule
# cd UpdateCapsule/
# cp /home/nvidia/TEGRA_BL.Cap .
With QSPI flash:
# cd /sys/firmware/efi/efivars/
# printf "\x07\x00\x00\x00\x04\x00\x00\x00\x00\x00\x00\x00" > /tmp/var_tmp.bin
# sudo dd if=/tmp/var_tmp.bin of=OsIndications-8be4df61-93ca-11d2-aa0d-00e098032b8c bs=12
  1. Reboot the target device
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