ZED Mini Box Carrier Board UART Connection

Software
1

We have a StereoLabs Mini Carrier Board and are trying to connect a serial device (gimbal) over UART (PINOUT GPIO #09, #10 with ground #08). We are currently unable to get any communication with the serial device.

To isolate the problem, we did a physical loopback test (connecting pin #09 to #10) and could not receive any messages we sent (using pyserial). Tried ttyTHS1, ttyTHS2, and ttyAMA0 (there is no ttyTHS0). Repeated same test with an oscilloscope; same results. On boot, with the oscilloscope attached, we see data output when the boot text scrolls across the screen before the login screen. We have confirmed the same behavior with two Orin NX modules (we only have 1 carrier board).

The user is part of both tty and dialout groups as per this.

What is the configuration to use pins #09 and #10?

2

Hi @penguin
The UART of the Mini carrier board is connected to the pins of the UART2 of the NVIDIA Jetson module.
UART2 is configured by default as a debug port, and we are working to provide a guide to reconfigure it as a general-purpose UART if possible.

You can read more on this NVIDIA Developer Forum thread

3

Do you have an approximate timeframe on the guide? We have a deadline approaching and may need to pursue a different solution in the interim. Is there a less ‘invasive’ method to setup a serial device with the carrier board?

4

Unfortunately, it seems that the debug port cannot be easily reconfigured as a general-purpose port.
We are still investigating to find a way to do that.

5

If the Mini Carrier Board UART is connected to NVIDIA Module UART2, what is the Mini Carrier Board “DEBUG” (Micro-USB) connected to?

Also, is there a wiring diagram available?

6

It’s connected to USB0, not to a serial-USB converter.

This is not publicly available.

7

Hi @Myzhar,

any update on this thread?

Can we then conclude that the UART from the GPIO port of ZED mini carrier cannot be used as a general UART?

Thanks!

8

Yes, this is the current status.

9

Hi Myzhar @Myzhar ,

Thanks for the reply.

Then, although I like your carrier design, I still highly suggest you extend the connectivities of the ZED Jetson carrier board in the next generation to make it more competitive. At least +1 USB 3.2 port, + more GPIOs, + UART1. Maybe also a mini PCIe.

Cheers,

Haoming

10

Hi @hz658832

Thank you for the suggestions. Improvements for the new carrier boards are on the roadmap for 2026.

11

Would the below work:

sudo systemctl stop nvgetty.service
sudo systemctl disable nvgetty.service

I know in the Jetson Orin Nano Dev kit, this is how you enable the UART port(Pin 8 and 10 on the Expansion Header) to unlock the UART to be used. By default it is used for Debug.

Could the same be applied on the mini carrier board or is it connected to other UART?

12

Have you tested these commands?

13

Yes, I have used these on the Jetson Orin Nano Dev Kit and unlocked the UART. Unfortunately, I do not possess a Zed Mini Carrier board or Zed Mini Box to test on them. However, I am keen to know if the commands work as I am planning on buying the mini carrier board.