Unexpected data on ttyTCU0

We are using an existing customized Jetson,
And it provides the only UART channel “ttyTCU0” connecting to an external device.

When I tried to send out couple of bytes with 3rd-party tool “cutecom”,
I send the hex data “00 11 22 33 FF” and the external device received “00 11 22 33 FF FF”.
An extra “FF” byte is there
Once the data stream contains data “0xFF”, Jetson will duplicate once when it transmitters out via ttyTCU0.

“00 FF 11 22 33” => “00 FF FF 11 22 33”
“00 FF FF 11 22 33” => “00 FF FF FF FF 11 22 33”

Can somebody help on this?

Hi chrischang1,

Do you mean that you are using the custom carrier board for Orin Nano?

What’s your Jetpack version in use?

ttyTCU0 is Tegra Combined UART for serial console log.
Please use UART1(/dev/ttyTHS0) to connect with your UART device.

Incidentally, that particular UART does not have the ability to be used for other purposes. You’re sending bytes to a console login and it is probably sending errors back about that user not existing for login.

1 Like

Yes, it’s a customized carrier board.
And the ttyTCU0 is the only communication channel to the specific external device.

And OK, I 'll try to change another way to do the communication between devices.


There should be 3 UART interfaces for Orin NX/Nano.
You can refer to OrinNX : How to check UART is working? - #3 by KevinFFF for details.

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.