Using more UARTs for serial communication on DevKit

I want to use more UARTs on the DevKit. According to the Pinmux configuration, there are three.

  1. One on the GPIO 40 pin header
  2. DEBUG one on the J14 header
  3. One on the baseboard M.2

Is there a way to access the 2) DEBUG J14 UART pins to establish serial communication with devices? (I assume that the default settings is that the 2) is used as a serial console to control Xavier NX).

Thank you!

hello mmmysl,

you may access NX Product Design Guide via download center, and please check [Chapter-10.3 UART] chapter for the uart signal connections.
please also access NX Developer Kit User Guide, you may using J14, by wiring pin-3 and pin-4 for UART receive and send.

Thank you for the tips.
I managed to establish the serial communication through the 40-pin header UART at /dev/ttyTHS0, but no success with the /dev/ttyTHS1 nor /dev/ttyTHS4 (I assume that one of them has to be the J14 UART).

  • nvgetty.service is disabled
  • fuser command shows no processes on the THS1 and THS4

The J14 is officially a Debug UART, so is there anything particular I should do to establish communication through it?
Thank you

Hi mmmysl,

You can use TX/RX cable and connect from J14 pins on Xavier-NX to USB port on your host mahcine.
Pins 3: RXD
Pins 4: TXD
Pins 7: GND

And check “ll /dev/ttyUSB*” on your host Ubuntu machine and using picocom or minicom tools to open uart log.

Yes, thank you, if I understand well, that would be the case of the serial console.

But my original question was if I could use UART on J14 to other tasks - I want it to communicate with a wireless transceiver that uses Tx and Rx pins.

On the software side, I need to open the serial port and write to it/read from it. (And that is something I have not managed to do.)
No host computer will be involved in this case.

hello mmmysl,

it’s serial port for enabling ttyUSB* for sending serial data; we haven’t validate with a wireless transceiver yet.

Ok, thank you for your answer.