Jetson Xavier NX how to use the UART J14 port

i am trying to use the uart ports of the J14 button header (RXD, TXD) of the jetson xavier nx but the problem is that in the documentation i can’t find where are specified the name that ubuntu gives to these port, so i try testing with the 3 available references: ttyTHS0, ttyTHS1 and ttyTHS4 ports, but none port worked, so my question is this UART J14 port is enabled or i have to do the same thing that was done with the jetson tx2 to enable the ttyths2 port?.

hello andresbeltc,

may I have your confirmation you’d working with NX or TX2?

for Jetson Xavier NX, it’s pin-3 and pin-4 respectively for UART Receive and Send of J14,
pin-3 and pin-4 were UART2_TXD,UART2_RXD / UART3_TX,UART3_RX =pin 236,238, the port is mapping to ttyTHS2.

please also access NX Developer Kit User Guide from download center for reference.
you might also also access NX Product Design Guide and check [Figure 11-5. Jetson Xavier NX UART Connections]

here’s similar discussion thread, Topic 145106 for your reference.