the uart number are based on “SoM connector” in Jetson-TX2-Series-Pinmux-Template_v1.08.xlsm file. We tried to upload the xlsm, but failed. You may get it from the download center.
UART3 is pin# H9, H10. according to the dmesg, it seems that UART3 is UART-d, serial@3130000. and UART3 has been mapped to ttyTHS3. but, it does not work.
echo “uart3 test” > /dev/ttyTHS3 no signal cought on uart3
and what`s more serious, DT has configed UART1 to 115200 baud rate, but it works at 9600 in fact. could you give some help on it.
there’s Mux for UART-3, pin# H9, H10, which choosing WiFi/BT or UART on Jetson TX2.
that’s uarta for the default debug port, you’ll need modifications to treat it as normal serial port. please see-also Topic 199133 for an example to configure debug port from UART-0 to UART-1.
OK, let me explain it.
On a windows test PC, we use a USB-RS232(ch340) tool connect the xshell and UART1.
Then, open a terminal on TX2.
echo “uart1 test” > /dev/ttyTHS2
xshell can get the strings only when we set baud rate to 9600.
and no errors print on screen.
This topic 201881 realy works and helps us a lot. But, stty command can change baud rate temporarily. If we reboot tx2 baud rate will go back to 9600. So, we need config it when uart init. Could you give some suggestions?
We are so confused that baud rate has been setted to 115200, why it does not work?
We debuged in the following file.
Found that, the function tegra_uart_starup() and tegra_uart_hw_init() were never invoked.
So that, the baud rate was not setted.
We added configuration in the nvgetty.sh on the host pc, and used “flash -r -k kernel jetson-tx2 mmcblk0p1”. But, when device brought up, the script did not chang. Could you give the right command to flash?
can you please test on single device to confirm adding the configurations in nvgetty.sh resolve your issue.
once you confirm the solution, you may modify the file on your local host.
that’s rootfs for flashing to targets. for example, ~/nvidia/nvidia_sdk/JetPack_<version>_Linux_<platform>/Linux_for_Tegra/rootfs/etc/systemd/nvgetty.sh