Uart serial port does not print information


I’m sorry I am sad to say I only speak English. The typical issue though about serial port is getting the wrong connector. If not using J21, then switch to J21. Here is a wiring summary:

If you use a USB serial UART which is device powered instead of bus powered, then you may have to detach and re-attach the serial UART.

If the TX1 module work, what signal pins need to be set? I designed the development board, no serial print information, do not know whether the module is running

Regular console mapping to tty0 and serial console mapping to ttyS0 is done via extlinux.conf APPEND parameters:

fbcon=map:0 console=tty0 console=ttyS0,115200n8

Note that it may be necessary to set up the serial port for that speed or mode of operation. In the device tree you’ll find a stock Jetson L4T has several blocks starting with something similar to “serial@70006000”…these set up serial UARTS (I don’t know which serial ports your custom board routes, but the controller address would be the numeric half of the “serial@70006000” is the base address for that controller).

You can view what the orginal dtb file has in it via reverse compile:

dtc -I dtb -O dts -o /tmp/extracted.dts /boot/the_firmware_in_extlinux.dtb

…then edit, and build back a new dtb:

dtc -I dts -O dtb -o /tmp/modified.dtb /tmp/extracted.dts

My TX1 module in the buy board is available to work and also print information, but the TX1 module used in my own design of the circuit board, the module fever but no serial print information, my circuit design is a reference Development board, power supply is normal, what causes it can not work?

The serial UART must be set as a serial console in extlinux.conf. Once that is set the device tree must also be set. Beware that U-boot has its own serial UART setup, so configuration via device tree relative to Linux only begins once the kernel loads. I’m not sure what the serial UART setup is from U-boot.

Has your serial UART been set to valid values? You’ll want 115200 8N1. If you have other values the port may work, and yet not show up if your serial terminal software is set differently. Put an oscilloscope on the RX/TX and see if there is traffic.

TX1 module in the development board can work, and I according to the official reference design circuit design, tx1 can not work, UART settings should be no problem, I think TX1 module does not start.
Configuration signals are: POWER_BTN, VIN_PWR_BAD_L, FORCE_RECOVERY_L, RESET_OUT_L, RESET_IN_L, CARRIER_PWR_ON, CHARGER_PRSNT #, there are other needs configuration?

I have not studied startup power sequence, just the serial port, so I am unable to answer beyond current serial port comments.

Hi ??,

Firstly, please measure the power sequence as showed in figure 4 of OEM DG. Since module work well on Jetson carrier board, you need to check your own carrier board carefully to find out the violation.