I installed minicom and connected the J21 6.8.10 pin of the TX2 board. In addition, I set the parameters as ttyS0, 115200, 18N, but when I boot the board it cannot print the boot log. I just want to know the process of u-boot to optimize it. Thanks
Which connector on the TX2 did you use? It should be the J21 connector with a 3.3V logic level.
Minicom has been around for a very long time, and originated when people used modems. As such it has a lot of modem init features which might not always do what you expect. I’ll recommend you try with “gtkterm” (“sudo apt-get install gtkterm”). Assuming your serial port on the host PC is “/dev/ttyUSB0”:
gtkterm -b 8 -t 1 -s 115200 -p /dev/ttyUSB0
Also, are you certain you are using the correct “/dev/tty#” on the host PC? I recommend verifying by monitoring “dmesg --follow”, and then see what shows up as you plug in the USB side to the host PC.
I use J21 3.3v connector and ttyS0 of TX2 board but I forgot to chose the port of host machine. Maybe I set the wrong port . Thank you.
I also encountered the same problem.
I followed this procedure, but minicom cannot print the startup log.
I saw “virtual machine” mentioned. Is this from a VM? If so, then that is why it fails. VMs need to be given ownership of the serial UART on the host PC side. It would also need the FTDI serial UART driver installed (this is present by default on most PCs, but perhaps not on a VM).
FYI, if you were to actually flash the Jetson from a VM, then even if the USB starts as working it would still usually fail because the USB disconnects and reconnects during flash…and a VM seldom correctly picks the USB back up (the parent o/s tends to take USB after a disconnect/reconnect unless you’ve configured the VM to always own that USB device).
I use ubuntu.
Ubuntu installs the FTDI serial driver by default, and I have configured the VM to always use the USB.
So I don’t know why minicom cannot print the log.
There are a lot of USB errors and it is quite difficult to guess what the actual problem is. There is a very strong chance (based on past experiences) that this is still a VM problem. However, if we ignore the VM, then the problem could be divided into two categories: Power delivery, or signal quality. Just remember while reading that I suspect the issue is related to the VM.
A serial UART does not consume much power and is basically what a keyboard is. However, if you use a powered USB HUB, then you will know immediately if this is a power issue. Do you have a powered HUB? Are you currently using a HUB of any kind with the UART?
In terms of signal quality, are you going through a HUB? If so, then try direct without a HUB. If not, then use a HUB (powered or unpowered, though powered is best) with nothing else on the HUB other than the USB serial UART.
Even if you are not set up for dual boot with Linux I highly recommend testing the UART with a native Linux installation.
According to what you said, I tried to test the UART with an Ubuntu PC. But minicom did not print any information, as if the signal was not transmitted from TX2 to PC at all.
What should I do?
It would be better to not have too many threads in the forum for a single topic. See the reply here: