JetsonNANO p3449 HDMI HDMI_HPD interface design problem

the reference shcematics P3449, MMBT3904LP is NPN, which result into the logic is: interface 5V->HDMI_HPD 0V, 0V->HDMI_HPD 1.8V; is that correct? where I can download the P3450 carrier board reference schematics?
now I redesign the carrier board, found the HDMI does’t work, and the HDMI_HPD is low when outside HDMI interface is plugged in.

Sure, it is correct to be low when plug in as said in OEM DG: HPD level shifter on the Jetson Nano Developer Kit is inverting. HDMI_HPD will be low when device plug in.

P3450 is dev kit, P3449 is the carrier board of it.

Hello trumany:
thanks for the reply.

Hello Trumany:
I have leave the Debug port, is there any debug operation manual I can reference including the HDMI port? Really thanks.

This is the method we use to enable uart console on nano devkit.

If your board is still able to boot up, use remote access to dump the dmesg.

Hello Everything look good except the login part; here my JT is stucked and cannot input the login name and password, or no responce, actually my login name/account is anather name not ‘Data-Monitor’, I have try both accout, no response; I have try 2 JT module with p3450 carrier board (not my new board) and minicom of ubuntu and also putty in windows10, same result.
What’s the possible reason?

  1. When you want to paste any log. Attach it as a text file. It will be more clear for other people to read.

  2. Do you ever configure your user account through oem-config in your first boot up during this whole debug?

  1. my JT module can not link to the intenet due to company internet limit, so I use the screenshoot;
  2. I will try oem-config first.
    Really thanks.

Is your board able to dump the serial console? It is very common setup when bring up peripherals.

Now my method is like this: configure the JT module(SD card) with p3449 carrier board, so the HDMI and USB are normal, the display is good. First, configure the modue through oem-config with a username and password, then insert this JT module with SD card into my own develoed carrier board, and use the UART interface to debug the new board. In this newly designed board, I add a five port switch, inboard wifi module through PCIE interface, One ethernet interface is connect to ethernet of JT module inboard;this board also include HDMI USB interface.
Question1 : Does this work for my case???
Question2: how to use the ‘oem-config’ tool in the JT module with P3449 to create a useername & password for UART debug,HDMI and USB are good and canbe used. specific operation steps are needed, really thanks.

Hello, How to debug the HDMI through the UART interface, is there any reference to follow? thanks.


Sorry, there is no document for it. You can check the dmesg and grep “tegradc” and see if any error when hdmi is connected.