Xavier NX : using GPIO tx, rx making LED indicator

Hi there,

Im trying to make a LED indicator, when my device(Xavier NX developer’s kit) is receiving/transmitting ethernet packets.
There is already a yellowish-green and orange at the ethernet connector attached on the board, but I wanted to make another, which works just the same OUTSIDE the board, in order to check the status from outter case( our xavier board will be fixed inside a case).

I have already installed Jetson.GPIO library using python, but it seems that when i setup pin 8 and 10 ( which are tx and rx pins), ValueError occurs, and could not proceed further.

Hope to get some answers!

Hi jkang,

The LED indicator on RJ45 port is actually controlled by ethernet phy and its own driver. Thus, it is actually not controlled by GPIO on board.

Does your setup have anything to do with the ethernet port?

Currently I am using jetson xavier nx as my board of my device. And xavier sits inside the device case, so in order to know if the power is on, or to see the board is connected to ethernet properly, i wanted to make an led indicator out side the board using gpios.

For the power indicator i managed to use the 5v gpio(pin no.2) and it works great. But for the ethernet packets which was transmitted and received, I hope to make an led indicator whenever the board is transmitting data or receiving data, the led goes on and off.

Would there be a callback function of sorts, or linux kernel function?


Please check the realtek driver code (kernel-4.9/drivers/net/phy/realtek.c) and see if any function can help you.

You could also contact realtek for the RTL8211FDI Gigabit Ethernet PHY. This is defined by Realtek.

I looked up the specification of the carrier board spec (xavier NX dev kit) and the pin drive or power pin max current of my pins( pin no 29, 33) are ± 20 microA.

Cound the gpio itself can lighten a led with at least 20mA? Because i hope i could use the gpio as a voltage and power supplier, not as the signal switch as i am using right now with a transistor.

Is the pin’s max current unchangable?

hello jkang,

please also check Max current from NX GPIO - #3 by edli1983 for reference,