Jetson Nano and AGX Xavier GPIO Level 3.3V or 1.8V

Robotics & Edge Computing Jetson & Embedded Systems Jetson AGX Xavier
1

Hi.

I have both Jetson AGX Xavier and Nano.
I want to use a button as GPIO input to identify a signal to gracefully shutdown the devices. The problem is that I don’t know what voltage level can I safelly input to them.

I also have a GPIO output signal configured to control a reset pin of another dev board. In AGX Xavier the output pin is 40pin Expansion Header pin#22 (gpio417 in sysfs) and in Nano is 40pin J41 Header #31 (gpio200 in sysfs).

In Xavier, I have J514 header configured in GPIO 3.3V (1-2 connected as described in “Nvidia Jetson AGX Xavier Developer Kit Carrier Board Specification”) but when I measure the output high voltage it shows me 1.5V.

In Nano, the same. I read in the forum that all GPIO’s are 3.3V level (About GPIO voltage). But when I measure the output high voltage it shows me 1.8V.

I would like to know if I can safelly input 3.3V on both modules (I would use 40pin Expansion Header pin#15 in Xavier and 40pin J41 Header pin#33 in Nano) even with output showing me lower voltage ?

3

Hi, there is request on the load of 40-pin header pins as you can find in below AppNotes and Configuration in DLC which is relevant to the level shift used on devkit.

4

Hi.

Both links that you sent me in the answer are regard to Jetson Nano GPIO’s. I saw that there are some considerations that I have to think when working with Nano’s GPIO. These are the same for Jetson AGX Xavier GPIO’s too ? I didn’t found any documents about AGX Xavier GPIO’s.

But I imagine that I wasn’t able to measure 3.3V on AGX Xavier GPIO output because the high capacitive load too. That’s right ? So, to drive a signal from AGX Xavier I have to use a transistor to control the signal, right ? And I can input 3.3V with no problems, right ?

Thank you for your attention

5

The docs are for Xavier too as the level shift used is same to nano. The custom design should note that the load to the GPIO pins should be light as the level shift used is bi-directional and has weak drive strength.