Using GPIO on Jetson Xavier NX

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

Hello, I am really struggling to get anywhere with usage of GPIO on a jetson Xavier NX with fresh image (5.1.3)… I am using the python library Jetson.GPIO
I need to read a button press… but I have tried everything without success
for example, using pin 12 (which I understand is pulled down by default reading the specs https://download.kamami.pl/p579520-Jetson_Xavier_NX_DevKit_Carrier_Board_Specification_v1.0.pdf
but even if I use a pull up as below:

import time

# Define the GPIO pin number
BUTTON_PIN = 18  # Change to the GPIO pin you are using

# Set up the pin as an input with an internal pull-up resistor
GPIO.setmode(GPIO.BCM)  # Use BCM numbering
GPIO.setup(BUTTON_PIN, GPIO.IN, pull_up_down=GPIO.PUD_UP)

try:
    while True:
        if GPIO.input(BUTTON_PIN) == GPIO.LOW:  # Button pressed (pulled to ground)
            print("Button Pressed!")
        else:
            print("Button Released!")
        time.sleep(0.1)  # Debounce delay
except KeyboardInterrupt:
    print("\nExiting...")
finally:
    GPIO.cleanup()  # Reset GPIO settings```

The pin seems to be floating, ie if connected to 3.3v it goes HIGH, if connected to GND it goes LOW, but it never goes back to LOW by itself...
I have few limit switch to monitor, I would like to avoid doing the pull down externally...

I have not tested successfully on terminal, I don't get how to do that, the command cat /sys/kernel/debug/gpio does not show for example the pin 199... which, if I understand correctly, is connected to pin 12 on the board.

Can someone help me?
Thank you
3

Hi,
Please check this post for GPIO control:
GPIO customization on Jetson Platform

4

Hello,
Thanks, I have read these post and many others!
I have managed to identify pins (although it is incredibly cumbersome), my issue is internal pull down (or up).
I have seen post about their strength 100kO, but for me it is not conclusive.
Can they work or not? On certain pins? With certain config?
If internal PU / PD do not work it would be clearer for everyone to state it in documentation.
Thanks,

5

anyone can confirm if internal pull up down resistors are functional on xavier NX?? thank you

7

There is no update from you for a period, assuming this is not an issue anymore.
Hence, we are closing this topic. If need further support, please open a new one.
Thanks ~0326

Hi yandssiegel,

Are you using the devkit or custom board for Xavier NX?

Which PIN would you like to check?
PIN12 of 40-pins expansion header?
If so, please share the pinmux spreadsheet with us to check how did you configure this pin.

Why it is PIN 18 here?