Jetson GPIO not working anymore

Autonomous Machines Jetson & Embedded Systems Jetson Xavier NX
1

Hello,
I have two Jetson Xavier NX developer boards, which are in custom baseboards for testing purposes. The first board is working fine, but the second one has a lot of GPIO issues. I don’t know what the problem is, as I put the SD-Card from the working Jetson to the not working Jetson and even with the same SD, Jetson #2 is not toggeling any pin or even detecting interrupts on pins. The error is described below. I suspect a hardware issue with the second one, or a hardware update, but do not know enough to say something like this.

I would really appreciate any kind of help.

These are the ways I tested the toggeling the (board)Pin 23: The first one is a python script which I started with sudo:

import Jetson.GPIO as GPIO
import time

led = 23

GPIO.setmode(GPIO.BOARD)  
GPIO.setup(led, GPIO.OUT, initial=GPIO.HIGH)

while True:
    GPIO.output(led, GPIO.LOW)
    time.sleep(0.1)
    GPIO.output(led, GPIO.HIGH)
    time.sleep(0.3)

Output:

WARNING: Carrier board is not from a Jetson Developer Kit.                 # Ignore this message, as we do not use a pinmux but the GPIOs are the same as in Jetson devkit
WARNNIG: Jetson.GPIO library has not been verified with this carrier board,
WARNING: and in fact is unlikely to work correctly.
Traceback (most recent call last):
  File "gpioTest.py", line 10, in <module>
    GPIO.output(led, GPIO.LOW)
  File "/usr/lib/python3/dist-packages/Jetson/GPIO/gpio.py", line 455, in output
    _output_one(ch_info, value)
  File "/usr/lib/python3/dist-packages/Jetson/GPIO/gpio.py", line 179, in _output_one
    ch_info.f_value.flush()
OSError: [Errno 19] No such device

Shell test:

jetson@jetson:~$ sudo su
root@jetson:/home/jetson# echo 192 > /sys/class/gpio/export
bash: echo: write error: Invalid argument
root@jetson:/home/jetson# echo 480 > /sys/class/gpio/export
root@jetson:/home/jetson# echo out > /sys/class/gpio/gpio480/direction
bash: /sys/class/gpio/gpio480/direction: No such file or directory
root@jetson:/home/jetson# ls /sys/class/gpio/
export  gpiochip240  gpiochip248  gpiochip288  unexport

This code is not throwing any error, but is also not working:

jetson@jetson:~$ sudo gpioset gpiochip0 192=1
jetson@jetson:~$ sudo gpioset gpiochip0 192=0

The user jetson is also in the gpio group:

jetson@jetson:~$ groups
jetson adm dialout cdrom sudo audio dip video plugdev i2c lpadmin lightdm sambashare weston-launch gpio

Thanks

3

hello fabio.manz,

if your board schematic differs from that for Jetson Xavier NX Developer Kit board, you must change the pinmux configuration applied by the software.
since you’re having customize boards. had you updated board configure files to those two Xavier NX?
see developer guide for reference, Jetson Xavier NX Platform Adaptation and Bring-Up.
thanks

4

Hello JerryChang,
thank you for your help. I fixed the issue and it was a problem where two programs accessed the same GPIO. I know that this will not work and I didn’t even know that program number 2 is accessing the GPIO.
Appologies from my side.

Thanks,
Fabio