Enabling and working with Jetson GPIO Pins with Python

Question

I want to use GPIO of Jetson Xavier AGX.

I followed all the procedures mentioned below to run the GPIO pins but I am not able to run it. What can be the issue? What am I missing or doing wrong?

The procedure I followed is as shown below:

1. Configure the GPIO expansion header for PWM or any other PIN, To configure run the following command. sudo /opt/nvidia/jetson-io/jetson-io. and follow this link

2. Install GPIO Jetson using command sudo pip3 install Jetson.GPIO

3. Copy new rules sudo cp lib/python/Jetson/GPIO/99-gpio.rules /etc/udev/rules.d/

4. Run the following python code to toggle the voltage value. Check with a multimeter with GND and PWM (or whatever enabled) PINs

import Jetson.GPIO as GPIO
import time
GPIO.setmode(GPIO.BOARD)
channel = 15

GPIO.setup(channel, GPIO.OUT)

while True:
   GPIO.output(channel, GPIO.HIGH)
   
   time.sleep(1)
   GPIO.output(channel, GPIO.LOW)

   time.sleep(1)

GPIO.cleanup()

@mkrieger1 When I check it with a multimeter, voltage does not toggle for any PIN. — Imran, Sep 09 '21 at 08:43
Have you tried the tools from `libgpiod` project? Does it work for you? — 0andriy, Sep 09 '21 at 19:40
I do not know about libgpiod and its tools. Can you explain a little bit please — Imran, Sep 10 '21 at 13:38

score 0 · Answer 1 · edited Oct 12 '21 at 23:03

Try it after removing the udev rules. It is my understanding that they are obsolete. I don't have any trouble running this library on my Xavier. I would try it by just setting the value high, and checking the pin voltage - rather than toggling it. Your multi-meter may not respond fast enough for the toggle. Better to use an oscilloscope if you can get access to one.

Also check what voltages are enabled for your Xavier. There is a header labelled J514 that must be set to connect pins 1 and 2 to enable 3.3v outputs. Also note that many of the pins are very low current - only pins 11,16,29,31,32,33, and 37 are rated at 1ma or higher. So again a simple multi-meter may not see enough current.

Enabling and working with Jetson GPIO Pins with Python

1 Answers1