Jetson Nano GPIO at 1v4 not 3v3

Autonomous Machines Jetson & Embedded Systems Jetson Nano
1

Hi!

I am having the Jetson Nano Developer Kit and I am trying to interface it with a relay module which needs logic level of 3v3. But the 40pin GPIO on jetson nano developer kit is output only 1.4v on all the GPIO pins.
I have searched this forum regarding similar posts but am unable to resolve the issue. It has been an year since I had this board and earlier I didnt have any such issue. But recently when I tried its logic level is at 1.4v
I have tested using a multimeter as well as a logic analyzer. I also verified the output of 3v3 voltage pin on the 40 pin GPIO connector and it is working fine. Even the relay module is working with the 3v3 pin.

How can I resolve this issue? As mine is an year old so its out of warrenty.
Thanks!

3

There is load requirement to the pin of 40-pin header because of the level shift. Please refer to below doc for detail.

Jetson Nano Developer Kit 40-Pin Expansion Header GPIO Usage Considerations Applications Note

4

I went through the document and still am confused on how to get it to 3v3. I reffered the Button LED example. Also my GPIO is at 1.4v not 1.8v. How can I fix it?
In my relay module there is an optical isolator (PC817), my GPIO signal directly goes to the isolator with a 100ohm resistance in between.
I am suing the simple blinky code

import RPi.GPIO as GPIO
import time

# Pin Definitions
output_pin = 18  # BCM pin 18, BOARD pin 12

def main():
    # Pin Setup:
    GPIO.setmode(GPIO.BCM)  # BCM pin-numbering scheme from Raspberry Pi
    # set pin as an output pin with optional initial state of HIGH
    GPIO.setup(output_pin, GPIO.OUT, initial=GPIO.HIGH)

    print("Starting demo now! Press CTRL+C to exit")
    curr_value = GPIO.HIGH
    try:
        while True:
            time.sleep(1)
            # Toggle the output every second
            print("Outputting {} to pin {}".format(curr_value, output_pin))
            GPIO.output(output_pin, curr_value)
            curr_value ^= GPIO.HIGH
    finally:
        GPIO.cleanup()

if __name__ == '__main__':
    main()
5

The doc tells that the load of device should not exceed the spec, otherwise the voltage level would be pulled lower. You can use a multi-meter to check the voltage level without load to make sure 3.3V is correct.

7

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