Jetson.gpio mode already set?

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX2
,
1

I’m trying to trigger a relay using my Jetson Nano with GPIO, but using the following code I get an error that “A different mode has already been set!”

    #!/usr/bin/env python
    import Jetson.GPIO as GPIO
    import time
    from adafruit_servokit import ServoKit
    
    # Pin Definitions
    output_pin = 18  # BOARD pin 12, BCM pin 18
    kit = ServoKit(channels=16)
    
    # Pin Setup:
    # Board pin-numbering scheme
    GPIO.setmode(GPIO.BCM)
    mode = GPIO.getmode()
    print(mode)
    # set pin as an output pin with optional initial state of HIGH
    GPIO.setup(output_pin, GPIO.OUT, initial=GPIO.LOW)
    GPIO.setwarnings(False)
    print("Mode is %s" % mode)
    
    def turn_on_relay():
    	while True:
    		choice  = input('Enter 1 to turn on, Enter 0 to turn off; Q to quit: ')
    		if choice == '1':
    			GPIO.output(output_pin, GPIO.HIGH)
    		elif choice == '2':
    			GPIO.output(output_pin, GPIO.LOW)	
    		elif choice == 'q':
            		break
    
    
    turn_on_relay()
    
    #GPIO.cleanup()

Resulting error is:

Traceback (most recent call last): File “cheetah.py”, line 12, in

GPIO.setmode(GPIO.BCM) File “/usr/local/lib/python3.6/dist-packages/Jetson.GPIO-2.0.8-py3.6.egg/Jetson/GPIO/gpio.py”,
line 312, in setmode ValueError: A different mode has already been
set! Exiting… Cleaning up pins

Why can’t I set the mode?

3

I guess it probably means this pin has been occupied by some drivers. What pin are you using?

4

Hi briwil1978,

Have you managed to get it working? Or it’s still an issue to support?

8

I had some problems with the oled display form adafruit.
I solved changing the init line form: “oled = Adafruit_SSD1306.SSD1306_128_32(rst=None, i2c_address=0x3C)”

To: “oled = Adafruit_SSD1306.SSD1306_128_32(rst=None, i2c_bus=1, gpio=1)”

It seems that the problems comes only when forcing the adress and not when you give the whole bus

9

Glad to know the issue resolved, thanks for the update.