On the AGX Xavier some of the pins, which have the option of being used as gpio or pwm, (such as pin15) show the voltage as 1.8V/3.3V. Pin 37 is a gpio pin that shows 3.3V only.
Can I toggle this 1.8V mode to a 3.3V mode? I have not been able to use these pin for anything. I have tried using pin 15 as a gpio pin. I get nothing out of it. I have tried using pin 15 as a pwm pin after setting it to pwn with
sudo /opt/nvidia/jetson-io/jetson-io.py . I get no signal out of it. I connect an electrometer to the pin during the attempt at gpio and during the attempt at pwm. I get no change in voltage out of it. The voltage seems to be at 0.1V or 0.3V with no changes.
When I set pin 15 to pwm and run a program that is supposed to send a pwm signal through pin 15 I expect it to move the motor and to have a specific signal of voltage out of the pin when I touch the electrometer to the pin.
import RPi.GPIO as GPIO # Import the GPIO library. import time # Import time library GPIO.setmode(GPIO.BOARD) # Set Pi to use pin number when referencing GPIO pins. # Can use GPIO.setmode(GPIO.BCM) instead to use # Broadcom SOC channel names. GPIO.setup(15, GPIO.OUT) # Set GPIO pin 12 to output mode. pwm = GPIO.PWM(15, 100) # Initialize PWM on pwmPin 100Hz frequency # main loop of program print("\nPress Ctl C to quit \n") # Print blank line before and after message. dc=0 # set dc variable to 0 for 0% pwm.start(dc) # Start PWM with 0% duty cycle try: while True: # Loop until Ctl C is pressed to stop. for dc in range(0, 101, 5): # Loop 0 to 100 stepping dc by 5 each loop pwm.ChangeDutyCycle(dc) time.sleep(0.05) # wait .05 seconds at current LED brightness print(dc) for dc in range(95, 0, -5): # Loop 95 to 5 stepping dc down by 5 each loop pwm.ChangeDutyCycle(dc) time.sleep(0.05) # wait .05 seconds at current LED brightness print(dc) except KeyboardInterrupt: print("Ctl C pressed - ending program") pwm.stop() # stop PWM GPIO.cleanup() # resets GPIO ports used back to input mode
I tried the solution to a similar question here. It leads to a pdf which says “$ cat /proc/device-tree/nvidia,dtsfilename
If the file name is tegra210-p3448-0000-p3449-0000-a02.dts, the version is a02. If it is
tegra210-p3448-0000-p3449-0000-b00.dts, the version is b00.”
When I typed
$ cat /proc/device-tree/nvidia,dtsfilename