Hey,
I have a Jetson nano 2GB, I’m trying to control two servo motors using the 32 & 33 PWM pinouts.
When running a simple test python code:
import Jetson.GPIO as GPIO
import time
output_pin = 33 # Servo2, Servo1 is at 32
if output_pin is None:
raise Exception(‘PWM not supported on this board’)
def main():
GPIO.setmode(GPIO.BOARD)
GPIO.setup(output_pin, GPIO.OUT, initial=GPIO.HIGH)
p = GPIO.PWM(output_pin, 50)
val = 0
incr = 5
p.start(val)
p.stop()
GPIO.cleanup()
print(“PWM running. Press CTRL+C to exit.”)
try:
while True:
time.sleep(2)
if val >= 100:
incr = -incr
if val <= 0:
incr = -incr
val += incr
p.ChangeDutyCycle(0)
finally:
p.stop()
GPIO.cleanup()
if name == ‘main’:
main()
I get the following error:
PWM running. Press CTRL+C to exit.
Traceback (most recent call last):
File “/home/nk47/SeeShoot/tests/Servo_test.py”, line 39, in main
p.ChangeDutyCycle(0)
File “/usr/lib/python3/dist-packages/Jetson/GPIO/gpio.py”, line 655, in ChangeDutyCycle
self._reconfigure(self._frequency_hz, duty_cycle_percent)
File “/usr/lib/python3/dist-packages/Jetson/GPIO/gpio.py”, line 680, in _reconfigure
_set_pwm_duty_cycle(self._ch_info, self._duty_cycle_ns)
File “/usr/lib/python3/dist-packages/Jetson/GPIO/gpio.py”, line 262, in _set_pwm_duty_cycle
ch_info.f_duty_cycle.seek(0)
ValueError: I/O operation on closed file.
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File “/home/nk47/SeeShoot/tests/Servo_test.py”, line 45, in
main()
File “/home/nk47/SeeShoot/tests/Servo_test.py”, line 41, in main
p.stop()
File “/usr/lib/python3/dist-packages/Jetson/GPIO/gpio.py”, line 660, in stop
_disable_pwm(self._ch_info)
File “/usr/lib/python3/dist-packages/Jetson/GPIO/gpio.py”, line 278, in _disable_pwm
with open(_pwm_enable_path(ch_info), ‘w’) as f:
FileNotFoundError: [Errno 2] No such file or directory: ‘/sys/devices/7000a000.pwm/pwm/pwmchip0/pwm2/enable’
I have checked my L4T version using the command “sudo apt-cache show nvidia-jetpack”, and got the following output:
Package: nvidia-jetpack
Version: 4.6.1-b110
Architecture: arm64
Maintainer: NVIDIA Corporation
Installed-Size: 194
Depends: nvidia-cuda (= 4.6.1-b110), nvidia-opencv (= 4.6.1-b110), nvidia-cudnn8 (= 4.6.1-b110), nvidia-tensorrt (= 4.6.1-b110), nvidia-visionworks (= 4.6.1-b110), nvidia-container (= 4.6.1-b110), nvidia-vpi (= 4.6.1-b110), nvidia-l4t-jetson-multimedia-api (>> 32.7-0), nvidia-l4t-jetson-multimedia-api (<< 32.8-0)
Homepage: Autonomous Machines | NVIDIA Developer
Priority: standard
Section: metapackages
Filename: pool/main/n/nvidia-jetpack/nvidia-jetpack_4.6.1-b110_arm64.deb
Size: 29366
Would love to get assistance… totally stuck.