PWM can't work

[2496328629]

hi,
Firstly, I’m kind of new to Jetson Nano. When I want to use the PWM function, I found neither pin32 nor pin31 can geneate the PWM signal. Here’s my operating steps:

1. Firstly, I install the C++ GPIO library from GitHub - pjueon/JetsonGPIO: A C++ library that enables the use of Jetson's GPIOs.

2. Then I configure pwm0 and pwm2 by:

sudo /opt/nvidia/jetson-io/jetson-io.py

3. And I compile and run simple_pwm.cpp from the project.

4. I connected an oscilloscope on pin 32, there is no waveform at all.

I also use

sudo cat /sys/kernel/debug/pwm

but it returns this(Upper Window)

That means pwm-2 is func normally, but I can’t see any wave on the oscillo!

Any ideas? Thanks a lot!

[KevinFFF]

Hi 2496328629,

Are you using the devkit or custom board for Jetson Nano?

Could you help to refer to the following thread to generate PWM?
Strange behaviour with Jetson Nano DevKit PWM signal - #5 by WayneWWW

[2496328629]

Thanks for the reply

I’m using the devkit,
and I used linux pwm sysfs to control the pwm signal before, but the situation is the same as what I described above.

[KevinFFF]

What’s your current Jetpack version in use?

I found PWM should be used on PIN32, PIN33 of 40-pin expansion header for Jetson Nano devkit.

Could you help to configure these 2 pins for PWM and control it through sysfs and share the result?