PWM 30hz can not be set. On JETPACK 4.2

Autonomous Machines Jetson & Embedded Systems Jetson TX2
1

HI

PWM 30hz can not be set.

When to do in JETPACK 4.2

echo 0 | sudo tee -a /sys/class/pwm/pwmchip0/unexport
echo 0 | sudo tee -a /sys/class/pwm/pwmchip0/export > /dev/null; sleep 0.5
#SETTING 30Hz
echo 33333333 | sudo tee -a /sys/class/pwm/pwmchip0/pwm0/period > /dev/null; sleep 0.1
tee: /sys/class/pwm/pwmchip0/pwm0/period: Invalid argument
echo 6666666 | sudo tee -a /sys/class/pwm/pwmchip0/pwm0/duty_cycle > /dev/null; sleep 0.1
echo 1 | sudo tee -a /sys/class/pwm/pwmchip0/pwm0/enable > /dev/null

PWM does not work

But
When to do in JETPACK 3.2

echo 0 | sudo tee -a /sys/class/pwm/pwmchip0/unexport
echo 0 | sudo tee -a /sys/class/pwm/pwmchip0/export > /dev/null; sleep 0.5
#SETTING 30Hz
echo 33333333 | sudo tee -a /sys/class/pwm/pwmchip0/pwm0/period > /dev/null; sleep 0.1
echo 6666666 | sudo tee -a /sys/class/pwm/pwmchip0/pwm0/duty_cycle > /dev/null; sleep 0.1
echo 1 | sudo tee -a /sys/class/pwm/pwmchip0/pwm0/enable > /dev/null

PWM operation

Regards.

2

Hi,

We will check this issue. Also, could you check if other frequency would work?

3

Hi

Values above 50hz are set well.

4

Please set this inside device tree if you want to use lower frequency.

pwm@3280000 {
    ...
    ...
    pwm-minimum-frequency-hz = <30>; /* required rate in Hz */
};