Jetson TX2 fan control L4T 32.5.1

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX2
1

Hi,

I am able to control fan using below commands on Jetson tx2 (L4T 32.5.1) :
to set speed:
echo 127 > /sys/devices/pwm-fan/target_pwm
(0 to 255)

cat /sys/class/hwmon/hwmon2/cur_pwm to read set value

but how to read tachometer?

I have tried:
cat /sys/devices/pwm-fan/rpm_measured
cat /sys/class/hwmon/hwmon1/rpm
cat /sys/devices/pwm-fan/rpm_measured

return zero always.

Please suggest proper command to read tach

3

I get below error with L4T v: R28.2.1 : Are my commands are wrong for this revision? Please let me know the correct commands:

nvidia @ tegra-ubuntu: ~ $ cat / sys / devices / pwm-fan / target_pwm

cat: / sys / devices / pwm-fan / target_pwm: No such file or directory

nvidia @ tegra-ubuntu: ~ $ echo 0> / sys / devices / pwm-fan / target_pwm

-bash: / sys / devices / pwm-fan / target_pwm: Permission denied

nvidia @ tegra-ubuntu: ~ $ sudo echo 0> / sys / devices / pwm-fan / target_pwm

-bash: / sys / devices / pwm-fan / target_pwm: Permission denied

4

Hi,
For r28.2.1, please try to execute sudo su to be super user, and then execute the commands.

1 Like