I require some assistance please.
I have a Libre Computer Tritium - ALL-H3-CC-H5v1.1a. I received it yesterday (Feb 7 2024). I am running debian 12 (bookworm) for arm64 systems downloaded from the libre computer website.
I have my PWM fan wired to the 3-PIN UART for ground, tach, and pwm, the power is coming from GPIO.
As per the pinout header guide- UART pin1 is ground, UART pin2 (PA4) is tach, and UART pin3 (PA5) is pwm0. I am getting power from GPIO pin2, which is a 5V rail.
Here is a link to the site with the pinout header guides:
This device only seems to have one controllable PWM–pwm0 which I have enabled using the ldto command.
I configured the fan according to 2 other threads I found on these forums.
sudo ldto enable pwm0
sudo echo 0 > /sys/class/pwm/pwmchip0/export
sudo echo 1000000 > /sys/class/pwm/pwmchip0/pwm0/period
sudo echo 500000 > /sys/class/pwm/pwmchip0/pwm0/duty_cycle
sudo echo 1 > /sys/class/pwm/pwmchip0/pwm0/enable
I then executed:
sudo ldto merge pwm0
When I reboot I no longer have to execute the ldto enable pwm0 schema/overlay however the system does not save the /sys/class/pwm/pwmchip0/pwm0 values. As a side note, after rebooting if I execute sudo ldto status it shows no active overlays, although the fan slows down once I set the pwmchip0 values–I do not need to re-execute the sudo ldto enable pwm0.
Is there some way I can make the OS save these values or at the very least is there a recommended place in /etc I should store the values?
If there isn’t a consensus I will just add it to the system startup scripts.
FYI as per Libre Computer Board BIOS/Firmware Update Images my board does not have firmware.
Thank you for taking the time to read my thread.