OESF Portables Forum

Model Specific Forums => Cosmo Communicator => Cosmo Communicator - Linux => Topic started by: jakfish on February 13, 2022, 05:20:42 pm

Title: Lost Ability to Control Brightness
Post by: jakfish on February 13, 2022, 05:20:42 pm

In Gemian/Cosmo, my Fn-B/Fn-N shows the slider for decreasing/increasing brightness, but the device remains at full brightness.

Any ideas why this has happened? And does anyone know where the /sys/class/* directory is along with the proper terminal command for control of brightness?

Thanks,
Jake

Okay, a reboot restored the fn key ability. Still, I would love to know where the backlight directory lives. Tx.

Title: Re: Lost Ability to Control Brightness
Post by: MonkeyControl on February 14, 2022, 12:23:32 am

I'm not sure if this is relevant at all, but I occasionally get my Cosmo (running Ubuntu Touch) getting stuck on full brightness.  It happens about maybe every couple of weeks, it is seemingly random, I can't reproduce it and a reboot always resolves it. 
As for the terminal command for brightness control, I found this on GitHub that looks promising to my untrained eyes:  https://github.com/gemian/gemian/wiki/HardwareHacking#screen-backlight
Hope this helps
 :)
MC

Title: Re: Lost Ability to Control Brightness
Post by: jakfish on February 14, 2022, 11:22:12 am

Sorry to hear you have the same issue, now and then, and thank you for link's heads-up:

Code: [Select]

echo 150 > /sys/class/leds/lcd-backlight/brightness
This is indeed the proper directory/command.

Much obliged,
Jake