DougieLawson / backlight_dimmer

Control the backlight on the official RPF display based on a touch event.
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Not returning to full brightness RPI3 B+ Raspbian Buster / Octoprint #2

Open morganlowe opened 4 years ago

morganlowe commented 4 years ago

I use the official RPI Touchscreen as a kiosk with Chromium displaying the octoprint page. The script works placed in root's cron @reboot however it will not return to full brightness. It stops at level 12 it seems.

Any ideas why? The script is placed in /usr/local/bin and has 120 seconds and event0 set. The screen is the only input on this Pi and it does go from off to dim when touched then off again after 2 minutes.

The behavior is the same weather in /etc/rc.local, run in terminal or in cron.

Thank you for any help!

msweany commented 4 years ago

I know this is late, but I used this script for a Raspberry Pi project I am working on. I found it was dropping to 12, even when I changed it back to 255 manually. In the timeout.c code, it says that it grabs whatever the value is at when timeout is first called. I found that if you set the brightness right before calling timeout in run-timeout.sh, it looks like it returns to that value on boot, after touch etc...

This fixed it for me.

sudo bash -c "echo 255 > /sys/class/backlight/rpi_backlight/brightness" nice -n 19 /usr/local/bin/timeout $timeout_period $dev &