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notro / fbtft

Linux Framebuffer drivers for small TFT LCD display modules. Development has moved to https://git.kernel.org/cgit/linux/kernel/git/gregkh/staging.git/tree/drivers/staging/fbtft?h=staging-testing
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Power Management #64

Closed michaelmruta closed 10 years ago

michaelmruta commented 10 years ago

tested on adafruit22a - fb_ili9340

after some time of being idle, maybe around 20 mins or more, screen will sleep, i was unable to awake it running startx on it's framebuffer awakes the backlight only

notro commented 10 years ago

It probably happens after 30 minutes, and is the result of the console blanking setting. See https://github.com/notro/fbtft/wiki/Boot-console#console-blanking You should be able to wake it up by touching a key on a connected keyboard.

daveho commented 10 years ago

Is there any way to turn the backlight back on without pressing a key?

I'm experiencing the same issue, and my application is an embedded system without an attached keyboard (there are some buttons attached via the GPIO pins.)

Any help appreciated!

daveho commented 10 years ago

A couple more details: I configured the LCD as a boot console, with my application running on /dev/tty1. I tried the equivalent of "setterm -blank poke" within the application whenever a button is pressed, but this does not seem to turn the backlight back on. Connecting a USB keyboard and pressing a key does turn the backlight back on, so it would seem that the problem is not just the console blanking timeout.

notro commented 10 years ago

I didn't work for me either: SSH session: sudo sh -c "TERM=linux setterm -blank poke >/dev/tty0" But if I set the blanking period, it turns on: sudo sh -c "TERM=linux setterm -blank 30 >/dev/tty0"

You can also control the backlight directly: https://github.com/notro/fbtft/wiki/Backlight

notro commented 10 years ago

Closing issue since there has been no activity for more than 2 months. Reopen if needed.