Shutdown Pi will not power off LCD

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Shutdown Pi will not power off LCD

Postby youall » Thu Dec 04, 2014 4:29 pm

Hi all,

if I shutdown my pi with following command "sudo shutdown -h -P now", the display is on after the pi is halted.Why?
I can also measure a voltage of approx. -3.3V on the 3.3V and 5V Pins.

Can anybody help me? I want to shut down the Pi with one of the display buttons, but with that behavior, it's not so nice!

Best regards

Posts: 1
Joined: Thu Dec 04, 2014 4:23 pm

Re: Shutdown Pi will not power off LCD

Postby joe » Mon Dec 08, 2014 10:15 am

The shutdown command will not switch off the power.

If you want to switch off the power, you must implement some kind of hardware that cuts the power after a short delay time. That hardware can be wired to the button or an GPIO port that is controlled upon shutdown.

If you don't want to build such hardware, you can switch off the LCD backlight upon shutdown by setting the brightness to zero. The command depends on the display type. For the PI40 the command is
Code: Select all
echo 0 | sudo tee /sys/class/backlight/lcd-pi/brightness
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Joined: Wed Nov 26, 2014 11:40 am

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