Want to turn off my monitor

[robmcc83]

So I’ve been looking through the net and have found I can use vcgencmd display_power 0 to turn off my monitor and the same again to power 1 to turn it back on, it also explains it can be run as a cron job but I’ve never done one of them so not to sure.
Would it all be possible to hook up a push button switch to the gpio and have them commands somehow turn the display off and on.
Thanks

[doubleT]

Don’t forget that the monitor will still be on, it’s just in standby, still consuming power. The Pi can’t switch the power of the monitor itself off.

[robmcc83]

Yeah cheers I’m aware of that, it’s just monitor uses 37w whilst on and 2w in standby so I really don’t mind it being in standby at night.
I think I’m going to look into mmm-remote as trying the other method using vgenmcd power makes my screensaver come back to life even though it’s Been disabled for the last 8 months.
Is there any tutorials anywhere in setting up mmm-schedule and mmm-remote.
Cheers all

[robmcc83]

Ok so after trying various ways to get my monitor to turn off I have still been unsuccessful.
What I am trying now is with a webcam.
I found in my box of computer bits a Microsoft lifecam hd 3000.
After a little Google research I can confirm the webcam works with the pi using motion software.
I also found a site explaining how I can add a start and and event on detection so I set vgencmd display_power 1 as start event and vgencmd display_power 0 as end event but still no luck it just keeps display on but if I enter the command in terminal my display turns on/off as it should.
Am I going about this in the most awkward way or is there a simple way to get the monitor to sleep using the usb webcam.
Thanks in advance

[Mykle1]

@robmcc83

You could try this for ON

if (something) {
exec("/opt/vc/bin/tvservice -o", null); }

And this for OFF

{ exec("/opt/vc/bin/tvservice --preferred && sudo chvt 6 && sudo chvt 7", null); }

Or

{ exec('xset dpms force on', null); }
{ exec('xset dpms force off', null); }

[cruunnerr]

did u try:

sudo tvservice -o to turn off your Monitor
sudo tvservice -p to turn on your monitor
?

If this isn’t working i think your Monitor or your HDMI Cable are not supporting CEC.

If this works u have several options.
For example u can create two *.sh files and make them executable. Put these scripts into cronjob file for time based turning on or off the monitor.
Or u can use a PIR or a simple Button to do that. Let me give you a small software tutorial for this example:

Tutorial beginning:

cd
nano monitor_on.sh (creates the file)

write this in this file:

sudo tvservice -p

save with “ctrl+x” and say “y” to save the file.

nano monitor_off.sh

write this in this file:

sudo tvservice -o

save with “ctrl+x” and say “y” to save the file.

chmod +x monitor_on.sh (to make it executable)
chmod +x monitor_off.sh

So now you have two options. Write a python script to automatically start the shell scripts by using a GPIO or just put the Shell scripts into a cronjob.

Here is the first way:

nano pir.py (creates a script which executes the *.sh files via PIR or Button)

write this into the file:

#!/usr/bin/env python

import sys
import time
import RPi.GPIO as io
import subprocess

io.setmode(io.BCM)
SHUTOFF_DELAY = 119 # in seconds, how long the monitor will be on until next button press or PIR detection
PIR_PIN = 25       # 22 on the board (this needn't to be a PIR. Can be a button also)
LED_PIN = 16      # optional

def main():
    io.setup(PIR_PIN, io.IN)
    io.setup(LED_PIN, io.OUT)
    turned_off = False
    last_motion_time = time.time()

    while True:
        if io.input(PIR_PIN):
            last_motion_time = time.time()
            io.output(LED_PIN, io.LOW)
            print ".",
            sys.stdout.flush()
            if turned_off:
                turned_off = False
                turn_on()
        else:
            if not turned_off and time.time() > (last_motion_time + 
                                                 SHUTOFF_DELAY):
                turned_off = True
                turn_off()
            if not turned_off and time.time() > (last_motion_time + 1):
                io.output(LED_PIN, io.HIGH)
        time.sleep(.1)

def turn_on():
	subprocess.call("sh /home/pi/monitor_on.sh", shell=True)

def turn_off():
	subprocess.call("sh /home/pi/monitor_off.sh", shell=True)

if __name__ == '__main__':
    try:
        main()
    except KeyboardInterrupt:
        io.cleanup()

save with “ctrl+x” and say “y” to save the file.

chmod +x pir.py

You can check if your button works by simply typing python pir.py. Every time u move through the PIR or press the button it will show you some …
End the test with “ctrl+c”

now we editing the rc.local to start the script after booting the Pi:

sudo nano /etc/rc.local

write this in the file (above the “exit 0”):

python /home/pi/pir.py &

save with “ctrl+x” and say “y” to save the file.

after all it should look like this:

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.

# Print the IP address
_IP=$(hostname -I) || true
if [ "$_IP" ]; then
  printf "My IP address is %s\n" "$_IP"
fi

python /home/pi/pir.py

exit 0

Here comes the second way:

Next steps we will do as root to be sure it works. Maybe not the best way, but i am just a simple guy, who is still learning the stuff. ^^
Lets say we want to turn on the monitor every day at 6am and turn off at 8pm:

sudo nano /etc/crontab (to open the crontab)

write this into the file:
0 6 * * * /home/pi/monitor_on.sh
0 20 * * * /home/pi/monitor_off.sh

this should look like this:

# /etc/crontab: system-wide crontab
# Unlike any other crontab you don't have to run the `crontab'
# command to install the new version when you edit this file
# and files in /etc/cron.d. These files also have username fields,
# that none of the other crontabs do.

SHELL=/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

# m h dom mon dow user  command
17 *    * * *   root    cd / && run-parts --report /etc/cron.hourly
25 6    * * *   root    test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily )
47 6    * * 7   root    test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.weekly )
52 6    1 * *   root    test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.monthly )
0 6     * * *   root      /home/pi/monitor_on.sh
0 20    * * *   root      /home/pi/monitor_off.sh
#

I wrote this just out of my head so i hope i didn’t forget anything.

Tutorial ending!

That is just an example of using a GPIO to turn off and on your monitor via HDMI-CEC.
How i said, if your monitor or cable doesn’t support this u need to choose another way (turn a relays on and off to the power supply of the monitor e.g.)

edit:

sorry @mykle1, did not notice that you already answered, because I already started to write while you answered :D

[Mykle1]

@cruunnerr

No worries, mate. I hope to learn something from your answer. (which is totally amazing to me)

Peace!

[robmcc83]

Thanks this is very useful information that I didn’t know before.
I have issued the sudo tvservice -o command and it did indeed shut down my monitor.
But what I am trying at the moment is to have it shutdown and wakeup the monitor with a usb webcam now.
That’s what I’m struggling with.
Cheers

[robmcc83]

One interesting thing I like about the second way is it seems easy :) lol.

Would it be possible to say have the screen come on 6-9am in the morning Monday to Friday then come on again 4-10pm as everyone out at work or school during the day. Than say set it so that its on 8am till 10pm on a saturday and sunday when everyone is usually about.

Thanks

[cruunnerr]

Sure, this is possible. For the beginning it seems easy, because u needn’t any optional hardware :)

For your understanding how cronjobs works u should note the following:

* * * * * user executive_command
┬ ┬ ┬ ┬ ┬
│ │ │ │ │
│ │ │ │ └──── Weekday (0-7, Sunday is 0 or 7)
│ │ │ └────── Month (1-12)
│ │ └──────── Day (1-31)
│ └────────── Hour (0-23)
└──────────── Minute (0-59)

So for your special wish ^^it should look like this:

# /etc/crontab: system-wide crontab
# Unlike any other crontab you don't have to run the `crontab'
# command to install the new version when you edit this file
# and files in /etc/cron.d. These files also have username fields,
# that none of the other crontabs do.

SHELL=/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

# m h dom mon dow user  command
17 *    * * *   root    cd / && run-parts --report /etc/cron.hourly
25 6    * * *   root    test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily )
47 6    * * 7   root    test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.weekly )
52 6    1 * *   root    test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.monthly )
0 6,16  * * 1,2,3,4,5   root  /home/pi/monitor_on.sh
0 9,22  * * 1,2,3,4,5   root  /home/pi/monitor_off.sh
0 8     * * 6,7   root  /home/pi/monitor_on.sh
0 22    * * 6,7   root  /home/pi/monitor_off.sh
#

Or if you don’t want to create the *.sh files u can also just type the directly command.
Like this:

0 6,16  * * 1,2,3,4,5   root  /usr/bin/tvservice -p
0 9,22  * * 1,2,3,4,5   root  /usr/bin/tvservice -o
0 8     * * 6,7   root  /usr/bin/tvservice -p
0 22    * * 6,7   root  /usr/bin/tvservice -o

Last thing is the extremely easiest way because u just need to modify the crontab. there is nothing else needed at all.
Just put these commands in your crontab and u are done ^^