Programmatically turn screen off

Does anyone know how I might be able to programmatically switch the monitor off? It's connected by HDMI. I'd be happy if I could just disable output from the HDMI port, and then the monitor would switch itself off, but I can't manage even this!

I've tried

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$ xset dpms force off

but this just blanks the screen - the LCD monitor remains on. I think this is because the monitor is connected over HDMI, and so the EnergyStar stuff doesn't work.

I've also tried code that's supposed to disable the driver in the kernel:

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# echo "bcm2708_fb" > /sys/bus/platform/drivers/bcm2708_fb/unbind

This seemed to work (/dev/fb0 disappeared), but the display (with X running) carried on regardless.

Anybody got any other ideas? I think HDMI-CEC would be the gold-plated solution, and I know people are working on libcec, but I've no idea when this will be released.

The project is an always-on device, but to save power I want to power down the monitor when it's not needed.

[dom]

try
/opt/vc/bin/tvservice -o

That looks like just the ticket! but..

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root@raspberrypi:~# /opt/vc/bin/tvservice -o
Powering off HDMI
root@raspberrypi:~# /opt/vc/bin/tvservice -s
state 0x12000a, 1920x1080 @ 60Hz, progressive
root@raspberrypi:~# /opt/vc/bin/tvservice -M
Starting to monitor for HDMI events
[I] HDMI cable is unplugged
[I] HDMI in standby mode
^CShutting down...


Which looks like it's all working great, except the monitor rather stubbornly remains on, and is still showing updates from X..?

[dom]

Can you try it again. I've a slight recollection it needs to be told twice...

Just tested, and it's not working for me. I'll look into it.

It worked for me once - now it seems to be a bit intermittent.

I can get it to reliably turn hdmi off if I run /opt/vc/bin/tvservice -p before running /opt/vc/bin/tvservice -o.

The hdmi port can then be turned on again by running /opt/vc/bin/tvservice -p.

My challenge now is to get X to "reconnect" to the re-available monitor; I can do it by killing X, unbind'ing and bind'ing the driver and then restarting X but that seems a bit overkill!

Hi Guys,

Found this thread while searching for a way to put my HDMI->DVI connected monitor to sleep.

I discovered that switching virtual consoles once the screen has been turned back on gets the system going again.

I've been tinkering with a few custom graphics apps, launched via a script passed as an argument to startx.

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startx /usr/bin/graphical_launcher `fgconsole`

In doing so I pass the foreground console session number, then as soon as the app starts I retrieve the new foreground session number that X is using.

The first thing the script does when executed by startx is retrive the consoles.

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VT_START=$1
VT_XSERVER=`fgconsole`


Then upon turning the screen back on I simply run:

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chvt $VT_START
chvt $VT_XSERVER


It's a bit of a hack but seems to be working nicely,

Hope it helps,

Phil

Hi Phil, Thanks for your reply!

I've been struggling with how to get the screen going for an age now and your method above works really well, except when the monitor comes back the image is moved over by about 200 pixels; and wraps around from the other side. It's a bit odd really and I can't find a way of fixing it!

@rob_pi What's the resolution of your screen? Would be interested to see if I can reproduce the wraparound you've been experiencing. You using a PC monitor or TV?

Hi Guys,

Found this thread while searching for a way to put my HDMI->DVI connected monitor to sleep.

I discovered that switching virtual consoles once the screen has been turned back on gets the system going again.

I've been tinkering with a few custom graphics apps, launched via a script passed as an argument to startx.

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startx /usr/bin/graphical_launcher `fgconsole`

In doing so I pass the foreground console session number, then as soon as the app starts I retrieve the new foreground session number that X is using.

The first thing the script does when executed by startx is retrive the consoles.

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VT_START=$1
VT_XSERVER=`fgconsole`


Then upon turning the screen back on I simply run:

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chvt $VT_START
chvt $VT_XSERVER


It's a bit of a hack but seems to be working nicely,

Hope it helps,

Phil

Hi, can you elaborate just a bit. Is this

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VT_START=$1
VT_XSERVER=`fgconsole`

what goes in your /usr/bin/graphical_launcher shell script?

Thanks so much and sorry for replying to an old post, but this is the closest I've found to a solution after much searching.

Apologies for bumping an old post; but have finally revisited this and figured out a way to achive this:

download/install cec-client from http://sourceforge.net/projects/selfprogramming/files/libCEC.deb/libcec_2.1.0-1_armhf.deb/download

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sudo dpkg -i libcec_2.1.0-1_armhf.deb

Verify it's working ok:

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pi@raspberrypi:~$ cec-client -l
Found devices: 1

device:              1
com port:            RPI
vendor id:           2708
product id:          1001
firmware version:    1
type:                Raspberry Pi


Turn TV off(standby):

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pi@raspberrypi:~$ echo "standby 0" | cec-client -s -d 1
opening a connection to the CEC adapter...


Turn TV on:

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pi@raspberrypi:~$ echo "on 0" | cec-client -s -d 1
opening a connection to the CEC adapter...

libcec didn't work for me. I didn't have time to debug further, but here's the output in case anyone wants to give it another spin:

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echo "standby 0" | cec-client -s -d 0
== skipped log-level parameter: invalid level '0' ==
opening a connection to the CEC adapter...
DEBUG:   [             142]   unregistering all CEC clients
DEBUG:   [             145]   Broadcast (F): osd name set to 'Broadcast'
DEBUG:   [             148]   InitHostCEC - vchiq_initialise succeeded
DEBUG:   [             151]   InitHostCEC - vchi_initialise succeeded
DEBUG:   [             153]   InitHostCEC - vchi_connect succeeded
DEBUG:   [             156]   logical address changed to Broadcast (f)
DEBUG:   [             158]   RegisterLogicalAddress - registering address e
DEBUG:   [             340]   logical address changed to Recorder 1 (1)
DEBUG:   [             340]   logical address changed to Free use (e)
DEBUG:   [             340]   Open - vc_cec initialised
NOTICE:  [             340]   connection opened
DEBUG:   [             342]   << Broadcast (F) -> TV (0): POLL
DEBUG:   [             345]   initiator 'Broadcast' is not supported by the CEC adapter. using 'Free use' instead
TRAFFIC: [             346]   << e0
DEBUG:   [             347]   processor thread started
DEBUG:   [             439]   command 'POLL' was not acked by the controller
DEBUG:   [             439]   initiator 'Broadcast' is not supported by the CEC adapter. using 'Free use' instead
TRAFFIC: [             439]   << e0
DEBUG:   [             530]   command 'POLL' was not acked by the controller
DEBUG:   [             530]   >> POLL not sent
DEBUG:   [             530]   TV (0): device status changed into 'not present'
NOTICE:  [             530]   registering new CEC client - v2.1.1
DEBUG:   [             530]   detecting logical address for type 'recording device'
DEBUG:   [             531]   trying logical address 'Recorder 1'
DEBUG:   [             531]   << Recorder 1 (1) -> Recorder 1 (1): POLL
TRAFFIC: [             531]   << 11
DEBUG:   [             531]   UnregisterLogicalAddress - releasing previous logical address
DEBUG:   [             532]   logical address changed to Broadcast (f)
DEBUG:   [             535]   RegisterLogicalAddress - registering address 1
DEBUG:   [             717]   logical address changed to Free use (e)
DEBUG:   [             718]   logical address changed to Recorder 1 (1)
TRAFFIC: [             718]   << 11
DEBUG:   [             718]   >> POLL not sent
DEBUG:   [             718]   using logical address 'Recorder 1'
DEBUG:   [             718]   Recorder 1 (1): device status changed into 'handled by libCEC'
DEBUG:   [             718]   Recorder 1 (1): power status changed from 'unknown' to 'on'
DEBUG:   [             719]   Recorder 1 (1): CEC version 1.4
DEBUG:   [             719]   AllocateLogicalAddresses - device '0', type 'recording device', LA '1'
DEBUG:   [             719]   Recorder 1 (1): osd name set to 'CECTester'
DEBUG:   [             719]   Recorder 1 (1): menu language set to 'eng'
DEBUG:   [             720]   GetPhysicalAddress - physical address = ffff
DEBUG:   [             723]   SetDevicePhysicalAddress - not setting invalid physical address ffff
NOTICE:  [             731]   setting HDMI port to 1 on device TV (0)
DEBUG:   [             733]   << Recorder 1 (1) -> TV (0): POLL
TRAFFIC: [             734]   << 10
DEBUG:   [             825]   command 'POLL' was not acked by the controller
TRAFFIC: [             826]   << 10
DEBUG:   [             916]   command 'POLL' was not acked by the controller
DEBUG:   [             916]   >> POLL not sent
DEBUG:   [             917]   Recorder 1 (1): physical address changed from ffff to 1000
DEBUG:   [             917]   << Recorder 1 (1) -> broadcast (F): physical adddress 1000
TRAFFIC: [             917]   << 1f:84:10:00:01
NOTICE:  [            1068]   CEC client registered: libCEC version = 2.1.1, client version = 2.1.1, firmware version = 1, logical address(es) = Recorder 1 (1) , base device: TV (0), HDMI port number: 1, physical address: 1.0.0.0, host: armv6l-unknown-linux-gnueabihf, features: 'P8 USB' 'P8 USB detect' 'RPi', git revision: 3ff78be, compiled on: Mon Mar 25 06:49:17 UTC 2013 by pi@raspberrypi on Linux 3.6.11+ (armv6l)
DEBUG:   [            1068]   << Recorder 1 (1) -> TV (0): OSD name 'CECTester'
DEBUG:   [            1069]   << Recorder 1 (1) -> TV (0): POLL
TRAFFIC: [            1069]   << 10
DEBUG:   [            1159]   command 'POLL' was not acked by the controller
TRAFFIC: [            1160]   << 10
DEBUG:   [            1250]   command 'POLL' was not acked by the controller
DEBUG:   [            1250]   >> POLL not sent
DEBUG:   [            1251]   not sending command 'set osd name': destination device 'TV' marked as not present
DEBUG:   [            1251]   << requesting power status of 'TV' (0)
DEBUG:   [            1251]   << Recorder 1 (1) -> TV (0): POLL
TRAFFIC: [            1251]   << 10
DEBUG:   [            1342]   command 'POLL' was not acked by the controller
TRAFFIC: [            1342]   << 10
DEBUG:   [            1433]   command 'POLL' was not acked by the controller
DEBUG:   [            1433]   >> POLL not sent
DEBUG:   [            1433]   not sending command 'give device power status': destination device 'TV' marked as not present
DEBUG:   [            1434]   << Recorder 1 (1) -> TV (0): POLL
TRAFFIC: [            1434]   << 10
DEBUG:   [            1525]   command 'POLL' was not acked by the controller
TRAFFIC: [            1525]   << 10
DEBUG:   [            1616]   command 'POLL' was not acked by the controller
DEBUG:   [            1616]   >> POLL not sent
NOTICE:  [            1616]   << putting 'TV' (0) in standby mode
DEBUG:   [            1617]   << Recorder 1 (1) -> TV (0): POLL
TRAFFIC: [            1617]   << 10
DEBUG:   [            1707]   command 'POLL' was not acked by the controller
TRAFFIC: [            1708]   << 10
DEBUG:   [            1798]   command 'POLL' was not acked by the controller
DEBUG:   [            1799]   >> POLL not sent
DEBUG:   [            1799]   not sending command 'standby': destination device 'TV' marked as not present
DEBUG:   [            1799]   unregistering all CEC clients
NOTICE:  [            1799]   unregistering client: libCEC version = 2.1.1, client version = 2.1.1, firmware version = 1, logical address(es) = Recorder 1 (1) , base device: TV (0), HDMI port number: 1, physical address: 1.0.0.0, host: armv6l-unknown-linux-gnueabihf, features: 'P8 USB' 'P8 USB detect' 'RPi', git revision: 3ff78be, compiled on: Mon Mar 25 06:49:17 UTC 2013 by pi@raspberrypi on Linux 3.6.11+ (armv6l)
DEBUG:   [            1799]   Recorder 1 (1): power status changed from 'on' to 'unknown'
DEBUG:   [            1799]   Recorder 1 (1): CEC version unknown
DEBUG:   [            1800]   Recorder 1 (1): osd name set to 'Recorder 1'
DEBUG:   [            1800]   Recorder 1 (1): device status changed into 'unknown'
DEBUG:   [            1800]   unregistering all CEC clients
DEBUG:   [            1801]   UnregisterLogicalAddress - releasing previous logical address
DEBUG:   [            1805]   logical address changed to Broadcast (f)

are you using a desktop monitor, or a tv?, only tv's have cec

Is tvservice really not working? Power off monitor:

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tvservice -o

Power on:

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tvservice -p; fbset -depth 8; fbset -depth 16