In the Yodeck Portal, the “Turned Off” option provides an easy way to turn off the connected screen.

How does it work?

The Yodeck Player (or Raspberry Pi in general) includes a CEC adapter on its HDMI monitor port. If your screen supports HDMI-CEC, then the Player issues a CEC “standby” (or “power on”) command to turn your screen off (or on).

If your monitor does not support CEC (e.g. you have a computer monitor. Check out the CEC compatibility chart ), the Player deactivates the HDMI port to allow the monitor to power-down by itself. This function is supported by all current computer monitors, even some TVs.

How should the custom script behave?

• The script should take 1 command-line argument.
• This argument will always be present.
• It will only have one of two possible values: on and off
• The script should be idempotent. (that is, if it is called twice with the same argument (e.g. on), it should not cause trouble) .

That’s it.

The “standard” script

The script below simulates the standard behavior provided by the Yodeck Player. You can customize this script, adding anything you need, and use it.

yodeck_custom_power_script

#!/bin/bash

echo 'on 0' | cec-client -s | grep 'not present' > /dev/null
NOT_CEC_COMPATIBLE=$?
tvservice -s | grep -i 'tv is off' > /dev/null
TV_IS_OFF=$?

if [ "$1" == "off" ]; then
    if [ $TV_IS_OFF -eq 0 ]; then
        echo 'Screen already off, aborting...'
        exit 0
    fi
    echo 'Turning off screen'
    if [ $NOT_CEC_COMPATIBLE -ne 0 ]; then
        echo 'standby 0' | cec-client -s > /dev/null
    fi
    tvservice -o
elif [ "$1" == "on" ]; then
    if [ $TV_IS_OFF -ne 0 ]; then
        echo 'Screen already on, aborting...'
        exit 0
    fi
    echo 'Turning on screen'
    FB_DEPTH=$(/bin/fbset | grep 'geometry' | awk '{ print $6 }')
    tvservice -p
    fbset -depth 8
    fbset -depth $FB_DEPTH
    xrefresh
    if [ $NOT_CEC_COMPATIBLE -ne 0 ]; then
        echo 'on 0' | cec-client -s > /dev/null
    fi
else
    # Just for debugging, not required or used
    echo "Screens supports HDMI-CEC: $NOT_CEC_COMPATIBLE"
    echo "Screens current status: $TV_IS_OFF"
    echo 'You must specify "on" or "off"'
fi

It does not HAVE to be a bash script. You can always provide an executable file, or a script in any other language, like Python or Perl. Yodeck will use the contents you provide in Base64 (details below), will write the file to the filesystem, make it executable ( chmod +x ) and call it every time it is required.

Changing the standard script

In your Linux command line, you can use the yodeck_custom_power_script directive to provide your own custom TV on/off script. To create the custom script entry, run:

echo yodeck_custom_power_script=`base64 -w 0 script_filename.sh`

You should get a player directive (directive_name=base64_encoded_data) ready to be pasted in the Advanced Player Directive field. For the above standard script, that would be:

yodeck_custom_power_script=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